If your tracks are sounding 'muddy' on big speakers, some judicious use of EQ can work wonders - and our resident studio hound Chris Lyth is here to help!
Equalisation is a strange mix of art and science, and is an engineer’s biggest weapon when sculpting a mix into shape. EQ is fundamentally a problem- solving process, whereby we try to create space in a mix for every instrument, remove any sounds that are unpleasant and occasionally accentuate good bits that aren’t coming through.
Often, you will hear top engineers talking about a certain EQ unit and how they prize its particular character. This is because EQ units vary greatly in design: some classic units sound very nice when boosting, but are not great with precise, detailed work. I would suggest that, to really tackle a mixdown, you need two EQs; a 'character' EQ and a 'surgical' EQ.
Character EQ: Analogue EQs do more than just cut and boost frequencies. They colour the sound in complicated ways, by introducing distortion and phase- shift which make an important contribution to the sound as a whole. Often these distortions are musically pleasing to the ear, and are why some classic outboard EQs are revered. Digital plug-in EQs take great pains to model the characteristics of these classic units and attempt to emulate these behaviours as closely as possible. Great character EQ plug-ins include the Waves API 550A, UAD 1073 and Maag Audio EQ4.
Surgical EQ: Character can be good, but it’s not always the answer. If this is the case, it’s time to head for a type of digital EQ called a Linear Phase, which is free from phase-shifting. This is generally a more surgical tool, used for corrective jobs such as notch filtering, where you identify a problem frequency and use a very narrow bandwidth to cut it out. For such a task, an analogue EQ would not be as clean and precise. Some great surgical EQ plug-ins include the FabFilter Pro-Q 2, Sonnox Oxford EQ and DMG EQuilbrium.
Now you’re armed with a couple of different EQs, you may find the tips below helpful when approaching your next mix…
1. Sweep and listen
A great way to get acquainted with how an EQ unit or plug-in works is by playing a track through it in your sequencer and listening subjectively to how the changes you make alter the material. Play with different Q settings (how broad or narrow the cut or boost is set). What you will probably find is that narrow EQ boosts tend to stick out as being very obvious and unnatural sounding, while narrow EQ cuts tend to sound quite natural. Conversely, a broad EQ boost will tend to sound musical and natural, whereas a broad cut will sound much more drastic and obvious. So it would be a good rule of thumb to go for narrow cuts and broader boosts.
2. Clean up your h-h-house
Band-pass filtering is a powerful way of cleaning up your mix. A classic example would be a track that has a big, full-range pad sound or thick Fender Rhodes chords. Often these sounds can have a lot of low-frequency content that is not required, and that can make the low-end of your mix sound muggy and unfocused. In such a situation, try a filter with a 12dB/octave or 24dB/octave slope. You can use this on most instruments, as unless it’s a kick or a bass instrument there won’t be much musical content below 150Hz. Not only does this make your mix sound much clearer and louder, it frees up space for your low end harmonics to be heard properly.
The same can be said at the other end, as most instruments have little need for extending to the top of the frequency range. So just as we have controlled our low-end, we can do the same for the high-end by filtering most instruments at 15kHz. This clears up space for our cymbals and the high-end sheen on vocals.
3. Flying solo
One trap to avoid is EQing sounds excessively in solo. Soloing an instrument can be a useful method to isolate a sound when you are hunting down a particular frequency, as a little magnification can help you hear your changes far better. However, try to avoid spending a lot of time on a sound in solo mode as it’s easy to get carried away and lose sense of the big picture. The most important factor is how it sits within the context of the mix alongside your other instruments.
4. Cut, don't boost
Often we use an EQ boost to make a sound brighter, but at times this can make it appear harsh in the mix. A better strategy is cutting out muddy lower and mid frequencies, in order to reveal more transparency higher in the frequency range. The material itself will determine how you proceed, but often cuts between 250 and 500Hz will have the appearance of lifting out the higher mids. This kind of "subtractive" EQ should account for the majority of your mixing strategy.
5. Stay sharp, tread lightly
In general, unless absolutely necessary, avoid boosting any more than 6dB. You will be surprised how much a small amount of EQ can change your mix. Compare and contrast often by bypassing your EQs to keep you on track. This allows you to review your work and is best done at the start of a session when your ears and objectivity are fresh.
6. Switch to mono
Not everyone will listen to your music siting in your perfect mix position. Someone may be listening in a car, in the kitchen or standing right in front of a speaker stack in a club. So move around your room, swap between different speakers and headphones, and always check in mono. EQing in mono forces you to work much harder at instrument separation, as it makes frequency masking more obvious. If you can get your mix sounding great in mono, stereo will be the icing on the cake as you can then move competing sounds further away from each other.
7. To EQ or not to EQ?
Does it really sound better, or just louder? When listening to anything that you have boosted, adjust the gain output on your EQ to decide if your part actually needs EQ or simply needs the volume to be raised in the mix. Volume is very seductive, and an EQ’d sound is often perceived as better when in truth it’s just louder. If you find that your mix has lots of EQ boosts and is sounding strained, revisit each part and adjust your volumes.
8. Tame harsh mids
When cutting, it’s a common technique to set your EQ to a narrow peak, boost and then sweep through until you hear the problem frequency pop out and cut that area. A technique I prefer is to set the EQ to cut, turn up your monitors so that it’s obvious where the problem lies and then sweep until it disappears. This works very well for midrange and high frequencies, and is a good technique for tempering harshness. If it sounds harsh on your studio monitors, it’s a fair bet that it will sound even harsher over a club PA when it's being thrashed like a Tory MP’s rent boy.
9. Every sound is different
Allow your material to determine your EQ choices. For example, if your track is very bare and contains just strings and a vocal, you could probably leave the string sound as it is, warm up the low-end and add a touch of high- end sheen. However if those same strings were in a dense mix, they would cloud the mix and need to have most of the low-end EQ’d out to make room. In short, the denser the mix, the more EQ cuts are required.
10. The star of the show
Work your EQ strategy around the lead part of your mix and treat it like a star. All your EQ decisions should be based around making sure this part is front and centre. If a supporting line is competing for space, find the offending frequency range and make space by hacking away at it like a demented woodpecker. If any part needs a sexy boost in the mix from your best EQ unit, it’s the lead!
Words: Chris Lyth