Trust me, measuring with multiple mics is addictive. Once you’ve used more than one mic for measurement purposes you immediately understand why having multiple mics is so helpful and saves a lot of time. On my last measurement process I used (7) mics which made it obvious that having even more is better. 6o6 has suggested to me that a 16 mic measurement rig is ideal.
How does one build a 16 mic measurement rig? For starters you need an audio interface with 16 mic inputs which is a rare bird. You can build one from 8×8 devices that include ADAT i/o but one must remember that there is a bit of latency involved any time you use a digital connection between boxes. As long as you stay on top of that, there is no reason it shouldn’t work. The more I measure the more I realize that “acceptable” and “ideal” are far apart and ignoring budget restraints, “ideal” is the target. Why? Time. In the world of professional audio where there are a chance for a loss of ticket sales or corporate accounts, time is money. If you can’t get the system up and running in the time you have, get faster! The element where I see speed greatly achieved regards RF based measurement. There other element is multiple mics. Put the two together and I think we have achieved an “ideal”.
One system engineer I know is doing just such things. Arthur Skudra has been invaluable in my pursuit of these two audio measurement elements (multiple RF mics) so it is not surprising that he has gone out of his way to make sure others have access to the same information he has learned.
This Rational Acoustics forum thread reveals how to take (2) Roland Octa-Capture audio interfaces and build a 16 channel measurement rig.
rationalacoustics.com forum – Why just settle for ONE Octacapture
http://www.rolandus.com/products/octa-capture/
One of the things Arthur shares in this forum post is how he measures impedance of each speaker using a Dayton Audio DATS rig.
http://www.daytonaudio.com – DATS audio test system
A follow up with Arthur reveals that he’s now using a NTI MR-Pro for impedance measurement purposes.
ntiaudio.com – Minirator MR-PRO
Note that you also need the 70v/100v protective adapter kit to perform impedance tests.
ntiaudio.com – MR-Pro 70v/100v protective adapter PDF