Amplifier blowing speakers

I want to apologize up front if this has been covered, but I could not find anything like the issue I'm having.

 

I just installed a hand-me-down amp/sub box with a PAC LOC. In doing some multimeter (Novice) testing, the splice into the stock HU rear speaker wires are reading 12v, the amplifier is on and not faulting.

 

I did a read of voltage coming from the speaker wire output from the amplifier and it was reading over 1000 volts...is that right? That seems crazy! Also, the speaker wires were sparking when you just flick them together...are they supposed to?

 

In addition to all of this, I decided to try my friend's sub-woofer that I know worked before and the end result was no sound a blown sub-woofer (or burnt to be exact).

 

Long winded, but can anybody help?

too many empty holes to say for sure.

 

firstly the PAC LOC is attached behind the HU or at the rear speaker? (small matter, but longer the run the more resistance)

 

from the LOC, you are using an RCA hookup to the amp right?

 

when first working with the amp you do have the gain all the way at the lowest position right?

 

you do have something for the amp turn on lead right? (i know you said it was on, but where are you getting this source from?)

 

brand and wattage of amp? RMS not peak

"""""""" of sub?

 

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now, just some assumptions on what the most common causes would be. 1 - bad signal. a poor signal run though a LOC can be read as distortion and thus clip the signal, you get a multiplication of wattage for an instant and cook the sub. This is combatted by having a dedicated line out unit processor (audio control, not generic 30 dollar)

 

2 - gain was up to high and just fed too much power to the sub and it died on first volt.

 

3 - sub was already broken (stuck pole, or frayed lead) so it just baked instead of moving.

 

Side note - when taking the reading at the speaker leads, you want to measure in wattage. Voltage only works for testing dedicated line out preamps. a speaker does not take the same signal, thus needs more power, so the voltage will go up to get the right wattage.

 

side note, for the amp, you DO have it grounded with the same size ground wire as power, and it is grounded CLOSE to the amp (3-4 feet) and its to the body of the car, and not some thin sheet metal, right?

 

T

Thank you very much for the response!

 

- Amp: Rockford Fosgate 325.1

- PAC LOC is actually under the passenger seat with the amp by splicing behind the HU and running 18gauge to the LOC (tapped rear speaker leads from HU)

- Using RCA from LOC to amp

- gain has been at the lowest and bass boost remote set to lowest

- remote wire is coming from HU pin 10 (12v accessory)

- sub woofer was running prior to me hooking it up to my system (in my friend's car)

- amplifier is grounded with 8gauge same as power wire

 

Is there anything I can test with a multimeter to make sure the amp is in good shape? Is there an issue with the amp output speaker wire sparking the way it is?

 

I'm a novice with as multimeter, but am willing to learn/try to get some readings on it.

 

Thanks again for your help!

what was the sub you were using? I had a 150.1 years ago and if I remember right that was 150RMS...

It was a Rockford Fosgate Punch P1 (150 rms/300w max)

Yea I had one of those subs, that amp is way too powerful for that sub. it smell like eggs? lol done that twice, once with the 150.1 and once with my hiphonics(thought the 2000 that it was rated for was peak, it wasn't, it was RMS!)

 

I had the 150.1 hooked up to a P2 back a few years ago. Your amp is way to powerful for that speaker. Easiest thing i can think of is go to walmart and buy a sub for that spec, I would use the lightning audio, if they still sell it, made by rockford just not the same quality, then try again, walmart is usually good for exchanges if you keep the reciept. Then after you solve your problem, you can always return it.... and buy the sub you want...

fosgate amps suck. your amp has a bad channel and is sending DC voltage to that channel. Any speaker you hook up to that will die.. I had a Fosgate Power series 800a4 that killed 650.00 worth of boston pro speakers.

 

DO NOT HOOK UP ANY SPEAKERS!!!!! if you have a DVOM you can switch it to DC current and check the output. It is probably putting out 65v of DC currant. your better off buying a new amp, the cost to repair is going to be close to what the amp is worth, and when another channel blows, you will lose another speaker.

 

OLDSCHOOL PPI for the win.

Thank you for the replies...

 

The amp did seem to have too much output power when I was doing some reads with a multimeter. It probably is a bad amp, but figured I would ask.

 

Thanks again!

OMG no no did I just hear that fosgate amps suck?!!?!?!? That is far from the truth there. I'm not saying that because im a fosgate fanboy. I say it because their product is truely top notch. A little over priced.....but what can you expect from a mainstream brand. Either you got a bad amp or its not installed correctly. They under rate all their equipment too unlike others that inflate them to get buyers. Their power T2500 amp does 3300 rms and your saying they suck?? I owned a Punch P300.1 and a smaller 2 channel punch and they never gave me a single problem. A simple way I use to check if my amp is working properly and its not just a wiring issue is I have a battery just chillin in my garage and i hook the amp up to that Like you would in a car. And then I just hook my ipod up to it and start messing around with settings and what not to check if everythings ok. If thats somthing you want to try i can go into further detail but it basically gets rid of all the other factors that could be messing the singnal or anything else up

Thank you for the info...I'll give that a whirl. It is odd the amp turns on and appears to read fine regarding input, but its the output that really concerns me. Thanks again!