Shocker USA Sig 15" build log

[hispls]

A cute little something I put together. Got the Shocker Sig motor off a forum. It's close to 70 pounds, Magnet slugs are about = TC 4hp. This particular motor has a very tall top-plate and supports a 3" coil. You'll notice the gap is quite large so I've used a dual 1 ohm 8 layer flat-wound coil that I got from Pierce Audio Products (a rather impressive coil). I like the ability to run 2 ohms for daily and .5 for comps.

Cone and dustcap are also from Pierce. The carbon fiber layer adds a bit of mass so this in addition to the heavy coil makes this sub not too optimum for my goal (peak at 54hz for SPL competitions). I used a single spider with dual sewn leads that I got from Sundown (a very nice spider). My theory was that I'll probably not have x-max issues at >50hz so I'll go for efficiency.

My limitations are 3 cubic feet for the box (for local SPL organization category). Oddly enough they have a 4" limit on round ports and no limit on slot ports so I went with about 90" of port area tuned to 52hz.

End results were pretty dirt for low extension but a 146.7db on the termlab at the dash windows and doors closed (db drag style). Amp is DC Sound Labs 2000.1 (same as Sundown 2K and a few other Zenon 2000W boards...quite an under-rated amp and stable down to .5 ohm). I had intended to throw much more power on this when not at competitions (limited to 2KW) but all my larger amps are out of town getting tuned up so we'll have to wait to see how this handles 3, 5, and 8KW.

I have since added an insert to the port tuning me down to 45hz ish. Sounds much better for daily but I haven't had a chance to meter yet at my peak. I'd have high hopes for this driver tuned in the mid 30's, sadly at this point I'd have to shrink my port to impractical area to acheive this so it's something I'd try with passive radiators or in a much larger box.

Photobucket has the pics in reverse order, but whatever. Will update more as I test if anyone cares.

[hispls]

Seems the forum doesn't link to the full size pics. See if this helps....