hi all...
can anyone help me as soon as....
i have recently changed my headunit for a dvd player... unfortunatly it does not have a remote out lead for the amp...
now i decided to connect the remote lead to the acc position of the ignition... only problem is when i turn the headunit on it causes the amps to thump and usually sends at least one of them into protection mode...
now question is, is there a way to stop this... either via a change in wiring or adding a device to stop it... any comments will be greatly appreciated..
thanks in advance...
jay
Replies (13)
UKinstaller on 09/3/2005 15:39:44
is it connected to the red wire coming out of the dvd player harness?? if not, connect it there. if it is, you can try going to your ignition harness.
what kind of car is it??
-UK
minijay on 09/3/2005 15:51:22
hi there thanks for the reply
its a renault laguna,,,
i have the remote wire attached to the red wire before the fuse on the dvd player...
it seems the player sends out a spike or what ever down the rca leads and causes the thump... i cut the remote cable and turn on all the kit then place the wire together again and its fine...
is there a filter or something that could be fitted to stop the spike....
swez on 09/4/2005 10:41:25
Many older amps and cheap knock offs, don't have a "soft start" mode.
Most newer amp and older quality amps have this feature now.
It's a problem in the power supply, (inside amp) as it fires up the amplifier circuits. Not sure there is much that can be done, other then adjusting your amp gains closer to the 3-4 volt settings.
Swez
PS What amp do you have? (Make & Model #)
minijay on 09/4/2005 18:15:19
ah right
thanks for that...
i have three amps now... one is a sony thing two channel purple colour dunno what number....
the two others are new but cheap low poawer ones tat run my stock speakers in the car... both two channel hense why i got two
the new dvd player i got for some reason will not use the standard speaker outs if i choose to have an amp for the subs so i had to go fully with the rca leads and run the whole sound side off amps...
much better sound now... and louder....
but this thump has now arrived... did not do it on my last head unit so i assume its the head unit thats causing it...
i think if i could put some kind of delay in the remote circuit it should solve it..
that way the head unit would have fired up and done all its stuff then the amps would come online and there would be no thump...
the same as if i connect the remote lead after the dvd player is on...
seems like a bit of messing around but cannot think of an alternative...
anyone have any ideas on how to build a delay...
may just put a switch in would be alot easier....
thanks for the replies so far
jay
swez on 09/4/2005 18:58:24
Since you have 3 amps on one power line, may wish to use a relay circuit on your REMOTE turn on line. (only on REM line though, not main power feeds)
There are relays that can delay turn on for up to several seconds if needed. This is common for large audio power amps in big night clubs. Here, we stage amps to come on at different times at turn on, to prevent huge surge currents.
Can it be done in 12 volt realm? Check the autoparts stores in your area and see what they recommend.
Swez
minijay on 09/4/2005 19:04:24
that sounds perfect...
thanks for that... ill have a look as soon as i get a few mins...
i get the thump when it turns off as well but that wouldnt be to bad as at that point the remote lead would go dead and reset any protection modes that occur until the next turn on...
then if i use a phased turn on like you suggest with relays it should all run smoothly again...
thanks for the help... much appreciated...
jay
ttocs on 09/5/2005 09:40:28
I was thinking about this myself and wondering, would a cap inline fix this swez? It would probably keep the deck on for a sec er two after he turned it off but?
minijay on 09/5/2005 09:42:46
hi there
i have a cap already...
may need to reconfigure it slightly to allow for the new amps but it may be worth a try..
jay
swez on 09/5/2005 12:49:25
A thought here... consider a time delay relay on your speakers (subs) to delay amp signals to sub between 250 -2,000mS. (1/4 - 2.0 seconds)
This will allow the amplifier to stabilize before the speakers are engaged by the relay. By doing this, the amp is turned on first, then allowed to power up normally and become stable, before audio signals pass into the speakers. (subs)
Another option to consider, would be a simple polyswitchby Raychem. These devices are cheap and have various power ranges too. They work by blocking DC spikes and excess power (amperes) to a speaker. When it senses too much power, (voltage x current) the poly- switch opens and will pass no signals (voltage) until the threshold voltage drops below the regulated range of the poly-switch. Here are some options from Raychem.
http://www.partsexpress.com/webpage.cfm?&DID=7&WebPage_ID=3
The trick to choosing the right one, is knowing what power range to use for your amplifier/sub switch. One thing I cannot find, is the tripping characteristics of these polyswitches. The can handle 60 volts and up to 40 amperes of power dissapation, but the tripping power range seems to be too low for high powered speakers and sub systems. Here, relay circuits would be best.
Swez
minijay on 09/5/2005 13:11:05
hi there
looked into those polyswitches like you said, cant see one that would suit...
i think the relays would be best but im finding it hard to find one with a delay.
anyone know of such a thing if so where may i find one and what would its name be....
thanks
jay
swez on 09/5/2005 16:29:31
Before going out and buying an exotic relay, try a simple test to see if it works. Here's the drill:
1. Disconnect one speaker wire from your amp to speaker/sub
2. Start the car & turn on the system (a helper can do that)
3. After the count 1000.1, 1000.2, connect speaker wire again
4. Note if thump was present or gone while doing this
If thump is gone, can install a manual remote switch and standard Bosche type relay and use the manual switch as you become the timer. This is the simplest form of remote turn on relay/timer I can imagine.
In fact, can simplify it even more by using a SPST/DPDT switch as your remote speaker/sub turn on device. Here's a brief map of what to try:
1. Speaker lead (Pos) from amp output is "line", speaker/sub is "load"
2. Insert switch between "line" and "load"
3. Turn on system with switch off, count to 2 (medium volume pls)
4. Flip switch to complete circuit & Viola
5. Observe results
A common switch has 3 lugs:
A. Load disabled (OFF)
B. Center lug is line in
C. Remaining lug is load enabled (ON)
If you are running 2 subs, (1 per channel) a DPDT switch is needed. Same idea here too. Just be sure to use a switch that can handle the power (wattage) for the amps' output rating to subs.
Does that make sense to you now?
Swez USFLAG
minijay on 09/6/2005 09:11:37
hi swez
yes it makes sense...
ill have a look to see what the best way is and get some relays to solve the problem...
may be fine just to relay the remote lead but if it turns out to be the amps ill then do as you suggest with the relays on the speaker side....
thanks for your help
jay
swez on 09/6/2005 11:36:22
After some research and talking to a fellow tech with lots of experience in Pro Audio, (my twin brother) we agreed the best way to manage this, would be to delay the speakers/sub turn on until the amp(s) have reached "equilibrium". This usually takes a few seconds in high powered amps, but faster in smaller ones.
Installing a relay on the REMote line will probably not help this issue much. The amps will still thump the cones this way. If you want to remove the thumps at power up/down on an amp, use the relay on the speaker leads as mentioned earlier. It would also be a good idea to use a blocking diode on the relay as well. This will prevent reverse currents from feeding back to the power line, as the inductor coil of the relay dumps its' stored energy as the field collapses. That can also be managed by using a small fuse on the power line to relay. Some relays come with a bleeder diode. Others do not, but one can easily add one.
The remote speaker cutout switch is also effective and requires no relay, diodes or power feed lines. The switch is just a make/break device, between the amp outputs and speakers/subs. This will work fine all by itself. I would start with this option and see what results.
Swez
can anyone help me as soon as....
i have recently changed my headunit for a dvd player... unfortunatly it does not have a remote out lead for the amp...
now i decided to connect the remote lead to the acc position of the ignition... only problem is when i turn the headunit on it causes the amps to thump and usually sends at least one of them into protection mode...
now question is, is there a way to stop this... either via a change in wiring or adding a device to stop it... any comments will be greatly appreciated..
thanks in advance...
jay
Replies (13)
UKinstaller on 09/3/2005 15:39:44
is it connected to the red wire coming out of the dvd player harness?? if not, connect it there. if it is, you can try going to your ignition harness.
what kind of car is it??
-UK
minijay on 09/3/2005 15:51:22
hi there thanks for the reply
its a renault laguna,,,
i have the remote wire attached to the red wire before the fuse on the dvd player...
it seems the player sends out a spike or what ever down the rca leads and causes the thump... i cut the remote cable and turn on all the kit then place the wire together again and its fine...
is there a filter or something that could be fitted to stop the spike....
swez on 09/4/2005 10:41:25
Many older amps and cheap knock offs, don't have a "soft start" mode.
Most newer amp and older quality amps have this feature now.
It's a problem in the power supply, (inside amp) as it fires up the amplifier circuits. Not sure there is much that can be done, other then adjusting your amp gains closer to the 3-4 volt settings.
Swez
PS What amp do you have? (Make & Model #)
minijay on 09/4/2005 18:15:19
ah right
thanks for that...
i have three amps now... one is a sony thing two channel purple colour dunno what number....
the two others are new but cheap low poawer ones tat run my stock speakers in the car... both two channel hense why i got two
the new dvd player i got for some reason will not use the standard speaker outs if i choose to have an amp for the subs so i had to go fully with the rca leads and run the whole sound side off amps...
much better sound now... and louder....
but this thump has now arrived... did not do it on my last head unit so i assume its the head unit thats causing it...
i think if i could put some kind of delay in the remote circuit it should solve it..
that way the head unit would have fired up and done all its stuff then the amps would come online and there would be no thump...
the same as if i connect the remote lead after the dvd player is on...
seems like a bit of messing around but cannot think of an alternative...
anyone have any ideas on how to build a delay...
may just put a switch in would be alot easier....
thanks for the replies so far
jay
swez on 09/4/2005 18:58:24
Since you have 3 amps on one power line, may wish to use a relay circuit on your REMOTE turn on line. (only on REM line though, not main power feeds)
There are relays that can delay turn on for up to several seconds if needed. This is common for large audio power amps in big night clubs. Here, we stage amps to come on at different times at turn on, to prevent huge surge currents.
Can it be done in 12 volt realm? Check the autoparts stores in your area and see what they recommend.
Swez
minijay on 09/4/2005 19:04:24
that sounds perfect...
thanks for that... ill have a look as soon as i get a few mins...
i get the thump when it turns off as well but that wouldnt be to bad as at that point the remote lead would go dead and reset any protection modes that occur until the next turn on...
then if i use a phased turn on like you suggest with relays it should all run smoothly again...
thanks for the help... much appreciated...
jay
ttocs on 09/5/2005 09:40:28
I was thinking about this myself and wondering, would a cap inline fix this swez? It would probably keep the deck on for a sec er two after he turned it off but?
minijay on 09/5/2005 09:42:46
hi there
i have a cap already...
may need to reconfigure it slightly to allow for the new amps but it may be worth a try..
jay
swez on 09/5/2005 12:49:25
A thought here... consider a time delay relay on your speakers (subs) to delay amp signals to sub between 250 -2,000mS. (1/4 - 2.0 seconds)
This will allow the amplifier to stabilize before the speakers are engaged by the relay. By doing this, the amp is turned on first, then allowed to power up normally and become stable, before audio signals pass into the speakers. (subs)
Another option to consider, would be a simple polyswitchby Raychem. These devices are cheap and have various power ranges too. They work by blocking DC spikes and excess power (amperes) to a speaker. When it senses too much power, (voltage x current) the poly- switch opens and will pass no signals (voltage) until the threshold voltage drops below the regulated range of the poly-switch. Here are some options from Raychem.
http://www.partsexpress.com/webpage.cfm?&DID=7&WebPage_ID=3
The trick to choosing the right one, is knowing what power range to use for your amplifier/sub switch. One thing I cannot find, is the tripping characteristics of these polyswitches. The can handle 60 volts and up to 40 amperes of power dissapation, but the tripping power range seems to be too low for high powered speakers and sub systems. Here, relay circuits would be best.
Swez
minijay on 09/5/2005 13:11:05
hi there
looked into those polyswitches like you said, cant see one that would suit...
i think the relays would be best but im finding it hard to find one with a delay.
anyone know of such a thing if so where may i find one and what would its name be....
thanks
jay
swez on 09/5/2005 16:29:31
Before going out and buying an exotic relay, try a simple test to see if it works. Here's the drill:
1. Disconnect one speaker wire from your amp to speaker/sub
2. Start the car & turn on the system (a helper can do that)
3. After the count 1000.1, 1000.2, connect speaker wire again
4. Note if thump was present or gone while doing this
If thump is gone, can install a manual remote switch and standard Bosche type relay and use the manual switch as you become the timer. This is the simplest form of remote turn on relay/timer I can imagine.
In fact, can simplify it even more by using a SPST/DPDT switch as your remote speaker/sub turn on device. Here's a brief map of what to try:
1. Speaker lead (Pos) from amp output is "line", speaker/sub is "load"
2. Insert switch between "line" and "load"
3. Turn on system with switch off, count to 2 (medium volume pls)
4. Flip switch to complete circuit & Viola
5. Observe results
A common switch has 3 lugs:
A. Load disabled (OFF)
B. Center lug is line in
C. Remaining lug is load enabled (ON)
If you are running 2 subs, (1 per channel) a DPDT switch is needed. Same idea here too. Just be sure to use a switch that can handle the power (wattage) for the amps' output rating to subs.
Does that make sense to you now?
Swez USFLAG
minijay on 09/6/2005 09:11:37
hi swez
yes it makes sense...
ill have a look to see what the best way is and get some relays to solve the problem...
may be fine just to relay the remote lead but if it turns out to be the amps ill then do as you suggest with the relays on the speaker side....
thanks for your help
jay
swez on 09/6/2005 11:36:22
After some research and talking to a fellow tech with lots of experience in Pro Audio, (my twin brother) we agreed the best way to manage this, would be to delay the speakers/sub turn on until the amp(s) have reached "equilibrium". This usually takes a few seconds in high powered amps, but faster in smaller ones.
Installing a relay on the REMote line will probably not help this issue much. The amps will still thump the cones this way. If you want to remove the thumps at power up/down on an amp, use the relay on the speaker leads as mentioned earlier. It would also be a good idea to use a blocking diode on the relay as well. This will prevent reverse currents from feeding back to the power line, as the inductor coil of the relay dumps its' stored energy as the field collapses. That can also be managed by using a small fuse on the power line to relay. Some relays come with a bleeder diode. Others do not, but one can easily add one.
The remote speaker cutout switch is also effective and requires no relay, diodes or power feed lines. The switch is just a make/break device, between the amp outputs and speakers/subs. This will work fine all by itself. I would start with this option and see what results.
Swez
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