Subwoofer Wiring (turning into a mic)

deadair · Post by **deadair** » Thu Feb 16, 2006 5:48 pm

I've seen the various threads regarding turning a speaker into a mic, so i think i have the idea down.....

whats confusing me is that i was just given a subwoofer, i opened it up and there's two sets of terminals on it, i.e. 4 wires coming off the speaker, two from each side. i have no experience with subwoofers, so i don't know if this is common, but it confused me from guitar speaker experience only...... should i solder some of the cables together? ignore some of them? any suggestions would be appreciated. alternate idea being just get a new 15 to put in this cabinet.....

rodabod · Post by **rodabod** » Thu Feb 16, 2006 6:12 pm

I wonder why there's four wires?......

Have you got a multimeter? Try for two which give roughly the impedance rating of the speaker - there should only be two real connectors - are you sure the wires aren't connected together? I think you'll be ignoring two of them.

Anyway, wire both wires to XLR pins 2 and 3 fix a wire to the speaker chassis going to XLR pin 1. If the phase is wrong, then swap the wires at pins 2 and 3 round.

You may get away running unbalanced using a speaker cable into a mic input though..... Depends how much effort you want to put in.

deadair · Post by **deadair** » Thu Feb 16, 2006 6:50 pm

well, maybe this will help. the speaker wiring on the outside of the box allows for an input left and right input and then an output to left and right speakers after passing through the sub. there's some capacitors back there too, which i'm wondering if act as some sort of a crossover? i don't know much about this stuff, so i'm sorry if this comes across as stupid, just my best guess.

confusing to me in all of this is that both the left input and output go to one set of terminals on the speaker, and then the right input and output go to the other set of terminals, if i remember correctly.

i don't know what the rating is ohm wise of the speaker, but perhaps i will try the multimeter.

RodC · Post by **RodC** » Thu Feb 16, 2006 6:51 pm

If there isnt a set of fancy LEDs then its a dual coil SUB. Pretty popular, gives you a way to route left and right channels into the same speaker if you dont have a sub out. The 2 coils are not connected, sorta like 2 speakers sharing the same cone.

Some newer car woofers have LEDs, they will have 2 sets of terminals.

CORRECTION, after reading your post it sounds like they are for hooking up a parrallel speaker.

deadair · Post by **deadair** » Thu Feb 16, 2006 7:12 pm

rodc, what would you guess this means in terms of wiring it to be a mic?

there are no fancy LEDs that i saw.

RodC · Post by **RodC** » Thu Feb 16, 2006 7:36 pm

If there are some Caps that is a connection for a high range speaker, crossover. Dang I missed that.

See my correction, I think its just a parrallel connection for another speaker. Use the + and - that go directly to the voice coil. Hook them to an XLR connector.

Pin 2 on your XLR is +, pin 3 is negative.

I would reverse the polarity or keep it the same if you end up flipping your Bass drum polarity a lot. This will give you some thump, I like to combine it with a 57. Not may ppl I record want that kind of thump.

I like a 8" speaker, a normal speaker seems to move better than a sub. But the larger area def picks up more.

RodC · Post by **RodC** » Thu Feb 16, 2006 7:42 pm

Sorry if I confused you, its a mess here today, I'm working on my 3rd band today.

If there are caps in there its def a crossover, pretty common for subs.

Two of the terminals will go directly to the voice coil, this is the connection for the sub.

The other two terminals will be connected through a cap, this blocks the lows. THe cap prob goes from one + terminal to the other +.

If you use an OHM meter on the 2 terminals for the sub you will get between 3 to 8 ohms depending on the impeedance. The other set will be pretty high resistance due to the cap blocking the voice coil, dont use these connnections.

deadair · Post by **deadair** » Thu Feb 16, 2006 8:26 pm

the multimeter only confused me somehow, i think maybe i was using it wrong, which seems unlikely, but somehow true.

maybe these pictures will help:

rodabod · Post by **rodabod** » Thu Feb 16, 2006 8:42 pm

Lost my post....

That's a crossover.

Try one pair of terminals on one side connected to XLR pins 2 and 3. Pin 1 goes to chassis.

RodC · Post by **RodC** » Thu Feb 16, 2006 8:55 pm

That is a crossover, but it is a dual coil sub. The crossover is there to feed the subs and the external speakers. (Caps for highs, Coils for the subs)

Ditch everything except the speaker and use the wire to try out diff connections.

You have 3 options:

1 Just use one coil, just use the + and - on one side 8ohms

2 wire them in series, this may sound the best because it would be 16 ohms and using all the coil wire avaliable. Just hook the + on one side to the - on the oppisite NOT the terminal right next to it. Just like 2 speakers. What you will have left un used will be a + and a - Use those terminals to hook to your XLR cable.

3 Wire them in parrallel, this will give you 4ohms and use all the coil. Just connect both + to each other and both - and use either + and - to go to the XLR connector.

You may want to try them all, should be pretty fast to see which sounds best.

deadair · Post by **deadair** » Thu Feb 16, 2006 8:56 pm

i suppose i will just have to try it. i think i'll do the connect to a 1/4" and then run through a d.i. technique that i heard about in other threads, but i was just wondering if that means i'll only get half the power or what(?) since i'm only using two of the four terminals.

deadair · Post by **deadair** » Thu Feb 16, 2006 8:58 pm

that makes a lot of sense, i hadnt thought about the whole series/parallel aspect, but yes, i think i'll try that. thanks for that insight!

RodC · Post by **RodC** » Thu Feb 16, 2006 9:02 pm

If you just use 1 set of coils you will just get the voltage you would from one speaker, if you use both you should get more. Maybe close to 2X?

RodC · Post by **RodC** » Thu Feb 16, 2006 9:04 pm

I have heard about the DI, I have never tried it. I always wanted to try a small speaker output tranny. Some of the old tube ones are in the 1K to 4,8, 16 ohm range.

Dang, too many things I want to try.

deadair · Post by **deadair** » Sat Feb 18, 2006 9:21 pm

wired them in stereo, hooked it up to a d.i. damn it sounds sweet. very whooomp-y. the snare bleed etc sounds like its underwater, or like youre outside a club. but the kick mixed in is very nice. used it in a session today..... probably will tomorrow...... gotta give it the run through. thanks tapeoppers for coming through again.

ps - also tried micing bass and guitar with it the other night. interesting mixed in, hard/impossible to get the phase to seem perfect, but definately heavy sounding, albeit muddy on its own.

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Subwoofer Wiring (turning into a mic)

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