Monday, May 7, 2012

Cascading Dynamics

I never realized there was a term for daisy chaining your processing, but it's often referred to as cascading or telescoping. If you're not getting the concept try sending the output of a delay into a reverb and watch as a whole new world opens up.  The topic today though is dynamic processing though so I'll leave those complicated effects patches for another time.

There are a lot of situations where you're processing dynamics in multiple consecutive stages even within the same piece of gear. Think of all those compressors that also have a gate and or expander built in.  But the different stages in those boxes are acting on the audio in different ways. What I'm talking about here is performing the same function on the signal a little bit at a time for a smoother result.

Just this week while helping a couple friends get set up on theatre gigs I had a chance to implement this in two different ways.  One was mixing on a Presonus digital console and had full dynamic processing on every input and output. The other guy was on an Allen & Heath four-bus with a rack of dbx compressors for outboard.

Let's start with the digital setup. It's great having a comp on every channel, but with any compressor, you can start to make things sound unnatural if you really crush the signal and in the theatre you want your vocals as natural as you can get them. (Unless you decide to break that rule for an effect, but you want it to be a choice, not a byproduct of bad engineering.) So I encouraged him to only comp the channels where the actors would really be belting, or if he did do it on every channel to take it easy.  Then in the signal routing, there were four groups, for chorus boys, chorus girls, lead boys and lead girls.  Each of those groups also has compression and that's where we set up another safety net. Those comps aren't going to do anything until you get a lot of people singing in a group, or a couple of actors screaming at each other. It takes the pressure off the operator and let's the focus be more on balance.

In the other situation things were somewhat similar, but there were only six channels of compression available so inserting on the channels was a luxury not to be had this time around.  Four of the comps were inserted on the groups but set to do a little more work because there wouldn't be any help from the individual channels. With only two comps left you might think to save them for a couple tricky channels but then you're out of luck if you get a third problem child.  So those went on the two bus to act as a safety net and kick in during big numbers. 

It's a popular method with mastering engineers to have two compressors each shave off a dB or two than to just have one do the job and add excessive color. They might make their selections based on the color the boxes add though. A little punch, a little brightness, a little midrange coloring, by picking their patches well they can ease off or even eliminate the EQ they need to use.  
 
In the DAW realm this can be just as effective. I've been stuck myself with a wild guitar track at mixdown from a live event. Overdubbing wasn't an option and I just had to work with what I had. With a comp running up to 28 dB of reduction it was murdering the performance. It didn't totally fix the problem, but cascading multiple compressors made things more manageable.

Brethren of the Knob and Fader, divide and conquer is the word of the day. Got any ideas or similar tricks? Hit the comment section below. And don't forget that we're on Facebook and Twitter (Links at upper right) if you have suggestions or submissions to contribute.

1 comment:

  1. I'm glad you addressed this. Sometimes I feel silly cascading compressors, but it really does make a difference sometimes rather than trying to make it sound right with one.

    Dig it.

    Kevin

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