[QUOTE]Originally posted by soundhound:
[B]Bosso:

I wonder what your take is on this: what ever happened to 'acoustic suspension' speakers in the transistion to Home Theatre? Those speakers were certainly capable of going down to 30-40hZ easily and cheaply, and with modest cabinet dimensions.
_________________________________

acoustic suspension, or sealed box speakers, are everything you say except the 'cheaply' part. the driver has a low Fs due to the greater cone mass required, super-high excursion, a large magnet structure, long voice coil and a cone that won't distort
when subjected to the radical forces necessary at low freqs. it costs a pile-o-dough to build a good one.
_________________________
Can you think of any reason why they would not have been a better solution than a vented box, which can flail it's woofer if presented the wrong frequency and level of bass?
__________________________

vented enclosures aid the driver to acheive a response lower than Fs. and, because the vent takes over at the lower freqs, the driver is less taxed. it is usually more efficient with less distortion due to less excursion...and...is cheaper to build. yes, it can unload at lower freqs, but this is easily overcome by inserting...yes...a high pass filter before the amp. (the filter Fx and Qx must be specific to the driver, is the catch). bottom line is, vented drivers/enclosures are cheaper to produce with better results. the car audio people use acoustic suspension more often because most vehicle interiors have an acoustic response that rises at 12db/ octave from about 50hz, giving the sealed box (12db/octave roll off, as bstan said) a flat response down low. (plus, they seem to have unlimited funds for drivers, caps, batteries, alternators, amps, etc.)