Tempest Questions

[grampi]

Here goes. The project started with a 4 X 8 ft sheet of 3/4" birch ply. I was going to use oak veneered MDF, but it was almost $60 a sheet, and I got the ply for less than $30. It's a very good, void-free, 7 ply plywood that Home Depot had on sale. It also has a very nice looking grain to it. I not only wanted a nice sounding sub, but a good looking piece of furnature as well.

I chose Adire's recommended mid "Q" sealed enclosure design, which was supposed to be 4.6 c.f. I say supposed to be because when I cut all the corners at 45 degree angles, I apparently don't know how to measure correctly because I ended up with about 4.4 c.f. Good thing sealed enclosures are more forgiving than some of the other enclosure types when it comes to size.

With the exception of the lid, the entire enclosure was assembled using no nails or screws. It's held together entirely by yellow wood glue. Getting all 4 sides together at one time was a bit tricky, but with a little help, we got it together and held it in place with a strap and a tightening aparatus. It actually worked very well. The driver hole was cut out and the "T" nuts installed in the bottom piece previously. Next the internal braces were installed, then the lid was tacked on using finishing nails and yellow glue. Every joint on the inside was then sealed using caulking. The outside was sanded using 220 grit sandpaper, and the hole was cut for the plate amp.

Next it was time to make the table top and the trim pieces. The top was made from 1 X 8 birch stock. It was plained, sanded, the edges were squared and glued together using biscuits. The edges were rounded using a router. The top ended up being about 5/8" thick, and it overhangs the enclosure on all sides by about 1 1/2". The effect I was going for was to make it look somewhat like a lamp table. For the enclosure's vertical corners, I cut 3/4" square pieces, then cut a 1/2" square out of that to form perfect 90 degree, 1/4" thick "L" shaped corner pieces. The table saw really makes this an easy task. The other trim pieces were 1/4" X 3/4" that mounted horizontally just below the table top, in between the corner pieces.

On with the stain and sealer. I used Minwax #230 stain, which I think is Old American Oak. It ended up being almost the perfect match with our oak living room furnature. The sealer was a spray laquer in a satin finish. At this point I knew my wife would want to keep this thing regardless of what it sounded like. It turned out to be a damn nice looking piece of furnature! I was shocked because this was my first time ever at REAL woodworking. Of course I had a lot of help from the folks at the wood shop. Sure I've built lots of enclosures before, but they were all made out of MDF, and I never did any finish work to any of them.

Time to take it home and install the driver and amp. It didn't turn out as heavy as I expected it to be. I'd say it weighs right around 80 lbs. Keep in mind the only sub I've personally had to comapre this one to in my living room was also a DIY sub I built out of MDF. It was a 2.5 c.f. sealed enclosure using an MTX series 4000 15" car audio driver and the same PE plate amp I'm using on the Tempest. The first thing I noticed was I had to turn the amp's volume control up slightly higher (from about 1/3 to just under 1/2) than where I had it set for the MTX to obtain the same volume level. I've got to admit, there isn't a lot of difference between the Tempest and the MTX. At low to moderate volume levels, there doesn't seem to be much difference in sound at all. At high volume levels the Tempest seems to maintain its composure a bit better, and I'm not even sure the difference here is in the drivers. When I built the enclosure for the MTX, I fukced up by not adding any internal bracing. As a result, you could literally watch the sides and top of the enclosure bow out during heavy huffing and puffing. So I don't know if at high volume levels the MTX driver is actually being pushed beyond its limits, or if the flimsy enclosure is the cause of the not so perfect sound. Both seem to handle music and HT duties equally well. I was expecting the Tempest to blow the MTX away because so many people had said the Tempest is a far superior driver. Not that the Tempest isn't a stout performer, because it is, it's just that MTX must have not been as much of a slouch as many have claimed. The Tempest absolutely gives me more flexibility than the MTX though. The MTX was pretty much at its power limit with this amp, whereas the Tempest can handle a lot more power should I decide to upgrade to something like the PE 500 or 1000 watt plate amp. Would I recommend a Tempest? Yes, especially considering its $125 price. I'm tempted to say this driver/enclosure combination's performance rivals, or even exceeds that of manufactured HT subs costing well over $1000, but I've only heard them in audio shops, not in my living room. At any rate, even if the sub blows, I've still got a nice piece of furnature!