Thinking Inside The Box, Part Two – Analogue vs. Digital Summing – We All Make Music

Thinking Inside The Box, Part Two – Analogue vs. Digital Summing

Welcome to the latest installment of Production Tips, our new monthly feature offering, well, production tips, hosted by Simon Langford.

Before we take a deeper look at what “summing” actually is, let’s briefly recap what we looked at last time. You may remember that we looked at how you could set up your DAW to more closely replicate the workflow (and, to a lesser extent, the look and “feel”) of a traditional mixing desk. The natural way to follow this is to look at the final stage of the mixing process: that of mixing everything down to a stereo format for public consumption.

Sum-thing To Think About
“Summing” has become a bit of a buzz-word in recent years, but go back ten years and you would probably struggle to find anybody talking about it. Summing essentially refers to the process of combining the signals from multiple channels and mixing them down to just two (or a few more, in the case of surround mixes). It was always just called “mixing down” but, since the inexorable rise of digital audio, it has somehow become known as “summing”.

Comparatively few modern recordings are 100% analogue (recorded to tape, mixed on an analogue console and then mastered to tape) as there will usually be at least some stage of digital audio in there somewhere. More often than not this will be the actual recordings themselves. A great number of records are made by using digital recordings which are then sent out through D/A converters before being mixed on a large format console and then the resulting stereo file being recorded back into a digital system.

So why would we even want to go to the trouble of going from the digital domain to the analogue and then back to the digital again? Well, to many, 100% digital recordings can sound a little “sterile” and “clinical” and lacking in warmth and character. There is an extensive debate about just how much of a difference analogue equipment in the signal path actually makes and it is one that will probably go on for quite some time. Personally, I believe that it can make a difference, but I believe that the difference isn’t quite as clear-cut as some people believe it is, and I don’t believe that, as a step, it is absolutely necessary in order to have “professional” results.

The Sum And The Difference
Before we can really decide what is best for you, we should probably explain the difference between the two, and we can do that pretty well in one word: accuracy. With the quality of digital recording systems these days, digital summing systems are supremely accurate. A digital summing system adds together the value of the two (or more) separate signals and gives a mathematically correct result. In theory, this is exactly what happens with analogue summing as well, but because of its very nature (and some complex electronics theory that I won’t go into here), the end result is often less than 100% accurate.

Therein lies the problem. Analogue “warmth” is actually the result of subtle distortions added to the original sound. And I don’t mean distortion in the obvious guitar amp kind of way. These distortions are much more subtle, but these are the imperfections that make analogue sound so pleasing to the ear.

So if this analogue tone is something that you are after, then analogue summing is probably the way forward. While it won’t give you the full sound of mixing through an analogue console (there are many other stages that a signal has to pass through in a fully analogue console, each of which imparts its own little “signature” on the sound even before it gets to the summing stage) it will at least give a hint of that sound to your (otherwise) fully digital mixes.

Thermionic Culture Fat Bustard
There are numerous options on the market which range from the extremely simple and “clean” (such as this) through to the more “colourful” (this is a good example) and then on to some devices which add tubes to the mixing stages to give even more scope for adding character (like this for example). Whichever you go for will depend on your personal tastes and, as always, your budget.

Rather than use an analogue summing box, some people prefer to pick up a second-hand small console. These will give them everything a summing mixer does and more at the expense of taking up a little more room and perhaps not having quite as good a technical specification.

Un-digitizing Digital
But what, if any, options remain for those of us who wish to stay fully digital while injecting a little of that analogue “mojo”?

Fortunately, there are actually a few plug-ins available that simulate analogue (and particularly “tube”) saturation effects (such as the URS Saturation and Wave Arts Tube Saturator plugins). These can be placed on the 2-buss (or master) outs of your DAW to help “warm up” the final mixdown. When used carefully, they can go quite a way towards adding some vintage flavour to your mixes. They can also be used on every other channel, but it’s important not to “drive” each channel too hard on its own because the cumulative effect can very easily become too much.

Slate Digital VCC (Virtual Console Collection)
One of the more recent players to join the game, Airwindows Desk, goes a little further in their attempt to recreate an analogue desk experience, aiming to model some of the “non-linearaties” of analogue consoles. By placing this plug-in on every channel, every submix and even the 2-buss outputs, it is said that the series of subtle differences adds up to create something very close to the complex changes to audio that happen as they pass through an analogue console. Another new contender, Slate Digital’s Virtual Console Collection, aims to do much the same thing, but offers “models” of six famous consoles rather than the Airwindows’ more generic approach.

I really cannot tell you whether “real” analogue summing or the digital version is better, because what is better is so subjective. What I can tell you, however, is that there have never been more options for those of you who wish to embrace the analogue sound without actually needing analogue equipment.

Purists will no doubt say that it is nowhere close to “the real thing.” They will claim they can tell the difference, when given an A/B test, between a fully digital ITB mix and one that has been at least summed analogue.

But the fact remains that we are getting closer than ever before to replicating the sound of big format analogue mixing desks inside our DAWs where we have all the added convenience that the DAW gives.