> On 23 April 2013 21:05, Matthew Palmer <palme...@mymail.vcu.edu> wrote: > > Thanks for the heads-up. Which mics do you use? > >
Another 2 cents worth. For Ambisonic recording there are a few alternatives. Soundfield research has several models, mostly based on the original Calrec design. http://www.soundfield.com/products/mkv.php http://www.soundfield.com/products/sps422b.php http://www.soundfield.com/products/dsf2.php There is another model, the SPS200, which uses MBHO capsules. http://www.soundfield.com/products/sps200.php >From the competition we have: http://www.core-sound.com/TetraMic/1.php Also, there was a very expensive tetrahedral microphone array manufactured by AGM, called the MR-1: http://www.agmdigital.com/page42/page22/page22.html which is a tetrahedral array constructed of DPA 4012 type capsules. I mention this, even though it is no longer offered by AGM, because DPA has told me that they have stock of the tetrahedral hardware, and if I want another one I can simply send them a check. I didn't get so far as to ask how big the check should be... As it happens, I've used all of these. The AGM MR-1 has a little trouble due to the size of the array, but at lower frequencies its performance is flawless. And there are a number of home-built alternatives. An probably some others. At which point I should point out that the quality of the results depends most critically on the calibration of the system, and secondarily on the size of the array. As discussed in previous emails of the past couple of weeks the arrays very well up to a critical frequency f = c/2pi*r , where r is the radius of the array. What this means is that a tetrahedral array the size of the original Calrec design works almost perfectly (if properly calibrated) up to about 7 .3 kHz, pretty well up to 10 kHz, and then goes to hell. If this sounds bad, then just look at the polar patterns of a typical omni microphone. A half-inch omni gets bad above 7 kHz or so. A 1" Large-diaphragm microphone is pretty horrible above about 4 kHz except in its figure-eight patterns. To reiterate, one of the primary things that the mfgrs of tetrahedral microphone arrays have to offer is the accuracy of their calibration. The inescapable variations in the frequency response which result from the size of the array, not the quality of the capsules, require that the array be calibrated (equalized) to get proper response. Eric Benjamin _______________________________________________ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound
