Hi,
All,
I am getting a white noise "Shhh" when the system is on, I am also getting a buzz when the car engine is on, the volume on the HU and the preamp does not affect the noise.
I tried moving the low RCA output away from the power cable.
Thanks
Regards
Replies (17)
cplkittle on 08/31/2006 16:51:09
please list all of your equiptment and how you have it connected.
b_bass59 on 08/31/2006 20:05:16
My Setup
Pioneer HU 480mp, Power Acoustic Preamp, Boss ch800,
The front rca connection is connected to the preamp then to the amp.
The sub out from the HU to the amp, I get no noise through the sub.
and both sub and front rca cable run together.
I think the preamp is the problem.
Is there any device to connect to take the noise out.
thanks
emoboywyl on 08/31/2006 21:53:06
I have two suggestions here that might help. I'm sure there are more, but these are my 2 cents.
1. Rerun your power wire down the center of your vehicle away from all other wires, the current running though that wire can cause noise.
2. There's a device called a ground loop isolator that can sometimes help.
3. Try regrounding everything, or at least checking the grounds on your HU and Amp to make sure they're good grounds. If your HU is grounding to the factory harness try regrounding it to the frame. (Nice bare metal)
emoboywyl on 08/31/2006 21:53:26
Ok, so that was three... it was a long day.
=)
b_bass59 on 08/31/2006 22:26:21
Can I run the low level RCA cables with the speaker outputs from the amp.
thanks
ttocs on 09/1/2006 00:49:47
"Can I run the low level RCA cables with the speaker outputs from the amp."
I don't understand? In general you always want to seperate power and signal cables. Try disconnecting the rca's from the back of the radio, then turn the radio on and see if you still have noise. Try wetting your thumb and connecting the tip and shield and see if it gets louder. Are the sub and rca the same type of cable? You could have a bad rca, switch the two rca's at the deck and see if the noise moves....
swez on 09/1/2006 09:46:02
I have the same read as you do... that PA preamp may be the culprit here. This is one more link in the audio chain that needs to be well grounded and if it has any gain controls, these have to be used sparingly.
What is the model number of this PA preamp?
Can you remove (bypass) the PA preamp from the RCA signal circuit and see if your "hiss" goes away? If yes, that device is the problem. If you intend to use it later, we'll need a model number and details on it to help determine the best way to use it w/ minimal noise issues.
Your P480MP has 3 pairs of RCA outs and these are 4.0 volts each. That's plenty to drive most any amplifiers to full potential.
Say more about this preamp please,
Swez
b_bass59 on 09/1/2006 21:31:12
Sorry the problem is not the Preamp, its the HU. I disconnected the preamp and the noise got worst. now i even hear the cd motor through the speakers.
thanks
swez on 09/2/2006 11:08:51
OK, it seems to be isolated to the HU now. Or, amp gains are a tad too high.
Your amp gains should be set to about 4.0 volts. That matches the HU RCA outs for F/R & sub outs. The LPF on your sub amp probably filters out this range of noise and is not present in your subs... yes? (Noise only noted in Mid/highs?)
The other thing that is very common here, is improper grounding of the HU. Aftermarket HU's need to be grounded to bare metal like a floor board section, under the dash... NOT the harness ground. If the HU is not grounded well, it will seek grounding via the antenna jack or RCA's. Neither are good grounds and lead to noise problems. Is this a newer HU? It seems not as the numbers indicate an older Pioneer Premier version. Depending on who wired it up and how they did so, the internal amps can be turned off via menus in the setup to allow the RCA's only, to power outboard amps. This is preferred if the HU amps are not needed to power other speakers.
As ttocs mentioned, the main power feed should be separated from RCA's by at least 18 inches or more. Have done several installs with speaker and RCA wires bundled together and NO NOISE problems noted at all.
Comments?
Swez
emoboywyl on 09/2/2006 22:33:00
Just one...
=)
And we come back to my original suggestions =)
The buzz sounds like alternator whine, which can be solved by checking the grounds on everything and making sure they're good grounds and seperating the power, speaker, and RCA's. When I installed my amps, I ran 2 4g wires, plus 10g wire for the fans and neon down the center of my car (which nessesitated removing the passenger front and rear seats, but is easy to do in my car) the RCA's down the left side, speaker wire down the right. I also used platinum grounding blocks to bare shiny metal. =)
Victor on 09/3/2006 04:21:40
If its a pioneed HU, try gounding the RCA's and the HU frame to bare metal on the car.. shud be solved...
emoboywyl on 09/3/2006 05:03:51
That's a good habit anyway, especially on foreign cars it seems.
swez on 09/3/2006 08:20:21
Th "hiss" is often associated with a few main issues:
1. A damaged Source (HU filtering has gon kaput)
2. The amp gain is/are set so sensitively, that it amplifies signals and any noise we get from the audio chain (Try adjusting amp gains to see if you can knock out the "hiss")
3. Cheap preamps in the amp are not doing a good job at filtering out this hiss. (poor quality preamp circuits in the early amping stages can caused this too)
Boss is not a high quality amplifier to begin with. Yes, it may play loud, but it might be too noisy too.
?'s for you:
1. What are the amp gain settings used on your Boss amp now? (Midpoint is a good place to start, and adjust to quieter setting if needed to knock out hiss)
2. What is the series amd model # of your Boss amp? (Chaos C800?)
This amp is roughly rated at 100 RMS x 4 @ 4 ohms per channel. That's pretty strong, but if the amp is noisey at rated power, what's the point... it's a low budget amp.
Consider trying another amp in place of this one and see if your hiss goes away. If yes, the amp may indeed be the problem.
Swez
b_bass59 on 09/3/2006 11:20:34
I just have the boss CH800 amp for now until I get my Earthquake PH2200, the amp is not the problem I connected the amp directly to my laptop, got no noise and also it sounds a lot louder than the HU.
Thanks I'll try that
Later
ttocs on 09/3/2006 13:56:47
try a different rca from the deck to the amp. It does not have to be buried under the carpet, just temporarily ran to see if you have a bad rca.
swez on 09/3/2006 17:27:17
OK, since you tried your laptop as a source and there was no hiss, we can pretty much rule out the amp as the problem. It is only amplifing what it receives at the inputs.
The only 2 options remaining, are the HU and RCA's. You can figure out which one is the root cause by unplugging your RCA's at the HU and use you laptop as the source with these RCA's. If that is normal and strong, the only option left, is the HU.
I take it your noise sounds like a high pitch "Hissing" sound that is primarily heard from your tweeters and maybe a little form the mids?
Are all 4 channels of the mid/highs giving you this hiss, or can it be isolated to 1 or 2 channels? (eg: FR, FL, RR, LR) Do your RCA's have that little tag wire (#18-20 gage) line in the bundle? If yes, try grounding that tag wire to the HU chassis and the other end to your Boss amp. This grounds the amp and HU together and if this is a ground loop noise, it should go away.
This is one of those snigglet type issues that can drive a practiced diagnostics guy buggy. It's pretty much a process of elimination thing and right now, there are only 2 points left to test. The RCA's out of the HU, (Not likely) and the HU itself. (Highly probable)
I believe this is an older Premier HU right? Did you have it working fine before this level of install? It may have sounded OK off the HU amps and such, but if this is an older HU, it may have some internal filtering circuits that are not doing the job when amped. In short, you may need to have it serviced or consider replacement of same if it turns out to be the source of this noise.
Good luck,
Swez
b_bass59 on 09/3/2006 21:40:01
Thanks alot but I think its the HU. I'll try this out.
Thanks
All,
I am getting a white noise "Shhh" when the system is on, I am also getting a buzz when the car engine is on, the volume on the HU and the preamp does not affect the noise.
I tried moving the low RCA output away from the power cable.
Thanks
Regards
Replies (17)
cplkittle on 08/31/2006 16:51:09
please list all of your equiptment and how you have it connected.
b_bass59 on 08/31/2006 20:05:16
My Setup
Pioneer HU 480mp, Power Acoustic Preamp, Boss ch800,
The front rca connection is connected to the preamp then to the amp.
The sub out from the HU to the amp, I get no noise through the sub.
and both sub and front rca cable run together.
I think the preamp is the problem.
Is there any device to connect to take the noise out.
thanks
emoboywyl on 08/31/2006 21:53:06
I have two suggestions here that might help. I'm sure there are more, but these are my 2 cents.
1. Rerun your power wire down the center of your vehicle away from all other wires, the current running though that wire can cause noise.
2. There's a device called a ground loop isolator that can sometimes help.
3. Try regrounding everything, or at least checking the grounds on your HU and Amp to make sure they're good grounds. If your HU is grounding to the factory harness try regrounding it to the frame. (Nice bare metal)
emoboywyl on 08/31/2006 21:53:26
Ok, so that was three... it was a long day.
=)
b_bass59 on 08/31/2006 22:26:21
Can I run the low level RCA cables with the speaker outputs from the amp.
thanks
ttocs on 09/1/2006 00:49:47
"Can I run the low level RCA cables with the speaker outputs from the amp."
I don't understand? In general you always want to seperate power and signal cables. Try disconnecting the rca's from the back of the radio, then turn the radio on and see if you still have noise. Try wetting your thumb and connecting the tip and shield and see if it gets louder. Are the sub and rca the same type of cable? You could have a bad rca, switch the two rca's at the deck and see if the noise moves....
swez on 09/1/2006 09:46:02
I have the same read as you do... that PA preamp may be the culprit here. This is one more link in the audio chain that needs to be well grounded and if it has any gain controls, these have to be used sparingly.
What is the model number of this PA preamp?
Can you remove (bypass) the PA preamp from the RCA signal circuit and see if your "hiss" goes away? If yes, that device is the problem. If you intend to use it later, we'll need a model number and details on it to help determine the best way to use it w/ minimal noise issues.
Your P480MP has 3 pairs of RCA outs and these are 4.0 volts each. That's plenty to drive most any amplifiers to full potential.
Say more about this preamp please,
Swez
b_bass59 on 09/1/2006 21:31:12
Sorry the problem is not the Preamp, its the HU. I disconnected the preamp and the noise got worst. now i even hear the cd motor through the speakers.
thanks
swez on 09/2/2006 11:08:51
OK, it seems to be isolated to the HU now. Or, amp gains are a tad too high.
Your amp gains should be set to about 4.0 volts. That matches the HU RCA outs for F/R & sub outs. The LPF on your sub amp probably filters out this range of noise and is not present in your subs... yes? (Noise only noted in Mid/highs?)
The other thing that is very common here, is improper grounding of the HU. Aftermarket HU's need to be grounded to bare metal like a floor board section, under the dash... NOT the harness ground. If the HU is not grounded well, it will seek grounding via the antenna jack or RCA's. Neither are good grounds and lead to noise problems. Is this a newer HU? It seems not as the numbers indicate an older Pioneer Premier version. Depending on who wired it up and how they did so, the internal amps can be turned off via menus in the setup to allow the RCA's only, to power outboard amps. This is preferred if the HU amps are not needed to power other speakers.
As ttocs mentioned, the main power feed should be separated from RCA's by at least 18 inches or more. Have done several installs with speaker and RCA wires bundled together and NO NOISE problems noted at all.
Comments?
Swez
emoboywyl on 09/2/2006 22:33:00
Just one...
=)
And we come back to my original suggestions =)
The buzz sounds like alternator whine, which can be solved by checking the grounds on everything and making sure they're good grounds and seperating the power, speaker, and RCA's. When I installed my amps, I ran 2 4g wires, plus 10g wire for the fans and neon down the center of my car (which nessesitated removing the passenger front and rear seats, but is easy to do in my car) the RCA's down the left side, speaker wire down the right. I also used platinum grounding blocks to bare shiny metal. =)
Victor on 09/3/2006 04:21:40
If its a pioneed HU, try gounding the RCA's and the HU frame to bare metal on the car.. shud be solved...
emoboywyl on 09/3/2006 05:03:51
That's a good habit anyway, especially on foreign cars it seems.
swez on 09/3/2006 08:20:21
Th "hiss" is often associated with a few main issues:
1. A damaged Source (HU filtering has gon kaput)
2. The amp gain is/are set so sensitively, that it amplifies signals and any noise we get from the audio chain (Try adjusting amp gains to see if you can knock out the "hiss")
3. Cheap preamps in the amp are not doing a good job at filtering out this hiss. (poor quality preamp circuits in the early amping stages can caused this too)
Boss is not a high quality amplifier to begin with. Yes, it may play loud, but it might be too noisy too.
?'s for you:
1. What are the amp gain settings used on your Boss amp now? (Midpoint is a good place to start, and adjust to quieter setting if needed to knock out hiss)
2. What is the series amd model # of your Boss amp? (Chaos C800?)
This amp is roughly rated at 100 RMS x 4 @ 4 ohms per channel. That's pretty strong, but if the amp is noisey at rated power, what's the point... it's a low budget amp.
Consider trying another amp in place of this one and see if your hiss goes away. If yes, the amp may indeed be the problem.
Swez
b_bass59 on 09/3/2006 11:20:34
I just have the boss CH800 amp for now until I get my Earthquake PH2200, the amp is not the problem I connected the amp directly to my laptop, got no noise and also it sounds a lot louder than the HU.
Thanks I'll try that
Later
ttocs on 09/3/2006 13:56:47
try a different rca from the deck to the amp. It does not have to be buried under the carpet, just temporarily ran to see if you have a bad rca.
swez on 09/3/2006 17:27:17
OK, since you tried your laptop as a source and there was no hiss, we can pretty much rule out the amp as the problem. It is only amplifing what it receives at the inputs.
The only 2 options remaining, are the HU and RCA's. You can figure out which one is the root cause by unplugging your RCA's at the HU and use you laptop as the source with these RCA's. If that is normal and strong, the only option left, is the HU.
I take it your noise sounds like a high pitch "Hissing" sound that is primarily heard from your tweeters and maybe a little form the mids?
Are all 4 channels of the mid/highs giving you this hiss, or can it be isolated to 1 or 2 channels? (eg: FR, FL, RR, LR) Do your RCA's have that little tag wire (#18-20 gage) line in the bundle? If yes, try grounding that tag wire to the HU chassis and the other end to your Boss amp. This grounds the amp and HU together and if this is a ground loop noise, it should go away.
This is one of those snigglet type issues that can drive a practiced diagnostics guy buggy. It's pretty much a process of elimination thing and right now, there are only 2 points left to test. The RCA's out of the HU, (Not likely) and the HU itself. (Highly probable)
I believe this is an older Premier HU right? Did you have it working fine before this level of install? It may have sounded OK off the HU amps and such, but if this is an older HU, it may have some internal filtering circuits that are not doing the job when amped. In short, you may need to have it serviced or consider replacement of same if it turns out to be the source of this noise.
Good luck,
Swez
b_bass59 on 09/3/2006 21:40:01
Thanks alot but I think its the HU. I'll try this out.
Thanks
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