Slight hiss / static
08-10-2006, 10:05 AM
#1
Slight hiss / static
Hey guys, well I'm looking for a couple of opinions here...
Last weekend I basically redid my system. I installed a 4 channel amp in addition to my mono sub amp, changed the subs and boxes and swapped out the factory rear speakers (fronts and deck were already done).
The Good:
Everything sounds great! 10x better than before, sounds better cruising with all of the windows down than it did with all of the windows up before (previously on deck power).
The Bad:
I have a slight hissing sound or static type sound when the volume gets to 1/2 and up. The sound is very faint, I first heard it while tuning in the garage and only when there was silence between tracks or when I had the deck on aux input with my ipod off or on pause. It is coming thorugh both amps, sub and 4 ch. at the same volume level (i.e. the subs aren't more noisy than the interiors or vice versa.) I could only tell it was happening to the subs too becuase I could feel the slightest of movement on the cone.
While driving around I can't tell its there at all I guess due to environmental noises in the car, but I still know its there.
I can live with it, but I don't want to hurt any of my equipment so I'd like to get rid of this sound if possible. Thinking back about it now I guess the same sound was there under deck power under the same conditions but I thought it was just the deck amp trying too hard.
Any suggestions? I have already checked the amp grounds and I firmly believe that they are both good. I measured 0.3 ohms from both of the amp negative terminals to the battery negative terminal, this was using an extension wire on my DMM that measured 0.1 ohms on its own.
The amps are grounded at the same point. I tried separating the grounds and moving them and the sound was much more noticeable than before so I put them back.
The deck has its own power cable ran directly to the battery from when I was using deck power (Its high power 60x4) but I switched it back to 40x4 mode in hopes of getting a cleaner signal through the preouts. It also has its own ground which I took directly to the chassis. It is a factory ground point (something was already grounded there, I'm tempted to think that its the factory stereo grounding point.) and I believe I have my alarm / remote start grounded at the same location.
Any opinions / suggestions would be greatly appreciated.
Last weekend I basically redid my system. I installed a 4 channel amp in addition to my mono sub amp, changed the subs and boxes and swapped out the factory rear speakers (fronts and deck were already done).
The Good:
Everything sounds great! 10x better than before, sounds better cruising with all of the windows down than it did with all of the windows up before (previously on deck power).
The Bad:
I have a slight hissing sound or static type sound when the volume gets to 1/2 and up. The sound is very faint, I first heard it while tuning in the garage and only when there was silence between tracks or when I had the deck on aux input with my ipod off or on pause. It is coming thorugh both amps, sub and 4 ch. at the same volume level (i.e. the subs aren't more noisy than the interiors or vice versa.) I could only tell it was happening to the subs too becuase I could feel the slightest of movement on the cone.
While driving around I can't tell its there at all I guess due to environmental noises in the car, but I still know its there.
I can live with it, but I don't want to hurt any of my equipment so I'd like to get rid of this sound if possible. Thinking back about it now I guess the same sound was there under deck power under the same conditions but I thought it was just the deck amp trying too hard.
Any suggestions? I have already checked the amp grounds and I firmly believe that they are both good. I measured 0.3 ohms from both of the amp negative terminals to the battery negative terminal, this was using an extension wire on my DMM that measured 0.1 ohms on its own.
The amps are grounded at the same point. I tried separating the grounds and moving them and the sound was much more noticeable than before so I put them back.
The deck has its own power cable ran directly to the battery from when I was using deck power (Its high power 60x4) but I switched it back to 40x4 mode in hopes of getting a cleaner signal through the preouts. It also has its own ground which I took directly to the chassis. It is a factory ground point (something was already grounded there, I'm tempted to think that its the factory stereo grounding point.) and I believe I have my alarm / remote start grounded at the same location.
Any opinions / suggestions would be greatly appreciated.
08-10-2006, 10:27 AM
#2
2000 Watt CAFz'r
Join Date: Jan 2001
Posts: 2,026
You sound like you know what you're doing. I would agree with trying to reground the HU. btw, what HU is that? Can you turn the HU amp off entirely?
The other thought I had was reducing the gains on your amps. If your RCA wires are picking up a slight induced noise from somewhere, reducing the gains will clean that up a bit. It just means that you will have to turn the deck louder to get the same volume - which shouldn't be a problem considering almost all deck preouts are distortion free even at 100% power, so your amps will still receive a clean signal.
3rd, you might just have to live with it. My Alpine - CDA 9845 makes a soft "clump clump clump" noise at the beginning of ever track - MP3 and Cd. I Can't hear it when the song starts loud. I can't hear it when the car is running. I can't hear it when the volume is 1/2 or lower. But when the song begins quietly, the car is off and the volume is up I hear it. I ran different RCAs out of the car to my home amp and speakers, and the sound was still there, so I concluded it was the deck. I took the deck back to the dealer and they could not help me either. I posted here and nobody responded. I have learned to live with it.
You can do some more diagnosing. Try and isolate the component it is coming from.
I don't think the problem is your amps or your amp ground because the problem is affected by the volume that your deck is set at. If it was a constant static regardless of HU volume, then blame the amps. But since it is variable, I believe it is HU/RCA related.
The other thought I had was reducing the gains on your amps. If your RCA wires are picking up a slight induced noise from somewhere, reducing the gains will clean that up a bit. It just means that you will have to turn the deck louder to get the same volume - which shouldn't be a problem considering almost all deck preouts are distortion free even at 100% power, so your amps will still receive a clean signal.
3rd, you might just have to live with it. My Alpine - CDA 9845 makes a soft "clump clump clump" noise at the beginning of ever track - MP3 and Cd. I Can't hear it when the song starts loud. I can't hear it when the car is running. I can't hear it when the volume is 1/2 or lower. But when the song begins quietly, the car is off and the volume is up I hear it. I ran different RCAs out of the car to my home amp and speakers, and the sound was still there, so I concluded it was the deck. I took the deck back to the dealer and they could not help me either. I posted here and nobody responded. I have learned to live with it.
You can do some more diagnosing. Try and isolate the component it is coming from.
I don't think the problem is your amps or your amp ground because the problem is affected by the volume that your deck is set at. If it was a constant static regardless of HU volume, then blame the amps. But since it is variable, I believe it is HU/RCA related.
08-10-2006, 11:03 AM
#3
Originally Posted by maltesechicken
I don't think the problem is your amps or your amp ground because the problem is affected by the volume that your deck is set at. If it was a constant static regardless of HU volume, then blame the amps. But since it is variable, I believe it is HU/RCA related.
HU: Pioneer DEH-80MP
Amps: Phoenix Gold Xenon X400.1 (c/w with 12 guage wiring x 2) and Alpine MRP-F450 (c/w with 16 guage wiring x 4)
Speakers: Infinity Reference 6010cs up front and 6012i coaxs rears
Subs: 2x Inifnity Reference 1030ws
4 guage power to 2 x 8 guage in the trunk, each amp grounded with 4 guage.
Monster Cable single twisted pair RCA cables.
Power is run down the driver's side, RCA and Speaker cables are down the center of the car, speaker wires from amps wired to factory car wiring behind deck.
I would've done more troubleshooting at the time but I had to pick up the girlfriend from work and she would've killed me if I was late lol. And I was working on the car for 12 hrs so I was pretty well done for the day.
I also don't think it's the amps as the sound is not a constant volume with regardless of HU volume level. Right now the gains are set with the deck to be @ 3/4 volume level. I will try lowering gains to provided max output at a higher deck volume.
My other thought was that in the trunk, due to the amp locations, I have run all of the cables together for 3 to 4 feet. Of course there are RCAs, speaker wires, power, ground and remote line all along the same path. Could this be inducing the noise in such a short distance?
08-10-2006, 11:55 AM
#4
"My other thought was that in the trunk, due to the amp locations, I have run all of the cables together for 3 to 4 feet. Of course there are RCAs, speaker wires, power, ground and remote line all along the same path. Could this be inducing the noise in such a short distance?"
definitely a possibility, and most likely your problem. Separate power, ground, remote from speaker and rca cables. Try to run the rca's as far away from any other electrical wiring as possible (this includes factory wiring harnesses). I had a similar problem, and just had to move the rca's 2 inches to get rid of the noise.
definitely a possibility, and most likely your problem. Separate power, ground, remote from speaker and rca cables. Try to run the rca's as far away from any other electrical wiring as possible (this includes factory wiring harnesses). I had a similar problem, and just had to move the rca's 2 inches to get rid of the noise.
08-10-2006, 09:19 PM
#5
So I redid the deck ground, moved the RCAs as far away from the power/ground cables as I could with the slack (about 6 inches) and reset the gains to 50 out of 60 on the deck.
The hiss is now almost completely gone that I can only hear it with the car off and all the windows up and if I want to hear it. Now what I hear is the background noise embedded in the recordings lol.
Much better, thanks guys
The hiss is now almost completely gone that I can only hear it with the car off and all the windows up and if I want to hear it. Now what I hear is the background noise embedded in the recordings lol.
Much better, thanks guys
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