10" pioneer

Systems

i looked through the forums earlier to see if a 10" pioneer sub i have, tsw29c, would work good for a small practice bass amp. I actually have 2 of them, but i dont feel like lugging two of them around, i just need something that hits deep and isnt monstrous. I hooked it up freeair to a lil 40 watt guitar amp and it sounds good, hits harmonics decently, so i figure ill make a lil enclosure for it. I got some 1" thick Pine stair treads for the sides, (they had bullnosed fronts, so the front of the amp will look cool) and a sheet of 3/4 poplar for the front and back, im figuring about 1cu ft interior, give or take. I read a post from a while ago where it was suggested that a midrange might be necessary, but i dont think so... btw i have a fretless 4 string bass that will eventually have flatwound strings... if i ever put em on and a 100 watt amp that will power it for now

neomagus00

um... cool?

Systems

i was just wondering if there are any pitfalls to what im doing, im no expert, and i dont want to waste time building something and have it not work... im thinking of using 11 1/4"^2 for the front and back since thats the smallest size that will accomodate the speaker mounting flange (or whatever it is they call the outside edge of the speaker that u fasten...) itll probably be about 11 inches or so internally on all sides because of the treads im using and the front and back. On the scematics i pulled it says it needs a foot^3, will that make a huge difference? if so would dacron/polyfill/pillowstuff help?

neomagus00

my brain hurts, so i can't multiply right now, or else i'd doublecheck your numbers, but as long as you have the 1728 in^3 you need, with at least 1 inch clearance behind the magnet of the sub, you'll be good.

if you do the 11"x11"x11" like you're planning, you'll miss the goal by more than 30%, which is bad. if you want an 11"x11" (internal) face, you'll want a 14-1/4" internal depth to make it 1 cubic foot.

there's a tradeoff with the smaller box - it takes more power to get it to the same volume level as a larger box, but the smaller one has a higher maximum powerhandling - at full excursion, you'll have more volume in the smaller box. oh, yeah, the bigger box will hit a bit deeper. and if the box is TOO small - 30% probably qualifies - it can make the bass sound weird and boomy. and polyfill can correct only up to about - conveniently - 30% of box volume. so, if you were to keep your 11" internal cube, you'd need to stuff it completely packed with polyfill, and you may not get the performance of a real 11"x11"x14.25" box.

whew, turns out i can add with a migraine...

Systems

sorry to make u thinkwith a migraine, I get them just before it rains... but dammit, its a good thing i asked, cause now ill have to get some more wood to work with, the stuff i have isnt going to make an enclosure much bigger than what i described, so if i kept the 11 inch depth, i would need at least a 12 in^2 face and back?

Systems

--im sorry, i mean a 14in^2 face and back

neomagus00

nah, an 11"x14"x14" would give an enclosure 25% too big. note that the front needn't necessarily be square, and to find the internal volume you multiply the three internal dimensions... the closer that product is to 1728, the better

Systems

oooooooo... my bad, i suck at munbers :-P

Systems

if i made enclosures for the db 650s i have, how big would they have to be, and i noticed that the middle of the woofer cone is free, it isnt attached, so should i even bother?

neomagus00

i'm not sure i understand that the middle if the cone is free, but if you're talking about the dustcap, then it's no biggie, you can still benefit from an enclosure.

as to volume, dunno, very small... i think we figured out here once that for the mm6, you essentially wrap the basket in fiberglass (that's a mild exaggeration, but you get the point). the bigger the enclosure, the more bass extension you'll get at the cost of pure dbs. any size enclosure should help with bass response, though, simply because the backwave can no longer interfere with the front.

Systems

so those shallow plastic things they sell in pepboys would probably work, size wise... not that i would buy them, but they always looked too shallow to be any good. Hmm... So it wouldnt have to extend much deeper than the magnet?

neomagus00

the shallow thingies you're referring to are probably just covers for the back of the speaker, so when it rains the water doesn't fall into the speaker... if they're anything like these baffles, they won't work for this.

as to volume, put it this way - i'll be putting my mm6s in a fiberglass tube that's a bit narrower than the speaker itself and about five inches longer. take that as you will, but i'm not sure you're gonna get a better answer than that. sealed boxes are very forgiving with volume, so there will be little difference between a medium-small box and a medium-big box. pretty much, make a big enough enclosure that the thing has space to breathe, and it should be okay.

Systems

ohhh ok thats what i was looking at before.... i didnt think they would make a difference :-P

Systems

well, i went on ebay and got a set of ported cabinets, i hooked one up and it sounded pretty good, it has a little boominess to it, i dont know if its the amp setup or if a lil polyfill would help, other than that its great.

The amp im using is an old mono PA amp, Bogen c100, and it has multiple impedence outputs, i know the cabinet is 4 ohms and its hooked up as such, but theres a wire that comes out of the back of the amp thats labelled as "impedence selector" and that was hooked to 16 ohms when i got it so i left it there. I think I might be overdriving the amp because i turn the volume to 2 and the thing is loud. (i have the gain set low) I also have Dimarzio Split P pickups in the guitar, theyre high output too... maybe its just that theyre too powerful, i dont know, so i figured id ask

MacLeod

Dont know squat about guitar amps but Ill take a stab.

My guess would be that the "impedance selector" should be set to the proper load which in this case would be 4 ohms.

AustinKP

Originally posted by neomagus00
as to volume, dunno, very small... i think we figured out here once that for the mm6, you essentially wrap the basket in fiberglass (that's a mild exaggeration, but you get the point). the bigger the enclosure, the more bass extension you'll get at the cost of pure dbs. any size enclosure should help with bass response, though, simply because the backwave can no longer interfere with the front.

I called polk's customer service for this one. They don't really recommend a sealed enclosure for the MM6's since they're designed to be IB. if you do seal it, they say .2-.3 cu ft. Freq response starts to fall off at 50-60 Hz that way, which is where you normally want to cross over anyway.

exalted512

.2 is about standard for all sealed enclosures for 6.5s
-Cody

Systems

Thats kinda what i thought Mac, but its a strange setup... theres a screw terminal strip on the back of the amp, with the different ohms on each screw,4 8 16. i would assume these are attached to the output, whether it be a tranny or not, i dont know, i havent looked yet. anyway, theres a wire next to the strip that's labelled "impedence selection" and its hooked to the 16 ohm screw. Im not sure if i have to have both wires on the same screw or not... i tried googling for a manual, but all i find is the new model, not the old mono, which i would estimate to be from at least the 70's, i think
the amp works, and im just trying to keep it that way

Systems

nevermind, i opened the thing up and found out what it was, it was part of the 70v system that i dont even use... so im not gonna worry about it