Car audio expert help needed

[scottminot]

I installed a Pioneer AVH-P4300DVD head unit in my F150 last year with a brake bypass. I also upgraded the front door speakers at the time. I had an annoying hiss/static noise that would get louder as the volume was increased.


Fast forward to this weekend. I installed a Kenwood KAC-7005PS five channel amp, MB Quart 12" sub, and new rear door speakers.

The annoying hiss/static is still there. I've tried grounding the head unit in other locations and removed the brake bypass thinking that might be the culprit but still no luck, the noise is still there.

I'm stumped. I've installed systems in just about every vehicle I've owned and never had this issue before. I think I may have a bad head unit.

Any input would be appreciated.

 

[Woody6799]

try grounding the head unit directly to the battery.... cant get a better ground. If that doesn't work I would lean to the bad head unit as well.

Just making sure you are running your door speakers off the head unit and not a speaker amp correct? Eliminates the RCA noise interference...

 

[scottminot]

All speakers are now powered by my five channel amp. The noise was there when the speakers were powered by the head unit before I installed the amp.

 

[svtcop]

You say the noise increases with sound, but does in increase with vehicle/engine speed?

Is the sound there when the engine is shut off?

It's really difficult to diagnose car audio via internet.

If it bothers you that much take it to a professional.

 

[Five-ohh-Love]

Maybe your speaker wires are interfering with something :shrug: And also when do you get this interference noise? Like when radio is on, when a cd is playing, when maybe an ipod is connected, or just all the time?

 

[Monster Mach]

Make sure your rcas are run on the opposite side of the vehicle as the power wire.. make sure its not pinched or the rcas arnt grounded out... make sure all grounds are touching bare metal and that your ground wire is bigger than power wire...

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[scottminot]

You say the noise increases with sound, but does in increase with vehicle/engine speed?

Is the sound there when the engine is shut off?

It's really difficult to diagnose car audio via internet.

If it bothers you that much take it to a professional.

The noise exists when the vehicle is and isn't running and it's there no matter what music source I use.

 

[scottminot]

Make sure your rcas are run on the opposite side of the vehicle as the power wire.. make sure its not pinched or the rcas arnt grounded out... make sure all grounds are touching bare metal and that your ground wire is bigger than power wire...

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I had the noise before my amp was installed too. So that rules out rca issues.

 

[mineralgrey01gt]

honestly sounds like a bad h/u to me. Like a bad ground internally in the h/u or something

 

[jrd699]

Wiggle ground/power/ect.. Have a bare spot on one of the wires, like when a plug wire is arching

 

[Monster Mach]

I had the noise before my amp was installed too. So that rules out rca issues.

Check the speaker wire also... sounds like you have a speaker wire pinched

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[SweetSVT99]

You have a bad head unit if it's happening with or without the vehicle running, and it increases with volume rather than engine RPM.

 

[scottminot]

Check the speaker wire also... sounds like you have a speaker wire pinched

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Speaker wires are fine. I was running the factory speakers until this weekend. I ran all new wires to the doors.
It's gotta be the head unit. Did some searching around online and found others who had the same issue with Pioneer units and they couldn't figure it out.

 

[Planter]

2 bad head unit's in a row though? sounds like something else.

try a ground loop isolator, or try getting some 80 grit sandpaper, scuff up the spot where you ground to real good and remove all the paint, make sure the surface is nice and shiny, bolt the ground down with a metal screw or bolt and nut and see if that resolves.

if not, take it to a car audio place and have them check it out.

is the annoying hiss/static coming from 1 speaker? or is it coming from all 4 speakers?

have you tried adjusting the audio settings on the unit? make sure the "LOUD" is turned off, turned down the SLA (volume gain) if it's equipped, it's actually like the "LOUD" feature.

does it do it on radio, disc, satellite, mp3? or just one of the sources? is your radio antenna connector plugged into the back of the head unit?

my intuition says it's the speakers, because I don't see two head units in a row being bad, makes no sense.

was the first unit (the Pioneer) new or used when you put it in? Was the Kenwood new or used when you put it in?

 

[scottminot]

2 bad head unit's in a row though? sounds like something else.

try a ground loop isolator, or try getting some 80 grit sandpaper, scuff up the spot where you ground to real good and remove all the paint, make sure the surface is nice and shiny, bolt the ground down with a metal screw or bolt and nut and see if that resolves.

if not, take it to a car audio place and have them check it out.

is the annoying hiss/static coming from 1 speaker? or is it coming from all 4 speakers?

have you tried adjusting the audio settings on the unit? make sure the "LOUD" is turned off, turned down the SLA (volume gain) if it's equipped, it's actually like the "LOUD" feature.

does it do it on radio, disc, satellite, mp3? or just one of the sources? is your radio antenna connector plugged into the back of the head unit?

my intuition says it's the speakers, because I don't see two head units in a row being bad, makes no sense.

was the first unit (the Pioneer) new or used when you put it in? Was the Kenwood new or used when you put it in?

I've only installed one head unit, put it in last year along with new front door speakers.
This weekend I installed new rear door speakers, sub, and amp. Everything is new. Had the noise after I installed the Pioneer head unit last year and it's still there now even though everything has been re-wired. The noise comes from all speakers and occurs no matter what the music source is.

 

[Monster Mach]

I've only installed one head unit, put it in last year along with new front door speakers.
This weekend I installed new rear door speakers, sub, and amp. Everything is new. Had the noise after I installed the Pioneer head unit last year and it's still there now even though everything has been re-wired. The noise comes from all speakers and occurs no matter what the music source is.

O sounded like you put two in... in that case sounds like a problem internally... I must have read wrong lol.. yea first place to check is always the headunit

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[Planter]

I've only installed one head unit, put it in last year along with new front door speakers.
This weekend I installed new rear door speakers, sub, and amp. Everything is new. Had the noise after I installed the Pioneer head unit last year and it's still there now even though everything has been re-wired. The noise comes from all speakers and occurs no matter what the music source is.

ok, nevermind, I see that was a Kenwood amp, not a h/u. yeah, definitely the head unit. my bad, read that initial post wrong.