I wonder what’s amiss. Maybe some cancellation in your setup? How did you set levels, delays, and EQ for each group of subs?
Nothing is amiss. I didn't describe the subs being powered by the PL380 well enough.
Two dual bms 18n862 ported subs, for stereo. One sub per channel on the amp. (I'm not into the multi-sub approach or home theater.)
Simple case of subs being able to take more power than amp can deliver, and being driven there.
Running two subs on one processing channel kneecaps your optimization possibilities to some degree, so it’s possible you’d be able to get better results with less power, more channels, and improved optimization.
Like said, not into multi-sub...which sounds muddy and rounded over to me compared to a simple stereo setup (actually, mono can often sound best of all i think)
So levels, delays and EQ for the sub are just a function of dialing in a full-range speaker. I do this as quasi-anechoically as possible, outdoors.
Processing is via Q-Sys, utilizing FIR for linear phase. Currently running 4-way synergies and a sub, per stereo side.
Flat frequency response, and flat phase are an easy given to achieve. Most tuning works comes from trying to optimize polars.
My most critical listening is done outdoors. I live with the results indoors without much further EQ/processing other than suppressing room modes.
I try too many proto-type experiments, build too many speakers, to get serious with trying to optimize any one of them to my main room.
I say all the above to impart my goal, which is the cleanest, highest linear (both mag and phase) SPL (both average and peak), with as low a bass extension as possible (with
<3dB EQ boost).
It's my ticket to what i feel is the most life-like fidelity I've heard..
For reference, our main system sub controller-amp (Crown DCI4|1250n) has never reported a clipping event. Each sub is on a dedicated channel, and gains/delays/EQ are individually set by Dirac Live Bass Control aside from individual Linkwitz transforms. Subs are also wired as easy loads, nothing below 4 Ohms nominal, and most double that. That’s what should result from stupid cone area (here, an 18, 2 15s, and 2 12s, all in closed boxes) and stupid power. The 20A (120V circuit) breaker has never tripped either.
Nice amp. I'm such a fan of prosound install amps (other than their typically loud fans, dammit).
Do you use a BLU processor and send audio over ethernet? I'm guessing not, since you have Dirac in the loop.
Sounds like you're into the multi-sub approach big time. Cool.
I use QSC's CXD-Q's network amps, and various other QSC amps that take signal from ethernet I/O frames.
They all of course have amp monitoring similar to the Crown DCI's. I see Crown has released a Q-Sys plugin, to allow monitoring the DCI's over Q-Sys.
Gotta love amp monitoring for being able to really know how things works, huh?
I’m not sure what any of that means, tbh. My read of Geddes and Toole is the steady state FR is what matters in the modal region and below. I’ve not heard anything in my listening to contradict that.
What i meant to be imparting, is that having linear phase (shall we just say flat phase) extend as low in frequency as possible, holds timing advantages that can be heard on certain well recorded material. Bass notes and transients just seem to be more in time with the rest of the spectrum.
As we know, phase starts lagging where ever the low end rolls off. And the more the roll-off, the more phase lags, the more the group delay, yada.
I think the biggest reason folks often prefer sealed subs to ported, is sealed have a second order roll-off, vs ported having a steeper fourth order roll-off.
(I'm sure you know all that...wrote it for others following along...)
Anyway, even if there is no musical content below 30Hz, and the sub is fully capable of 30Hz, whatever phase lag/group delay there is at 30Hz will be reduced/flattened by a sub that maintains flat magnitude response below 30Hz.
All we really want for super bass is a sub flat to DC Lol.
Back to IPAL as closest alterative today I guess. Check out this Dave Rat vid...get's downright funny as he holds on to the cone past the 6:00 mark