I'm actually pretty happy with my existing sealed cabinet speakers (after a fair bit of development). But we have re-arranged things in the living room, and the speakers are now on one of the short walls, firing down the length of the room.The room has a very strong 40Hz mode, and moving the speakers to one end means that they excite this mode more strongly.
40Hz has a wavelength of 8.6m, so pulling the speakers forwards so that the woofers are about 2.15m from the back wall should produce a null at 40Hz. Sure enough I have tried this and it works really well. The speakers sound very good. Unfortunately this is not a domestically acceptable solution. Back to the drawing board.
I got to thinking that an OB speaker would not excite the room mode in the same way. And (to my surprise) I have been given the OK for a pair of OBs from an aesthetic POV. Quasar types are a non-starter apparently (even though I think that James D's are gorgeous), but something along the lines of the Pure Audio Project Trio 15s have met with favour.
So that is the design brief:
- Similar looks to the PAP Trio 15
Placed near to the short wall of a long room - one of them near to a corner
Not excite the 40 Hz room mode
Drivers (at least for iteration 1) will be Alpair 12P and a pair of Eminence Beta 15 per side. The 12Ps have been sourced (thanks Colin). I need to save up for the Betas. I've started work on some modular baffles for experimentation, using some 19mm mdf I've had knocking around in the garage for years.
I used to use LSP CAD software, I shall have to see if the old PC with that on still works. LSP CAD appears to be still available, but no mention on the website of win 10 support. Maybe I should look for something more modern.