At wits end, tried (almost) everything fixing bad crackle and pop when engine running

[Quinn000]

I don't know if I have the brain power to correctly describe my problem, but I'm hoping this forum will be nice enough to guide a car audio newbie.

I've spent the past 5 days rewiring and trying every known possible fix to this problem (which I don't even know what to call)

My speaker system:

Kenwood kdc x997

SSL 50rms x 4 amp

Pioneer speakers

****** speaker cable

It all sounds great until the engine turns on. I get:

Bad alternator whine (gets progressively worse the longer the engine is on WEIRD)

Hiss and crackle with the occasional pop

THE WORST: sound randomly cuts in and out, this gets progressively worse and more frequent the louder the speakers are playing.

Again, no problem with the engine off.

Things I've tried to fix:

Checked ground for amp and HU, regrounded with progressively thicker wire, directly to sanded thick bare metal.

Checked power, run directly from battery with fuse opposite side of RCA lines

Changed rca cables 4 seperate times, amp still crackles when disconnected from HU

Used RCA to AUX directly from phone to Amp. Same crackle pop cuts

used homemade Ground loop isolator, no change

Used storebought passive inline power filter, no change

Run high level outputs to high level inputs on amp, removed RCA wiring ( I actually flipped my lid when this didn't work) no change.

FINAL STRAW:

Ungrounded amp and HU, used seperate battery to power both while engine running (guaranteed ungrounded from rest of elec. system) exact same problem

I am fairly comfortable with electrical systems, but this problem makes no f****ng sense to me at all!

All of this is in a beat up 1976 Chevy Nova, I just installed a brand new engine and checked all of the electrical. Spark wires are fully connected, but the distributor shocks you if you touch it. I haven't figured out that problem, and it may just be the solution, but I was looking for some advice. WHAT THE HELL IS GOING ON!?!?

I am a broke college student who has no time or money to take this to a shop, I'd be happy to provide any additional information. All wire is of correct gauge according to that one online wire chart with the colors.

Click to read more...

 

[juanmgarza26 10+ year member]

Check all grounds. Make sure your alt and battery have good solid drounds to chassis. Also amp as well. Make sure its on bare metal. Sanded and paint free.

 

[Jeffdachef 5,000+ posts]

Since you did the phone to aux to RCA amp test, it could just be the amp having a low signal to noise ratio or just something messed up inside it. It is one of the bottom tier brand of amps known for being unreliable. Also where is the amp mounted, amps mounted on metal surfaces in the car will run into signal problems due to grounding.

 

[Quinn000]

Since you did the phone to aux to RCA amp test, it could just be the amp having a low signal to noise ratio or just something messed up inside it. It is one of the bottom tier brand of amps known for being unreliable. Also where is the amp mounted, amps mounted on metal surfaces in the car will run into signal problems due to grounding.

Alt, Batt, Amp all grounded tight and solid. The amp is sitting on a rubber spacer.

I would love you to tell me it's my amp, I regret spending so little on it, but I truly am scraping by.

I just tried powering the amp through the windshield wiper plug, and I got the same result, but noticed that the amp actually amplifies and plays the motor noise out through the speakers. To me this make no sense at all, no aux cables or rca lines are plugged in, the amp is actually accepting a signal on the POWER line... WTF?!

 

[CSCStang]

Alt, Batt, Amp all grounded tight and solid. The amp is sitting on a rubber spacer.I would love you to tell me it's my amp, I regret spending so little on it, but I truly am scraping by.

I just tried powering the amp through the windshield wiper plug, and I got the same result, but noticed that the amp actually amplifies and plays the motor noise out through the speakers. To me this make no sense at all, no aux cables or rca lines are plugged in, the amp is actually accepting a signal on the POWER line... WTF?!

Got a buddy with another amp you can swap out for testing? If so, try that.

 

[Quinn000]

I don't have access to another amp, but if someone can recommend a sub $100 50rms x 4 amp. $100 is LITERALLY all I can spend as I'm dealing with some serious credit card debt already. If this is truly my last option then I'm going to swap amps. It just makes no sense to me that it works fine with the engine off, I'm scared that I swap amps, pay $100, and nothing changes

Edit: I should also add that the sound system functioned normally before I added the amp, originally all speakers were wired directly to HU speaker-outs. It's definitely the amp, but I want to know WHY before I throw it out

 

[Jeffdachef 5,000+ posts]

I don't have access to another amp, but if someone can recommend a sub $100 50rms x 4 amp. $100 is LITERALLY all I can spend as I'm dealing with some serious credit card debt already. If this is truly my last option then I'm going to swap amps. It just makes no sense to me that it works fine with the engine off, I'm scared that I swap amps, pay $100, and nothing changes
Edit: I should also add that the sound system functioned normally before I added the amp, originally all speakers were wired directly to HU speaker-outs. It's definitely the amp, but I want to know WHY before I throw it out

http://www.caraudio.com/forums/wiring-electrical-installation-help/548878-noise-troubleshooting-guide-eliminate-your-alternator-whine.html -More stuff to check in that thread. Do all of these before moving on to my next bit of advice lol.

Its called alternator whine of course it works fine without the car off, you cant get any noises without the alternator spinning. The car is a noisy environment and when amps cheap out in internal parts, in your case its probably the rcas, either they made bad shielding on it or something is loose.

If worst comes to worst, here are some amp choices, lots of people on the forum have dealt with the black ice lines of amps from PPI and its probably the best bang for buck out there.

Precision Power PPI BK520 4 BK5204 4 CH Class A B Black Ice Car Amplifier Amp | eBay 10 dollars above your budget but well worth it. Very proven amp.

Precision Power PPI i520 4 I5204 520W 4 CH ion Series Class D Amplifier Amp | eBay another choice, a lot smaller in size.

Full clamp test for actual output power on the 520 ION by a famous and trusted spl competitor on this thread. My test: Precision Power iON 520.4

If your 100$ budget is still too constraining and you have to keep it under, you should try buying used, You are protected by paypal and can file a claim against scammers and get your money back if things go sour with the equipment so no worries on that front. I've personally used the ion 520 and its great, I still have it in perfect working condition but i'm missing two speaker terminal screws. I can hunt them down at home depot for you. I'll let it go for 80$ shipped. You can check the classifieds for other deals also. Its much better then pouring your hard earned/saved money on door stoppers like boss, pyle, power acoustik, lanzar, pyramid, ssl, spl, performance tecknique, autotek etc.. all end up to be useless bricks in the long run.

Just do your research and completely narrow everything down first before you pull the trigger on any amp.

 

[Jes 42 10+ year member]

I don't have access to another amp, but if someone can recommend a sub $100 50rms x 4 amp. $100 is LITERALLY all I can spend as I'm dealing with some serious credit card debt already. If this is truly my last option then I'm going to swap amps. It just makes no sense to me that it works fine with the engine off, I'm scared that I swap amps, pay $100, and nothing changes
Edit: I should also add that the sound system functioned normally before I added the amp, originally all speakers were wired directly to HU speaker-outs. It's definitely the amp, but I want to know WHY before I throw it out

Ground the rca outputs on the Kenwood.

 

[Quinn000]

Bought a new Kenwood amp at BestBuy just to test. So far everything works, but it's not wired in 100%

If this was a lesson to anyone other than me, don't cut corners buying cheap parts