What is this? (Citation 7.4)

[rdgrimes]

http://www.ebay.com/itm/361329407844?_trksid=p2060353.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT

(http://www.ebay.com/itm/361329407844?_trksid=p2060353.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT) 65932

[Don C]

Harman Kardon Citation 7.4 passive subwoofer.

[SEAWOLF97]

.
“Unit powers on and passed basic tests.Unit can power up.. unit can play loud sound, however, the unit needs to be re-foam. damage on the foam see pictures.”

[rdgrimes]

Harman Kardon Citation 7.4 passive subwoofer.

I knew I'd seen one before. Anybody know the volume or tuning of the box?

[RedCoat23]

Quick search found this, though you've probably seen it already :)

http://www.audioheritage.org/vbulletin/showthread.php?2164-Citation-7-4-sub&p=18740&viewfull=1#post18740