Lesson 64

In the Box and Out of the Box Summing

There’s a great online debate about what’s better, in the box or out of the box. Well, I’m not here to say one is better then the other, but there are certainly differences, and advantages and disadvantages of each. That’s what I’m here to talk about. There are professional mixing engineers who mix exclusively in the box, and there are professionals who mix exclusively out of the box. Although I do have a preference, I’ll try to keep this lesson informative and unbiased, and I’ll reveal my own opinion at the end.

First, what am I even talking about? What is this in the box, out of the box concept? Ok.... let’s go.
The box is basically the computer. Some engineers like to do the entire mix within the software on a computer, and some prefer a good old fashioned analog mixing board, just like back in the day before computers. You might be thinking... what... they still do that? Why? And the answer is because they like it. Boom.. it’s that simple. When you’re a professional mixing engineer, you can do whatever you like, even if it’s mixing a song on a big old analog board.
So your next noobie question might be... well.. why do they like it? Ok, now we’re getting somewhere.

When I was new to home recording, I was really passionate about it. I would spend a lot of time reading about gear, and looking at pictures of studios, and checking out their gear. It jumped out at me that a lot of studios had a huge analog mixer front and center. This was often the single most expensive piece of gear that they had. I didn’t get it... why did studios spend so much money on one of these? You still need an interface with lots of inputs, and you can just mix and master on the computer. What’s this big board for? Then one day I was visiting a studio with a modest setup... an older computer, the recording interface was nothing special, overall mediocre gear... and a one hundred thousand dollar analog board. He was telling me about his preamps, and signal flow... from the mic, to the preamp, to a compressor, then into the interface. So now I was really confused, he’s not even using the board. So I asked him... what does he even use the board for. He said mixing. I was still confused. Like.... aren’t we in the 21st century? What do you mean?
So he explained, he sends all the individual tracks within the daw to their own output channel on the interface. Then, each track goes to a channel on the mixing board. As the song plays in the daw, he can have real time control with his hands on the mixing board. The boards output gets sent to an EQ, then a compressor, then gets recorded back into the daw as a mixed and mastered song. So the mixing board provides analog EQ on each track, analog level adjustments, and most importantly, analog summing.

The summing is an often overlooked part of the chain. On a computer, it just happens so seamlessly we don’t even notice it, or think about it. On a mixer, somewhere in our brains we know that it is happening, but we do t really put any thought into it. Well, the good people who design this gear certainly do put thought into it. They put a lot of thought into it, because they know how big of a difference it can make. 
Basically, the summing is the process of adding the tracks all together. This can be done on a computer, or on an analog mixer. 
When it is done on a computer, it uses a mathematical algorithm to add the waves together. This algorithm has limitations, because it can make errors, and it has limitations as to how precise it can be. It does not have incite values, and therefore needs to round off each value to the nearest that it can process. For instance, what’s 10 divided by three? It’s 3.33333 and it goes on forever. The number of decimal points of precision that it can process is determined by the bit depth. Higher but depth means more decimal points, therefore more precision, but also requires more processing power. A few years ago, 32 bit was the standard for most daws to operate at. Now, 64 bit is the standard. This might not seem like a big jump... only double, but actually, it’s way more than that. Picture it like a grid that the wave is placed on. Since there are not infinite values on this grid, then there must be a limited number of values. Well, I’m 32 bit, we have 4,294,967,296 values. Yeah, that’s 10 figures, over 4 billion, and that’s a lot of precision. But 64 bit has even more than that. Way more! In 64 bit, there are 18,446,744,073,709,551,616 values. That’s 20 figures. It’s more than double, more than quadruple, more than 100 times.. more than a million times.. it’s literally more than 4 billion times more values than 32 bit! So 32 bit has roughly 4 billion possible values, and 64 bit has roughly 4 billion times 4 billion. That’s insane.. it’s a very high level of precision, and 64 bit summing compared to 32 bit summing does in fact make a noticeable difference. But even 64 bit summing is not as good as analog summing. With analog summing, there literally is infinite value possibilities. The waves do not get rounded off to the nearest value, and there are no mathematical calculations to figure it all out. It happens in the natural world as the waves are blended together on a circuit board. While this might seem better in theory, the problem with analog is throughout the circuit, there’s noise and distortion added to the signal. This noise is cumulative from each track. So, the summing itself is more precise, but the overall sound is not necessarily better. Some mixers add more noise than others. That’s the main difference between a cheap board and an expensive board. There are of course other differences, such as the features on the board. They pretty much all have eq on every channel, but some also have compression, group busses, aux sends, motorized faders, 2 bus effects, and digital effects. Some analog mixers however don’t have any features... not even an EQ... all they do is summing. These actually aren’t even called mixers, they’re called line summers. These are a hybrid between in the box and out of the box, but technically they are out of the box because the summing takes place in the analog domain. These units are normally rackmount, and will have a number of stereo inputs, and maybe some mono inputs. Since they only do the summing, the mixing is still performed in the box. Each track gets its EQ, compression and effects added on the computer, and then it’s sent to its own channel on the line summer. The line summer’s output is then routed back into the daw, and recorded as its own track. 

So, just to recap, we have in the box, which is mixing in the computer, out of the box, which is mixing on an analog board and recording it back in, and we have hybrid which is mixing on the computer but using a line summer to perform the summing in the analog domain, and record it back in. Each of these methods can also have variations. You can mix in the box, but send individual tracks out through analog gear, and back in again. You can mix out of the box, but still use the daw to apply e effects to each channel, and you can use the hybrid method and use analog gear on any track, or the output of the line summer, such as an EQ’s and compressor. 

Now as promised, or perhaps, as threatened, I said I would talk about my own preference at the end. 

Mixing in the box in 64 bit is hard to beat. Especially when using high quality 3rd party plugins. You can get a big full sound with a very low noise floor. However... I said it’s hard to beat... not impossible. A really high quality analog setup does sound undeniably better. Remember when I said the downside to analog summing is the added noise from analog amplification, well the really high quality mixers have extremely low noise, and the advantage of analog summing becomes apparent. These are the best of the best boards, and often cost in the range of a hundred thousand bucks, more or less. In the context of a mix, each part just sounds fuller and clearer. 

Most out of the box options under 10 grand will be roughly equivalent to in the box in terms of sound quality.

Let’s do some comparing. These sample files are available to download so you can listen in your own daw.

Here’s 2 versions of the same song, same mix, same everything except for the summing. In the box summing on one, and high quality analog summing on the other.