# Sub not working



## jklewter (Jul 17, 2014)

I was playing around with putting some LED ambient lighting in my car and I accidentally pulled the audio fuse from my car's fuse box. I put it right back in and heard a loud pop. Now my sub is not working. The radio works fine, the amp's green light is on indicating that it has power but the sub is doing nothing. It was working fine up until I pulled that fuse. Please help...I need my bass!!


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## etaf (Dec 28, 2008)

> I put it right back in and heard a loud pop


 is that the only fuse for the audio - what sort of pop - a pop from the speakers or a pop from somewhere else


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## jklewter (Jul 17, 2014)

According to fuse panel that was the only "audio" fuse. It was definitely an audio pop


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## etaf (Dec 28, 2008)

i'm not an expert here , but 
how are the devices all connected together 

The radio is a head device that connects to an amp , the amp then provides audio to all the speakers and has a connection for the subwoofer
OR
does the amp just provide subwoofer signals?

when you put the ambient lighting in - any chance that you may have disconected any of the speaker cables at all - or pulled on them and disconnected the speaker / amp or any junction connections inbetween 

I would have thought an audio POP as you power up and AMP would be normal 

Amps I have dealt with in the Hi-fi would do that - some even have a suppresion to stop the POP when switched on


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## jklewter (Jul 17, 2014)

the amp provides audio to all speakers. i stopped with the ambient lighting once i heard that pop and then check my sound then started trying figure that mess out. So i didn't do anything with the ambient lighting.


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## etaf (Dec 28, 2008)

and its just the subwoofer section thats stopped working and you have checked out all the cables for a good connection 

with that audio fuse , if you pull it out , then everything goes dead , the radio - the amp etc


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## jklewter (Jul 17, 2014)

Correct, i pulled the fuse and everything doesn't work. I pulled the battery cable, put the fuse back in hooked the battery back up and still no sub output. 2 fuses on the amp look fine. Remote, Power, ground, RCA, and output wires to speakers all look fine.


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## etaf (Dec 28, 2008)

afraid, i'm out of ideas - other than any menu settings on the amp/radio that may have been reset due to the lose of power and need re-setting up at all ?


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## jklewter (Jul 17, 2014)

The radio has a subwoofer function and I've turned that off and on. the amp doesn't have any kind of reset button. I'm going to take the radio out later today and see it has any kind of reset button on the back of it and check the amp on the back of it?


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## jimscreechy (Jan 7, 2005)

You have 3 fuses to the amp correct? one in the battery line and two in the amp itself, and they all look good? If you have a multi-meter you can check that you have power at the amp, both the remote and the main powerline. If you have power you can check the sub with the multimeter also. If you don't have a multimeter you could check the sub with a 1.5 volt battery, AA or AAA. Connect it to the sub terminals and the diaphragm will move out (pos to pos) or in (pos to minus).

A loud pop is not a good sign, though some fuses do make this sound when they go. Also some subs will give you the green power light with just the remote positive being on, while the battery power line -the main one- can still be disconnected or have a fues blown.


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## jprince526 (Oct 31, 2013)

The cars radio is fused in the fuse panel. Some amplifiers are fused as well. The power wire feeding the amplifier should be independently fused near the battery. Some head units have a fuse on the back of the radio near the wiring harness. Have you checked "all" of the fuses? You indicate that the amp's power indicator is showing a green light, take a test light or multimeter and see if the subwoofer is getting power on the output side of the amp. I can't imagine pulling a fuse to the audio circuit would have anything to do with the amp, seeing as its independently fused at the battery. If the amp is in fact outputting power to the sub, the next thing I would check is the signal to the amp from the radio. With a multimeter check the voltage from the head unit at the amp through the RCA signal cable. A nominal voltage should be around 2volts, some head units may read around 5volts. Another thing you might try is smelling the interior of the amp through the vents. 9 times out of 10 if it smells like burnt electrical, something inside has failed. The same is true with the subwoofer itself. Im kinda stumped on this one. I do have a friend I can call and ask, I bet he would know something, he is a pro installer. I'll post back here when I talk to him.


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## jprince526 (Oct 31, 2013)

I asked my friend and his first thought was the amp took a surge and blew an internal component. He said the the dedicated fuse should be an ATO fuse probably 30 amp. He said they act like low resistance resistors, but if the surge isn't big enough to melt the link, the circuit boards resistors try and absorb the surge. He said its possible that the capacitors absorbed the surge using stored energy, the same way a computers battery backup absorbs 120v surges. The loud pop could have been one or more capacitors blowing. If it was a cheaper amp, he said it will cost more to fix it than its worth. He mentioned its best to have the car off when pulling and replacing fuses. If the fuses don't fit snug in the block, a "short" can be created when replacing the fuse. When working on live circuits, even low voltage, its best to disconnect the batteries negative cable before starting.


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## jklewter (Jul 17, 2014)

Thanks guys. I'll check it with a multimeter. I'm going to pull the head unit out as well later today. It has a fuse on the back of it as well. The amp only has 2 fuses, here is a pic of the amp (not my actual one) mine is less than 1 week old as well as my sub. Also is a pic of the back of the head unit.


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## jklewter (Jul 17, 2014)

The battery was connected when I pulled that fuse and put it back it but the car was not running. i know...dumb forgot to disconnect the battery first.


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## jklewter (Jul 17, 2014)

UPDATE: I checked some stuff with a multimeter. At the amp side of the speaker output i got 2.5-3.0 and the other end, input into the sub I got up to 4.0. I disconnected the RCA cables whle checking the output from the amp and the reading went down to 0 so that means the amp is getting something from the RCAs right? The 12V going into the amp from the battery was up to 29.0, is that to high?? 
All this is with the meter set to AC.


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## Basementgeek (Feb 7, 2005)

I think your meter should be on DC, not AC.

Have you checked the speaker itself with an ohm meter?

BG


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## jprince526 (Oct 31, 2013)

Current from a battery is DC. That may explain the readings.


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## jklewter (Jul 17, 2014)

OK, dumb question time, should the car be running? do I ground the black out by putting it something metal?


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## Basementgeek (Feb 7, 2005)

Use the frame if you use the frame as your Negative (Ground) connection. If you ran a separate wire for the ground use that.

You need to measure the resistance of the spearkers them selves at the speakers terminal, not through any wiring. 

BG


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## jimscreechy (Jan 7, 2005)

Sorry should hve been more specific. The engine does not have to be running. But, with some ICE systems, depending on how they are wired, you won't get power to the remote (the positive control wire that turns on the amp) until the ignition is on. Also some radios (head units) don't come on without the ignition either.

When checking the voltage set the multimeter to DC volts. digital ones are mostly self-ranging, anlalog set it to a range greater than 12 v

To check the Sub, set the multimeter to Ohms. digital again, self ranging, anallog to less than 1000 ohms, or 100 ohms. If it is still good/working, it should range from 2-16 ohms depending on the setup or impedance.


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## Basementgeek (Feb 7, 2005)

The speakers HAVE to tested at the speaker terminal, i.e. they have be disconnected from all the associated wiring or you could get a false reading. 

BG


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