Creative Audio Processing
08 - Compressors and EQs : about transparency

 

 

Now, let's confront all that we've said about compressors & EQs with the notion of a machine's "transparency". Many constructors claim that inside their machine, the signal follows a "pristine" path. While this may be true for machines such as Massenburg EQs and compressors, this is definitely not accurate in many cases : Manley machines, though very expensive and very beautiful sounding, are just not meant to sound "pristine". Try the Variable Mu compressor : at high levels, it's anything but transparent, and that's a very good thing, that's why this machine is interesting. So, on the whole, a constructor selling analog outboard gear claiming that his machines have "pristine" sound, that's marketing, mostly.

 

When do we need transparency, then ? The answer is obvious : if I take a machine, put a signal through it, and all the settings are "no compression, no EQ", then I expect transparency. More generally, many machines that are suitable for "stylizing" have linear behavior zones and non-linear behavior zones. Those machines are expected to be transparent only in the linear behavior zone.

 

Analog, digital, analog modeling Non linear behavior zones are more likely to be interesting in analog machines. However, the TC Electronics Finalizer, for instance, though a purely digital machine, is very good at non linear behavior. At the other end, some digital processing units, such as the Digidesign EQII plug-in series are not meant at all to function in non linear regime. It all depends on the machine conception and purpose. Some digital units and plug-ins are sometimes openly declared as willingly "non linear" when the constructor uses the mention "analog modeled". But every single "non linear behavioral" digital compressor or EQ is actually analog modeled : in the field of audio, non linear behaviors are always emulated from analog phenomena. Let's also notice that in the digital field, non linear behaviors are much more difficult to implement than linear behaviors. Digital computing is by essence linear.