feedback issue
10-19-2003, 06:04 PM
#1
0 Watt CAFz'r
Thread Starter
Join Date: Oct 2003
Posts: 8
hey guys got a question.......
now wired up the sub and amp but when i turn on the deck i get some bass but alot of feed back (distortion).. now i connected up to a friends car and it work (actually worked amazing).. so wat could be wrong here either a cable isn't connect into deck all the way or could a cable be split open??? and suggestion would be great
now wired up the sub and amp but when i turn on the deck i get some bass but alot of feed back (distortion).. now i connected up to a friends car and it work (actually worked amazing).. so wat could be wrong here either a cable isn't connect into deck all the way or could a cable be split open??? and suggestion would be great
10-21-2003, 06:49 AM
#2
500 Watt CAFz'r
Join Date: Jul 2003
Posts: 756
The sound could be ground related, check your amplifier ground, and ensure that you have a good ground point selected.
Also, check your RCA connections to ensure they are securely plugged into both the deck and the amplifier. If the cables are run too close to the power cable or directly beside it, you may induce a fair bit of noise into the signal path. Even the remote turn on wire can cause noise. Keep the RCAs away from and power cables, and if the problem persists, you may want to get twisted/noise rejecting RCA cables with some heavy shielding.
Faulty equipment can also be a cause of excessive noise. If you can single out the component that is causing the noise, you may want to take it in for repair or warantee replacement.
Good luck though.. nothing worse than noise in the signal path.
Also, check your RCA connections to ensure they are securely plugged into both the deck and the amplifier. If the cables are run too close to the power cable or directly beside it, you may induce a fair bit of noise into the signal path. Even the remote turn on wire can cause noise. Keep the RCAs away from and power cables, and if the problem persists, you may want to get twisted/noise rejecting RCA cables with some heavy shielding.
Faulty equipment can also be a cause of excessive noise. If you can single out the component that is causing the noise, you may want to take it in for repair or warantee replacement.
Good luck though.. nothing worse than noise in the signal path.
10-21-2003, 12:49 PM
#3
2000 Watt CAFz'r
Join Date: Jan 2001
Posts: 2,026
Is the amp receiving the audio signal from RCA's or from speaker level inputs?
If the amp is run off of the speaker level inputs, and you are running the rear speakers still, there is a possibility that the rear speakers are vibrating from the bass of your sub woofer. This creates a loop. As they vibrate from the bass, they will send a signal down the line to the input of the amp. The amp will produce that note at a greater volume causing the speakers to vibrate more sending a stronger signal down the line to the amp again. The loop will continue like this. This is feedback.
However, if you are not using highlevel inputs and you are using the RCAs this is not the case. Then I would be inclined to agree with the above post -> a ground issue.
If the amp is run off of the speaker level inputs, and you are running the rear speakers still, there is a possibility that the rear speakers are vibrating from the bass of your sub woofer. This creates a loop. As they vibrate from the bass, they will send a signal down the line to the input of the amp. The amp will produce that note at a greater volume causing the speakers to vibrate more sending a stronger signal down the line to the amp again. The loop will continue like this. This is feedback.
However, if you are not using highlevel inputs and you are using the RCAs this is not the case. Then I would be inclined to agree with the above post -> a ground issue.
10-21-2003, 06:23 PM
#4
0 Watt CAFz'r
Thread Starter
Join Date: Oct 2003
Posts: 8
[img]graemlins/headbang.gif[/img]
FINALLY ......... I have found a forum that gives good info !!!!!!!!!
lemonlime :
i drive a 98 cavalier and have the ground cable connected from the amp connected to the back metal part of the trunk (which im sure is part of the body).
maltesechicken:
rca's
I found that the one rca cable was not fully connect when i installed the first time so i fixed that and also the deck ground cables weren't a 100 % ground'ed so i fixed that too.
Now im running a phoenix gold amp kit. now i do have the rca and power cable running down the same side, now i think it must be that cause the rca cable isn't the best. looks like ur average house hold rca. now im going on weekend to get new cable and redo the wire'ing and hopefully that is the problem..
thks for the help and hopefully it solves it......
[img]graemlins/beer.gif[/img]
FINALLY ......... I have found a forum that gives good info !!!!!!!!!
lemonlime :
i drive a 98 cavalier and have the ground cable connected from the amp connected to the back metal part of the trunk (which im sure is part of the body).
maltesechicken:
rca's
I found that the one rca cable was not fully connect when i installed the first time so i fixed that and also the deck ground cables weren't a 100 % ground'ed so i fixed that too.
Now im running a phoenix gold amp kit. now i do have the rca and power cable running down the same side, now i think it must be that cause the rca cable isn't the best. looks like ur average house hold rca. now im going on weekend to get new cable and redo the wire'ing and hopefully that is the problem..
thks for the help and hopefully it solves it......
[img]graemlins/beer.gif[/img]
10-21-2003, 07:14 PM
#5
2000 Watt CAFz'r
Join Date: Jan 2001
Posts: 2,026
All of those sound like good avenues to Pursue.
There have been debates about running the power wire and RCAs separately to avoid signal degradation, but most installers will say that this is not the case. There have been systems with power and RCAs run together with no noise and there have been systems with them separated and there has been noise. End conclusion, only a weak corelation between location of power and RCA lines.
As for the grounding of the amp, make sure all of the paint has been removed at the point of grounding. Paint is not a good conductor and will impede an otherwise good ground.
There have been debates about running the power wire and RCAs separately to avoid signal degradation, but most installers will say that this is not the case. There have been systems with power and RCAs run together with no noise and there have been systems with them separated and there has been noise. End conclusion, only a weak corelation between location of power and RCA lines.
As for the grounding of the amp, make sure all of the paint has been removed at the point of grounding. Paint is not a good conductor and will impede an otherwise good ground.
10-22-2003, 03:52 PM
#6
0 Watt CAFz'r
Thread Starter
Join Date: Oct 2003
Posts: 8
well i have tryed al ur suggestions and have not been sucesful....... still getting the feed back and making me mad really mad!
i have no other clue wat it copuld be going to go try a different ground for the amp and see wat happens.
will be back in 20 min to tell u the conclusion
i have no other clue wat it copuld be going to go try a different ground for the amp and see wat happens.
will be back in 20 min to tell u the conclusion
10-22-2003, 07:41 PM
#8
2000 Watt CAFz'r
Join Date: Jan 2001
Posts: 2,026
Maybe there is something wrong with the RCAs on the deck . . . try running a different RCA wire from the output of the deck to a home amplifier or something like that. If the noise is still there, then you know what the problem is, if the problem is not there, try plugging the far end of the RCAs (the RCAs at the Amp) into your home receiver.Do all sorts of tests like this to isolate what part of the line is the problem.
10-24-2003, 10:17 AM
#9
0 Watt CAFz'r
Join Date: Oct 2003
Posts: 1
I've had that sort of problem before. What it ended up being is the altenator was making the noise because of the stress that it was under from powering the amps. and the only way i found to fix it was to use double sheilded RCA's and double sheilded splitters because i was running 4 amplifiers at the time. so you could try changing the altenator or find some good rca cables. you've got to remember that the signal that that comes from the deck to the amp is at very low power and therefore is able to pick up noise from anywhere and then the noise will be amplified so any money that you spend on rca cables wont be a waste. It is often an overlooked part of the chain. and something else that you should look at is the deck it self, when I had that prob, not long after I swaped the deck for a nakimichi 45z and never ran into the problem again. If you can find another deck that you could test the system with the way it is wired now. wiring a deck is a pretty quick job and could be the heart of the matter in the first place.
