Kinda off topic compressor to operate at line level?

[therecordingart]

This isn't a stompbox application, but I need to build a cheap compressor to go between my media computer and TV. Some movies are just WAY too dynamic and I want to reel in that dynamic range a little bit. I've built the G-SSL and a bunch of other pro audio gear, but don't want to spend $300+ for this application.I could just buy a used Alesis 3630 or something similar for $50, but I'd like to build something instead. I'm thinking two identical compressors controlled by dual gang pot(s).

Any thoughts?

[Mark Hammer]

Buy the Alesis.  Save the time and aggravation for something that deserves your effort.  A simple limiting function that will likely stay set doesn't strike me as deserving that.

[Processaurus]

The "late night, everyone else is in bed, horror movie compressor", brilliant!  Pedal compressors like the dynacomp and orange squeezer are (sorry) pretty worthless in a hi-fi sense, but maybe a DOD 280 with one detector circuit that the L and R signals are summed to, that controls both channels gain, as it is optical and probably can't mess up the sound that bad.  Two independent compressors will sound weird, as, if they compress at different amounts the stereo placement of sounds will wander.  There are some great app notes at THAT corp for designing around their VCA IC's, that would work better than guitar specific designs for program material.  There's also an Analog Devices compressor on a chip (I think Jack Orman may have made a pedal design around it)

One thing that's nice about commercial compressors is the gain reduction meter, to let you know in no uncertain terms if/how it is working.  I'd agree with Mark, unless you needed the excuse for a project.  I might keep my eye out myself for a cheap alesis or DBX rack compressor for movies!

[Mark Hammer]

One of the little Nano Compressor units would be perfect.

Honestly, I don't know why contemporary video devices don't just come with audio limiting built in.  Nearly 30 years ago, one of the regulars at Stereo Review, either Julian Hirsch or Len Feldman, noted that much of the dynamic range that the "new" digital recording methods made available was simply wasted. As they noted, most lstening was done against a backdrop of some 60db of ambient noise, whether from ventilation, street noise, AC, the dishwasher across the house, the wind, the kids in the other room, your upstairs apartment neighbours watching the hockey game, or whatever.  Given that this was the noise floor, you'd set your volume to be able to hear above it, so there was no point in having more than another 50db dynamic range.

At the time, and for some years later, I thought "Well, manufacturers are realistic.  A/V amps will probably come with a limiter so you don't have to put up with sudden loudness shifts from TV ads, or explosive gunfire."  But it never happened, which just seems strange to me.  I just took a quick peek at Pioneer's line of home A/V amps and they all seem to emphasize their capacity to deliver dynamics with no mention of maybe reining them in when they get irritating.  That probably accounts for magazine projects I've seen since the 80's aimed at providing limiting between video playback devices and amps.

[therecordingart]

Definitely. I'm all for dynamic range, but it's pretty ridiculous when you have to ride the volume button on the remote because you can't hear dialog, but explosions will wake the neighbors.

Yeah...a cheap-o compressor might be money better spent.