> How does the eq make the capsules more(virtually)coincident? http://tech.groups.yahoo.com/group/SoundfieldMic/files/Ricardo/
has details. The phase as well as the amplitude has to be corrected. > What would the noticable audible negative side effects of an ambisonic mic be which was not adjusted with eq to make the capsules more coincident? The same paper also shows up to 6 dB wonkiness in the frequency response and this will be the most obvious effect of not incorporating the EQ. In fact, this is likely to be even greater for a practical mike; up to 10dB on the Soundfields. There's a lot of myth about "coincidence" correction. But this is inextricably linked with the frequency response correction. The correct EQ for one also solves the other. A less obvious but important effect is the response of simulated mikes will vary with pattern and direction. You get this with all variable pattern mikes but the variation is much less with a properly aligned and EQ'd tetrahedral mike. If the soundfield mike is NOT properly aligned & EQ'd, the variation will be even greater. Lastly, some effects of "non-coincidence" will be manifest. The most important of these is that the W omni signal will no longer be more omni than a 1/2" B&K measurement omni. You will see signs of combing. A big advantage of a tetrahedral mike is that the mono signal is excellent and 'free' from these artifacts. This is important to broadcasters. One perceived effect of 'non-coincidence' is that the omni & Blumlein fig-8s will no longer capture the reverberant field of a good recording venue accurately. These are the only 2 'stereo' arrangments which can theoretically do this. But only a properly aligned & EQ'd tetrahedral mike demonstrates this clearly as it requires flat frequency response in ALL directions. _______________________________________________ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound
