Amp getting very bad "noise" with engine on

[llmercll 10+ year member]

Hi everyone, I just finished installing my new system, but I hear a terrible click like sound from my rear speakers + sub when the engine is on.

With the engine off I still get some slight distortion (especially when in cd mode), but it's not much.

If I unplug the rca cables from the amp and hook up dummy's, I don't get any noise at all. My front speakers are hooked up directly to the head and don't get any noise either.

This is my amp, it's new

Amazon.com: Sound Storm Laboratories F4.400 400-Watt 4-Channel Power Amplifier with High/Low Crossover: Car Electronics

Is this likely the culprit?

thanks!

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[bgowdy 5,000+ posts]

check you grounds. may be loose somewere

 

[DonH 5,000+ posts]

check you grounds. may be loose somewere

really? yeah no, that would not cause an engine whine.

Did you unplug the RCA's with everything on? HU and amplifier? What HU are you using?

 

[bgowdy 5,000+ posts]

oooohhhh but it can cause feedback through your speakers when they are not playing. been there and done it

 

[llmercll 10+ year member]

I turned everything off then unplugged the rcas from the amp. then turned everything back on.

My head unit is an older Pioneer model DEHP4700

thanks!

also, my rca cables are running on an opposite side from the power

 

[quackhead 10+ year member]

Hi everyone, I just finished installing my new system, but I hear a terrible click like sound from my rear speakers + sub when the engine is on.
With the engine off I still get some slight distortion (especially when in cd mode), but it's not much.

If I unplug the rca cables from the amp and hook up dummy's, I don't get any noise at all. My front speakers are hooked up directly to the head and don't get any noise either.

This is my amp, it's new

Amazon.com: Sound Storm Laboratories F4.400 400-Watt 4-Channel Power Amplifier with High/Low Crossover: Car Electronics

Is this likely the culprit?

thanks!

I would not blame the amp completely due to the possibility of RF interferences entering the system through the RCA's being placed near a source such as power wires, or ignition wires, or air conditioning wires....basically any other wire carrying a decent amount of 12v current. The construction of the RCA's can be an issue as well. This is an amp exactly like yours with regards to the "stated" power ratings -

MSW | Car Audio Stereo, Car Subwoofers, Car Amplifiers and Speakers

But the "statement" of power output is the only resemblance between the two. There is a lot more involved in the cost than just a name. I am not saying you should have bought this amp because there are many, many others to choose from in between this one and yours. You will not find a decent new 4 channel power amp for less than about $125 to $150 that will provide you with quality sound, power and reliability...and this is just where decent quality engineering starts to come into play...there are some 4 x 50 watt amps that cost over $1,000.00...I am simply making the point that your equipment choice could be the culprit more than anything else.

 

[DonH 5,000+ posts]

Since you have a pioneer, its probably that. Ive had my fair share of problems with my pioneer... try the grounding of the RCA's just use the search function to find the how to on here. try it and report back with news of success or ongoing failure.

 

[akheathen Premium Member]

well, i'm assuming that you do not have another amp to check with. i 2nd checking the grounds. that is pretty much the definition of ground loop symptoms. if the amp tries to search power through the rca's, it will create that signal in the rcas and play. another bad reaction, is that any real power run through the rca shield can and eventually will cause damage somewhere, either in the preamp section, or noise cancelling jumper, or in the head unit. many pioneer head units are notorious for protecting the head with a "pico fuse" some amps have them, too. makes things easier/cheaper to repair for a tech, but not for the end user, without rigging something up. you may have to slide your head unit out and check there. unplug the rcas at the head, and it should go away. next step is to install a jumper from the shield to the head unit body. if noise persists with the rca shield grounded to the head body, plugged in to the head, or not, you still have a grounding issue, imo...

 

[cagep88 10+ year member]

Check and make shure the rcas are in the right spot on the headunit. Sub in /component in . Sub out/ component out, because if u have an older headunit they usualy made them with cheaper sub outputs which would make your mids make a clicking noise and your sub to buzz

 

[llmercll 10+ year member]

Ok I unplugged the rcas at the head unit and left them in the amp, no noise there either so I don't think it's my rca cable run. It must be something with the head unit or ground.

I don't really know how to do this but am going to make a few searches and try it out

 

[llmercll 10+ year member]

Tried grounding the rcas, no luck =(

 

[SplAffair 10+ year member]

its most likely the amp......

 

[llmercll 10+ year member]

I ran a 4 gauge cable from my amp ground point to the negative terminal on the battery and it's giving me 1.1ohm. That's high right, could it be the culprit?

I have it grounded to the metal of my trunk. I drilled a hole, sanded the area, and put a screw in. I thought I did everything right =/

 

[daboyfrumdabx 10+ year member]

I ran a 4 gauge cable from my amp ground point to the negative terminal on the battery and it's giving me 1.1ohm. That's high right, could it be the culprit?
I have it grounded to the metal of my trunk. I drilled a hole, sanded the area, and put a screw in. I thought I did everything right =/

Yeh, that does seem very high. However, depending on the DMM you're using, it may not be anywhere near that high. Did you just take the readout on the screen or did you measure the impedance of the DMM leads themselves first, then subtract that from the screen. I was using a friends DMM the other day that read .5ohms by itself.

 

[llmercll 10+ year member]

The internal resistance of the DMM is .2, so with that it brings it down to .9