How To Bring Cohesion To Your Mixes

For the novice producer, one of the trickiest and most evasive aspects of mixing is nailing the essential sonic weight and solidity that plays such a big part in defining the sound of a professional, commercially viable track. Success in this endeavour means deploying a range of processes and concepts to individual instrument channels and, crucially, group busses to ‘glue’ them together into a cohesive whole that presents itself as something far greater than the sum of its parts – in other words, a release-quality mix!
 
Here are some of the core techniques you need to get on top of to be able to give your tracks that decisive thickness, heft and sense of conviction.

Bus compression: put on some weight

The most powerful tool at your disposal for pulling disparate mix elements together into a unified collective is bus compression. This is the routing of multiple signals to a shared group channel (bus) with a compressor inserted into it, which reacts to all of them together and thus applies dynamics shaping to the combined signal, rather than each individual component of it, as would be the case with separate compressors on each source channel. Indeed, the channels routed to the bus may well have their own compression already in place for discrete dynamics shaping.
 
The coalescing effect of bus compression can be profound, and beyond using it on drums (which is often a must, since the drum kit is so dynamically wild and ‘spiky’ without it), guitars, vocals and other ‘sections’, the most transformative place for a compressor is on the mix bus – that is, the final output of the mixer, to which all channels and busses are ultimately routed. While instrumental bus compression might be quite fast and high-ratio, depending on the sound you’re looking to realise, the goal with mix bus compression is to gel everything together as transparently as possible, avoiding an over-compressed or ‘crushed’ sound. A common starting point is a low ratio of around 2:1, increasing to no more than 4:1 if more aggressive control is called for, with the threshold set to achieve 1-2 dB of average gain reduction. Set a moderate attack time (around 20-40ms) to preserve transient punch, and either use ‘auto’ release if your compressor offers it, or adjust the release so that the compressor breathes in time with the rhythm of the track, which will typically land you somewhere in the region of 100-200ms.
 
Should you find that your bus compressor is having the desired densifying effect but reducing dynamic range more than you’d like, try running it in parallel to blend the uncompressed and compressed signals to taste. If your compressor doesn’t feature a dry/wet mix control with which to do this, you’ll need to put it on an auxiliary return and route the bus in question to it via a send.

Bus EQ: shape the sound

Just as on individual mix channels, EQ is frequently employed alongside compression on group busses in order to sculpt the collective frequency profile of the bussed channels, whether to compensate for the altering effect of compression or simply in its own right. EQing resonances and harshness out of the drums bus, for example, can be a lot easier than addressing it within the source channels.
 
On the all-important mix bus, EQ is helpful for addressing tonal issues, but if you find yourself needing to apply anything more than a very gentle, broad curve or two, head back upstream and address the problem you’re trying to fix in the instrumental channels causing it instead. Drastic changes at this final stage of the signal path should never be necessary, and less is invariably more when it comes to gluing the mix together with regard to both EQ and compression.

Saturation: turn up the heat

You may already be aware of the ear-pleasing influence that a little analogue-style saturation can have on the warmth and impact of drums, basses, guitars, vocals and synths in particular, but it’s also well worth calling on in the pursuit of a cohesive mix. We’re not talking overt, pulverising overdrive, clearly, but the sort of soft harmonic enhancement provided by a good tape or tube emulation, which not only has a lovely gluing effect due to the subtle compression it brings to bear, but adds a touch of fizz and high-end presence, too.
 
As with compression and EQ, you can apply saturation to bussed groups within the mix to work its magic on summed instrumental sections, or to the mix bus as part of your ‘master’ processing chain. Once again, though, don’t overcook it on the latter, as the last thing you want to do is audibly damage the mix by pushing it into full-on distortion territory; and if your plugin features multiband filtering, use it to focus different amounts and even styles of saturation on the lows, mids and highs, if required and appropriate. Also, like compression, saturation can be used in a parallel configuration when you need to combine the articulation and tonal characteristics of your saturated and clean signals.

Reverb and imaging: find your space

Another major contributor to the aggregate sonic unity of any mix is the spatial environment in which its component sounds reside, be it the captured ambience of a real recording space or – more likely these days – a reverb plugin or hardware module. As well as the primary reverb(s) to which your instruments and vocals are no doubt already being sent, putting a short, low-level reverb on the mix bus can bring even more glue to the party – although this should be considered very much an optional creative technique, not a staple. If you do elect to give it a try, dial the reverb in so subtly that it’s all but inaudible: just enough that a reduction in cohesion is apparent when it’s bypassed.
 
Finally, stereo imaging also plays a role in establishing mix solidity, so use mid-side processing plugins on groups and the mix bus to narrow the bottom end, keep the mid-range tight, and open up the highs. Do watch out for phase issues when doing so, though.
 
Cohesion and ‘glue’ are intrinsic to any quality mix, and learning how to apply the above techniques – most notably, bus compression – effectively should be considered non-negotiable if you want your tracks to truly hit the mark. Understanding the intricacies of each process and using them with intention rather than habit is key; and like everything else in the study of music production, practice, patience and research into genre-appropriate commercial mixes that you love the sound of will yield dividends.