Core Sound Piano Mic Hack
Years ago I bought a binaural microphone set from Core Sound so I could do live recordings of mostly small jazz combos. The recordings I got were excellent but there were two fundamental problems. The first is that it was very hard to get the balance right unless it was perfect in the performance, and the second is that the excellent mics did as good a job at picking up audience noise as they were the music.
So eventually I bought a Zoom R-16 multitrack recorder so I could do close micing. I decided to repurpose the binaural mics as piano mics. I wanted the mics close to the strings and soundboard but not too close and the rig to be compact and easy to transport and set up at a gig.
After some experimentation I came up with a flat 2' long base that rests on the central braces of the harp, with two very heavy-duty cable ties sticking straight up from the base onto which to clip the mics with their alligator clips. I'm especially happy with the cable ties, because they are stiff enough to hold up the mics yet flexible enough to flatten during transport and nearly impossible to damage.
While I could have used pretty much any material for the base, I bought a 2'x2-1/2"x3/8" polycarbonate bar, part 1749K439 from McMaster-Carr so it would be less visible. The cable ties must be big and stiff enough to hold up the mics. I used Pro Tie B24EHD25 24.9-Inch Extra Heavy Duty Standard Cable Tie, UV Black Nylon, mostly because they seemed to be the biggest and baddest cable ties I could find in about five minutes of shopping. I drilled two holes in the base, one near each end, big enough for the cable ties, and threaded the ties through the holes and cinched them on tight, where they stay. I cut the ties so they stick up about a foot from the base. I haven't discovered the best height to place the mics, but you'll need to cut the cable ties shorter if you want to use the short stick of the piano.
The final setup, which I do every time so I can keep the mics protected during travel, is to wind one mic cable a few times around the bottom of one cable tie and then along the base and wind it up the other cable tie and clip the mic near the top. Then I wind the other mic cable only up the first tie and clip the mic to that one. That's the best way I know to keep the cables off the strings. Usually I just leave the battery box sitting somewhere inside the piano, wrapped in a sock. (In fact, I sacrificed another sock to make two small fabric tubes to wrap around the base to isolate the base from the piano harp, but I think that's overkill because the harp doesn't vibrate much.
Have a listen to some of my recordings!
Here are some more photos. Click on each for a larger view.