i have a pioneer deh p6800 head unit which i am pretty sure i bought from you guys. i have two amp, one for the interior speakers and one for the subs. about 4 months ago my wife got my 2004 jeep grand cherokee jump started due to not being ran in 3 months. ever since then the speakers make a crackling noise, whether the jeep is on or off. when the jeep is on it is even louder. i have also had some after market speakers put in my door, since i did not do it myself i cant speak for the quality of the install, but had no problems till recently. the noise has started to pick up more so in the past few weeks. what should i look for as far as troubleshooting or repairing the malfuction.
Replies (5)
richard25ad on 09/5/2008 13:32:56
2004 jeep grand cherokee 4.0
pioneer deh p6800 head unit
sony explode w/remote bass powering two 10' bostons
crossfire powering interior speakers
think the tweeters are blown
swez on 09/5/2008 14:22:11
If this started recently after a "jump", one would wonder if there was damage to noise supression circuits in the ALT's regulator and/or rectifier bridge. A trip to a good autoparts store for a free ALT charging test and battery health test would be a good idea.
Another thing to look at is the HU grounding system. If the HU is not grounded to "bare metal" like the firewall,floorpan or similar metal to body, noise is common. (Aftermarket HU's should not use factor harness grounds only) The same is true of your amps. They need bare metal grounds as well.
Also, Pioneer has had a spate of noise issues with their HU RCA output jacks. Many have found a good repair is to attach/solder jumper wires to the grounding claws of the male RCA plugs. This is most noticable in mids and highs, but not so much in the subs.
Quote: "I have a pioneer deh p6800 head unit which i am pretty sure i bought from you guys."
We don't sell products on this site. CK is a forum to help others who need information on installs and products to consider. If one of our guys did sell products, they are doing it of their own accord and not endorsed by CK.
Comments?
Swez
PS Is this Pioneer deh-P6800 still under warranty? If yes and the other recommended options do not pan out, consider having the HU tested and repaired or replace if found defective. (Good luck)
DominicanKiddo on 09/5/2008 23:26:07
If you are not sure of the installation make sure you also check that the power cable and the RCAs are on opposite sides. Either check it yourself or ask the person who did the installation for you. But like swez says check your altenator if it just started happening after the jump start.
richard25ad on 09/6/2008 09:40:25
yeah sorry about the "i thought i bought it from you guys" i also asked another sire i think i bought the head unit from. i took it to a radio shop, they installed a noise suppressor on my rca cables and the noise is gone. i am wandering if it just covered the problem or fixed it. i will try the auto store for a alt test still. i did a bit more troubleshooting before i took it in. what i found was that if i wiggled the rca cables the noise got louder, i also found that one speaker wire had a noticeable bit of voltage to the one side of my amp, should the amp have any power to any channel if the ignition is turned off. i also noticed that if i turn the ignition on that the noise is now in all four door speakers with the radio in the off position. with the ignition on and stereo playing the one channel that had power before now has less power. the grounds for the amps are connected together at one grounding point under the seat. it is bare metal. could just one channel of my amp be faulting causing this issue. i havent checked out the back of head unit yet.
swez on 09/7/2008 03:51:53
The noise suppressor is a good fix when they work. Some vehicles have noisy electrical circuits and that's about the only way to get rid of them. (Most really don't work very well and in your case, it seems to have helped)
In this case, having noise on the battery line with the engine off, leaves me wondering what other circuits would be causing this noise.
The amps have power at all times through the B+ power lug. The amps should not turn on though, until the HU is switched on and the REMote signal line sends a 12 volt signal back to the amps. Then the amps turn on.
As for noise and other odd issues mentioned, it's best to bench test your 4 channel Crossfire amp. There are noise filters in the power supply and preamp input sections of most quality amps. In this case as stated, we often recommend a diagnostics check to elimiate or home in on specific parts of the system.
Tech Tip: To bench test an amp, you can do this at home with some basic tools and a patch cable.
1. Use a portable CD/MP3 player as the music source
2. Use the headphone jack as the signal source
3. Obtain or make an audio patch cable (Headphone jack on one end, a pair of RCA's on the other, 3 feet of cable is good)
4. Remove all existing RCA's from your Crossfire amp (Mark which channels they came from)
5. Plug in the other player's RCA's and turn on the HU to activate amp
6. Test front channels for audio quality and noise
7. Test rear channels for audio quality and noise
If there is noise and signal levels are not balaced on L & R channels of either half of the amp, there's a board level problem in the amp and needs internal repairs. (Factory repairs are best)
If all speakers are quiet and balanced during this test, that suggests problems with your HU. That means more testing of the HU, repairs or replacement of the HU as you wish. This test is best done by a Tech with the proper tools and equipment.
Comments/questions,
Swez
PS When posting details like this, we really appreciate paragraphs and spaces between topics. The "Wall of Text" method is not easy to read and best to avoid. (Thanks in advance)
Replies (5)
richard25ad on 09/5/2008 13:32:56
2004 jeep grand cherokee 4.0
pioneer deh p6800 head unit
sony explode w/remote bass powering two 10' bostons
crossfire powering interior speakers
think the tweeters are blown
swez on 09/5/2008 14:22:11
If this started recently after a "jump", one would wonder if there was damage to noise supression circuits in the ALT's regulator and/or rectifier bridge. A trip to a good autoparts store for a free ALT charging test and battery health test would be a good idea.
Another thing to look at is the HU grounding system. If the HU is not grounded to "bare metal" like the firewall,floorpan or similar metal to body, noise is common. (Aftermarket HU's should not use factor harness grounds only) The same is true of your amps. They need bare metal grounds as well.
Also, Pioneer has had a spate of noise issues with their HU RCA output jacks. Many have found a good repair is to attach/solder jumper wires to the grounding claws of the male RCA plugs. This is most noticable in mids and highs, but not so much in the subs.
Quote: "I have a pioneer deh p6800 head unit which i am pretty sure i bought from you guys."
We don't sell products on this site. CK is a forum to help others who need information on installs and products to consider. If one of our guys did sell products, they are doing it of their own accord and not endorsed by CK.
Comments?
Swez
PS Is this Pioneer deh-P6800 still under warranty? If yes and the other recommended options do not pan out, consider having the HU tested and repaired or replace if found defective. (Good luck)
DominicanKiddo on 09/5/2008 23:26:07
If you are not sure of the installation make sure you also check that the power cable and the RCAs are on opposite sides. Either check it yourself or ask the person who did the installation for you. But like swez says check your altenator if it just started happening after the jump start.
richard25ad on 09/6/2008 09:40:25
yeah sorry about the "i thought i bought it from you guys" i also asked another sire i think i bought the head unit from. i took it to a radio shop, they installed a noise suppressor on my rca cables and the noise is gone. i am wandering if it just covered the problem or fixed it. i will try the auto store for a alt test still. i did a bit more troubleshooting before i took it in. what i found was that if i wiggled the rca cables the noise got louder, i also found that one speaker wire had a noticeable bit of voltage to the one side of my amp, should the amp have any power to any channel if the ignition is turned off. i also noticed that if i turn the ignition on that the noise is now in all four door speakers with the radio in the off position. with the ignition on and stereo playing the one channel that had power before now has less power. the grounds for the amps are connected together at one grounding point under the seat. it is bare metal. could just one channel of my amp be faulting causing this issue. i havent checked out the back of head unit yet.
swez on 09/7/2008 03:51:53
The noise suppressor is a good fix when they work. Some vehicles have noisy electrical circuits and that's about the only way to get rid of them. (Most really don't work very well and in your case, it seems to have helped)
In this case, having noise on the battery line with the engine off, leaves me wondering what other circuits would be causing this noise.
The amps have power at all times through the B+ power lug. The amps should not turn on though, until the HU is switched on and the REMote signal line sends a 12 volt signal back to the amps. Then the amps turn on.
As for noise and other odd issues mentioned, it's best to bench test your 4 channel Crossfire amp. There are noise filters in the power supply and preamp input sections of most quality amps. In this case as stated, we often recommend a diagnostics check to elimiate or home in on specific parts of the system.
Tech Tip: To bench test an amp, you can do this at home with some basic tools and a patch cable.
1. Use a portable CD/MP3 player as the music source
2. Use the headphone jack as the signal source
3. Obtain or make an audio patch cable (Headphone jack on one end, a pair of RCA's on the other, 3 feet of cable is good)
4. Remove all existing RCA's from your Crossfire amp (Mark which channels they came from)
5. Plug in the other player's RCA's and turn on the HU to activate amp
6. Test front channels for audio quality and noise
7. Test rear channels for audio quality and noise
If there is noise and signal levels are not balaced on L & R channels of either half of the amp, there's a board level problem in the amp and needs internal repairs. (Factory repairs are best)
If all speakers are quiet and balanced during this test, that suggests problems with your HU. That means more testing of the HU, repairs or replacement of the HU as you wish. This test is best done by a Tech with the proper tools and equipment.
Comments/questions,
Swez
PS When posting details like this, we really appreciate paragraphs and spaces between topics. The "Wall of Text" method is not easy to read and best to avoid. (Thanks in advance)
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