Tempest Car Audio

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Tempest Car Audio

Not your ordinary Car Boomer

by Chris Tsutsui

My 4 runner felt the need for some more bass than my current dual 10" PPI subs could output. I decided to design and build a subwoofer box for it. Designed primarily for fitting in the back along with amps and my capacitor, I now plan to calculate the internal volume and tune the enclosure to my liking. the 15" tempest will be powered by a 600W RMS Alpine amplifier which will rest on top of the "shelf" next to a single 1 farad stiffening capacitor.

Assembly and build took only a couple hours to make. My friend Steffen, (The professional contractor) decided to build this box in about an hour while I was building the bass traps. It's amazing how perfectly accurate the box ended up being as he simply followed the autocad dimensions and cutlist for everything to go smoothly.

I'll finish the box and make a better page once I'm done with the install.

Using screws, glue, and a nail gun meant ultra fast assembly. Designed on AutoCAD 2002 and made of 3/4" MDF with 1/2" MDF bracing. Holes were hand cut with a jig saw and the panels were done with a table saw. Router used to make the sides panels. The box has an internal volume of about 3.5 to 4 cubic feet (haven't calculated yet). The port clearance allows dual 3" flared ports with a maximum 10" long center tube. The center tube is 10" right now making the box tuned to approx 24-25hz. 20oz of polyfil line the sides of the box, the box was glued so no internal caulking was needed. Painted flat orange by Behr paints it was $6.99 for a quart at Home Depot. The orange color is complimentary to the blue interior to stand out and hopefully discourage people from stealing it. (And I think it looks cool)

	A standard router was used for the sides after first cutting the excess pieces off with a jig saw. The side extensions will help support a separate MDF speaker box that will Velcro on top. The box is about 29" wide, and 17" tall. The speaker driver clears the amp rack about 1/4" on the inside. I bet nobody has ever seen a box like this. :)
	I won't be filling the screw holes with Bondo as I think it adds a bit of detail look to the box. I'll lightly sand the sides and edges and throw on 2 layers of paint and all should be well.

	This is the view from the backseat of my 4runner. You can see the rack where I planned to mount the Alpine MRV-1507 amplifier I bought used. Unfortunately, the amplifier I bought was off the HTF hardware for sale forum and it did not function properly when I bought it. It was off a member named Scott Falkler who said it worked flawlessly, but when I used it for 10 minutes that proved otherwise. I cannot get my money back but I am handy with amps and I think I can fix the damaged areas.
	The amp caught fire in two areas and now my car smells like electronic smoke. The flames burnt the orange paint on my box so I had to sand and repaint it. From closer inspection it looks as though only a couple dozen parts were fried so it is fixable. I'm just thankful that my car didn't catch fire or that the amp didn't take any other components with it.
	For now I have my spare amplifiers powering it, the PPI 200-watt amp is for the tempest which seems to be very happy indeed. The Soundstream 40wpc amp is for my Alpine Component speakers I plan to mount in a separate MDF box soon.

Measurements were done, and playing the song "Andale" by Nelly achieved SPLS nearly exceeding that of which the Radio Shack SPL meter could handle which meant spikes at 124db. Keep in mind this SPL is not completely due to cabin gain as I do have a moderate 3db hump in the response according to program testing for some added punch. The measurements were taken with the back window and front windows rolled down with myself wearing -21db ear plugs just in case I'd damage my hearing with the mic on my lap in the front seat. (fast C-weighted)

Subwoofer Enclosure (MDF, Polyfil, Flared Ports, Paint)	$50
Adire Audio Tempest 15" Dual 4ohm VC high excursion driver	$150 for Driver at Adire Audio
200w amplifier	$150
1 Farad Capacitor	$70 at Parts Express
Wiring (4ga, Gold ring terminals, IC, wafer fuse)	$40 at Parts Express

That equals a budget of about $460 for a smashing bass audio system. When you think about it, it costs $500 or more for people to buy package audio deals at places like Al and Ed's. The only difference is that I don't have your typical car boomer, mines simply the orange flavored audiophile bass maker. (OFABM)