On Sat, 17 Jul 2004 18:56:42 +0100, Chris Morriss
wrote:

In message , Eiron
writes
Don Pearce wrote:

The driver is a 15 inch Adire Tempest mounted in an 80 cubic foot
concrete cupboard, which extends under a staircase on the other side
of the wall. The mounting board, which replaces the cupboard door, is
18mm MDF, braced extensively with scaffolding board, screwed and glued
edgewise onto it. It is very solid.
The whole thing tunes pretty nicely with the room to make an almost
flat response down to something very low indeed.


Stewart screwed up:
According to LSPCad as available from the Adire website, that has an f3 of
about 75 Hz, so you'll need some heavy EQ to get a flat response.
OTOH, if you ceiling mount a Tempest with one voice coil shorted, it's
ruler-flat to 20Hz..................

OOOOOOPS! I misread cu ft for litres!

Should be pretty flat to 30-35Hz, especially if you short one of the
voice coils to optimise the Qts.
--

Stewart Pinkerton | Music is Art - Audio is Engineering