I have a practically unused 15" Salk Sub with dual 15" passive radiators. Seen here:
http://www.audiocircle.com/index.php?topic=72962.0As far as I know, its one of the first of its kind with Mr. Bagby, Mr. Salk, and Mr. Ding collaborating to bring this design to us.
Located in Omaha, NE. I've had this sub several years but I'm in a job that moves around quite a bit and just never got to use it as much as I hoped. Making another move, and decided its time to move on.
Can ship via freight to your door for $1200 (total price inclusive of shipping).