bad rear speaker channels HELP

[954runner 10+ year member]

I have a JBL GTO 755.6II amp, with the sub channels bridged, and originally I was just running my speakers off the front channels of the amp.

However, the speakers were not loud enough for my liking, so I decided to bridge them with the back channels. I bought a 4 channel RCA from knukonceptz and ran it from the headunit to the back of my car. Unfortunately, the RCA's were about 2 feet short, and so I was stuck without sound until my RCA extensions came in the mail today.

I put them in, hooked up the speaker wires to the correct input, and fired up my car. The only problem is, the RIGHT speaker doesn't play anything unless I turn up the volume to the max. My gains are set at 60/80, but I have to turn it up to 80/80 to get anything out of the right speaker. When I turn it down, the right channel shuts off.

So, I know that the rear channels DO play music, but the connection isn't very good. I tested all the other rear speaker input combinations and they are all gave me the same outcome.

Is there a way to fix this problem? Is it a difficult or easy fix? Or should I look into a new amp? Or revert to my old settings (run speakers off FRONT channels)?

Thanks for the help

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[jpexpc 10+ year member]

It sounds like you have an RCA grounding out. If you wired your HU wrong for that speaker you could very well be getting a crossed signal in your RCA connection. Verify your speaker AND the HU is wired correctly for + and -.

 

[954runner 10+ year member]

I plugged the REAR RCA's into the FRONT RCA input and it worked just fine, so I know it isn't an RCA problem.

Any other thoughts?

 

[954runner 10+ year member]

bump?

 

[djman37 5,000+ posts]

when bridging, you don't need the rear RCAs and you have to re-wire the speakers outputs right??? there's markings on the speaker outputs for connecting bridged and i'm pretty sure it just uses the front RCA connections.

 

[954runner 10+ year member]

I'll try only hooking up the front RCA's... I thought I already did that but I'll double check just to be sure.

And yes, I rewired the speaker wires to exactly what the amp manual specified.

 

[Mass Car Audio 10+ year member]

when bridging, you don't need the rear RCAs and you have to re-wire the speakers outputs right??? there's markings on the speaker outputs for connecting bridged and i'm pretty sure it just uses the front RCA connections.

You need to have a input signal going to all the channels on your amplifier if you want to bridge it. How will the rear channel produce sound if there is no input signal going to that part of the amp.

 

[djman37 5,000+ posts]

You need to have a input signal going to all the channels on your amplifier if you want to bridge it. How will the rear channel produce sound if there is no input signal going to that part of the amp.

DOH, i just woke up and came in here to tell him to try the left front and left rear inputs!!!

 

[subzero 5,000+ posts]

You need to have a input signal going to all the channels on your amplifier if you want to bridge it. How will the rear channel produce sound if there is no input signal going to that part of the amp.

http://manuals.harman.com/JBL/CAR/Owner%27s%20Manual/GTOAmpIIOM_web_rev_12_14_04.pdf

According to page 5 and page 8, If you did this wrong, then you fried the amp. Quick Question...... Did you change the channel select switch on the amp? It should have one that says 3, 4, 5, 6 channel mode. You would want 3 channel mode. and also, The $ you spent buying that 4channel RCA was not necessary. Most amps can run only one set of RCAs. Like my soundstream 4 channel. I can use all for channels with only L R in, not rear in. Try checking the amps output mode...

 

[954runner 10+ year member]

I'm drunk so i'll try to explain my best

I found out the problem tonight.

I turned on the radio tonight and it was playing fine. I played a cd and it was fine but when i played my ipod it wasnt.

So, it turns out its my cable that connect my ipod to my headunit.

I'm gonna hae to go back tnad fix that tomorrow r something woo!

 

[Mass Car Audio 10+ year member]

http://manuals.harman.com/JBL/CAR/Owner%27s%20Manual/GTOAmpIIOM_web_rev_12_14_04.pdf
According to page 5 and page 8, If you did this wrong, then you fried the amp. Quick Question...... Did you change the channel select switch on the amp? It should have one that says 3, 4, 5, 6 channel mode. You would want 3 channel mode. and also, The $ you spent buying that 4channel RCA was not necessary. Most amps can run only one set of RCAs. Like my soundstream 4 channel. I can use all for channels with only L R in, not rear in. Try checking the amps output mode...

Then whats the point of having the rear inputs....lol