Thursday, December 22, 2011

Recording the Show: Redux

I do a choral show a couple times a year and I usually take a recording off the board as a favor to some friends of mine in the chorus. I always caution them that what the board hears is not what the audience hears. I don't tell them that setting up to do the recording, and cleaning up the results, takes quite a bit of time.

The needs of a live show and a recording are largely orthogonal. In a large venue, you can split the feeds (which you are going anyhow for the sake of Monitor Beach). And everything is mic'd anyhow. In a small space, a good part of the act is acoustic -- which means a lot of the performance never gets close enough to a microphone to get captured by it. And in a small intimate space, you don't want to be sticking microphones in front of everyone and everything.

Well, I just got done working a show in which recording was intended from the start. As it happens, I put a very, very little bit of the vocal microphones into house speakers. But basically the audience was on its own; they were getting the concert through air, not through wires.

The downside is I basically had to do this with my own small assortment of gear.

Presonus Firewire as the main A/D converter. That's only 8 channels. Using the ability of the Mac platform's Core Audio to create an Aggregate Device, I added another two channels from the line in. I also set up a second laptop, with a USB recorder as back-up, taking 48/24 audio (96/32 kept crashing) from a flying, mix-as-you-go stereo mix-down.

Over a long brunch at a local cafe I made up a channel plan. This was a chorus. I knew they had a keyboard. I planned ahead for bass and drums even though no-one had told me about them. A day before the performance I found out the keyboard wasn't electronic; it would be a baby grand.

Same difference. The rough plot was all stereo busses, sent to the hard disk recorder as five pairs; two chorus mics, two piano mics, a stereo mix-down of the drum mics, and a pair of mics set up at a distance.

During the tech I found out they also had a violinist, and the band was all playing percussion toys for one number. So I added an omnidirectional mic in the middle of the band area, and a violin mic. I also saw a number of places in which one member of the chorus would come forward to do a solo, and, concerned about localization (with them passing between the choral mics) I added a stand mic in the center.

Since I didn't have the spare record channels I mixed the center mic into the stereo bus of the choral mics, and the violin mic into the stereo bus of the piano. I figured if the added signal got too hot, I could always invert one of the channels to sum the center out. Of course, there is no similar trick for boosting the center...!

So already I was being a little foolish and trying to hold on to elements of the original plan that weren't working. After two performances I bit the bullet and re-configured. Since the stereo piano mic'ing wasn't working anyhow I took that down to a single mono channel. That freed up a channel for the violin. And since the drums were hardly playing (and it wasn't that great a kit anyhow) I gave up on stereo drums and also summed that to mono. That gave me a spare channel to isolate the center vocal mic.

Because as the concert progressed and I was doing my stereo mixes, I found there were several places where I needed that center mic to be on its own. So it made sense to pull it out of the bus.

I switched the direct audio in for the USB connection and better A/D converters of an Ozone, but the Mac had trouble with the end of the concert I discovered the rear mics had not been captured in the multitrack. Switched back to the Mac's own input jack. A videographer showed up, and they adjusted some of the lights. Final concert. Something in that changed setup was now sending dimmer hum into my rear microphones every time the lights changed.

Well, SoundSoap seems to have gotten rid of the worst of the hum (at a noticeable drop in quality however). And now I can finally work on the multi-tracks and see if the choices I finally gave myself are going to let me mix the show the way I want it.

(And, actually, the 10 tracks of recording wasn't the worst limitation. I barely had that many microphones that were worth using, and I used up all of my personal cable and most of the house cable to boot just connecting them. Plus that basically maxed out the board -- once you added stereo house feed, three reverbs, and a monitor feed. I think I had two outputs I wasn't using, in addition to the S/PDIF which -- as it turns out -- can only be switched on if you are using a PC to record from. The Mac version of the driver never got around to including that button -- not on that model, anyhow.)

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