Sunday, September 29, 2013

Snow Crash

Well, the crazy system I am running "Drowsy" on finally let me down.

It has been a show full of fun.  Opening night the main rag slipped the lower pulley and barely made it in and out, and the work lights were left on, spoiling the opening blackout.  One night the follow spot got locked out of all cues and they had to turn it on manually.  Which was good, because the next night the "robo-light" (some moving light, I don't know the make or model) didn't light, and they had to cover for it with a manual follow-spot.

I'm running all the sound through my laptop.  Well...everything but backstage and conductor's monitor.  Us old-school techs are scared of depending on a computer.  I've seen a BSOD in a booth.  I've had to restart a Mac a couple of times, too.

Here's the set-up; wired microphones along the proscenium line, four wireless belt-packs on actors.  All plugged into a Mackie 1602 mixing board.  Then the group outputs of the Mackie are run into a MOTU firewire interface and into the computer.

In the computer, Reaper takes the different buses (proscenium mics, wireless mics, off-stage chorus mic) and processes them with compression and graphic equalizer.  (Plus there's a little corrective EQ done in the MOTU itself with its on-board DSP.)  Then Reaper exports to the primary firewire outputs, which are plugged directly into the house mains.

The other outputs of the MOTU are being sent to effects speakers.  QLab speaks to those.  And as I mentioned in a previous post, QLab is also generating MIDI events which are translated into a serial signal via a Processing sketch, and sent to an Arduino that switches the practical ringing phone on and off.

Saturday I had no signal on the vocal bus.  Same night we lost the moving light.  And, of course, it was the night I had friends in the audience...!

There's no intermission.  There really isn't a spot in the show where it was safe to reset the systems or otherwise do anything more than the most conservative problem-solving.  So I routed all the mics to the one working bus and worked with that.  Which didn't sound anything as good, but got me through the show.

Part of the problem was, I couldn't send any useful diagnostics to headset, and the average vocal material was too low to tickle the meters.  As it turned out, I still had the chorus mic bus, and that would have helped me zero in on the problem.  But the only times I had a hot enough signal to trace via metering, were times I didn't dare do anything that might kill the signal.

Well, following the show I could.  And it turned out...Reaper was fine.  The computer didn't crash.  Even the MOTU was fine.  The problem was on the group faders on the Mackie.  For some obscure Mackie reason, if the button to assign a group back to the main bus gets some corrosion in it, the signal out of the unique group output goes dead as well.

All it took to restore the sound was pressing the button a couple of times.  Today I sprayed the button, and the show went flawlessly.

And, yes; the contrast between not having the computer properly in the loop, and having the corrective EQ and dialed-in compression I'd set for the vocal mics....well, it was a huge difference in how transparent the reinforcement was.  So I am prepared to say this was a good way to do it.

No comments:

Post a Comment