Making ported cabs sealed

[Femto]

nail a board over the ports with weather stripping to seal it. use drywall screws, that way if it doesnt please you, it can be removed. johnny a

Aye, that's one way to do it I suppose so thanks for that Johnny. I was thinking of something that requires much less in the way of carpentry cos I don't really fancy screwing into the cab. It'd make it look utterly gash if I removed it. Nasty big gnarly screw holes and stuff.

I wonder if the feedback reducing plugs you can get for the soundhole of an acoustic guitar for when you have it miked up would do the job?? I dare say you can get them in various different sizes to fit the various sizes of soundholes you may encounter.

I suppose they'd have to be a fairly tight fit or else you might find that they get blown out of the speaker port as soon as you give it the big one on the low strings..

 

[toobalicious]

Yep. The whole "sealed" bit comes out of the fallacy that tube amps have too low damping to "properly" control a speaker, which is again, a fallacy.

of course you are right.

however IME, i prefer sealed cabinets (as a general blanket statement). also, lots of the "classic" cabinets (both good and bad) were sealed cabs. of course, some of them also were vented (and some of those vented in a way to be tuned to no particular frequency, at least not purposefully).

one cab i own is a fender HM215B, a big-ish solid plywood 2x15 (about 7.5-8 cubic feet; both drivers open to the entire cab) that was vented via two "holes" in the baffle, approx. 5" in diameter. the stock speakers were the "standard" fender eminence, which are already nothing special, even before they got into this crappy sounding cab.

i sealed (with 3/4" ply, screwed and glued from the inside and applied silicone on every joint in the cab), braced (with 2x2 also screwed and glued), and damped (about 4" of poly batting on every interior surface except the baffle) the cab and loaded it with 1502 black widows (which are evidently only "recommended" for vented enclosures). i also stripped the $hitty carpet off and sprayed it with bedliner coating.
it sounds FABULOUS, IMHO. lots of thick and deep low end, but musical and responsive, at least as far as 2x15 cabs go. no one-note bass at all, as was what it did with aplomb prior to the mod. also, the sound doesnt take nearly as far to develop, and it sounds great even a few feet away from it, whereas before, you really needed to be 15-20' away to "really" hear what the cab was doing.

OTOH, my "real" fender bassman 2x15 cab is also sealed, but smaller (only like 11" deep!). it sounds good at lower levels and with the bassman head. but if i drive it harder with my big amp (the speakers were replaced in this one too), it starts sounding kind of "choked", and the lowest octave sort of falls apart. it doesnt project so well either.

YMMV, but i think the size of the cab will be as critical to the results as the drivers that are in it.