High Zoot Sealed Cabs

[badman]

What methods/tricks have people come up with to making a sealed cabinet perform well?



Some I use (Many apply to all enclosure types):

Big roundovers or bevels for diffraction control (front baffle)
Magnet bracing for the drivers
Coating the inside of the enclosure (I like to use yellow woodglue for this, it soaks deep into the wood, is cheap, readily available, dries well, and strengthens the wood)
Flush Mounting of drivers
Careful attention to lining and stuffing
Irregularities in internal profile to combat standing waves. This can be achieved by gluing additional wood blocks to the inside, using bracing, and other methods.
Thorough treatment to make a very strong enclosure (doubled walls, extensive bracing, etc.)
Golden Ratio used for box design
Minimum baffle size, with depth as the largest dimension. This, to my way of thinking, helps backwave attenuation (more distance and damping material).

Right now I'm working on a Bofu sealed box, which does or will incorporate all of the above.

What other tricks do the masters have? I've yet to try Enabl on a cabinet, and am skeptical about that, but......

[johngalt47]

I just built Jay_WJ's sealed speakers using 0.5 cu. ft. enclosures from Parts Express.

I didn't do anything special and they sound fantastic! Way better than my DynAudio Contour 1.1 speakers.

[infinia]

idea's

You could use either sealed or vented in the same box. Vented tuned real low (around to Fs) to approximate sealed but with a tad more push in the bottom.
Alot more options to play with - like lightly stuffing to plugging the vent.

[Aengus]

Originally posted by badman

Coating the inside of the enclosure (I like to use yellow woodglue for this, it soaks deep into the wood, is cheap, readily available, dries well, and strengthens the wood)

What material are you building the cabinets from? I infer not plywood, since the glue wouldn't soak in past the first glue-line: so, MDF, solid wood, or ???

Regards.

Aengus

[badman]

It seems to soak a little deeper than 1 layer, but on the cut edges it goes much deeper. But yes, I'm using plywood. I suppose it'd be easy enough to port them to Fc and play with stuffing, good idea! BTW: You've got the wrong specs for the pioneer input.

I also forgot to mention using a good fastener/paying attention to the airflow on the mounting. I like "Hurricane nuts" from Parts Express, and black oxide stainless steel screws. I bevel or round over inside areas of the baffle cutout, wherever there aren't nuts.

[Aengus]

Originally posted by badman

It seems to soak a little deeper than 1 layer, but on the cut edges it goes much deeper.

It would certainly go deeper on the cut edges (especially in the layers with exposed end grain) and likely add strength, which could be especially useful at the speaker cut-outs. I doubt that it does anything much besides add weight on the flats of the panels, but it can't do any harm.

This thread would benefit IMO from further discussion of bracing, since some methods which work well may not be intuitively obvious (or at least were not so for me) - things like putting a single stiff 1x2 (about 18mm x 38mm) brace along the long axis of a panel being potentially better than a lot of cross-bracing between opposite panels. Now I'm going to get in trouble for the lack of a citation, but I can't remember whether I saw test results on this site or in AudioXpress, and I don't have time right now to go looking.

Regards.

Aengus

[edit]Corrected typo

[infinia]

Originally posted by badman
BTW: You've got the wrong specs for the pioneer input.

Sorry there alot of BOFU's parts from Pioneer. I used what PE has at the moment. My old boss used to say "If you don't specify any design will do" .

anyhow I hope I got the general idea across. It still should apply with the new "input".

[badman]

Originally posted by infinia


Sorry there alot of BOFU's parts from Pioneer. I used what PE has at the moment. My old boss used to say "If you don't specify any design will do" .

anyhow I hope I got the general idea across. It still should apply with the new "input".

Hi: The specific model we're concerned with is the pioneer 8" fullrange, as used in the Chang models of BVR and also Nelson Pass' TL design. BOFU!

The link has the vicious little sucker (why is it a vicious little sucker? Danged if I know)

Well suited to sealed cab usage. I plan to really give it a thorough test regimen, play around with coaxially mounted supertweeter, cone doping, whizzerectomy, etc. I've got a quad, so a nice test box to compare before and afters on is the impetus for the latest box work. Between these and the other cabs I'm working on, there's a lot of equity in the materials/time/etc, so wanted to get a little more input, if there's any tricks I didn't think of.

So, thanks for your input on adding an aperiodic option, makes good sense.

[infinia]

I'm sure youll have a *** of a zoot stuffing your own BOFU sealed cabs.