I'm offering my demo
Sealed Swarm for sale. Regular price is $1700 plus shipping, and I'm asking $1000, split the shipping. Cosmetics is an Audiogon 8/10.
The system consists of four subs, each measuring 14" by 14" by 14", and a 1000 watt rack-mount amplifier that drives all four subs. Each sub has a single 10" woofer with a very nice motor, and enough excursion that if the amp puts out a full power sinewave at 20 Hz, it still won't drive them to x-max. The alignment is Qtc = .50, so the rolloff is very gentle and the transient response is very good. Subjectively they are quick and tight.
For those not familiar with the Swarm concept, basically it's four small subs that are intended to be distributed around the room. There are several multisub placement strategies, with Earl Geddes, Todd Welti, and Jim Romeyn offering different but effective approaches. I embrace the asymmetrical placement ideas of Geddes and Romeyn, wherein each sub interacts with the room modes differently, resulting in multiple dissimilar peak-and-dip patterns at any given listening position. These dissimilar patterns sum much smoother than any single one alone would be, and because of the ear's relatively poor time-domain resolution at low frequencies, any minor differences in arrival time are inconsequential.
The amplifier has a fixed second-order highpass filter for the main speakers set at 80 Hz (which you don't have to use if you don't want to). The variable lowpass filter can be set from 30 to 180 Hz. You also have a 0 to 180 degree variable phase control, and a single band of parametric EQ. Now to the best of my knowledge none of my Swam customers have had to resort to parametric EQ to resolve a remaining room problem, so you can use that EQ to gently fill in the bottom end a bit. You see, typical room gain is 3 dB per octave below 100 Hz, and the woofers roll off at about 3 dB per octave down to about 40 Hz, accelerating to 6 dB pre octave below that. So the parametric EQ can be used to compensate for that extra 3 dB per octave of rolloff beyond what room gain offsets below 40 Hz. Or if you don't feel like fiddling with the parametric. and/or if you do need it to deal with a remaing room issue, you can engage the switchable bass boost, +3 dB at 25 Hz, which is just about right on the money for what you might need. The amp also has a switchable protective 2nd order highpass filter set at 18 Hz, so you don't waste power and excursion amplifying record warp.
Now the amplifier only has line-level inputs; no speaker-level inputs. So you need to have an extra set of preamp outs, or your preamp needs to be happy driving two amps at the same time (input impedance of the sub amp is 12 kohms).
Let me know if you have any questions, and thanks for taking a look.
Duke
