[amt_austin]

I am thinking about building 2 subs, each with a pair of the GR Research 12" drivers positioned opposite of each other and using one of the rhythmic amps per sub.  Anyone done something like this before?   The box would be sealed, and I would follow the per-driver size guidelines for the box size.

[mojave]

I just built a dual opposed sub two weeks ago using 12" drivers. I used an Eminence Lab 12 driver I bought from Danny and another one I got from Musicians Friend using some in-store credit I had. I used Danny's design, but modified the size. Mine is 21" high, 15" wide, and 20" deep. It is 2.173 cubic ft interior space.

I made a cutlist so one can buy two 4'x4' pieces of plywood and use them if they can't transport a 4x8' sheet of plywood. The cutlist picture below shows scraps between some the cuts. I just cut the plywood into strips the correct width and then cut the strips into the correct sizes.

[amt_austin]

Very nice job!  Do you like the sound of the sub?  Also, any reason to use plywood instead of MDF?

[Ron]

  Nice looking subwoofer cabinet Mojave! Should sound great with 12" GR Research duel opposed subwoofers.

 Approximately 8 years ago I built a single isobaric subwoofer using two (2) 12" Eclipse Model W1238R subwoofers mounted face to face in a 2.00 cu-ft vented cabinet. Bass was tight, clean, fast, and powerful down into the low 20 hz range. I would think that the 12" GR Research subwoofers should perform really well in a sealed isobaric configuration.

[mojave]

Very nice job!  Do you like the sound of the sub?  Also, any reason to use plywood instead of MDF?

Thanks. The Lab 12 drivers have a lot of output in the midbass but not as much down low. I added a Linkwitz Transform to lift the bottom end and it plays good down to about 25 Hz. I intended the sub for music and it does well. It sounds very good, but I plan to do some more measuring and EQ.

I used an 11 ply birch/poplar plywood that cost $30 for a sheet. It is almost as stiff as some Baltic Birch that I had bought for another project. It is lighter than MDF and you don't have all the MDF dust to deal with when cutting it. Since there are braces approximately every 4.5" the cabinet doesn't vibrate at all. I stuffed it with some polyfill before installing the drivers.

[JLM]

Good idea.

The Epik Legend is a sealed dual/opposing 12 inch woofer design using a 300 watt BASH amp ($500).  Like having a single 17 inch driver, but quicker with self cancelling vibrations, no port noise, and no out of phase passive radiators.  Epik also offers the 15 inch (Empire) version.

[amt_austin]

I just realized that Rythmik is right down the road from where I work.  I pass by them almost every day!  That's enough for me to go with them.  That, and I saw a picture of the back-side of the plate amp -very nice.

[Hank]

That reminds me - I've got one of his cabinets in my garage that he brought over to get me to quote veneer work.  I need to email him to come and get it.  Thanks!