Quote:
Originally Posted by spm_gl  If I understand the problem correctly, it's probably a stereo thing. Adding to phase-coherent correlated signals makes +6dB, adding non-correlated +3dB. Starting at a certain wavelength, both mics will receive more of the same signal, i.e. the bass signal becomes more similar.
Am I making any sense? Perhaps I should make a sketch.
Edit: (Trying to make more sense) With a low frequency and an A/B setup, we are actually sampling the same wave at two different points. The more similar the pressure level at these points is, the bigger the sum of the two. |
I think this aligns with my thinking and experiences. Observations as follows:
* Widening the spacing tends to reduce the problem, ie moves the coherent frequencies lower
* Moving away from the source, reducing the contributions from coherent additions of direct sound coming from glancing angles.
However, this doesn't gel with the stated phenomenon that two 4060's hanging just over the open piano lid, do not exhibit the problem. I haven't heard this so cannot comment. Perhaps the degree of omni-ness is relevant, although the 4006 is just as omni as a 4060 at the woofly frequencies.
Keep the theories coming in. Interesting thread.