Pop when amps shut down.
Thread Starter
Racer
Joined: Nov 1999
Posts: 319
Likes: 0
From: Sunnyvale, CA USA CA
Pop when amps shut down.
Is anyone else getting popping when they shut off power to their system. I know this isn't a first but I'd like to reduce or eliminate it if possible.
I'm running the stock HU with preouts to JL 500.1 and JL 450/4. Using switched 12V from the radio turn on / power antenna to switch the amps on and off.
Any help is appreciated.
Kris
I'm running the stock HU with preouts to JL 500.1 and JL 450/4. Using switched 12V from the radio turn on / power antenna to switch the amps on and off.
Any help is appreciated.
Kris
Race Director
Joined: May 2003
Posts: 14,137
Likes: 2,984
From: Iowa
St. Jude Donor '03 thru '26
Re: Pop when amps shut down. (2000Dream)
You have excellent amps but to be safe they are not the problem do this:
Unplug all RCA cables (AKA patch cords) going into the amps. Then turn car on and off like you normally do and see if speakers pop. If they do pop ,and I expect they won't, the amps are the problem. If they do pop, the poping is coming from the radio going down before the amps and sending the poping noise down the patch cords. With that info, you should use a different turn-on lead directly from the ignition to the amps. Better yet, buy and install a aftermarket HU and you should get no turnon/off thump and get better sound/features. Good Luck :cheers:
Unplug all RCA cables (AKA patch cords) going into the amps. Then turn car on and off like you normally do and see if speakers pop. If they do pop ,and I expect they won't, the amps are the problem. If they do pop, the poping is coming from the radio going down before the amps and sending the poping noise down the patch cords. With that info, you should use a different turn-on lead directly from the ignition to the amps. Better yet, buy and install a aftermarket HU and you should get no turnon/off thump and get better sound/features. Good Luck :cheers:
Thread Starter
Racer
Joined: Nov 1999
Posts: 319
Likes: 0
From: Sunnyvale, CA USA CA
Re: Pop when amps shut down. (2000Dream)
Thanks for the reply.
I actually took a few minutes to figure this out today. To sum it up it is the amp.
Although your method makes sense. It turned out that when the front signal from the HU is fed into the amp and internally split to the rear input it is causing a spike when the power is shut down.
After determining both the front and rears were clean I did the following. (by the way the rear from the HU is going to the sub so that is moot. I was only getting popping from the rear speakers. The rear speakers were getting the front signal by splitting it internally in the amp.)
I took the front signal and plugged it directly to the rear input. = no popping
So the same output (front from HU) is ok when plugged into either the front or rear input of the amp.
I plugged the HU front output to the rear input and switched the amp to split the signal to the front = pop in front speakers.
I changed the rca from the split output of the amp to the input of the other channel = pop
I figure a y adapter on the front signal from the HU split to the front and rear amp inputs will solve my problem.
[Modified by 2000Dream, 12:46 AM 8/29/2003]
I actually took a few minutes to figure this out today. To sum it up it is the amp.
Although your method makes sense. It turned out that when the front signal from the HU is fed into the amp and internally split to the rear input it is causing a spike when the power is shut down.
After determining both the front and rears were clean I did the following. (by the way the rear from the HU is going to the sub so that is moot. I was only getting popping from the rear speakers. The rear speakers were getting the front signal by splitting it internally in the amp.)
I took the front signal and plugged it directly to the rear input. = no popping
So the same output (front from HU) is ok when plugged into either the front or rear input of the amp.
I plugged the HU front output to the rear input and switched the amp to split the signal to the front = pop in front speakers.
I changed the rca from the split output of the amp to the input of the other channel = pop
I figure a y adapter on the front signal from the HU split to the front and rear amp inputs will solve my problem.
[Modified by 2000Dream, 12:46 AM 8/29/2003]
Race Director
Joined: May 2003
Posts: 14,137
Likes: 2,984
From: Iowa
St. Jude Donor '03 thru '26
Re: Pop when amps shut down. (2000Dream)
This is a new one for me :confused:
I sounds like you have a cheap solution (approx $10 for two y adaptors) and that is good. I was about to say you lost your fadar control from front to rear but reading it a second time I realized you did not have that control to start with. I assume you can adjust the sub level using the fadar contol.
JL is a high quality product and should not do what you are saying. I would talk to the place you bought the amp or contact JL Audio by the way of their web page. JL will answer your questions as they have done for me in the past. It may take them a few days but they will answer.
Anyhow, good find. Rock on. :thumbs:
I sounds like you have a cheap solution (approx $10 for two y adaptors) and that is good. I was about to say you lost your fadar control from front to rear but reading it a second time I realized you did not have that control to start with. I assume you can adjust the sub level using the fadar contol.
JL is a high quality product and should not do what you are saying. I would talk to the place you bought the amp or contact JL Audio by the way of their web page. JL will answer your questions as they have done for me in the past. It may take them a few days but they will answer.
Anyhow, good find. Rock on. :thumbs:
Instructor
Joined: Aug 2003
Posts: 115
Likes: 0
From: Fitchburg MA
Re: Pop when amps shut down. (knewblewkorvette)
Hello 2000....I do believe your problem lies in the fact that your remote on to your amp is connected to your power antenna......when you have speakers hooked up to an amp and the radio signal is shut off before the amp does...walla "pop"......now since you have a power antenna, the remote on still has juice going to it to pull the antenna down even though your radio signal has been shut off allready. You can see this by having someone shut off the radio while you watch your amp, I'm betting it's still on even though the radio isn't.....until the antenna is down that is....you can solve this 2 ways....
1) find another remote on...maybe the Bose Signal Processor "on" wire or another "key on accessory" wire...
2) there is an inline switch(box) that can be put in to make sure your amp turns off first...I belive http://www.darvex.com has one on clearance right now for $17.00..(I was just on the site)
Hope this helps you...... :cheers:
1) find another remote on...maybe the Bose Signal Processor "on" wire or another "key on accessory" wire...
2) there is an inline switch(box) that can be put in to make sure your amp turns off first...I belive http://www.darvex.com has one on clearance right now for $17.00..(I was just on the site)
Hope this helps you...... :cheers:
Thread Starter
Racer
Joined: Nov 1999
Posts: 319
Likes: 0
From: Sunnyvale, CA USA CA
Re: Pop when amps shut down. (2000Dream)
Thanks for the replies but it turned out to be one of my old problems. (not reading the instructions) The 450/4 allows you to drive all 4 channels with just one set or rca's. To make a long story short, I didn't need to run the extra set of rca's back to the rear channel to get all 4 channels to work. I think it was getting some noise from my wiring mistake. Removed the other set of rca's and switched the amp to drive all 4 channels from the ch 1&2 input. No more poping on shutdown.
What you say about the power antenna makes sense but was not the culprit in this case. That was my first thought too but I ruled it out when I found the source to be coming from the amp and not the HU. I also got the noise when I removed the 12v remote directly from the amp while the antenna and radio were still powered up.
By the way I contacted JL audio via e-mail and they replied. Didn't give me the exact fix but made me think about rechecking my amp's setup.
Thanks,
Kris
[Modified by 2000Dream, 12:50 AM 8/29/2003]
What you say about the power antenna makes sense but was not the culprit in this case. That was my first thought too but I ruled it out when I found the source to be coming from the amp and not the HU. I also got the noise when I removed the 12v remote directly from the amp while the antenna and radio were still powered up.
By the way I contacted JL audio via e-mail and they replied. Didn't give me the exact fix but made me think about rechecking my amp's setup.
Thanks,
Kris
[Modified by 2000Dream, 12:50 AM 8/29/2003]
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Le Mans Master
Joined: Sep 2002
Posts: 8,991
Likes: 2
From: Hanger 18 Taxachusetts
Re: Pop when amps shut down. (knewblewkorvette)
I never did figure this one out on my system from years ago. It was back in the late 80's when you had to use toggle switches to turn the amps on/off. If I remember correctly the speakers made that pop sound when the amps were turned off regaurdless of the order you shut things down??
I wonder if it is a relay coil spike? Might be able to put a diode on the power lead to supress it? Cheap enough to try it out. But I would think todays gear would have solved this issue by now.
I wonder if it is a relay coil spike? Might be able to put a diode on the power lead to supress it? Cheap enough to try it out. But I would think todays gear would have solved this issue by now.
Race Director
Joined: May 2003
Posts: 14,137
Likes: 2,984
From: Iowa
St. Jude Donor '03 thru '26
Re: Pop when amps shut down. (corvette-pilot)
I never did figure this one out on my system from years ago. It was back in the late 80's when you had to use toggle switches to turn the amps on/off. If I remember correctly the speakers made that pop sound when the amps were turned off regaurdless of the order you shut things down??
I wonder if it is a relay coil spike? Might be able to put a diode on the power lead to supress it? Cheap enough to try it out. But I would think todays gear would have solved this issue by now.
I wonder if it is a relay coil spike? Might be able to put a diode on the power lead to supress it? Cheap enough to try it out. But I would think todays gear would have solved this issue by now.
Le Mans Master
Joined: Sep 2002
Posts: 8,991
Likes: 2
From: Hanger 18 Taxachusetts
Re: Pop when amps shut down. (knewblewkorvette)
Actually the diode is not in series so the current doesn't go thru it. You put the neg side of the diode onto the positive terminal. Then put the positive side of the diode to the negative terminal of the amp. This causes any reverse spike caused by relays shutting down to be grounded.
