The Besta Subwoofer

[howard]

A very professional look! Great job.

[Ugg10]

nice job, looks great and I bet it sound great also.

I hope the first song you played on this was Nanowar of Steel - Valhalleluja! (Play it and you will see why!)

[Steve Lee]

Looks right at home!

Rattling things . . . Don't get me started - too many picture frames around here . . .

[wogg]

Final impedance sweep after gluing the port in and applying the denim lining shows the tuning went up a bit to 24Hz with a nice clear pit in the tuning now. The ~150Hz minor lump is still there, but not bothersome. The height of the peaks are diminished, consistent with lowering the Q of the box with the lining.



Sweep testing with sine waves is satisfying. There are no leaks or rattles anywhere, no port noise at crazy levels, and plenty of output down to near 20 to make a room hunt for rattling things needed.

Overall.... success!!!

[wogg]

And here's why I chose a Besta cabinet in the first place. The whole system together.

[wogg]

Curious how you ended up affixing the denim to the panels. Did you double up on the back? I like the aesthetic and inventive use of the existing furniture! Cheers,

Easy, just globs of hot melt glue. About 3 long sticks worth, and minor finger burns. Nothing is doubled on back, just a couple odd pieces trimmed with scissors and glued on to get coverage.

[gregrueff]

Curious how you ended up affixing the denim to the panels.
Did you double up on the back?
I like the aesthetic and inventive use of the existing furniture!

Cheers,

[wogg]

Port glued in and denim lining complete. It's fun to stick your head in the cabinet now and hear how eerily quiet it feels.



Little better shot of the port action. The cross brace is actually glued to each other, though it's hard to tell from this angle. There's Titebond in between to ensure they don't pick up some motion and rattle inside. You can also see the edge I had to shave off the port flare to fit.



The back panel got some treatment too, around the amp.

[wogg]

Free air vs. in box comparison.


The free air impedance sweep looks clean, with woofer break up showing at about 650 and 900Hz.

Here's the initial tuning check sweep, confirmed 21Hz. This is without any lining in the box, and the Precision port just press fit in there to check the tuning. I expect this to be a little cleaner once I line with a bit of denim insulation and glue the port up.



The woofer break up wiggles are still there at the exact same frequency, so no relation to the box at all there as expected. I do see a slight wiggle appear at about 150Hz. That corresponds to 1/4 wavelength of my ~22" internal dimensions, so that may be a weak standing wave. I don't see any other significant wiggles that would indicate a resonance problem with the cabinet itself. I'll do another sweep once lined and ready for use to see if that 150Hz tiny lump goes away. Purely out of curiosity at this point.

[wogg]

Got a wood rasp or horse shoe file?

Yeah, started with a file but there was too much to remove. Ended up taking passes at it with the jig saw from the back side. Turns out my main problem was paying attention to orientation while pulling the panel off, working it, then test fitting. I set the amp sideways then was surprised when it didn't fit the right way.... user error

It's in there now, and still has enough lip for the gasket!

I sealed it up to test tuning, got it set at 21Hz with the full length of the 4" precision port kit. The model suggested I would need a couple more inches than that, so now I have a 4" extension kit that wasn't needed. I'll post up some DATS images later, I want to compare free air to in cabinet very closely to see what blips are showing up that would indicate resonances in the IKEA cabinet skin. I'm sure I have it really solid, but the impedance will tell the tale.

[Steve Lee]

Got a wood rasp or horse shoe file?

[wogg]

This amp cutout is killing me. I keep removing material with the jig saw and the hole doesn't seem to be getting any larger so the amp continues to not fit. I think I found some sort of exception to the laws of physics with this thing.

[wogg]

The organ donor process is in full swing, the old cabinet was gutted and a spare Sony powered sub put in place to keep the entertainment center running while I finish assembly.

Here's the back panel, a bit of a swing and a miss with the cut out dimensions, probably 1-2mm off so I've got some work to do to open that up slightly for the amp module to drop in.



Here's the Lab12 sitting in the recess to locate and drill the holes for the threaded inserts. That sucker is thick, the 3/4" panel is just about right for flush. The JL audio grille going over that will still leave plenty of room for the woofer to do its thing.



Here's the spot where I did some cursing... while removing the woofer it rested on the polished edge for just a second and took a chip off. This is small, but highly annoying.



Any input on how best to do that little repair would be awesome. My current plan is to spray the primer and paint into little cups and use a small brush to touch up. Once cured I'll rub it a bit to try to blend it. It won't be noticeable from a distance, only under close inspection, but I'll know it's there.

[wogg]

Thanks Steve! That's the goal, blend right in the living room.

[Steve Lee]

Looks like furniture to me - you should be pleased.