[ghump]

I installed Sony Xplods front and rear 4 months ago and decided to get an Amp, Pyle 4ch, 400 w marine amp. I had read from many who have installed amps, that this is an excellent choice. I did the install last week and have been experiencing distortion with FM radio, CD (aftermarket, which is FM modulated thru the radio) and MP3 thru the aux. I went back in and checked all the wiring, checked for polarity and checked the ground connection. The speaker wires and power wire are well separated. No luck, still experiencing distortion. The gain is set at about 2/3 max and there is not any sunstantial hiss with the volume all the way down. I have set the gain lower with no luck. Above a setting of 20 the distortion is pretty bad.

I disconnected the inputs and plugged the MP3 via the RCA's directly to the AMP. Absolutely fabulous. I think that would let me eliminate an error on the output side. Anyway, I am looking for suggestions to troubleshoot the problem. I know that with an amp, if you put garbage in, you get garbage out. The audio was not great before, but much better than it is now.

I think I remember reading somewhere that you can run a ground to each negative speaker input and that could improve the situation. Any thoughts would be appreciated!!:shrug:

 

[ghump]

bump!

 

[dchristo]

are you going speaker wire from radio to rca on amp ?

 

[ghump]

are you going speaker wire from radio to rca on amp ?

No. I ran my MP3 directly to the Amp with the other inputs disconnected. I did that to test the operation of the Amp without the radio. With the MP3 hooked directly to the Amp, it sounded fabulous with the gain turned all the way up.

 

[LarryM]

If you have the gain on the input of the amp turned up 2/3, you may be overdriving the input. It is a common mistake.

Is the amp you bought is a PLMRA400?

 

[dchristo]

it sounds like hes going from hi level output from radio to low level input on amp

 

[pedro66]

As already stated it sounds like your driving speaker level into a line level input if so you need to convert to line level prior to the AMP using something like this

 

[LarryM]

Pyle amps already have line and speaker level inputs. There is no need for a converter.

If he had used the line level inputs, the distortion would be severe at nearly every volume level, and probably would have blown the inputs by the time he hit 20.

 

[ghump]

If you have the gain on the input of the amp turned up 2/3, you may be overdriving the input. It is a common mistake.

Is the amp you bought is a PLMRA400?

Yes.

Thanks for the input. I connected my MP3 directly to the RCA inputs of the AMP. I did this simply to see if I got any distortion by running directly to the AMP, bypassing the GL1800 audio unit, so I am not mixing low/high inputs. I never ran with both high and low inputs connected. Even when I turned down the gain to about 1/3 and even all the way down, when I turned the volume up there is more distortion than without the AMP. When I run the MP3 directly via the RCA inputs, the system, even with maximum gain souds fabulous. When I connect via the speaker wires, whether using the radio, MP3 (via Aux) or CD I get bad distortion. I looking for suggestions as to possible troubleshooting. Bad audio system or antenna ground??

 

[LarryM]

What you could be experiencing is the distortion that is the whole reason for the upgrade that I do. (of course it depends on how bad the distortion is.) If you take distorted audio and put it into an amp, you will get distorted audio out of the amp.

If you have the amp that I mentioned earlier, it does not put out 100 watts per channel. It is more like 20w/ch. Pyle's specs are grossly inflated.

You may actually have a problem with the Pyle amp. But whatever you do, do NOT ground the negative input. That input comes from the radio's power amp outputs, which are bridged outputs. Both positive and negative lines are driven by amplifiers. (8 power amps total.) None of those wires ground. I guarantee you that you will blow up the radio the first time you turn up the volume.