New audio setup has a BUZZ

[Corsair714]

I am relatively new to car audio and was originally quite excited, however, it has been a nightmare trying to figure out why my cars new audio system has a buzz. I have good grounds as far as I know, and I am getting a buzz in my speakers that changes when I turn up the volume even when nothing is playing. The noise stays the same when the engine is running or off and does not change from idle to driving. I am trying to figure out if something is faulty somewhere or is noise being added some other way? I'd appreciate any advice on how to diagnose the problem. I have watched a lot of youtube and still can not figure it out.

Things I have tried:

• I have redone the grounds making sure both the amp and the head unit have solid connections as well as redoing the ground from the battery to the frame of the car.
• I used a phone to rca adapter to test if the noise is cause by the cables, head unit, or amp. I found that there was a very small amount of noise still present however it was much better and the cables did not appear to be adding noise to the system. It would seem that the head unit might be the main problem and the amp also has a little noise?
• I have made sure to run the power and RCAs down opposite sides of the vehicle.
• The amp is isolated from the vehicle however is it close to the speakers(not sure if that matters).
• I also had two other used faulty amps that had the same noise issue but they also had other issues that caused me to buy a new amp. This leads me to believe that the noise is starting before the amp(most likely the head unit, but will buying a new head unit even solve the problem?)

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[dragon.breath 10+ year member]

Engine whine and ground loop fixes... take two

Alrighty guys, since we no longer have access to the other ground loop fix thread, thanks to someone (you know who you are), I'm making a new thread about it. Ground loops and engine whine cause common problems such as a high-pitched whine that varies with engine RPM's, various thumps while...

www.caraudio.com

Take a look at this thread. The image of the rca cables with wire wrapping around them is one of my first fixes for a noisy head unit.

 

[Corsair714]

Engine whine and ground loop fixes... take two

Alrighty guys, since we no longer have access to the other ground loop fix thread, thanks to someone (you know who you are), I'm making a new thread about it. Ground loops and engine whine cause common problems such as a high-pitched whine that varies with engine RPM's, various thumps while...

www.caraudio.com

Take a look at this thread. The image of the rca cables with wire wrapping around them is one of my first fixes for a noisy head unit.

Ok thanks, I'll take a look into that.

 

[Corsair714]

I looked into and it seems this is generally a pioneer head unit problem. I have a Kenwood but I will still give it a go. Any specific way to ground the wires? Should I wrap the front and rear separately or all together?

 

[Corsair714]

Went ahead and gave it a try. No difference at all that I can tell.

 

[1aespinoza 10+ year member]

The noise stays the same when the engine is running or off and does not change from idle to driving.

This has to be a hardware issue.

I used a phone to rca adapter to test if the noise is cause by the cables, head unit, or amp. I found that there was a very small amount of noise still present however it was much better and the cables did not appear to be adding noise to the system. It would seem that the head unit might be the main problem and the amp also has a little nois

Good testing. I did not see it posted, but is the radio amplifying the speakers or is there an amp?

 

[Corsair714]

This has to be a hardware issue.

Good testing. I did not see it posted, but is the radio amplifying the speakers or is there an amp?

There is an amp. It is a Recoil RED1800.5. It is a five channel amp however I haven’t even hooked up a sub yet. Working on the other issues first. The amp can put out quite a bit more then what my speakers are rated for so my gains are set quite conservatively.

 

[1aespinoza 10+ year member]

so my gains are set quite conservatively.

Having high clean signal input from the source and conservative gain settings is a great way to reduce the chances of noise. The fact that the phone to RCA still produced a bit of noise is not ideal, but that radio swap may be the best option.
If you have not done so, I suggest a ground cable from the engine block to a strut tower bolt if you have struts.

 

[Corsair714]

Having high clean signal input from the source and conservative gain settings is a great way to reduce the chances of noise. The fact that the phone to RCA still produced a bit of noise is not ideal, but that radio swap may be the best option.
If you have not done so, I suggest a ground cable from the engine block to a strut tower bolt if you have struts.

I will look into grounding the engine block to the strut towers.

The head unit has 5v preamp outputs which as far as I know should be quite good. Not sure I could do much better than the setup that I have, unless I spend a ton of money that I don’t have. I just want to eliminate the possibility of any other issues before I spend money on a new head unit. It would be quite frustrating to purchase a new head unit and find that the problem still persists.

 

[1aespinoza 10+ year member]

It would be quite frustrating to purchase a new head unit and find that the problem still persists

I agree. With no music, do you still get the buzzing? If yes, with the system off, disconnect the RCAs from the amp then turn on the system. If no noise, then reconnect and disconnect at the radio. If no noise, then the sound is starting at the radio.
Only things to try at the radio would be an in-line noise isolator, chassis grounding, and grounding the exterior clips of the RCAs. You have probably tried all those without success.

 

[Corsair714]

I agree. With no music, do you still get the buzzing? If yes, with the system off, disconnect the RCAs from the amp then turn on the system. If no noise, then reconnect and disconnect at the radio. If no noise, then the sound is starting at the radio.
Only things to try at the radio would be an in-line noise isolator, chassis grounding, and grounding the exterior clips of the RCAs. You have probably tried all those without success.

The noise exists with no music playing and gets worse with higher volumes still with no music playing. It changes when I turn the volume knob on the head unit. I do get noise when the amp is not connected to anything, however I heard that is actually somewhat normal that noise would be added to the system from other interference around when nothing is plugged in? Should I expect it to be completely silent? I had tried this earlier and I had just disconnected them when the system was already on. Do I need to shut it off and turn it on in between each test?

I tried grounding the exterior clips of the rcas at the head unit and the car is well grounded I think. And I have heard that one should do everything possible to avoid an in-line isolator.

 

[1aespinoza 10+ year member]

Should I expect it to be completely silent?

Yes, especially when the gains are conservative and the vehicle is off. Although I have no experience with Recoil Audio.

Do I need to shut it off and turn it on in between each test?

No, this is just a precaution so the RCAs would not touch ground and mess up the radio's output. We can thank Pioneer for this extra precaution.

somewhat normal that noise would be added to the system from other interference around when nothing is plugged in?

When the key is on accessory, there is no need for other components to be on. So no interference from other sources should be possible.

And I have heard that one should do everything possible to avoid an in-line isolator.

TBH I have never had success with those.

 

[Corsair714]

No, this is just a precaution so the RCAs would not touch ground and mess up the radio's output. We can thank Pioneer for this extra precaution.

Ok thanks. I have a kenwood not a pioneer. My wording may not have been clear on that.

Regardless, I will try testing it without anything connected when I get home. Even if there is some noise I still wouldn’t be exactly sure what to think. Since it is better but still exists when the phone is directly connected it would seem maybe the amp is part of the problem but why is it so much worse with the head unit? I can try and get a return on the amp and get another but I would have to buy a new head unit.

 

[1aespinoza 10+ year member]

I can try and get a return on the amp and get another but I would have to buy a new head unit.

I would try to bench test the amp before anything else. I have seen cases where chafed speaker wire touching ground also causes noise.
You could probably disconnect all speakers at the amp and connect a test speaker to one channel to see if noise goes away.

 

[audiobaun 5,000+ posts]

I will look into grounding the engine block to the strut towers.

The head unit has 5v preamp outputs which as far as I know should be quite good. Not sure I could do much better than the setup that I have, unless I spend a ton of money that I don’t have. I just want to eliminate the possibility of any other issues before I spend money on a new head unit. It would be quite frustrating to purchase a new head unit and find that the problem still persists.

What Pioneer HU do you have? did you buy it used or BNEW? Did you have the HU in operation while hooking up the RCAs? and speaker wires? How old is the HU?