[hesster]

Hey Danny and Audio Circle crowd - ever hear of one of these or had the opportunity to listen to one?  It is a Bill Fitzmaurice design Tuba HT. I built one out of curiosity last winter, and it is horn loaded with a 15" RSS 390-HF-4 Dayton Woofer.  It was a involved build, but not more so that the LS-9's.   I built the 30" x 36" version, and the spouse promptly said NO WAY was it going in the house, so I jam with it in my garage (not all bad - good music, cold beer, and wrenching on cars).  For now I power it out of a receiver with an older NAD Amp.  It DOES play low, AND powerful, but curious how a horn loaded affair stacks up in the High Fidelity Arena driven with a good amp.

[opnly bafld]

Heard an 8" tuba with some high efficiency speakers, sounded pretty good.
Haven't heard any other models/sizes.

[Bob in St. Louis]

You don't have to put the box in the room, just port the throat into the room.
Like an infinite baffle. 

[Danny Richie]

Putting woofers in a horn like that can increase their output in a range below what they would otherwise or if tuned higher they can just make a lot more SPL in a given area.

The trade off (from an audiophile standpoint) is that you have large un-braced panels that resonant pretty hard. Sometimes they become buzz boxes.