So, you have a multiple subwoofer system, and it measures perfectly. But what do you actually hear?
I did this exercise today. I built a system that was designed to achieve a measurement, because the technical side was interesting to me. But in the process I haven't re-checked to see how much difference there is, or what the perceptible difference actually is. For my test I enabled and disabled the DSP settings used to optimize my system, so it is all subs optimized, and all subs not optimized.
My answer is my optimized subwoofer setup gives me more detail and transparency from sub frequencies into the low mids.
I'm curious to know what you guys hear that is the biggest difference to you. Is it very noticeable, or more subtle? Which do you like better subjectively? And what configurations are you comparing?
I would add a few things.
All the usual good loudspeaker I have heard, all exhibit the same "woombf" in the bass, since they almost always use ports. Last time was Dali Epikore, and they still had that "woombf" sound, which to me is not satisfactory, since I do not mind a bit of overhang in the bass, as long as it is taught, deep and with enough volume to pressurize the room - effortlessly.
This is where - IMO - closed mains and subwoofers come into play. At the moment I have 2 x Satori WO24P in closed 75 liters, and 4 closed subwoofers - 2 x 12" and 2 x 15" - scattered around the room, but placed so that the two subwoofers on the right are connected to the right main channel - same principle goes for the left channel. In this way I have a hybrid between multi subs(often mono), and divided left/right subs. I sum(all receive the same signal) the subwoofers via my pre/DSP with the mains when I measure, to find the sum of how they produce bass in unison.
In my system, it delivers very deep and firm/dry bass over most of the area of my apartment, which I have tuned ever so slightly to the voluminous side - which means - that I have raised the lower bass a bit, creating some more tilt from lower frequencies to the upper.
To my experience, the combination of closed cabinets, subwoofers and a smooth downwards tilt from low to top, smoothly gives you a compensation for the Fletchy muncher theory, at normal listening levels. Leaving you with a fullness that does not boom, but augment the "fun" in the "thumb" when an artist tramps the stage floor and "whacks" on a drum. And the cool thing is that for example Erykah Badu does not sound boomy, but instead deep, detailed and engaging, leaving her voice clear, even though the rhythm of the mid-bass is tight, the very low is still full, and you can easily hear the notes change.
I just don't get that with conventional speakers, without subwoofers and EQ - no matter the price, brand, room, amplifiers or whatever you could think of.
So, what are your mains, subwoofers, room shape, setup, amplifiers, measuring technique? - so that we can compare and better understand the question