[NJBOB]

Just bought a pr of 8ohm SP12b dirvers 35 to 13K room is 18' x 13' have two amps either a SET 2a3 or Dynaco ST70.

I have extra tweeters around if needed.
My questions
WHat size baffle?
Do I counter sinc or mount from behind or in front?
Side panels or one center baffle holder? how big?

Thanks
Bob

[mcgsxr]

Hello Bob, could you post the specs for the drivers?  It might help to see the QTS, and FS, and XMAX in particular.

Thanks,

[NJBOB]

Here's what I found Thanks 12inch coax
Fs..............41
Vas Cubic feet..6.27
Vas Litres......177.73
Qms.............5.7
Qes........... 0.696
Qts........... 0.623
Re..............9.41
Le mH...........1.194
Mm grams........32.90
Eff 1w/1m.......94.13

[nullspace]

Hi Bob --

I heartily recommend JELabs OB: http://members.myactv.net/~je2a3/open.htm. Best of luck with your project. I used it with a pair of Goodmans 12" coax and they were quite nice.

Regards,
John

[opnly bafld]

Hello Bob,

Experiment, it is the only way.

For flat baffles, I would recommend starting with something around 49"h (4' x 8' sheet of wood cut width wise) x 26"w, then cut it down a little bit at a time. Listen for changes as you cut, for better or worse.
Generally speaking, wider=more bass   narrower=better imaging, you can usually find a happy medium.

For winged baffles, cut the center piece just wider than the driver.
With wings there is more force on them than you might think, so pay attention to that.

Have fun,
Lin