Detection and the Dynamics Duo (or Why Do Some Compressors Sound Great
While Others Just Plain Don’t?) A Discussion of the Benefits of True RMS Level
Detection and True RMS Power Summing
Detection? Dynamics Duo? Sounds like a confidential Gotham City document that Cat
Woman or the Riddler would like to get a hold of for blackmail purposes. Perhaps the terms
“sidechain” and “compression” sound a little more familiar. In this paper, we talk about these
terms and explain the important role that “detection” plays in a well-designed “dynamics
processor”. Although we briefly mention VCA’s, the purpose of this paper is to highlight
various detection schemes used by manufacturers, as well as the methods used to link
channels for stereo operation. We describe our True RMS Level Detection and True RMS
Power Summing methods that we at dbx profess to be the correct and logical, not to
mention best sounding ways to do dynamics processing.
1.Viscerally Compressed Amplitude
No, that’s not what “VCA” stands for, as anyone familiar with compressors could tell you,
but we have a gut feeling you already knew that (pun intended)! VCA, of course, means
“Voltage Controlled Amplifier.” The guts of any dynamics processor (compressor, limiter,
expander, gate, ducker, dynamic filter, modulator, etc.) contain, among other things, a VCA.
As a pioneer in the field of VCAs, dbx created the patented industry standard chip used by
the zillions by many major manufacturers of professional and consumer audio equipment.
You’ll find our chips in dbx noise reduction systems throughout the world.
But this paper is not about VCA’s.We know that it takes more than a great VCA to make
a great compressor. Much more. And that’s where the years of leadership and expertise in
dynamics processing design make all the difference.
2. Dynamics Duo
The real art in making a great compressor is not only in the design and implementation
of the VCA, but in the design of the other, more important half of the
Detection and the Dynamics Duo - November 1998
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Detection and the Dynamics Duo
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