I have the all the stuff for measuring with a calibrated microphone. Running sweeps for a couple of years now on my and several audiophiles friends requests.
For the old MMG in my room setup far from walls. I see that the frequency response goes down to ~50hz there it is dropping like a rock.. So MMG in my room is not playing anything below 50 Hz.
Yes, I could also say that "oh, it works for X type of music." BEFORE I knew better..
How can i know that playing down to 50 Hz is not enough?!
I have integrerated with a DSP, measurements and for example correction with PEQ with other things, that DSP is only controling my two 18" open baffle with a separate amplifier.
Even when it is only the bass and it amplifier that the DSP is controlling.
That DSP is doing 6 DIFFERENT duties/optimizations! (No DSP on the MMG)
But to get to the chase. I can then enable the bass amplifier and not the amplifier to the MMG. So I can clearly only hear what music content there is in the bass despite:
1. The crossover point is in the low range of 53 Hz and below
2. At 53 Hz it is a very steep slope of 48 dB/octave
So more or less only playing frequencies below that the MMG can not create and nothing else I can TODAY say with confidence.
That there IS stimulating music information EVEN on a Jazz trio (acoustical instruments!).
And on LP for example that everybody knows "Dark side of the moon" and we know there in the background there is a low rumbling "hart beat" sound.
Yeye everyone has heard that you say.. But actually there is several more "hart beats" sounds that is lower in level AND on couple more tracks than you probably did not know of. When those is not apparent and not played by a normal system.
Yes there is more on the d a r k side.. ;)
(And that on a LP!)
(Remember my subwoofers plays lower than my cartridge and tonearm resonance frequency! So you guys and girls that know what a rumble filter is can as you already suspect understand that it is much needed. My DSP is doing that duty also when it is needed during LP playback..)
But those MMG are gold! They can do THINGS that I never had heard a speaker do.