Originally Posted by 04rex
Hey guys, looking at possibly getting the AVM 50v. Quick question, I have 2 Paradigm Sub 12 subs and i have PBK. I noticed that the AVM 50v has 2 sub outputs but is stated at 7.1. If i connect each sub to each output, does ARC calibrate each sub individually then as a set? How does it calibrate the subs?
Since the AVM 50v has the full version of ARC, is there any need to run PBK for each sub?
There are actually FOUR Sub outputs -- 2 RCA and 2 XLR -- and they all output the identical signal, ignoring the standard +6dB hotter for the XLR outputs. I.e., any settings/calibration in the AVM 50v affect all 4 of those outputs identically -- no separate calibration.
There is certainly advantage to doing preliminary setup with 1 Sub at a time powered in aid of finding better positioning for each sub and seeing what you might have to deal with in room problems. But for the FINAL Room Correction solution what's really needed is for ARC to hear all the Subs playing simultaneously and correct their COMBINED output. This is necessary because of the possibility of resonance or cancellation between the Subs.
Anyway, that's how it works. If you want to use PBK to do preliminary correction for your subs individually, there's no problem with that. Just be sure to do the ARC setup LAST.
For the distance setting for the 2 Subs use the average of their distance from ARC mic position #1.
For the preliminary volume adjustment for the 2 subs, the usual Rule of Thumb with 2 subs is to set each to 72dB SPL (one sub powered at a time). When played together that will produce close to a combined 75dB SPL.
For the polarity/phase adjustment for the 2 subs, the Rule of Thumb is, again, to power one at a time and adjust each in turn for best match with the Left Front speaker. This has to be done using controls on each sub, as the controls in the AVM 50v setup menu will alter the 2 sub outputs identically and what you need is separate adjustment. When both are matched to Left Front then they are also likely matched to each other as well.
Note that since ARC hears both subs playing together it is necessary to set the Sub distance, the individual Sub polarity/phase, and the individual Sub volume knob adjustments *BEFORE* doing your ARC Measurement pass.