(09.20.03)
So I wanted to build a cheap subwoofer to supplement my Bose 141's. I chose a
Dayton 10" driver
that had decent listed specs and chose a ported enclosure using a concrete form (Sonotube).
I stumbled on a spankin' new Cerwin Vega S10VE amp on Ebay (The model is popular in Russia, I think..
..I had to get a 120V->240V converter.
Anyhoo, this is a picture of the baffle, which was made by
sandwhiching two pieces of 3/4" MDF together and sanding endlessly thereafter.
You can just see the pencil lines indicating the complexity (oh yes) of cutting a hole in a circular piece of wood.
This was a bunch of crap. You can see the Parts Express box in the center there, some white
Acousta-Stuf to the right, some speaker wire, and the concrete form on the back of the luv-seat.
Once I cut the hole in the baffle, I wanted to make sure the speaker fit and it did.
Oh, the baffle was 12" wide, as was the concrete form's diameter.
This was the beginning of the stand that would hold the tube in the symmetrical
crescent wrench pillars and the amp in the arched orthogonal plate (ha-ha!) to the left.
This is my favorite picture - you're looking down the tube to the back of the speaker. I sanded the baffle until it just fit in the tube,
put some glue on the outside of the baffle and some on the inside of the tube and then married them. Oh, and once that dried,
I put some Liquid Nails caulk-adhesive around the perimeter of the baffle to insure air-tightness.
This was the assembly of the subwoofer-amplifier-crescent-wrench-holding-unit
(SAMCHU). That dowel was *supposed* to stabilize it.
This was assembly of the other side of the SAMCHU where I attached the arched orthogonal plate to one pillar.
This was the final assembled SAMCHU replete with two *stabilizing* rods and that Stone Creations spray paint that
looks like, umm, stones.
This is the subwoofer in its final form. After mounting the speaker and filling the tube with Acousta-Stuf,
I had to do a bunch of tests to get the port length right. I think I finally tuned it to 34.5 Hz. The amp has a "subsonic"
18dB/octave high pass filter @ 30 Hz which cuts off the lowest tones.
After stuffing it and mounting the end cap and port, I covered it with gray carpet, mounted the amplifier, and let her rip.
It sounds very very good, IMHO. I'm confident that the sub is more sensitive (higher dB @ 1W/1 m) than the Bose and at some
point I'll use the SPL meter to quantify it. The amp's variable low pass filter (30 - 180 Hz) lets the Bose take on a narrower
spectrum, so their efficiency is increased. I'm really happy with the system sounds.
-dave
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