A good mix starts with a good performance and a good basic recording. While there are many things you can do while mixing to improve things that didn’t work out quite as well as expected, many musicians expect some kind of miracle cure that will magically compensate for bad tone, poor pitching and inaccurate timing. The reality is that the old saying, garbage in, garbage out still applies! The quality of vocal recordings made at home is often a problem where acoustic treatment has been neglected. Just hanging up a couple of duvets around the vocalist when recording makes all the difference.
The other important aspect that is often overlooked is the musical arrangement, not just what notes and chords are played and by what instrument but also details such as the actual chord inversions. To achieve a great mix then we need to start with a good performance of a well-arranged piece of music where the individual sounds are also chosen to work well together. Small flaws can be worked on and there’s still a lot we can do to adjust the sounds of the various instruments, but it helps to know the limitations of mixing and to recognise the stage at which mixing becomes mere salvage. Don’t worry too much about small amounts of spill between tracks though excessive spill can make it hard to achieve a clean sounding mix with a good balance.
Assuming you have captured what you need, much of what we tend to think of as mixing is actually preparation that needs to be done prior to the mix. It is a bit like painting a room where the hardest work is always stripping away the old paint, filling in cracks and preparing the surface for the new paint. If the preparation is done correctly the actual painting is the simplest part of the job — and so it is with mixing. The better you prepare the easier the mix will be.
Set a sensible monitoring level and try to stick to it apart from occasional checks to see how the mix sounds when played very loudly and very quietly. Use the sound level meter on your phone and aim for around 80 to 85dB. This will protect your hearing and allow you to work for longer without fatigue. My approach is first to listen to the individual tracks in turn to identify any problems. If they can be fixed by editing or copying a good part from elsewhere that’s fine, otherwise they may need to be rerecorded. I’ll also crop away periods that are supposed to be silence as there are often background noises such as spill from other instruments, hum from guitar amplifiers or the rustling of lyric sheets. However, be careful not to get rid of all the breath sounds in the vocal track as a vocal can sound very unnatural without them. While gates can be useful to cutting down spill during pauses, manual editing can be more accurate in some situations. For example, I always mute the tom mic tracks between tom hits as the heads seem to resonate continually in sympathy with the other drums.
Next I’ll ‘comp’ any vocal or instrumental parts where the performer has recorded multiple versions so that I can use all the best parts to produce the best sounding tracks possible. Where vocal parts are layered, you can move parts around to tighten up any timing errors and also ensure that any layered breaths are lined up. Unused material is then muted and hidden or removed from the workspace.
If your DAW lets you change the colour of tracks on screen, adopting a colour coding system can help you navigate your mix. For example, you might make all the drum mic tracks one colour and all the keyboard parts another.
A mix that comprises a large number of individual tracks can be very difficult to manage so I try to subgroup common elements, such as all the mics on a drum kit, so that the whole drum kit level can be adjusted using a single fader once balanced. With a modern DAW you can do this using simple fader grouping but I still like to also route groups via their own bus so that I can add global processing to the group, such as overall compression or EQ, when necessary.
Another important step is to use low-cut filters on any tracks that are not intended to contribute to the bass part of the mix. In most cases that means everything except the kick drum, bass and perhaps the low toms. It is surprising how much unwanted low frequency energy can find its way into vocal or guitar tracks so put in an 18dB/octave low-cut filter and adjust the frequency as high as you can get it without affecting the part of the sound you want to keep. With some instruments, such as acoustic guitars used in a pop mix, you may want to set the filter frequency even higher to prevent the low end of the guitar from making the mix sound muddy. The key here is that it’s not about how tracks sound in isolation but how they sound when heard in the mix. You’ll be surprised how much cleaner your mix sound after cutting out those unwanted lows.
Following on from this previous point, it’s fine to apply any obvious EQ that you think is needed to individual tracks but be aware that you may need to change these settings when the whole mix is playing. Bass guitar is a case in point where what sounds impressive in isolation may become an indistinct boom when the other instruments are added.
When it comes to signal processing, and that includes EQ, always use it for a reason, not just because you feel you are expected to. Vocals often need some compression to make them sound more solid but be gentle with the EQ as it is very easy to make vocals sound harsh or unnatural. If a vocal isn’t cutting through, try a simple shelving high filter
and add a few dBs of boost above 5 or 6kHz. If you boost much lower down the vocal can sound harsh and aggressive.
Those new to mixing often rely on plug-in presets but this can lead to problems when using compressors. A compressor works by reducing the gain when signals exceed a certain threshold level, but the preset designer doesn’t know how loud you recorded your track so the default threshold setting is likely to be incorrect. The solution is to call up a preset but then adjust the Threshold control so that the gain reduction meter shows between three and 10 dB of gain reduction on the signal peaks depending on the style of the vocals. The same is true when using compressor presets on instruments.
You’ll often get a better sounding result if you use your DAW’s level automation to smooth out any excessive level changes as this will make the compressor’s work much easier and it will avoid you having to apply excessive compression to keep the level under control. A little compression can add to the power of a sound but excessive compression can actually make a sound seem weaker.
Set up a reverb, such as a plate plug-in, plus a delay on two separate post-fader sends so that you can add them to your vocals as you mix. Modern vocal treatments almost always include a blend of reverb and delay where it is common to roll-off some top end from the delays to make them sit behind the vocal. Very clean and bright delays can sound too obvious. Listen to commercial records to see what they use — often the amount of delay and reverb added is less than you might imagine.
Different engineers approach balancing a mix in different ways, but unless you are very experienced, it might be useful to start with the bass and drums, then add in the vocals. These are key elements in modern pop music. The other instruments can then be slotted in as required starting with the guitar or keyboard part that carries the chordal structure of the song. Always leave plenty of headroom as the mix will get louder every time you bring in another track. Aim to leave around 12 to 18dB of headroom or safety margin on the individual tracks so that you don’t drive the main mix output into clipping — you can always bring up the overall level using plug-ins, such as compressors or limiters, in the master channel if you need to.
A mix needs perspective. When you are working on individual sounds, it is a temptation to try to make them all sound as big and as exciting as possible. However, in a good mix, some sounds such as vocals should appear to be at the front while others play a supporting role further back. If everything sounds big and bright your mix will sound congested with everything fighting for a place at the front. Keyboard pads, for example, can be tamed by removing both highs and lows using EQ and then mixing them in at a lower level. Effects such as reverb or chorus can also help push things further back in the mix.
Start your mix with all the sounds panned to the centre and try to achieve the best possible separation between instruments using balance and EQ. Only then pan elements to either side, making small level adjustments if necessary. Keep the bass, kick and lead vocals in the centre and then try to maintain a balance by panning, for example, a guitar slightly to one side and a keyboard to the other. Backing vocals may also be panned but this is where science becomes art so just do what sounds
right. Check your stereo meters to ensure that your mix is always roughly symmetrical so that the load is shared evenly by the two speakers of a stereo system. Also press the Mono button from time to time to make sure that your mix still sounds acceptable in mono.
A useful tip that many professionals also employ is to listen to a mix from outside the studio leaving the door open. This allows you to focus on the general balance without having to worry about the details and you’ll hear balance issues much more easily than if you are sitting right in front of the speakers. If possible get somebody who is unfamiliar with the song to check if the lyrics are clear. You can’t do this yourself very easily as once you know the lyrics, your brain fills in the gaps and fools you into thinking they are clearer than they may actually be.
Take regular breaks and also play a few commercial records that are in a similar style to the mix you are working on to allow your ears to ‘recalibrate’. Also, when you think your mix is ready, leave it alone for a couple of hours, then come back and check it again. It is also worth double checking your mix on headphones as small flaws often show up more clearly. It also confirms that your mix will sound good for people listening on ear buds or headphones.
Finally, if your mix isn’t going to be mastered at another studio, don’t apply final compression and limiting to the whole mix to make it sound louder — that’s the mastering engineers job. Don’t worry that your mix doesn’t sound as loud as commercial records at this stage‚ just get the best sound that you can.
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