Compression in the Live World

In the good old days of “making records,” compression was mostly used as an envelope modification tool. But around the beginning of “the great loudness wars,” some famous studio mixer dudes found they could get more work done in a shorter period of time by removing all the dynamics from the music, then equalizing it into place in the sonic arrangement.

Seeing as many of these dudes are charging several thousand dollars per song, and don’t really care how the final product hits the street as long as they can wail through a couple/three songs a day, it’s a great idea. Unless you happen to like music.

Unfortunately, the actual product – a hyper-compressed, no-dynamics ball of ick – is now viewed as normal for the presentation of music. The real irony is that this all started with the advent of the compact disc, which was heralded as the Next Great Thing due to it’s extended dynamic range.

So here we are in 2k5 with racks and racks of “studio quality” compressors traveling with so many live shows. Lately I’ve also been in clubs that had more Empirical Labs “distressors” than many studios.

The original problem with “live” compression was that it “sucked up” the stage sound between songs, which often caused feedback. But with the proliferation of “personal monitor” rigs, this is no longer the case. So squashing the heck out of the music has become perfectly acceptable.

Now, in addition to compressing the bass, in addition to compressing the drum sub, in addition to the studio trick of using parallel compression on the drum sub, in addition to compressing the vocals, the backing vocals and a maxi sub mix of all the vocals, I’ve seen more and more of the brothers compressing the “2 Mix” bus.

Why do I care? Because many of my live sound brethren employing this technique have been doing it in such a terribly inappropriate manner, and with such ineffective tools.

I know, I know – you’re just trying to get the show as “loud” as possible while living within the 98 dB (A-weighed; 105 dB C-weighted) SPL ceiling imposed by the local constable who just loves to hang at the FOH position with his little un-calibrated “Rat Shack” meter.

The harm, at least from my perspective, is that this often does not properly serve the artist, because the dynamics of the music are directly linked to the emotion of the performance.

There are some compression units that excel at allowing the emotion of the performance to creep through the reduction of dynamic range, and there are units that should never be used in this application.

Generally, if a compressor has a low-cut filter prior to the detector circuit (this keeps low-frequency energy from driving the gain reduction), it’s probably a suitable unit. If there is one set of controls governing both sides of the unit (true stereo versus linked dual mono), then it very well may be an appropriate unit to strap across a mix bus.

It has nothing to do with “toob” versus “squalid state” – there are great 2 Mix compressors that apply to either (and sometimes both) technologies. It has more to do with the internal headroom and overall frequency response of the unit (DC to light is about right). This, along with the ability of the unit’s gain reduction cell to control the dynamics of the presentation without pumping, wheezing, begging for mercy, nor removing the intensity and emotion.

During production rehearsals, simply listen to the mix with the compression engaged, and then disengaged, while making a concerted effort to knock down the dynamics of the presentation as seamlessly as possible.

When the pumping and wheezing ceases, you’re on the right track.

from Live Sound International. Used by permission.

David McLain | The Compressor Guy | CCI SOLUTIONS
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