>Drew -- doesn't your response overlook bass damping, inertia of the cone and the other parts of the moving assembly, and the ability of the cone to stop quickly when the input signal stops? All of which I think support what Kijanki was saying.
Bass damping is a separate issue which also isn't related to driver size.
It's determined entirely by the transfer function.
How you get to a given Q (the ratio of stored to dissipated energy) isn't relevant to decay. Even convolving the input to a sealed or open baffle enclosure with a Linkwitz-Transform or shelving low-pass filters works (although with a small box the distortion from air-spring non linearities and power required make a large box more desirable).
Resonant devices (ports and passive radiators) rely on stored energy and may cause audible problems when within the musical power spectrum, but work fine to gain infrasonic extension.
Stored energy in the room is a much bigger problem than in sub-woofers built for flat response, with decay and the resulting amplitude response being very frequency dependant.
The relative significance of time and amplitude aberations is not well understood here. Stimulating fewer room resonances through directional bass works well (this implies dipoles which are dumping most of their power into an acoustic short circuit). Equalizing for flat steady state amplitude response seems to work. Sub-woofers at a null or two sub-woofers centered on the null work according to literature. Catch-throw arrays look real interesting.
Two sets of two (mounted push-pull to cancel even order harmonics) dipole sub-woofers equalized to a second order roll-off with poles at 20Hz (Q=.5) did produce the most natural bass I've heard from any room-loud speaker system in spite of having only 13x19x8' to work with and no acoustic treatments.
Bass damping is a separate issue which also isn't related to driver size.
It's determined entirely by the transfer function.
How you get to a given Q (the ratio of stored to dissipated energy) isn't relevant to decay. Even convolving the input to a sealed or open baffle enclosure with a Linkwitz-Transform or shelving low-pass filters works (although with a small box the distortion from air-spring non linearities and power required make a large box more desirable).
Resonant devices (ports and passive radiators) rely on stored energy and may cause audible problems when within the musical power spectrum, but work fine to gain infrasonic extension.
Stored energy in the room is a much bigger problem than in sub-woofers built for flat response, with decay and the resulting amplitude response being very frequency dependant.
The relative significance of time and amplitude aberations is not well understood here. Stimulating fewer room resonances through directional bass works well (this implies dipoles which are dumping most of their power into an acoustic short circuit). Equalizing for flat steady state amplitude response seems to work. Sub-woofers at a null or two sub-woofers centered on the null work according to literature. Catch-throw arrays look real interesting.
Two sets of two (mounted push-pull to cancel even order harmonics) dipole sub-woofers equalized to a second order roll-off with poles at 20Hz (Q=.5) did produce the most natural bass I've heard from any room-loud speaker system in spite of having only 13x19x8' to work with and no acoustic treatments.
