Like so many other aspects of recording, the use of analog summing is completely subjective. It’s all about what sounds good to you or your client when the mix is done. On some tracks I use analog summing; on others I don’t. It depends on what sound I’m trying to achieve. The summing mixer is just another tool in my toolbox that I can choose to use, or not. So what exactly does an analog summing mixer do?
The purpose of this device is to take digitally recorded tracks, convert them to analog (or simulate this step in the case of a plug-in version), bounce it down to two tracks, and then send that stereo version to some output device. If you’re using a DAW, which I’m sure most of you are, the output would go back to your computer. So why would we want to take this extra step? When you’re routing your individual tracks to your stereo bus, you are summing your mix. When this is done in the digital realm, the summed mix is an exact duplicate of the individual tracks simply summed together to a stereo format (mixed). When you send your individual tracks (or in most cases buses) out to an analog device (like a summing mixer or a reel to reel machine), what you get back is not an exact duplicate of your tracks. You instead get a version sonically colored by the quality of the circuitry that is incorporated in analog devices, as well as the inherent distortion of the analog gain stages. This may be from tubes, tape or transistors. In any case, you will have changed how your final mix will sound. Sometimes this adds a sense of warmth to your song that’s hard to achieve by any other means. Sometimes it just adds noise. To make the decision on whether this noise is bringing anything to the party brings us back to the debate of digital recording versus analog recording. Which one is better? Which one sounds more natural or pleasing to the ear? That really depends on whose ears you’re asking.
Not to sound too ambiguous, but I think that if you’ve used good recording technique, good quality preamps, a reasonably high sample rate and bit depth and as few plug-ins as you can, your digitally summed mixdown will sound fine. On the other hand, there is something to be said for adding analog warmth to certain songs especially in certain genres of music. And there are few better ways of adding that sound to them then with an analog summing mixer.
So the bottom line is, will having an analog sound mixer in your signal chain give you better results on your final mixes? The answer is no. What will give you better sounding final mixes is practicing your mixing and recording techniques. I have an analog summing mixer, a software version of one that’s pretty dead on (including the cross harmonics). Do I use it on every track? No. Why? Because using it is not necessary on every track. I like cool plug-ins just as much as the next guy, but what I always have to ask myself at the end of each session is whether adding a plug-in or an extra device to my signal chain will make things sound better. If the answer is no, then I’m wasting my time.