Like; "Slaw" above. I use the Martin Logan "Depth" in my small system.
But use (4) of the Martin Logan, "Descent" subwoofers in my main rig.
Which is an actual, "Line Source", "Dipole" system.
Just (1) of the "Depth" subs will impress you. Especially for the amount of air it will move, and that air at very impressive speeds. And the accuracy still floors me. Nothing comes close to it at that size.
But having (4) of the "Descent" model subs integrated into a rig?
It can be beyond words...
The key is the "Integration".
I use a quality, "The best I could find" active crossover. The sub's use "Blue Truth, Air", "Balanced XLR" cables from the crossover to the subwoofer's amplification section. And then seamlessly integrated with, "Linkwitz-Riley", Constant Voltage, 4th Order, "24dB/Octave Slope".
Beyond Words...