So another week is upon us and I have more confessions of dumb things I’ve done as a recording and mix engineer. Now, I’ve been freelance recording for over a decade now and when I was first starting out, one easy way to make some cash in college was to record a lot of the music major’s senior performance recitals. We’re talking pianists, violinists, and of course vocalists.
I made little fliers all across campus advertising that I had a mobile recording rig and for a flat fee of a few hundred dollars I could give them a “professional” live recording of their recital. People lined up to pay!
Via MIKI Yoshihito Flickr
Stereo Recording Is Simple, Right?
And it was somewhat true. I owned a simple Pro Tools rig (i.e a laptop and an Mbox) and one condenser microphone. Now, I’m no idiot, and I knew people would want a stereo recording of their concert. So I was in need of one more microphone. Simple, I’ll just borrow another mic from a friend each time I do a recital.
I would get to the performance hall early, snag a seat in the middle somewhere, and set up my laptop rig. Then I’d take one mic stand (and microphone) and set it up on the middle right of the room and point it at the stage. After that I would do the same thing with the second microphone on the left side of the stage.
During a quick warmup performance I would easily dial in a balanced gain on each microphone and record them to a stereo audio track. Stereo recording couldn’t be any easier, right?
Phase Cancellation? Who Cares?!
Now at this point I had read a little bit in my audio textbooks about the problem of phase cancellation, but it seemed so obtuse and geeky that I wasn’t interested in paying attention. I couldn’t see how it was relevant to my recording life.
Boy was I dumb. Turns out I had a couple of major problems with my little stereo recording setup.
First, I was using two different microphones, not a matched pair. Now this is the more minor of the issues as I honestly believe you can get by in this scenario, but the truth is that each mic had a different frequency response (their own EQ curve if you will) and that created some weird phase issues when they were capturing the same source in the same room at the same time.
Second, my super wide spaced pair was set up without any precise measurement. The problem? The sound of the performer on stage was hitting each of the mics at slightly different moments in time (we’re talking milliseconds here), and as anyone who knows something about phase cancellation will tell you, this is going to actually harm the quality of the recording as certain frequencies become masked and everything sounds overly thin.
Sure the audio sounded pretty massive and super wide in headphones, but when played back on a normal speaker system or in the car, or anywhere else where you weren’t in the exact sweet spot of the stereo image, so much of the sound collapsed and the result was weak.
What Should I Have Done?
If I could do it all over again, here’s what I would have done. I would have taken a deposit on one of the recording gigs, purchased a pair of affordable matched condenser microphones, and then set them up right above my head in the center of the performance hall in a classic XY pattern.
XY is a great solution because you simply cross the microphones to point to each side of the stage (giving you a stereo image), but since each mic capsule is virtually in the same exact spot in the room, sound is hitting both mics at the exact same time. The result? No phase cancellation. At least nothing noticable.
Don’t Make Fun Of Me
I know, I know, you probably already knew about XY. What was I thinking recording recitals this way? How could I take people’s money to do this? I was young, excited, and willing to jump into the fray. I might not have known what I was doing, but I sure learned a lot along the way.
What about you? Have you ever done something similar in your recordings?