Forgot to put that it's for a BRIDGED wiring setup in the title
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Ok, so I have two 4 Ohm Single Voice Coil 12" RF Punch Z's mounted in a box (each wired independently from one another inside the box) and a single 4 Ohm 250watt Bridgable amp two channel amp.

Speakers:
http://www.crutchfield.com/p_575RFZ3...ures_and_specs

Amp:
http://www.mmxpress.com/Merchant3/00...log/p1973.html


I used to have this same combo in my previous car and it was MORE than sufficient for my needs - but it's sat unplugged (sans wires, they stayed with the old car) for about 3 years in the garage. Anyway, I've just run the power/ground/remote/signal lines and everything is cool except that I can not for the life of me remember how it used to be wired in BRIDGED mode so my amp pushes it's maximum 4 Ohm output and It's driving me nuts! LOL

Can anyone explain to me how to do this again? A local car audio shop hooked it up for me back in 2005 and I *thought* I remembered how it was wired - but apparently not now and so here I am

Thanks in advance guys!

 

You cannot run 4 ohms bridged with 2 4 ohm speakers. If you wire them in parallel (plus to plus, minus to minus), they would be 2 ohms for a final load. If you wire them in series (plus to minus, plus to minus), they would be 8 ohms for a final load. You could run them in straight stereo to the amp and be fine, or series, but not parallel, as it is not rated for 2 ohm mono. I suspect they were in series, but cannot swear to it since I never saw it.

Big Mack

 

How do you wire in a series?

The Car Audio shop in town had it wired up with only two terminals (those marked as the "bridge" ports) from the amp and it ran that way for 3 years with no issues I was aware of. Incorrect or not (which sucks if it really was incorrect) it seemed to work very well - but I'm no expert.

Case in point - why I'm here asking for info


Hmmm = I think I've found it:

http://www.termpro.com/articles/spkrz.html

 

You run the positive from the amp to the positive on the first speaker. Run a wire from the negative terminal of that speaker to the positive terminal of the other speaker. Run the negative to the negative output from the amp.

Again, not sure how they did it because I can't see it, but that's how you would do it. If you have two terminals on the box, that makes it easy. Run a wire between the negative of one and the positive of the other, and observe polarity from the amp going to the remaining openings of the terminal.

Big Mack

 

That's what I've done, and it worked......... but either my ears have grown since 2008 or the amp has deteriorated, because I'm not at all impressed with the results this go around.

From what I learned on that website I linked to above - my two 4 Ohm 12's run in series became a single 8 Ohm load on the amp - which was pushing 250Watts bridged originally, and @ 8 Ohms that dropped to 125 Watts per driver.

I really think I just need a new amp when all is said and done. I'm thinking a RMS 500watts @ 4 Ohms 2 channel amp (250 watts each channel) with no bridging needed. That way it's 4 wires total, 2 +/- to each speaker and each driver with RMS 250 Watts to live off of. I'd likely NEVER push them that hot but I prefer knowing the headroom is there.

Thoughts on that as the spec to hunt down for a replacement amp?


As for the moment, I've settled to leaving one of the two speakers unplugged and using the bridged connection from the amp to power a single 12" in the box. All in all it sounds better to me than how it was with both 12's wired in series. And when I wire the box in parallel (which makes a 2 Ohm load on the amp from the two 4 Ohm speakers) the amp consistently goes into protect mode with each heavy bass hit. Obviously this amp cant handle a 2 Ohm load and needs a 4 Ohm load to stay stable without damaging it's internals....

Live and learn I guess (just wish I had more money LOL)

 

Not quite. It's 250 W @ 4 ohms, meaning you're getting 125 total. You're getting 62.5 to each driver. You may want to see how it sounds just running stereo, since it's 75 to each driver. Not a huge bump, but may be enough.

Not sure what your budget is. You can get a lot of power cheap these days, so you have a lot of options.

I rather figured it would go into protect pretty quickly. Concept made good amps that were designed to save themselves well with their protection circuitry. I'd still give stereo a try. No sense riding around with a "passenger" speaker not doing anything. Keep in mind that doubling the cone area with a bit more power should yield a bit more output - and that may be enough, even in your old age .

Big Mack

 

hahahha, I guess I'm not in my 20's anymore so yeah, I'm sure it'll be enough for the time being to run it in standard 75 Watt stereo mode. (just need to find another terminal worm for that 4th plug slot so I can wire it up... currently missing one :O ).

Good call on that because I completely spaced on the fact that along with halving the wattage by way of increasing the Ohm resistance you also have half the wattage to each speaker because there are two.. DUH - it's obvious to me now that you said it