September 8, 2005

A little bit of summing, Pt. 1

by Chris Randall

As the Great Mutron Bi-Phase Hunt continues, I suppose I should spend a little quality time with some other subjects. I've noted that, due to my repeated mentioning of summing mixers and summing in general on this site, I've now received several questions regarding what the hell I'm talking about. So let's just note that (a) I'm no electro-mechanical engineer; I just know what sounds good, (b) I'm a gear-snob of the first order, and (c) Your Mileage May Vary. With that out of the way, here comes

The Analog Industries Guide To Summing, with your charming and handsome host, Chris Randall. (Pt. 1 of 3)

Why would someone want to sum outside a DAW, when the DAW has a perfectly good summing engine in it? Well, unless you use PT HTDM (and even then, really) the summing engine in your DAW sucks. Plain and simple. _Anyone_ that has a console and mixes stems instead of mixing "in the box" knows this. My experience is with Nuendo and Logic, so I'll refrain from knocking other DAWs, but a simple experiment is in order: make four group channels in your DAW, all four of which go to the main "stereo" output. Mix your song to these four stems. Once you have it sounding good, send each stem to its own pair of outputs, and do a unity gain mix on your console. Instant air, instant dynamics, and instant room in the mix. It's as plain as night and day. (Especially if you break those stems out while you're wearing headphones.)

Don't have an 8-output soundcard? Don't have a console? Don't know what the fuck I'm talking about? No biggie. This is the promised land that lives between pro-sumer making shit at home, and working in a "real recording studio" with, like, gear and stuff. It is quite a bit more expensive to do this than to just mix in the box, but not near as expensive as aquiring a proper console, etc. First, let's see what the hell a summing mixer is. We'll use the Dangerous Music 2-Bus LT for our example purposes.

The 2-Bus LT is the baby brother of the Dangerous 2-Bus, far and away the most popular summing mixer out there. Every single console, and in fact anything that combines two or more audio signals, has a summing mixer. What Dangerous did, much to everyone's surprise, is provide just the bit you actually need when mixing in the ProTools/Nuendo/Logic environment, the analog summing part. So you can think of this box as the part of the console after the faders but before the master section.

I'll spare you the nasty math, mainly because I care about it less than you. What this box does is combine your stems outside your DAW. You then take the stereo mix back in to your DAW or on to a 2-track recorder of some sort, where you then master it like normal. This doesn't make sense, does it? Well, first we need to talk about mixing to stems, rather than mixing everything to stereo. A graphic is in order:

So, you've got your group tracks. Now, the next phase of the operation assumes that you have an 8 (or more) channel soundcard. Rather than bussing all of those groups to your stereo output like normal, you'd buss Group 1 to outputs 1+2, Group 2 to outputs 3+4 and so on. You're left with 4 stereo sub-mixes rather than one. This next graphic illustrates how a summing mixer enters in to the picture:

So, as you can see, your four stems get summed outside the DAW. They are then returned to the DAW, where you will record them down to a stereo pair, which you can render like you would normally. Now, the major hiccup here is monitoring your stereo mix. This is where something like the Presonus Central Station comes in to the picture. In the next installment, we'll have more charts and diagrams and shit that explains in some detail more complicated setups. In the third and final installment, we'll round up all the currently available dedicated summing boxes, and go over their pros and cons.




Sep.08.2005 @ 5:14 PM
D' MacKinnon
But WHY does it sound better?

I've only been in a pro studio a few times and never did mixing while there so I'm limited to my DAW experiences. Is the difference pretty dramatic?


Sep.08.2005 @ 5:19 PM
Chris Randall
Depends on what you mean by dramatic, I guess, but it is quite obvious to me.



Sep.08.2005 @ 6:12 PM
But are you gonna use them all and see which sound the best?

Since selling almost everything analog in my studio I haven't had a chance to do summing experiments, but I can say (a) I've made stuff sound good in the digital world and (b) I believe it can be easier through some analog plumbing.

I have my eye on that Speck box...


Sep.08.2005 @ 6:30 PM
Chris Randall
"But are you gonna use them all and see which sound the best?"

Don't I wish. My fantasy setup, which I can't currently afford, will be put forth in the third episode. Being in the market and shopping around are two different things. I know what I want already; it's just a matter of being able to afford it.



Sep.08.2005 @ 6:41 PM
Your fantasy setup being something like a Neve sidecar? :)

That said: link []">link []

Mercenary will happily send you a few to try and you can send 'em back the ones you don't want... wouldn't recommend doing that if you weren't going to buy one tho.

And here's the Speck: link []">link []

$1500. Looks nice. I had a big Speck mixer for a year or two and it sounded great. Good headroom, very clean. Weird UI, but I don't think that carries over to a box like this.

(Hope I'm not stealing Episode III's thunder.)




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