Like Parallel Compression, Serial Compression is one of those esoteric terms that seems to pop up in recording magazines from time to time. While the name might seem abstruse and academic, the process is anything but:
“Putting one compressor before another is something that was going on long before it got a fancy name that made it sound like a ‘technique’,” says Joel Hamilton, one of the four NYC engineers we asked to weigh in on the subject.
“But the idea that you can kind of mine different things out of the same signal by chaining devices with different tones or time constants is totally valid.”
Simply defined, Serial Processing is the use of two (or more) similar effects on the same audio track. Most often, you’ll encounter the term as it refers to compression, EQ, and de-essing.
In addition to Hamilton [Tom Waits, Elvis Costello, Dub Trio], we talked to producer/engineer John Agnello [Sonic Youth, Dinosaur Jr., Kurt Vile] as well mastering engineers Randy Merrill and Scott Hull of Masterdisk, about their approach.
WHY DO IT?
“It’s like using shellac,” Hamilton continued. “You can’t buy a bucket of shellac, pour the whole thing out on your tabletop and expect it to turn out extra-glossy. But, by applying it in a dozen tiny layers, one on top of the other, you can bring the surface to a really high shine.”
All of our panelists agreed – sometimes, spreading the work across more than one unit leads to better results:
“It’s well-known that in general, the shorter the signal path the better the sound quality,” said Scott Hull of Masterdisk [Miles Davis, Bruce Springsteen, The Ramones].
“That’s true, and I’ll never use more gear than what’s needed to achieve the goal. But you can’t always get what you need from one device. What you may need is the complex interaction between two.”
“I would probably never choose to put two of the same compressors or EQs inline on the same track, but I will often use two different-sounding but similar types of processors if the combined result is better than without.”
When we boiled it down for this article, it became clear that our panelists consistently cited three basic reasons for stacking their effects: Tone, Tweak Points, and Time.
“There are some pieces of gear that just have a great character and I’ll use them when that character is needed,” mastering engineer Scott Hull said.
“What might confuse engineers that use primarily digital processing, is that an analog EQ isn’t always an EQ. And an analog compressor isn’t always a compressor. Running through my compressors with no gain reduction sometimes produces very favorable results from a tone or color standpoint.”
Producer/engineer John Agnello agreed: