Sound System Issue

[Jaybird]

I have had the following issue now for a few years. It began with my subs either not producing any sound or fading in and out. It would be as if I would turn the sub volume down then up and they would periodically not produce any sound at all. More recently my speakers have now stopped producing sound then come back on. I have changed my sub amp out a few times and still the subs would act as mentioned. I am guessing that it maybe one of two things (I could be way off on this as I am no audio pro):
First I have read that Pioneer head units have been known to have the pre-outs to fail. If this is the case would my sound fade in and out as opposed to just not work at all?
Second, probably the oldest link in the audio system, the cap (about 10 yrs old), is bad. My powerline runs from the battery to the cap then splits between the sub amp and the surround speakers amp. If she does not hold a good charge is it likely my amps are cutting/fading in and out due to lack of power?

[SeRiousZX2]

Sounds like a poor signal to me. Try running a cheap set of RCAs from the headunit to the amp. No need to run them under the carpet. Just slide the headunit out, plug them in, run them over the seats to the amp. If it resolves the issue, its the RCA. If the problem remains, since you replaced the amp, is could be the headunit.

I doubt it is the cap or the other speakers would be doing the same thing since both amps are ran off it. Remember caps only hold a charge for about 10 seconds. After that they don't store or recharge until the car is turned off.

[chasingsafety]

I had a pioneer head unit with the poor ground issue. All i got was alot of ignition interference. I split the ground in the rcas (spliced) and grounded it on the deck chassis

[Jaybird]

Thanks guys. Serious, I did forget to mention that I replaced the RCA's as well and there was no difference with the problem. I guess i am back to it being the HU as I had originally though.

[CJW]

JAYBIRD! Howdy!

Sounds like a poor signal to me. Try running a cheap set of RCAs from the headunit to the amp. No need to run them under the carpet. Just slide the headunit out, plug them in, run them over the seats to the amp. If it resolves the issue, its the RCA. If the problem remains, since you replaced the amp, is could be the headunit.

I doubt it is the cap or the other speakers would be doing the same thing since both amps are ran off it. Remember caps only hold a charge for about 10 seconds. After that they don't store or recharge until the car is turned off.

Agreed.

If the output from the headunit itself went bad you can check the other outputs. Chances are only 1 set went bad if they did. Testing like serious said with just a cheap set of RCAs. Can be caused by either the output from the HU being too low or being bad, can be caused by the RCAs being very old and the casing wearing away or deteriorating and the signal being bled off as well. On occasion amp signal inputs go bad as well. So if nothing fixes it, the RCA input on the amp wiring to the board may have oxidized and may not be getting the full signal either. This would have been a progressively worse problem if due to oxidation. And you would have been able to overcome it for a short time with the input level adjustments.

I generally never recommend a cap but in the audio world you get just as many who use them as hate them. If you can't hold voltage, I recommend a bigger alt and bigger battery.

Sidenote: I like to use shielded RCAs in all installs. This was very important with my eclipse hu because it was running ~8v outputs vs my pioneer premier unit which was running ~4v. The standard pioneer units were running ~2v at the time. Higher voltage is higher risk of interference. I also like to make my own RCAs to fit, but that's a whole other story. When grounding, only ground one end or else the shield was pointless. And while it doesn't matter, I always ground the end at the source. So at the headunit I ground the RCA to the body, but in theory it should work fine grounding it at the amp.

[SeRiousZX2]

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