Digital Convertors and Compressors

inSync reader N.A. (yes, these are the real initials) asks, “Some people have told me to use a compressor on my overall mix going to my DAT because it will maximize the potential of the converters. What does this mean and should I do it?”

There are many schools of thought and opinions on this topic so my quick answer is to simply try it and see if you like the results. You really hit on two different issues here: 1) The idea of using a compressor on the main mix at mixdown, and 2) Recording digitally in the most linear range of the A/D (See WFTD above) converters on your DAT.

1. Some engineers like to use a compressor (see WFTD archive “compressor“) on the overall mix at mixdown because they say it adds warmth and punch to the mix. In the domain of rock and popular music I see this done quite a bit, but most engineers, especially in other genre’s of music, will leave it alone and let the mastering house do this if necessary. I have to admit to being a fan of the sound of a really nice tube compressor on the overall mix of rock tracks so I do recommend trying it.

2. Without getting into a long winded explanation of how digital conversion works, suffice to say that you will get the most resolution (and best sound) out of your converters by recording the signal as hot as possible without any peaks. Some engineers use a compressor on the front end of an A/D converter to trim off some of the peaks. For example: If there are several peaks throughout a song that are 5 – 8 dB hotter than the average level, compressing them down 2 or 3 dB will allow you to record the overall mix 2 or 3 dB hotter without clipping. Not only does this bring up the average signal to the more linear range of the converters, but the difference this can make in the perceived power and punch of the recording simply by having a higher average level is amazing. Some high quality A/D converters such as Apogee have switchable compression built in for just this reason. Ultimately all of this is subjective so you will have to try it for yourself to see if you are happy with the results.