The whomp is still here! I could have sworn that I found the cure over the weekend, but listening to the same recordings later in the evening reveals the whomp in all its booming glory. Are my audial perceptions changing over the course of the day? I recorded some more last night using one microphone scanning over 8 or 9 different positions, repeating the passage in BWV999 that passes from D root through A on its journey to the E pedal. The boom is particularly noticeable as the root approaches A. The boom seems prominent on any part of the top, and much less noticeable on the sides. I start to think along the lines of phase cancellation; if the boom is in a positive phase in one part of the guitar, perhaps placing the second mic in a positions where the boom is in a negative phase would effectively cancel it.
I found a paper online by Dr. Daniel Russell at Kettering University on Acoustic Guitar (in this case, a Gibson) vibration modes, available online here; I think the information on the 2nd and 3rd modes might be relevant. If true, a mic over the saddle and one somewhere in the upper bout should have whomp cancellation. I'm not sure from the animations if the upper bout mic should be over the fret board or alongside it, but a recording test with both options should verify this. If true, I expect the spectrum graphs to show the whomp on both mics, but when combined it should not be as evident.
More to come.
No comments:
Post a Comment