OT: 12" or a 15" for a 6732 cubic inch bass reflex ?

**johnobub** · June 27th, 2013, 11:18 PM

I found a pair of 6732 cubic inch bass reflex boxes at the side of the road (in the garbage) the other day. They don't have any brand name on them but they have 1267A with 95DZ43 under that first number on the back panel. They are factory made. The grill cloths (brown/yellow grill cloth) were torn open and the speakers were removed.

They are made of 3/4 in plywood with a 1/16 inch vaneer on the outside with bass reflex baffle holes below the speaker holes. They have 12" baffle adapters in 15" precut holes. Above the main speaker holes they also have a rectangular hole covered with wood inside the baffle. One of them was sanded down a little and one is unsanded. Looks like the previous owner was planning to fix them up but didn't have time or whatever.

Nothing much wrong with the boxes except some small scraps and scratches, nice old style boxes, with legs, made of real wood and plywood. I'm planning to put some drivers into these boxes, according to the interior cubic inches, what size speaker would sound the best in these 6732 cubic inch bass reflex boxes? A 12" or a 15"?

**VolvoHeretic** · June 27th, 2013, 11:37 PM

6732 cu in or 3.9 cu ft.

**Phil-G** · June 28th, 2013, 12:11 AM

Originally Posted by VolvoHeretic

6732 cu in or 3.9 cu ft.

that's what i came up with. but that doesn't sound right.
how about some measurements?

**miker1** · June 28th, 2013, 06:58 AM

What type of system are you trying to build? Do you want to use these cabinets for bass only, and what frequency range are you trying to cover? Got a picture you can post?

Need a little more information to go on.

**zelgall** · June 28th, 2013, 07:31 AM

Every speaker is different and require different sized cabinets. You're working backwards trying to shoe horn a new speaker into an existing box.

**fpitas** · June 28th, 2013, 12:38 PM

If you get WinISD Pro, for each driver under consideration you can play with different box sizes to see what can be made to work. There's usually some latitude and tradeoff between box size, port tuning, rolloff etc.

**johnobub** · June 29th, 2013, 02:22 PM

Originally Posted by miker1

What type of system are you trying to build? Do you want to use these cabinets for bass only, and what frequency range are you trying to cover? Got a picture you can post?

Need a little more information to go on.

Mainly for bass, highs would be separate enclosures and bi-amped.
003A.jpg 004A.jpg 010A.jpg 016A.jpg 017A.jpg

**Audio_by_Goodwill** · June 29th, 2013, 03:38 PM

Oh, those are pretty nice looking cabinets!

**johnobub** · June 29th, 2013, 02:08 PM

Originally Posted by Phil-G

that's what i came up with. but that doesn't sound right.
how about some measurements?

Here are basic dimensions of the outside Dimensions.JPG.

GM · June 29th, 2013, 05:35 PM

Originally Posted by johnobub

They are made of 3/4 in plywood with a 1/16 inch vaneer on the outside with bass reflex baffle holes below the speaker holes.

OK, what is the exact area of the vent?

Net Vb wise, it's between a 612 and 614, so there's some 12" and 15" Altec options, though the vent may need re-tuning.

GM