Convoluted multi sub integration with 1 LFE/Antimode


Distinguished Member
Say you have a AVR with Mic (level and distance check) with one subwoofer pre out and antimode, with two (or more) subwoofers. You don't have multiple sub outputs with individual level/distance on each RCA sub output.
This is the system

Put dB meter at listening position
Switch SUB1 ON. SUB 2 to OFF. Reduce SUB1 volume to minimum (for safety)
Output manual pink noise test tone from AVR, set AVR to 00dB. On SUB1, phase at 0, adjust dial so dB meter reads 75dB. Write the number down let's say -15dB on SUB1. Run AVR distance check. Write that number down say 3.5m. Reduce volume SUB1 to minimum (leave powered on in case in/out loop needs amp to be on)
Switch SUB2 on. Phase at 0. Set to vol to safe level lets say -20dB
Run AVR distance check. Let's say it's 4M.
Now you have choice of
1) Move the sub2 closer/further away, re-run AVR distance check until it shows the same 3.5m
2) Adjust the phase dial on the sub, re-run AVR distance check until it shows the same 3.5m
Do not touch AVR level adjust. Output test tone, adjust SUB2 dial until dB meter shows 75dB.
On SUB1, go over to it and change volume you got from earlier -15dB
Now since both subs are outputting 75dB each, now run Antimode calibration
On AVR output test tone,adjust AVR level both subs outputting so calibrated to 75dB, or whatever your preference is (mine is 2-3dB hot)

If this correct, I did the volume part this way with single LFE/Antimode, but not having room EQ back then, with distance check, I just had to accept it could out.

I'm wondering if distance check this way may be a solution so both are dialled in (either with physical placement, or phase) with the issue of two or more subs running from in/out from one another. Or in installations where using in/out (say you have four subs along front wall ) is easier as in that situation you have a short RCA-RCA from in, out, then another in, out etc, rather than multiple long cables from AV pre to subs.

Of course you'd say "Get a minidsp" or "get a AVR with multiple sub out ie SUB XT32 Multi. HT or whatever Audssey calls it.

Or when it comes to phase, would it be best to put SUB 1 if that sub had 0-180 degrees, put it at 90 degrees, then do distance check. Then on the SUB2 because SUB1 is at 90 degrees, put SUB2 at 90, do distance check. Let's say its 4M again, so it's not the same. Now since SUB2 phase control is smack in the middle you have adjustment either way, so now adjust either side of 90 degrees, doing distance check on SUB2 until you get that 4M closer to the SUB1 3.5M distance check.

Am I right?

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