Get That Pro Sound The Ultimate Guide to Equalisation First Edition Publication date: February 2013 Published by George Robinson Getthatprosound.com © Copyright George Robinson, All rights reserved. No part of this publication may be reproduced or transmitted in any form or by any means, mechanical or electronic, including photocopying and recording, or by any information storage and retrieval system, without prior written permission from the publisher. While all attempts have been made to verify information provided in this publication, the Author does not assumes any responsibility for errors, omissions, or contrary interpretation of the subject matter herein. Of course, please let me know if you find any errors and I’ll correct them! The Purchaser or Reader of this publication assumes responsibility for the use of these materials and information. Neither the Author nor its dealers or distributors, will be held liable for any damages caused either directly or indirectly by the instructions contained in this book, or by the software or hardware products described herein.
Get That Pro Sound - The Ultimate Guide to Equalisation
Contents 1.
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Introduction......................................................................................... 4 The Pitch: Become A Sonic Sculptor What Is Equalisation, & Why Is It Useful?........................................ 4 Frequency Masking........................................................................... 5 Anatomy of an EQ Plugin................................................................... 6 Common Controls & Terms.............................................................. 6 Types Of EQ......................................................................................... 7 Equalisation Strategies: Using EQ In A Mix..................................... 9 A Smart Mix EQ Strategy................................................................... 9 Mix EQ Step 1: Fixing Purely Technical Problems & Deficiencies.................................. 10 Mix EQ Step 2:
Initial Balance; Bringing Out The Characteristics Of Feature Instruments, Diminishing Others.............................................................................. 13
Quickly Set Up An EQ: Boost, Search And Set.............................. 14 Mix EQ Step 3: Fitting Sounds Into A Mix; Low, Mid And High Adjustments................... 17 In What Order Should I Put EQ and Dynamics Processors?....... 19
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Advanced EQ Techniques................................................................ 20 The Fletcher-Munson Effect: 2 Tips............................................... 20 EQ Curves That Give The Impression Of Distance........................ 22 Getting To Know The Frequency Spectrum: Your Sonic Canvas Frequency Ranges Reference Table...................................................... 23 21 Bonus Compression Pro Tips.................................................... 26 Conclusion......................................................................................... 33
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Get That Pro Sound - The Ultimate Guide to Equalisation
Introduction
The Pitch: Become A Sonic Sculptor Equalisation, or ‘EQ’, is one of the most powerful and fundamental tools in your sonic toolkit, and can be your greatest enemy or your greatest ally in the quest for a Pro Sound. Many aspiring and intermediate music-makers don’t fully appreciate just how useful EQ can be, but experienced engineers and producers know how important EQ is to help them skillfully share the frequency spectrum among all the instruments, allowing each its own space without it having to fight the others for attention. Using EQ appropriately, in this way, can result in a powerful and full sound from a relatively small number of tracks. There are few hard and fast rules regarding the successful use of EQ. However, with practice of the strategic approach to using EQ outlined in this guide,you’ll be another large step closer to sonic mastery of your individual sounds and complete mixes. Let’s get into it!
What is Equalisation, & Why Is It Useful? The equaliser was one of the first audio signal processing devices to be invented, in the 1930s. The term ‘equalisation’ came about because the very first equalisers were developed specifically to rectify or ‘equalise’ shortcomings in telephone systems to make them sound more natural, but today equalisation (or ‘EQ’) is as much a creative, ‘sound-sculpting’ tool as it is used for technical troubleshooting. Through the decades the equaliser has been developed in myriad different ways, from the simple bass and treble tone control of the 1950s, through to modern multi-band graphic equalisers and more complex ‘parametric’ types. But essentially, an equaliser consists of a number of electronic filters which allow select parts of the total frequency spectrum to be adjusted – increased, decreased or removed completely; thereby altering the frequency response – the tonal characteristics – of a sound system or signal chain.
The job of an equaliser is to change the frequency content of an audio signal. If you have an audio signal that is ‘dull’, for example, lacking high frequency presence, the equaliser is often the tool used to fix this – provided that there is some high frequency content in the signal in the first place that the equaliser can bring up. Conversely, if the sound is too bright with too much high frequency ‘sizzle’ the equaliser again offers the solution, this time by reducing the sounds high frequencies in the specified range. Equalisers are made up of series of filters. This can be a source of potential confusion at first,
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Get That Pro Sound - The Ultimate Guide to Equalisation as we normally think of a filter being a device that removes something; but in the context of equalisation, ‘filters’ can boost frequencies as well as cut them. No matter how complicated or sophisticated an EQ device or plugin is, ultimately it’s really just a frequency-selective volume control. But don’t let this simple description of the function of EQ fool you: the subjective effect of EQ on a sound is often much more profound than you might suspect, and mastering the use of EQ is certainly one of the fundamental skills required to achieve a Pro Sound.
Frequency Masking: Why We Use EQ To Put Sounds In Their Place
To understand why EQ is so vital to creating a good mix balance, we need to know about a psychoacoustic phenomenon known as ‘frequency masking’. Frequency masking affects our perception of sound whenever we hear several instruments playing together at once: essentially if one instrument in your mix has lots of energy in a certain frequency region, then your perception will be desensitised to that frequency region of the other instruments. That is, those other instruments will effectively be masked in that frequency range by the stronger signal. For example, if you have a constant cymbal pattern filling up the frequency spectrum above 5kHz, you’ll perceive this frequency range a lot less well in the lead vocal part – the cymbals will be ‘masking’ the vocal above 5kHz. Remember, the vocal might sound bright and amazing on its own, but the moment the cymbals are added to the mix the vocal will suddenly appear dull. So what do we do? To retain the same apparent vocal sound against the cymbals, we would need to either reduce the level of the cymbal frequencies above 5kHz, or exaggerate those frequencies in the vocal sound. This is where EQ comes in. Of course masking will occur at any frequency range in the spectrum, not just the high frequencies, where two or more sounds overlap. The effects of masking mean that even when each individual instrument or part in your arrangement sounds incredible on its own, you’ll still need some EQ in the mix to compensate for frequency masking between the instruments and keep an impression of each sound having its own space and tone. So you can see that using EQ effectively is a key skill to grasp, because it’s such a significant aspect of mixing in general. You may have realised after that explanation that if you change the frequency content ofparts that sound perfectly good on your own, in a sense you’re actually often making instruments sound subjectively ‘worse’ in isolation so that they will do their job better in the context of a complete mix. Sometimes you might need to mangle a sound almost beyond recognition to fit it into a crowded mix. It is getting this balance right, sweetening individual sounds whilst also making them function well in a full mix that takes practice, patience and expertise. Of course, having an overall strategy clearly makes things a lot easier, so we’ll be covering that later.
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Get That Pro Sound - The Ultimate Guide to Equalisation
Anatomy Of An EQ Plugin EQ Types, Parameters & Terminology
Having a proper explanation of the typical feature set of an EQ plugin goes some way to explaining how EQ is designed to work in practice. There are a few different types of equaliser designed for slightly different EQ tasks, but they all operate using the same basic principles, parameters and terms.
Common Controls & Terms:
Centre Frequency The specific frequency to be attenuated by the EQ. Q The bandwidth of a cut or boost i.e. how broad or narrow the range of frequencies around
the centre frequency that will be affected. A high Q value corresponds to a very narrow filter; a low Q corresponds to a wide filter. High Q values are useful for picking out sounds that occupy a very narrow and precise part of the audio spectrum, whereas lower Qs produce a smoother, more musical sound.
Gain The amount of boost or cut applied by the EQ at the centre frequency. High-Pass Filter (HPF) Attenuates (reduces) low frequencies, letting the high frequencies ‘pass’ through unaffected.
Low-Pass Filter (LPF) Attenuates high frequencies, letting the low frequencies ‘pass’ through unaffected.
Band-Pass Filter (BPF) Attenuates both high and low frequencies, only letting a selected frenquency band pass through.
Notch Filter A filter that cuts out a very narrow range of frequencies. Cutoff Frequency The frequency at which a High- or Low-Pass Filter starts to take effect.
Slope The rate at which a High- or Low-Pass Filter reduces the level above or below the cutoff frequency. This is usually measured as 6, 12, 18 or 24dB/octave, where the higher the number the steeper the slope will be, and therefore the greater and more abrupt the level of attenuation beyond the Cutoff.
Pass Band The frequency range that is allowed through. Stop Band The frequency range that is attenuated.
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Get That Pro Sound - The Ultimate Guide to Equalisation
Types of EQ Parametric EQ
The type of EQ most commonly used for studio mixing. A parametric EQ give you controls for Frequency, Gain and Q. Frequency sets your centre frequency to be adjusted; Gain sets by how much; and the Q setting affects how narrowly the cut or boost applies to your selected centre frequency in relation to those around it. A single parametric EQ unit or plugin will often have several filter sections or ‘bands’: for example a 4-Band EQ allows you to treat four parts of the frequency spectrum simultaneously. Usually you can also switch the first and last filter sections to be used as high and low frequency Shelving EQs (see below for details).Parametric EQs can be time-consuming to set up properly, but they are the most powerful and flexible of the conventional EQ types. Semi-Parametric EQ You’ll sometimes encounter a Parametric EQ without Q controls, or which has a switch for setting either a ‘Narrow’ or ‘Wide’ Q – this is a Semi-Parametric EQ.
Program EQ
Sometimes you only have control over the amount of cut or boost and can adjust neither the frequency nor the Q of the equalisation shape. This ‘Program EQ’ is the sort usually found on most home stereo equipment with controls simply for ‘Treble’ and ‘Bass’, but 2- or 3-Band Program EQ (Low, Mid, High) is also found on every channel of most good mixing desks, both vintage and modern. Don’t let the apparent inflexiblity of Program EQ make you think it’s necessarily an inferior choice: well designed Program EQs on vintage desks, for example, are prized and can sound amazing.
Graphic EQ
A Graphic EQ is usually recognisable by the row of faders across the front panel, each fader controlling its own narrow section of the audio spectrum (the faders are generally set on octave or 1/3 octave frequency centres). For example, a 30-Band Graphic EQ provides independent control over 30 different bands spaced one third of an octave apart. Graphic EQ is best employed where a large number of subtle adjustments to the signal are needed – classic applications for Graphic EQ include equalising a control room’s main monitors, making final EQ adjustments to a complete mix at the mastering stage, or for making quick adjustments in a live performance/mix situation where speed and robust control are of the essence. Other than the highest and lowest faders, which control Shelving Filters, each of the filters in a Graphic EQ is a fixed-frequency Band-Pass Filter, where boost or cut is applied by moving the fader up or down from its centre position. Graphic EQs are relatively quick and easy to set up, but they are not as flexible, precise or generally as good-sounding as Parametric EQ. However, when you want a nice bite to your EQ, a relatively coarse-sounding Graphic might be more ap-
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Get That Pro Sound - The Ultimate Guide to Equalisation propriate than a smooth Parametric EQ. Aim to master both types and you’re covered for every eventuality.
Shelving EQ
Shelving EQ applies a cut or boost only to the frequencies above or below the Cutoff Frequency of the EQ (depending on whether the particular EQ section is based around a High-Pass or a Low-Pass Filter, see above). Shelving EQ isn’t limited to a center frequency and its associated bandwidth, and the resulting alteration in the frequency response is flat (like a shelf) beyond the selected frequency.
The Difference Between Shelving EQs and Filters
You may be wondering what the difference is between High- and Low-Pass Filters and Shelving EQ, as they both operate on the extreme high or low frequencies of a signal. However, there are a couple of key differences: EQ is used to boost or attenuate a range of frequencies in order to shape a sound, and so is not as well suited to more corrective, ‘clean-up’ duties as it is to more subtle, creative sound-shaping equalisation. High- and Low-Pass Filters generally have much steeper slopes (12, 18 or even 24dB per octave) than normal equaliser bands (which are typically only 6dB/octave), as they are intended for these more purely technical tasks. You can think of filters for cleaning up a signal, rather than for creative sound-shaping, as they only provide attenuation of unwanted frequencies, and there’s no scope to boost any part of the frequency range. For example, you can’t effectively remove sub-bass rumble with an EQ bass adjustment, as the attenuation simply won’t be enough to completely cut out the offending frequencies – this is more of a job for a High-Pass Filter. But conversely, you wouldn’t usually attempt to gently shape the tone of a bass guitar with a High-Pass Filter when you had an EQ to make those more subtle adjustments.
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Get That Pro Sound - The Ultimate Guide to Equalisation
Equalisation Strategies So now we know what EQ is designed to do in principle, and how the different types of EQ and their parameters can be used together to enable us to achieve that. But how do we implement EQ smartly in the real-world context of a mix, and as a creative as well as technical tool? It’s time to formulate a strategy, so that we can implement our use of EQ in the most effective, efficient and flexible way. Remember, our aim is to distribute our instrumetns and parts across the frequency spectrum so that each has its own space and doesn’t have to fight with the others for attention. Using EQ in this way will mean a powerful and full, Pro Sound from a relatively small number of tracks.
A Smart Mix EQ Strategy
In a mix context, EQ has two main functions, which could broadly be described as either ‘technical’ or ‘creative’.
1. In technical terms, we want to make sure that everything that needs to be heard, can be heard.
Much of this type of EQ is concerned with cutting away unimportant areas of the frequency spectrum from individual recorded parts, so that important frequencies in other parts can be heard. This can be as simple as using a high-pass or low-pass filter on specific tracks to remove any unwanted noise or hum, or it may require subtle cutting and boosting on every channel. The ease with which this can be done will often depend on how well the track has been arranged, as well as how well recorded or chosen were the original individual sounds and instruments: of course, even when dealing with technical issues a lot still depends on creative decisions you made earlier!
2. And more subjectively, we want to bring out certain characteristics of our sounds, using EQ ‘creatively’ to adjust and refine the tone of each sound to our own taste. With these two objective in mind, let’s look at using EQ effectively and efficiently in your mix.
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Get That Pro Sound - The Ultimate Guide to Equalisation We’ll break down the process of applying EQ over the course of a mix into three phases: Mix EQ Step 1: Fixing Purely Technical Problems / Deficiencies Removing sub-sonic rumble, electrical hum and buzz; High- and Low-Pass Filtering Mix EQ Step 2: Initial Balance, Bringing Out The Characteristics Of Feature Instruments, Diminishing Others Mix EQ Step 3: Fitting Sounds Into A Mix; Low, Mid And High Adjustments
Mix EQ Step 1: Fixing Purely Technical Problems & Deficiencies
Removing sub-sonic rumble, electrical hum and buzz; High- and Low-Pass Filtering
A key use for EQ is to clean things up and get rid of problems that lie within specific frequency ranges. You’ll probably want to do this type of correctional work as part of your mix preparation, before you even get into balancing.
Rumble, Plosives & Wind Noise In many recording situations, the microphone picks
up very low frequency rumble, at 40Hz and below.This unwanted low-end energy can come from many sources, from the building’s air conditioning to the traffic vibrations from nearby roads outside. Other low frequency problems fixed by a high-pass filter are the ‘plosive’ pops caused by a breath of air hitting the mic whenever the singer hits a ‘P’ or ‘B’ in a word. Or if you are working outside (doing live sound or collecting natural sounds in the field), you might find that even a light breeze across the mic can lead to low-end rubbish. Since very little music happens at such low frequencies, it’s often appropriate to insert a highpass (i.e. low cut) filter to remove all these super-low frequencies entirely.
Hum Electrical interference from power lines, power supplies, light dimmers, flourescent strip lights and other sources can introduce hum into your tracks. This usually appears at a very specific frequency – generally either 50Hz or 60Hz, depending on which type of AC power is used in your part of the world. To remove hum, again a high-pass filter can be used at a setting just above your trouble frequency.
Buzz Hum can also turn into full-on buzz if upper harmonics of the interference also appear
– in the case of a 60Hz hum, you might also get harmonics at 120Hz, 180Hz, and 240Hz. Buzz usually effects guitarists more than electronic musicians, as guitar amps and single coil guitar pickups are buzz breeding grounds because of the way they work. Again, a low pass filter helps
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Get That Pro Sound - The Ultimate Guide to Equalisation If you know the frequency of your mains hum (50Hz in the UK, for example) then you can apply cut with a narrow peaking filter to notch out the 50Hz fundamental and possibly its most prominent harmonics as well - 100Hz, 150Hz and 200Hz. If you find you’re having to cut too much/too many notches in your tracks, you might want to try a dedicated noise removal plugin instead for fewer audible side effects.
High-Pass & Low-Pass Everything You Can
Many instruments which are not known as ‘bass’ instruments nevertheless have a lot of low frequency content; cymbals for instance. This content, while not being particularly audible – and therefore not very musically useful – will still consume your available headroom, taking up valuable space in the frequency spectrum that could be more effectively used by another instrument. With this in mind, it can be a really good idea to prepare for your initial mix by cutting down, or out entirely, those frequencies which are not useful and don’t enhance the sound of each instrument. For example, it’s not uncommon to find that you need to take a lot of bottom end out of acoustic guitars or synth pad parts to avoid the mix getting muddy. Usually you can get away with taking quite a lot of low end away from such sounds before they start to sound thin in context, and this can allow important bass instruments and kick drums to come across much more clearly. Similarly, if you have an instrument that doesn’t need to be at the front of the mix, try rolling off some of its high end so that it doesn’t compete with the sounds that really need to stand out. You could use a shelving equaliser to do this, or a steep low-pass filter if you’re after more surgical removal. This sort of ‘topping and tailing’ of frequencies with EQ can make a significant difference to the clarity and accuracy with which you go about your mix, as it means your meters will be showing you only the levels of the useful frequencies on each track. You might be surprised how much headroom you save with this technique; headroom which can later be used to make the whole mix louder.
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Get That Pro Sound - The Ultimate Guide to Equalisation
Is It Better To Cut Or Boost? In traditional recording and mixing, the generally accepted wisdom is that it’s better to cut than to boost. The thinking here is that the less EQ boost you use, the less obtrusive the processing and the more natural the final sound will be. The human ear is far more tolerant of EQ cut than it is of boost, so, rather than adding lots of top to vulnerable sounds such as vocals in order to get them to sit at the front of the mix, try applying high-end cut to other sounds in the mix that are conflicting with the vocal. However, whether to cut or boost also depends on the style of music you’re making and mixing, and how important it is to you to even have a ‘natural’ sound. If you’re mixing classical music you’ll want to use as little processing as possible full stop; whereas in most electronic and dance music styles you’re after sounds with impact and interest, and whether instruments are ‘acoustically accurate’ barely registers as a concern. It’s natural to think in terms of boosting frequencies you want more of, but there are other good reasons to restrain yourself to the opposite approach of cutting frequencies you want less of: All of us have a strong tendency to like the louder of any two sounds we’re comparing, so if EQ boost makes your overall sound louder, then that’ll add an element of bias to your judgments. Any EQ boost will also always make the processed track more audible in the balance, so it’s trickier to be sure whether you’ve chosen exactly the right settings. The greater the boost, the more difficult it is to keep your perspective. Sticking to EQ cuts avoids this bias, or rather biases you against your own ‘in-built’ EQ curve, so that only settings that really work are likely to sound best when you toggle the EQ on and off. Avoiding EQ boosts also reduces the risk of introducing EQ-processing artifacts. As well as adjusting the frequency balance, most EQs also adjust the phase relationship between the track’s frequency components (also known as the track’s “phase response”), which is generally an undesirable side-effect. Making EQ cuts rather than boosts concentrates the phase shifts into frequency regions that you’re reducing rather than increasing in level, so any artifacts that appear as a result of the EQ will also be reduced, and so won’t matter as much. However, in reality a combination of cut and boost is usually required or is preferable: clearly there will be some situations where it makes more sense to use boosts than cuts for mix balancing purposes. For example, it’s a lot easier to handle a peaking boost than trying to implement a similar spectral change using a pair of shelving cuts. Moreover, with some classic EQ designs (and those plugins modelled on vintage EQ units), the sonic side effects of boosting – those artifacts we just mentioned above – may actually be desirable and improve the subjective tone of the processed track.
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Get That Pro Sound - The Ultimate Guide to Equalisation
Having said this, these boosting situations are best treated as the exception rather than the rule. Generally, be very careful when you boost to ensure a minimimal amount of degradation to the sound and to reduce the likelihood that you’ll confuse your own perception of the balance. One final tip: Think of EQ cut for solving localised problems, using a bandwidth narrow enough to achieve the desired effect without unduly altering adjacent frequency ranges; Whereas EQ boost should be over wider bandwidths and using as little gain as will suffice. For example, removing an unwanted vocal resonance may need a cut of several decibels, but with with a fairly narrow bandwidth over a very specific frequency range; meanwhile, adding high-frequency brilliance to a mix needs only about a decibel of boost, but with a much wider bandwidth setting over a broader range of frequencies.
Mix EQ Step 2: Initial Balance, Bringing Out The Characteristics Of Feature Instruments, Diminishing Others As we learned when discussing frequency masking, there’s little to be gained by making EQ adjustments to a part in isolation, with the solo button on, because you can’t judge the impact of any frequency masking between two instruments unless you listen to them at the same time. Soloing tracks while EQ’ing can be useful for hearing exactly how and where you’re altering the frequency balance, but it’s also important that you then validate and refine those EQ decisions within the context of the mix. With all this in mind, it becomes clear that the best approach to building up your mix balance is to introduce the tracks in order of importance. If each newly added instrument is less important than the previous one, then you can be pretty confident about which one needs to be fitted around the other, as and when masking conflicts arise. The first question to ask yourself is whether a sound would benefit from EQ. The best way to do this is to first mute all channels, then one-by-one unmute each channel as you play back the basic/raw balance of your track. Try to unmute the tracks in order of importance, which in modern music will mean starting with some combination of drums, bass and
Reference Tracks
One point which I mention often, including in the other Ultimate Guides on Reverb and Compression, is the importance of having wellselected reference tracks close-by as you balance, treat and process your mixes. Making quick side-byside comparisons with commercial releases of the same style of music will help you massively in judging the overall blend of instruments and frequencies, and will save you many hours of trial and error.
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Get That Pro Sound - The Ultimate Guide to Equalisation lead instruments. As you reintroduce each element back into the mix, listen carefully and try to answer these two questions: 1. Can I find a sensible fader level for this new track that allows me to hear all of its frequency regions clearly? 2. Is this new instrument leaving the balance of the more important tracks (already playing) intact? If the answer is ‘yes’ to both questions, you probably don’t need EQ here: move on to the next instrument. One of the skills of using EQ effectively is knowing when it’s not required, or not the tool for the job. A surprisingly large number of tracks in most productions only require a bit of high-pass filtering (more on this below). When your answer to either of the questions is no, though, it might be time to dial in some EQ to help place the sound into the mix balance.
Quickly Set Up An EQ: Boost, Search And Set
The most popular approach to dialling in an EQ setting is quite intuitive: boost, search, and set.
First boost the EQ bands Gain by a clearly audible amount, perhaps 12dB or more: this will allow you to clearly hear what’s happening at which frequencies in the next step.
Next, search by sweeping with the Frequency control until you find the part of the sound that you want to adjust.
Finally, set the EQ band’s Gain to the desired amount – either cutting the frequency if you don’t like it or finding just the right amount of boost (and bandwidth) if you do.
At this point it’s also a good idea to mute/unmute the EQ a few times as you listen back to the sound you’ve just processed, both in isolation and in the mix context, just to check you really are making a positive adjustment: it’s surprisingly easy to loose perspective while you’re sweeping and setting up EQ. Don’t be disheartened if you need to return to the EQ and make further changes – it’s better to resolve it now than to leave it until you’ve built more of your mix balance up on top of it.
EQ With Boldness
When adjusting the amount of EQ to apply (ie. the EQ gain), it’s tempting to adjust it very carefully and change the setting in small increments. The problems with this method are: (a) that if the EQ setting isn’t right then it is wrong and thus needs total reconsideration; (b) that the ear quickly grows used to changes in the frequency balance of a sound. It may not always be appropriate, but the next time you want to change the EQ level of a sound,
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Get That Pro Sound - The Ultimate Guide to Equalisation grab the control firmly, twist it all the way up and all the way down and quickly settle on a new position which will hopefully be just right.
Warning: EQ Changes Levels
One further technical point: changing the EQ of a signal nearly always changes the level, so each time you adjust the EQ you will have to consider moving the fader to compensate. Adding EQ adds level, and it is very easy to boost the signal so much with EQ that you run into clipping and distortion. Since the fader comes after the EQ, lowering the fader will do nothing to solve this. The answer is to reduce the gain, to allow the signal a little more headroom if necessary. It’s something that will come automatically after a time, but less experienced producers often concentrate more on the change in the sound itself and don’t notice that it has also suddenly become more or less prominent in the mix.
EQing Individual Sounds – Enhancing Or Diminishing
Beyond overcoming frequency masking and enhancing mix clarity, another natural application of EQ is to enhance a particular part of a sound, to bring out components of the sound you like. For the instruments and sounds you play or regularly feature in your tracks, it will pay big dividends to spend some time examining their spectral make-up with an equalizer: Look for the defining characteristics of the instrument and where they appear in the frequency spectrum; Also look for the less desirable noises that particular instruments, as it’s just as important to reduce these aspects of a sound as it is to enhance the more positive attributes. Being aware of, and perhaps making some notes on the spectral qualities of your key instruments will save you time in the heat of a recording or mixing session: you’ll know where to look in the frequency spectrum when you want more punch in the snare or more breathiness in the vocal, for example. Every instrument or sound source will have certain bands of frequencies that are stronger and some that are weaker. The human voice, for example, is particularly strong around the 3 to 4kHz region, regardless of whether it’s male or female, or which note is being sung. Remember that
Regular Breaks
During mixing sessions, remember to take breaks every now and then. The sort of critical listening required when you’re EQing and balancing parts tends to numb one’s senses relatively quickly, and can make your ears begin to give you a flase impression of the overall spectral balance. This is how many mixes end up sounding very harsh and toppy – as your ears and brain get tired, you’ll add more and more upper-mids and high frequencies to maintain an apparently ‘well-balanced’ mix. Your mix can then sound a lot different the next morning when you’re fresh again!
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Get That Pro Sound - The Ultimate Guide to Equalisation the strongest present frequencies are not necessarily the ones you want to bring up: you might very well want to enhance a less prominent aspect of the sound, which can often create a more rounded and interesting character to the part. So, when using EQ at this stage in your mix you’ll be considering which characteristics of the sound you want to accentuate, and which you want to reduce. Also bear in mind that you can only tailor the sound of an instrument so far without losing its essential character and identity; not every every instrument can be full, deep, bright and full of sparkle all at the same time, and we wouldn’t really want them to be - it would be extremely tiring and confusing to listen to! Remember to leave some room for contrast. When EQing a real instrument, you will either want to exaggerate its individual characteristics and make it more distinctive, or reduce its individuality and make it more like a hypothetical ‘average’ of this type of instrument.
EQing For Character: Walkthrough
First set the Gain control to a medium amount of boost - the three o’clock position of the knob is usually about right. Now sweep the Frequency control up and down to the limits of its range, listening as you go for the frequencies at which the effect of the EQ boost seems strongest and most prominent. These are the frequencies in which the instrument is rich. Boosting the instrument’s strong frequencies will enhance its individual characteristics and, for example, make a clarinet even more dissimilar to an oboe (or any other instrument). In effect, you’re making the clarinet even more clarinet-like. When you have found the instrument’s strongest frequency band, set the amount of boost according to taste - and always compare the changes you’ve made with the original sound to confirm you’ve made a positive difference before moving on. Enhancing the sounds of individual instruments in this way is useful, but watch out when mixing that you are not boosting the same frequencies on each instrument. It is a common trap to wind up boosting every instrument at around 3kHz to help it cut through at a frequency where the ears are very sensitive (see why this is in the later section on the (Fletcher-Munson Effect). This will produce a mix that is very tiring to listen to.
Diminishing Character With EQ
The opposite of the enhancement technique is where you lessen the individuality of each instrument and make it more like our hypothetical ‘average’ instrument. To do this, find the instrument’s strong frequencies with the mid EQ set to boost as before, but then cut these frequencies, by as much as you feel appropriate. This won’t make the instrument sound better in isolation, but it will help it blend in with the other instruments in the mix.
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Get That Pro Sound - The Ultimate Guide to Equalisation
Mix Surgery: Notch Filtering Drums
Notch filtering is basically applying a very narrow bandwidth/Q and reasonably deep cut at a specific frequency, to remove a very particular element of the sound. It’s the same technique we discussed earlier in relation to removing harmonic hum and buzz from tracks with very targeted cuts. Using EQ to carve notches out of sounds where troublesome resonances or undesirable features occur is particularly effective on drums. Whether you’re using samples or your own studio recorded drum tracks, there are usually a few dissonant drum resonances that stick out of the mix awkwardly even when everything else appears to be at the right level. In these cases you’re usually just dealing with a single frequency, so your best bet is to position a super-narrow filter/EQ notch precisely on top of it and just pull the offending resonance down and out of harm’s way. Generally you can do this without affecting the overall tone of the drum at all. One method of finding such drum resonances is to boost heavily with your equaliser bands Q set to it’s narrowest, and then hunt for the offending frequency by sweeping the filter around in the general area of the frequency spectrum. Another way to find such targeted frequencies is to use a spectrum analyzer plugin inserted across the drum track, which will probably show one or two ‘spikes’ at the appropriate points on it’s graphic display.
Notch Filtering Pitched Instruments
While notch filters are good for dealing with drum resonances, tampering with the levels of individual frequencies doesn’t usually help you when dealing with more melodically pitched parts, because a fixed frequency notch will inevitably affect different harmonics on different notes. Nevertheless, notching shouldn’t be ruled out if the musical part in question is quite simple and only features a small range of notes. For example, notches can be particularly handy for simple bass parts where the fundamental frequencies of different notes need evening out. Any part with a static drone or repeated note within it is also fair game if you want to rebalance the stationary note against any others, although you might find you need to attack more than one of the note’s harmonics to achieve the balance you need.
Mix EQ Step 3: Fitting Sounds Into A Mix; Low, Mid And High Adjustments
By this stage you’ll hopefully have a good working balance of your key instruments, so in this next step we’ll look at fitting additional instruments and parts into an already working basic balance. This where things can get tricky, as it’s often better not only to EQ the instrument itself, but to also or instead reduce those already occupying the same frequencies to make space for it; while doing this, however, it’s important not to undo or disrupt any of your previous work by carving out too much or the wrong parts of the established mix so far. If you’ve been clear up to this point about which instruments are the most important and which take precedence over others in the track, and have then balanced these key instruments
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Get That Pro Sound - The Ultimate Guide to Equalisation in descending order, you’re in the best possible position to move forward with fitting the remaining instruments in between. For example, if you want to hear the acoustic guitar while the string pad is sustaining, find a satisfyingly present midrange boost for the guitar and perform a complementary cut in the mids of the pad. This EQ cut on the string pad keeps the sound from competing with or drowning out the acoustic guitar. The trick is to find a spectral range that highlights the good qualities of the guitar without doing significant damage to the tone of the synth patch. It’ll take some trial and error to get it just right, but you’ll find this approach allows you to layer in several details into a mix. You can expect to apply this strategy in a few critical areas of a typical mix. When making cuts to existing balanced instruments in this way, you might find that you’re making them sound less good in isolation. This is no cause for panic, and just serves as a reminder of how important it is to make your EQ adjustments and level balancing in the context of the full mix - in the end, this is the only way listeners are going to hear it! For example, in the lower range you might be able to pull out a fair amount of low end from an acoustic guitar sound. Alone, it might sound too thin, but with the bass guitar playing it will still make sense, and now there will be spectral room for the low frequencies of the bass because the acoustic guitar no longer competes there. The acoustic guitar still has the illusion of being a full and rich sound because the bass guitar is playing along, providing uncluttered, full bass for the song – and for the mix. At this stage in the mix, then, you’re starting to think of your sounds not just individually, but as composite combinations of sounds working together in units or subgroups. In the highs, you might notice competition coming not only from obvious high frequency instruments like cymbals and percussion, but also from distorted guitar or synth sounds, or any sound that is processed with creative distortion. Spectrally speaking, this sort of creative distortion occurs through the addition of some upper harmonic energy, and it will tend to overlap with other high-frequency instruments - not to mention, other distorted sounds! Make distorted sounds fit with the same kind of ‘cut one, boost the other’ complementary EQ moves we discussed above. Maybe the cymbals get the highs above 10kHz, the lead guitar has emphasized distortion at around 8kHz, and the rhythm guitar further below this at 6kHz. Mirror image cuts on the other tracks will help ensure all these high frequency instruments are clearly audible in the mix. The mid frequencies are in many ways the most difficult region to EQ. It is very competitive space spectrally, as almost all instruments have something to say in the mids (see the frequency range chart later for more details on this). Moreover, it’s also naturally the most difficult place to hear accurately. We tend to gravitate toward the more obvious low and high frequency ranges when we EQ, but on the path to earning golden mixing ears, plan to focus on the middle frequencies - between around 500Hz-6kHz - as a key challenge.
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In What Order Should I Put EQ and Dynamics Processors?
The main issue to consider when ordering EQ and dynamics plug-ins within a track’s processing chain is that your dynamics processors may respond differently if you alter the frequency balance they are fed with. For this reason it makes sense to put EQ last in the chain if you’re already happy with the way the dynamics are operating. However, it’s not unusual for a frequency imbalance to prevent successful dynamics processing. A cabinet resonance on an electric guitar recording may well cause a single frequency to dominate the timbre only sporadically, depending on which notes happen to hit the resonance. If you compress a recording like this, the compressor won’t be able to even out the subjective level of the part, because it will act too strongly on the resonant notes. Dipping the resonance with a narrowband peaking filter pre-compression would improve this situation. So the general principle is this: if you’re happy with the way your dynamics processors are responding, then EQ after them; if you aren’t, then try EQ’ing earlier in the chain to see if you can improve things. In the latter case you may need to reassess your dynamics settings in the light of the altered frequency balance. There’s no rule against EQ’ing at multiple locations in the chain either, because you may need one EQ setting to achieve a musical compression sound, but another completely different one to slot the compressed track’s frequency spectrum into the mix balance as a whole.
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Advanced EQ Techniques Creating Impressions Of Loudness And Distance With EQ
The Fletcher-Munson Effect
The Fletcher Munson Effect is named after the two scientists who did the first research, in the 1930’s, into how the ear actually perceives different frequencies; as it turned out, there was a much larger disparity between the actual levels of tones of different frequency and the human ears perception of them, than had been realised until then. It sounds potentially abstract or complex, but the basic principle of the Fletcher-Munson Effect can be stated quite simply: Humans do not hear the low frequencies and the extreme high frequencies as well as the mids at low volumes. In fact, in comparing the difference in hearing between conversation levels and loud music playback levels, the human hearing system finds it 64 times as hard to hear the bass frequencies next to the midrange at low levels. It’s also about 16 times as hard to hear the extreme highs. There are a couple of repercussions of this phenomenon that can have a significant impact on your control, and the overall quality of your mixes:
1. Listening Level Partially Determines Perceived Frequency Balance The level at which you listen to the mix makes a huge difference in how the mix sounds. It becomes very difficult to judge, for instance, how much bass energy is the correct amount of energy for the mix. The end listeners will listen to the final product at different volumes depending on where they are, what they are doing and how they feel. The way to overcome this and be able to truly judge any mix is to listen to it at different volumes. You should endeavor to obtain a mix that sounds the best whether it is played loud, soft or in-between; and also whether it’s played in a car, on headphones or over a huge club soundsystem. Leaving the volume at one setting while working is pretty-much a guaranteed way to mess up a mix and make something that sounds good one day but bad the next. You can experience the Fletcher-Munson Effect right now by listening to any recording loud for a minute or so, and then dropping the volume right down and listening at a very low level. When the mix is played at the lower volume, you’ll probably find it more difficult to pick out the bassline, for example. Another way of expressing the Fletcher-Munson Effect and the fact that the human hearing curve isn’t flat and that we don’t hear extreme highs and lows so well at low volume, is to say
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Get That Pro Sound - The Ultimate Guide to Equalisation that our hearing is more sensitive to mid-range sounds than to frequencies at the extreme high and low ends of the spectrum. Of course, we don’t notice this, because we’ve heard sounds this way all our lives. However, as the level of sound we’re listening to increases, the ‘mid boost’ of the hearing system becomes less, and the result is that high- and low-frequency sounds seem proportionally louder.
As we can see in the graph above, which shows curves of equal loudness on a graph of sound intensity (in dB SPL) against frequency (in Hz), a 1kHz tone at 100dB SPL, for example, will be heard as being subjectively as loud as a 100Hz tone at about 105dB SPL; while a 1kHz tone at 20dB SPL will be heard as being subjectively as loud as a 100Hz tone at about 45dB SPL. The lowest points of each red curve on the graph are where the hearing system is most sensitive, and you can see that our ears are noticeably more sensitive to mid-range sounds than to frequencies at the extreme high and low ends of the spectrum (of course we don’t actually notice this because the brain compensates for it).
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2. A Smile-Shaped EQ Curve Gives The Impression Of Loudness Rather than being purely an annoyance to make our listening and mixing more difficult, however, the Fletcher-Munson Effect can also be exploited for our benefit, fooling the ear into believing something that isn’t entirely true. One key application of this is if we know that extreme high and low frequencies stand out more when we listen to loud music, we can create the impression of loudness at lower listening levels by attenuating the mid-range and boosting the HF and LF ends of the spectrum. The ‘Loudness’ button on some home and car stereos does exactly this, and if you look at the graphic EQs used in a club or PA system, you’ll often see them set up with a smile-shaped EQ curve to promote the illusion of loudness and power. In your mix you can build these sort of subtle ‘smile’ EQ curves quite naturally into the fabric of the music with low-level, broad bandwidth/Q EQ adjustments across the entire mid-range of key individual instruments, submixed groups of tracks or even the complete mix. This will help the mix sound loud and powerful regardless of the playback device or volume. Just remember that it’s often most effective when only treating a selection of the sounds in any given mix in this way, to maintain the proper contrast between the different sounds – be very careful whenever making changes to a complete mix, as it’s easy to undo all your hard work with a few inappropriate adjustments at this stage. It’s generally better to leave this kind of adjustment for the mastering stage.
EQ Curves That Give The Impression Of Distance Another related psychoacoustic effect which can be manipulated with EQ is the perception of the distance of a sound from the listener. In the real world, the air naturally dampens highfrequency sounds more than low-frequency ones. If a sound source is very close, the effect is negligible; but the further a sound has to travel through the air, the more pronounced is the high-frequency damping effect. Therefore, if you dial in some EQ to roll off a little high end from a sound, it seems further away. This technique is often used to bring a lead vocal to the front of a mix, whilst simultaneously pushing the backing vocals into the near distance behind. The backing vocals are cut maybe a bit above 10kHz, while the lead vocal is given a slight boost at the same frequency.
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Getting To Know The Frequency Spectrum: Your Sonic Canvas
As you get more experienced with EQ, mixing and critical listening in general, you begin to get very familiar with the entire frequency spectrum, knowing what each section or even specific frequency can add, or remove, from a sound or mix. This is exactly what we’re aiming for: to know the spectrum so intimately, we intuitively know which frequencies to adjust to get any sound we want. At first, when you think of 250Hz, it’s just an abstract number. But part of the satisfaction of learning about and mastering EQ on your tracks, you’ll start to automatically equate ‘250Hz’ with ‘possible problem area, potential muddiness but also body and fullness for vocals, or some nice weight for the snare drum…’ To help you get into visualizing the frequency spectrum as your amazing blank sonic canvas, here is a breakdown of the key frequency ranges, what each can bring to the overall sound, and which sounds and instruments can be adjusted in each range for particular effects.
Sub-Bass Range 20-80Hz
This region brings the sense of weight and power to the mix. The lowest possible pitch of a bass guitar or string bass is around 41Hz. Rumble below 40Hz can be removed with a high-pass filter for a tight sub-bass sound. For club music (to be played primarily on a large sound-system) you’ll want to aim for the slightly narrower 4060Hz range for your main sub-bass frequency. To properly set the amount of low bass in your mix or in your instrument sound, you must listen both loud and soft, and ideally on large and small speaker systems (see the explanation of the Fletcher-Munson Effect in the Advanced Technique section). Too much energy in this range will make the mix sound muddy on large speakers played loud, but still sound good on small speakers played at a medium volume. You want the mix or instrument to sound larger and more powerful over large speakers without sounding muddy. In dance music, individual instruments – the bass or kick – can be boosted below 80 Hz, but keep it to just these one or two instruments for clarity rather than mud. Having many sources of sub-bass end up cancelling each other out, as bass frequencies are very susceptible to phase problems. For example, if your bass drum disappears now and again in the mix, it’s probably because another sound is also hitting exactly the same frequency. It’s because of this that adding more bass to multiple things can often lead to a bass loss in your mix.
Bass Range 80-250Hz
Covering about one and a half octaves, from 80 Hz to 250 Hz, this range of frequencies helps bring nice fatness and fullness to a sound or mix. This is partly because the fundamental of bass parts usually sits here.
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Too much in this range can take away from the overall power of a mix, but it’s still needed for warmth. The best strategy to get this balance right often involves EQ around two frequency ‘centres’, 100Hz and 200Hz. For guitars, synths, bass and snare drums, the 100 Hz range can add body and fullness; too much energy here makes things boomy. Reducing the 100Hz energy on a guitar or synth line will usually bring some distinction between them and the bass part. You might also want to add a simultaneous boost at 200Hz to keep the instrument from sounding lumpy, where some notes stick out or disappear. (The lowest fundamental frequency on a guitar is around 80 Hz.) This range of frequencies is still greatly affected by the Fletcher-Munson Effect; this means you will need to listen to the mix and instruments at both loud and soft levels. The fullness of vocals is often determined at around 200Hz, and again can be reduced to increase the distinction between the vocal and surrounding parts. On the other hand, if higher-frequency boosts on the vocal have made the sound thin or ‘small’-sounding, a boost of 200 Hz will restore the missing fullness.
Lower Mid Range 250-500Hz
This could also be considered the Bass Presence Range. Covering about one octave from 250Hz to 500Hz, this range accents the ambience of the studio in recorded parts and adds clarity to the bass and other lower-string instruments. You can gain clarity and between the kick and bass by both reducing the kick and increasing the bass in this range, at the same frequency. This range is often reduced on overhead drum mics and cymbals to increase clarity and presence on these instruments. Too much boost can make higher-frequency instruments sound muffled and give lowfrequency drums like kick and toms a ‘cardboard box’ quality. Within this range, EQ is most often applied between 300 Hz and 400 Hz. Boosting between 250-350Hz can increase vocal distinction and fullness, especially for female singers.
Mid Range 500Hz-2kHz
The Mid Range of frequencies covers two octaves from around 500Hz to 2kHz. This range can be where the character of many instruments comes across, but it’s not actually especially pleasant-sounding and it’s easy to induce ‘listening fatigue’ and tinniness with too much energy here. For these reasons, typical Mid Range instruments like vocals, guitars, piano, synths, strings and percussion are usually reduced rather than accented in this range, allowing the vocals or lead instrument to cut through and stand out. Key EQ frequencies here are around 800Hz and 1.5kHz, but broader, shallow cuts across this range will help achieve a generally beneficial ‘scooped mids’ shape to the mix and avoid a ‘honky’ or ‘tinny’ sound. For example, reducing at 800Hz on a vocal gives it more body and presence and makes it sound less nasal; for snare drums a reduction at 800Hz can take the potential tinniness out
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of the drum, and gives the snares more ‘sizzle’ rather than ‘rattle’. Increasing 800Hz on a bass sound can bring out it’s ‘punch’; similarly, boosting at 1kHz can bring out a ‘knocky’ sound in kick drums, which can be especially useful for dance music. Boost around 1.5-2.5kHz to add edge to synths, guitars and some bass sounds.
Upper Mid Range 2-4kHz
Covering about one octave, this range of frequencies is responsible for the attack on percussive and rhythm instruments, and the projection of Mid Range instruments. EQ can be applied at any frequency in this range but often centres around 3kHz. Boosting a kick drum between 2.5-4kHz increases the attack: 2.5kHz sounds more like a soft felt beater, while a 4kHz boost sounds more like a hard-wood beater. These frequencies can also help to increase the attack sound on toms and snare drums. Guitar lines often get more attack and distinction with EQ in this range. A small boost of 1-3 dB to the vocal here will increase projection. Adding too much energy in this range makes it hard to distinguish the syllables of the vocal and again can cause listening fatigue. This range of frequencies is often reduced on background vocals to give them a more ‘airy’ and ‘transparent’ sound. Increase for more bass ‘pluck’, and more attack on lower guitar, synth and piano parts. Conversely, reduce in this range to soften sounds.
Presence Range 4-6kHz
Although this range covers a mere half-octave of 4-6kHz, it’s a really significant band of frequencies. Good levels in this range are what give vocals and other main instruments their sense of sounding closer and more distinct – literally, their perceived ‘presence’ in the mix. However, over-boosting here causes an irritating and harsh sound, so be careful! Conversely, reductions at around 5kHz can make the mix sound more distant and transparent, and you can cut here on specific instruments like synths and guitars to dull/soften them to taste (which effectively pushes them further into the background). A boost at 6kHz can be a good upper point for adding clarity to vocals, and is also effective on distorted guitars. Increases in this range can also work for accentuating most drums, cymbals and percussion, even low-frequency ones like the kick – provided there is sound to boost in the given drum sound!
Brilliance Range 6-20kHz
Covering approximately the upper two useful octaves between 6-20kHz, this band of frequencies is responsible for the sparkle, ‘air’ or ‘brilliance’ and clarity of instruments. It’s the area of a mix which often provides the sense of a polished, quality mix. Key EQ frequency
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centres are 7kHz, 10kHz and 15kHz. General vocal sweetening can be achieved with boosts between 6-10kHz. Be careful though, as the sibilant ‘S’ sounds in vocals reside at about 7kHz. You should also take care in reducing this range to remove sibilance, because the vocal will sound dull very quickly. Breath sounds on a vocal track are usually found at around 15kHz: a slight boost here can bring a nice bright and breathy quality suitable for some styles, avoiding accidentally accenting the sibilant S’s in the process. Boosts at 15kHz can also make sampled synths sound more real, and to bring out high-frequency shimmer and sparkle in pads – again, if the frequencies are there to start with. Boost at 7kHz to bring out the ‘metallic’ attack of drums, and 15kHz for the sizzle of cymbals. 10 kHz and above is often used as a general ‘brilliance’ range with light EQ boosts. Too much energy in the Brilliance Range will sound unnatural, shrill and brittle, so don’t overdo the sparkle! Cut or filter sounds in the Brilliance Range that don’t need to appear bright, to reduce overall noise.
21 Bonus EQ Pro Tips The following, final section of this guide is dedicated to a range of additional tips, tricks and techniques, as well as answers to some common EQ questions.
1. High-Pass All Non-Bass Instruments
I’ve mentioned this eariler, but it bears repeating because it’s pretty simply to do but can have a significant impact on the overall clarity of your mixes. Simply high-pass filter out the bass element of instruments which are not meant to specifically be ‘bass instruments’; it’s amazing how much unwanted junk there is lurking relatively unheard in your individual tracks, which nevertheless saps away at your available headroom.
2. ‘Mix Glue’ EQ
If you can’t get your tracks to blend together well in the mix, try making a series of cuts in the main frequency range of the principal/lead instruments. Keep carving away until things begin to come together better.
2. EQ When Recording
Miking and recording instruments is an art, and EQ can often be used to help you get the sound you’re after at this stage. Many instruments have complex sounds with radiating patterns that make it almost impossible to capture when close miking, and here EQ can compensate for these imbalances by accenting some frequencies and rolling off others. Remember though that
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Get That Pro Sound - The Ultimate Guide to Equalisation the goal is usually to capture the sounds as naturally as possible, so use EQ carefully and don’t overdo it – once a part is recorded with EQ already applied, you can’t undo it later if you want to make adjustments.
4. Brightening Dull Sounds: Enhancers vs. EQ
A mistake often made by newcomers to EQ and mixing is to try to brighten an inherently dull sound by applying large amounts of high-frequency boost. Because you can’t ‘boost’ frequencies that aren’t present in the sound to begin with, this often only increases background noise and grittiness. This is where psychoacoustic ‘enhancer’ plugins come in: an enhancer processes the frequencies that are present in the original signal (usually via a combination of compression, filtering and controlled distortion) to produce additional high-frequency harmonics designed to augment the existing signal. Because the added harmonics are related to the existing signal, the ear accepts them as being ‘real’ and a part of the complete sound. Overuse of enhancers will produce harsh or unnaturally abrasive results, but they can often rescue sounds that are not appropriate for EQ to deal with.
5. EQing A Different Part To Make The Current One Fit Better
It’s easy to forget, but sometimes if you’re trying to get a sound to fit better in the mix, the answer might not be to change that sound at all, but to make space for it by changing the other sounds around it. This is the case so often during the various stages of writing, arranging and mixing a track, and should be considered a part of the creative process. Just be really clear in your mind of what you’re aiming for when you start cutting holes in other instruments: you don’t want to end up constantly chasing your tail and never actually arriving at a decent blend of sounds and parts that you’re happy with.
6. Don’t EQ!
Never insert an EQ into a track that sounds fine, just because you think you should to get a Pro Sound. Part of the art of EQ, and mixing in general, is knowing when something’s working just fine and to leave it well alone! Apart from that, EQ, like many signal processors, will naturally impart unwanted artifacts to a treated sound on some level, so it’s never wise to use any processor or effect unless it’s for a specific reason.
7. High Frequency EQ
Treble is often accentuated to increase clarity or to enhance the presence of a vocal or string part that might otherwise be lost in the mix. Horns, cymbals, acoustic guitars and many other instruments can also be greatly enhanced in this way, but you must know where the most important characteristic frequencies for the various instruments (known as ‘formants’) lie. Boosting high treble on an instrument with little output in that region will do nothing but add hiss. In
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Get That Pro Sound - The Ultimate Guide to Equalisation fact, when dealing with such an instrument, this is when you might actually reign in the unnecessary high-frequency bandwidth with some high-frequency controlling EQ – done on all the appropriate tracks, this can make a substantial improvement in the overall signal-to-noise ratio of the mix.
8. Overuse Of EQ Leads To Brittle Mixes
If you over-rely on EQ to achieve the sound that you want, you might end up with a mix that sounds cheap, unnatural and generally gives people a headache. If you find yourself using a lot of EQ of every instrument, it might be time to go back and readdress the original recordings, the choice of sounds and samples, and the musical arrangement instead.
9. EQ Sweep FX
You can use a Parametric EQ to dial in automated sweeps up and down the frequency range for a simple but cool and highly controllable effect. Set up a pretty sharp and narrow mid-range boost, set your DAW to record your realtime adjustments as automation, and then as the track plays back, sweep the frequency knob up and down, as fast and across as wide a frequency range as sounds best. A classic technique for introducing more or less subtle movement and evolving interest to synths and pads in electronic music.
10. Make Space And Add Distance – Remove Some High-End
In composing the stereo or surround image of your mix, you not only have the option to pan things into their horizontal position, but you can push them back into the distance, away from the listener as well. Reverb is the most obvious tool for this job, but you can also achieve the illusion of distance by removing some of the high-frequency content of a sound.
11. Stereo EQ
A stereo sound is essentially created by sending different but related signals to each channel (left and right), and the more you emphasize, however subtly, the differences between each side, the more you enhance the stereo effect. And one way of enhancing the difference between the two channels would be to EQ them differently. For example, start by duplicating a single, mono track to two seperate channels on your mixer. EQ each of them slightly differently: if the signal on the left is made brighter than the same signal sent right, then the image will seem to come from the left, brighter side (remember, distance removes high frequencies). Consider EQ differences between left and right that are more elaborate and involve several different sets of cuts and boosts so that neither side is exactly brighter than the other, just different. In these cases the image will widen without shifting one way or the other. A mono sound source suddenly becomes more unusual, it’s image less precise, more liquid and much more interesting.
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12. EQing Drums For Power
When we consider that drums have a pitch, you can not only transpose them to work harmonically with the other tuned instruments in your tracks, but you can also use EQ to emphasize the pitched elements in the drums and percussive instruments: some producers find that this can lend these sounds greater punch. This can be done in a similar way to how we might EQ out hum and buzz harmonics (except this time we’re boosting): we set up an array of very narrow peaking filters to boost the fundamental and harmonics of the ‘drum note’.
13. Seasoning To Taste: Making Things Sound ‘Better’
Generally speaking, you would boost higher frequencies for clarity or presence (the mid-range can affect this too), and bass for fullness or punch. But sometimes it seems that no matter how much top or bottom you add, something is still not right. Often the real culprit here is one or more unpleasant resonances, caused either by microphone characteristics or placement when recording, or just by the fact that the instrument itself is out of adjustment or poor quality. Finding and eliminating these mid-range resonances with surgical EQ will often improve the sound and minimize a need to boost highs and/or lows. Physical resonances of instruments usually fall between about 100 Hz and 1 or 2 KHz, so sweeping this frequency range is a good starting point.
14. EQing Harmonics vs. Fundamental Frequencies
You don’t always have to EQ the fundamental frequency of an instrument to get the adjustments you want in a mix. Clarity of many instruments can be improved by boosting their harmonics. In fact, the ear in many cases actually fills in hard-to-hear fundamental notes of sounds, provided the harmonics are clear. Drums are one instrument that can be effectively lifted and cleaned up simply by rolling off the bass, which gives way to more harmonic tones.
15. Why Simply EQing In More Bass Doesn’t Lead To More ‘Powerful’ Mixes
Anyone can grab the low frequency knob and wind up the bass to the maximum, but if you are serious about your recording then you will realise that it isn’t just yourself you have to please; you have to consider what other listeners like and what systems they may be playing the recording on. There is also a good technical reason why you should think before adding a lot of bass: for a given level of input, any small or medium size loudspeaker will produce much more sound at mid frequencies than at low, and if you boost the low frequencies too much then the overall level the speaker can achieve without significant distortion is less -- sometimes much less. It’s a matter of compromise: the more bass you add, the lower the overall level can be. This also applies to other frequencies in the mixing console itself.
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16. EQ And Panning
Stereo mixing can confuse matters slightly when it comes to applying EQ, because panning, like EQ, can create a certain amount of separation between sounds that can be deceiving. There are still plenty of environments where playback systems work pretty much in mono, and in such cases your mix will lose the benefit of any panning separation and appear cluttered: to take these situations into account, it can be a good idea to check the tonal balance of your track in mono as well as in stereo, so that you don’t get caught out.
17. EQing Vocals
Clearly, every voice is different, with it’s own tonal characteristics: if your singer has a deep, booming voice you may find yourself cutting the bass and boosting the mids and highs more than with a vocalist with a lighter, airy voice, who might need some boost in the low and mid areas. Many vocal mics can have a slight midrange bias, but you might want to compensate for this if your vocalist doesn’t need the help, with a slight cut in the midrange along with slight boosts to the bass and treble frequencies. One trick for effective vocal EQ is to think of the vocal line as a series of sustained vowels and transient consonants. The vowels reside at lower mid frequencies (200Hz-1kHz), while the consonants occur further up at about 2 kHz. So if you want a richer vocal tone, manipulate the vowel range. For more intelligibility – clarity to the words and phrasing – manipulate the consonant range. Watch out for overly sibilant ‘S’ sounds, but don’t be afraid to emphasize some of the human expressiveness represented by the singer taking breathes before lines and words. You very often get frequency masking issues between vocals and guitars, so try and EQ these parts to emphasise different spaces in the spectrum – 2-3kHz is a good place to start. Boost the vocal here and cut them in the guitar, or something similar.
18. EQing Drums
As with the vocal vowels and consonants, try thinking of drums as being made up of two components, the initial transient attack and the body or tail of each hit. With a kick drum, you have the click of the beater hitting the drum – this might actually be all the way up in the 3kHz range – followed by the low frequency pulse of the drum itself resonating at around 60Hz. Make your EQ adjustments, as required, to each one of these elements independently for the most effective sound-shaping. The same transient/tail strategy can be applied to any drum, including the snare, toms, percussion, hats and cymbals.
Kick Drum The punch component of powerful kick drums lies between about 80 and 100Hz. To make space for the fundamental tones of the bass, you might want to remove some key frequencies from the kick – quite literally making holes for the bass to sit in. Try starting with cuts in the ‘warm’
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Get That Pro Sound - The Ultimate Guide to Equalisation 200-400Hz range, and possibly some tighter Q cuts at around 160Hz, 800Hz and 1.3kHz. A high pass filter at 50Hz will also help tighten up the kick, along with removing inaudible sub-bass components that can fool a kick compressor into responding to the wrong frequencies. Along with any cuts, kick drums usually need some subtle mid and/or high EQ boosts – try 2.5-6kHz – to emphasize the click/transient and enable them to cut through clearly on smaller speakers. It’s also worth remembering that the kick, like most drums, has its own pitch. If you have trouble EQing your kick and bass together, try transposing the kick around until you get it hitting at the same pitch as the bass – this can solve a lot of subsonic issues.
Snare Drum Most snare drum sounds are naturally very ‘present’ to start with, so a few cuts might be all that are needed. It can be beneficial to high-pass filter and low end out of snares, say below 150Hz. If the snare seems to be poking out of the mix too much, a cut at the magic 5kHz frequency can push it back a little – apply a small boost at 10kHz to brighten it back up. For a huge-sounding, fat and punchy Dubstep or D&B snare, look to emphasize the sound at around 250Hz. If the snare sounds small and ‘boxy’, try rolling off some energy in the 800Hz-1.2kHz range. The ringing / resonances of a snare drum reside between about 2-4kHz, and the crispness of the drum’s attack tends to be more in the 4-8kHz range.
Toms When EQing toms we’re generally thinking of providing colour rather than power. Most toms will benefit from a cut somewhere between 300-800Hz to remove excessive ‘boom’, and can be completely high-pass filtered below 100Hz so as not to interfere with kick and bass. A small boost just above 100Hz can bring some fullness to larger/floor toms.
High Hat & Cymbals High hats have very little useful low end information, so a high pass at 200Hz can clean up a lot of unusable mud here. The mid tones are the most important for defining the overall character of a high hat, particularly between 600-800Hz. To brighten up high hats, try a shelving filter at 12.5kHz. The clunk of a stick-hit on a ride cymbal or hat can be emphasized at around 300Hz; the ringing overtones of crash and ride cymbals can be brought up in the 1-6kHz range – be careful around the 1kHz range not to add too much though. The sizzle of cymbals can be emphasized in the 8-12kHz range.
Drum Overhead / Ambience Mics Ambience/room mics can really help define the overall sound and ‘colour’/character of a tracks drums. These mics can be rolled off completely below 150Hz so you don’t get any phase
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Get That Pro Sound - The Ultimate Guide to Equalisation or masking issues with the bass and kick drum tracks, and they usually benefit from a cut at around 400Hz as well. Cuts at 800Hz can bring more focus to the ambience, and a small boost at 12.5kHz with a shelving filter can provide some air.
19. EQing Bass Instruments: Boost, But Not Where You Think…
Bass instruments can be especially tricky to EQ for small-studio producers, who don’t generally have large enough speakers to hear all of what’s going on at a sub-bass level. However, one big misconception is that all the important EQ adjustments for bass instruments are at the low end. You will often find that your bass part will sound perfectly bright when solo’d, but once it’s slotted into the mix it all but disappears beneath the other instruments. The trick here is to bring out some of the higher-frequency components of the bass sound with EQ. You don’t need to be shy here either: it can be surprising just how much top end you need/can get away with to make the bass cut through in a busy mix. The extra advantage of using more of the higher frequencies to help define the bass parts is that they will come through much better on small speaker systems. The same principle applies to kick drums – just make sure you’re highlighting different higher frequencies for the different bass parts.
20. Natural vs. Unnatural EQ
A quick tip here is that electric guitars and synthesizers usually cope pretty well with being shaped to fit in with the mix in this way, because they have no inherently ‘natural’ sound of their own. Even if EQ places heavy emphasis on a particular frequency range, it may not be a problem, as pronounced resonances are characteristic of both these types of sounds.
21. Try Out Different EQ Plugins For Character And Transparency
It’s worthwhile experimenting with different EQ types and plugins on various material. All equalisers sound subtly different even with the same nominal settings, and you’ll often find that different models respond quite differently to the same signal. You should especially look to build up a library of digital and analogue (or analogue-modelled/vintage style) EQs because each type suits slightly different applications. The most highly-regarded analogue EQs induce musically useful phase changes in the audio passing through them, resulting in significant tonal changes that can add character and an extra degree of ‘musicality’ to treated sounds. On the other hand, straighter ‘digital’ EQs can be designed to leave phase relationships almost unchanged, meaing that you can make large gain adjustments to particular frequencies much less noticeably.
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Get That Pro Sound - The Ultimate Guide to Equalisation
Conclusion Throughout this guide we’ve covered everything you’ll need to quickly get EQ working for your mixes in the most effective and efficient ways possible. From examining and effectively configuring EQ parameters for a number of mixing tasks, to plotting and implementing a comprehensive EQ strategy for a full and busy mix, to some more advanced tricks and techniques for creating space, character and power in your productions. If you haven’t already, print this guide out and put it in front of you while you work on your music (or alternatively have it open in a window next to your DAW): this way you can refer to it as you work through the techniques, put things into practice, experiement with what is discussed, and see how it all works in the context of your own music. That’s what it’s all about. There’s a lot of information packed into this guide, so don’t expect to necessarily digest it all immediately after the first reading: it will take practice and experience as well as technical knowledge to really master EQ. By all means read or at least skim the guide cover-to-cover first to get an overall view of what’s covered, but after that you’ll probably get the most benefit from the text by using it as a quick-reference resource as you develop your abilities. Ultimately, this guide is designed to give you the tools and techniques to make an immediate and lasting improvement in the quality of your productions. I hope it serves you well in this regard - let me know how you get on with it at
[email protected]. Best of luck, George Robinson Get That Pro Sound If you found this guide helpful, you should check out the other guides in the same series:
The Ultimate Guide to Compression
The Ultimate Guide to Reverb
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