Hi folks,
When the RCAs are hooked in from the line level converter to the amplifier and I turn the ignition on and off, the amplifier sends a loud pop to the speaker. The speaker has a significant throw on it when this occurs.
I'm annoyed by it as well as I'm concerned about any damage it is doing.
It does not occur when I turn the amplifier on and off with the RCAs not plugged in.
It's hard for me to isolate whether it is the head unit or the amplifier discharging the input signal that is causing the pop.
My questions are:
1. How can I find out whether it is the head unit or the amplifier discharging an input signal that is causing the pop? I have a multimeter that has a bunch of features I don't know how to use but may be helpful.
2. If the problem was from the headunit, I can't just stick a capacitor on there because wouldn't that work as a high pass filter? What can be done if it's due to the head unit?
3. If the problem is within the amplifer, is there anything I can put between the amplifier and speaker to stop this?
I figure a capacitor in function would seem logical as it would absorb the high pulse of voltage and slowly release it however I do not want to alter the sound (especially not apply a high pass filter on my sub!)
Thanks in advance!
When the RCAs are hooked in from the line level converter to the amplifier and I turn the ignition on and off, the amplifier sends a loud pop to the speaker. The speaker has a significant throw on it when this occurs.
I'm annoyed by it as well as I'm concerned about any damage it is doing.
It does not occur when I turn the amplifier on and off with the RCAs not plugged in.
It's hard for me to isolate whether it is the head unit or the amplifier discharging the input signal that is causing the pop.
My questions are:
1. How can I find out whether it is the head unit or the amplifier discharging an input signal that is causing the pop? I have a multimeter that has a bunch of features I don't know how to use but may be helpful.
2. If the problem was from the headunit, I can't just stick a capacitor on there because wouldn't that work as a high pass filter? What can be done if it's due to the head unit?
3. If the problem is within the amplifer, is there anything I can put between the amplifier and speaker to stop this?
I figure a capacitor in function would seem logical as it would absorb the high pulse of voltage and slowly release it however I do not want to alter the sound (especially not apply a high pass filter on my sub!)
Thanks in advance!
Buy a remote turn on delay box on ebay. Most likely the amp is turning on right before the head unit so it is hearing the turn on thump of the deck. If you connect the turn on delay unit between the remote wire, the deck will turn on first and the amp will turn on after the deck thumps so the thump won't be amplified. I can't remember what they are called specifically.
http://www.sfxaudio.com/products/dispItem.asp?ProdId=63361
I think something similar could be built with just a cap, resistor, and relay.
I think something similar could be built with just a cap, resistor, and relay.
You say you get pop both when you turn the ignition on, and when you turn it off?
If so, the delay device will only work when turning the amp on. In my experience, the turn off thump is more prevalent, and difficult to address. If the amp's remote turn-on lead is properly connected to your head unit's remote turn-on lead, then this is a more difficult issue to address.
The head unit is supposed to have its preout signals up and ready prior to the amplifier turning on its outputs. This can be done with a delay on the remote lead, as ppia600 mentions. There should also be a small delay internal to the amp, that the power up cycle takes a half second or so after the application of 12V to the remote lead.
The turn off issue, however, is more difficult. When power is cut to the head unit (through the ignition), two things happen: the preouts are powered down, with the subsequent thump, and the remote turn-on lead is taken from 12 to 0V, telling the amp to turn off. What is happening to you is the amplifier is not fully shut down, or muted, prior to the head unit. The head unit is too fast, or the amp is too slow. Difficult to say which.
For starters, are you sure you have the remote leads connected properly?
edit: Sorry, I just noticed you are using a line level converter. So your are using the speaker outputs on the head unit? That is your most likely issue; the speaker outputs are not synchronized in the same way as the preouts. What type of head unit? Does it have any preouts?
If so, the delay device will only work when turning the amp on. In my experience, the turn off thump is more prevalent, and difficult to address. If the amp's remote turn-on lead is properly connected to your head unit's remote turn-on lead, then this is a more difficult issue to address.
The head unit is supposed to have its preout signals up and ready prior to the amplifier turning on its outputs. This can be done with a delay on the remote lead, as ppia600 mentions. There should also be a small delay internal to the amp, that the power up cycle takes a half second or so after the application of 12V to the remote lead.
The turn off issue, however, is more difficult. When power is cut to the head unit (through the ignition), two things happen: the preouts are powered down, with the subsequent thump, and the remote turn-on lead is taken from 12 to 0V, telling the amp to turn off. What is happening to you is the amplifier is not fully shut down, or muted, prior to the head unit. The head unit is too fast, or the amp is too slow. Difficult to say which.
For starters, are you sure you have the remote leads connected properly?
edit: Sorry, I just noticed you are using a line level converter. So your are using the speaker outputs on the head unit? That is your most likely issue; the speaker outputs are not synchronized in the same way as the preouts. What type of head unit? Does it have any preouts?
After further consideration, you may find some improvement by slowing down the head unit. There are a number of threads currently active about adding capacitors on the head unit's power supply, very near the head unit. From a sound quality standpoint, I'm not convinced, as most head units run right into switching power supplies internally, but regardless, adding a cap onto to the ignition lead may be sufficient to slow down the head unit.
Possibly an easy fix to your problem. You could find a suitable cap at Rat Shack for about $2.
Possibly an easy fix to your problem. You could find a suitable cap at Rat Shack for about $2.
A common head unit uses a bridged pair of amplifiers for each speaker. These have a DC bias point of ~1/2 of the B+ voltage. When you power up the head unit, the outputs swing from ground (0v) to the output bias voltage (~6v). A high power line output converter has a transformer for each channel. If you use a line converter without the transformers, there will be a significant pop as the outputs switch from 0-6v. With the transformers, there is no pop because BOTH inputs of the transformer are driven from 0-6v at the same time. If you have a pop, you may have the converter improperly installed or have the wrong converter.
If the amp pops on turn on, you probably have the remote turn-on terminal connected to the ignition instead of the power antenna output of the head unit. Most amps have a slight turn on delay. If the amp is turned on by the head unit's power antenna output, the amp won't be able to pop when the head unit is switched on because the amp won't power up for a second or two (due to the turn on delay).
If the amp pops on turn on, you probably have the remote turn-on terminal connected to the ignition instead of the power antenna output of the head unit. Most amps have a slight turn on delay. If the amp is turned on by the head unit's power antenna output, the amp won't be able to pop when the head unit is switched on because the amp won't power up for a second or two (due to the turn on delay).
By Rat Shack do you mean Radio Shack?
I might have to look into this as mine does the same thing..Always has...It's a PPI 100xi and I would love to get the turn on and off pop out of it. All wires connected properly as well...Remote and so on.
I might have to look into this as mine does the same thing..Always has...It's a PPI 100xi and I would love to get the turn on and off pop out of it. All wires connected properly as well...Remote and so on.
It is piggy backed off cable that runs to the cradle that the OEM Phillips head unit sits in. This is essentially off the ignition and not controlled by the head unit.
This explains the pop on and I will try changing it this weekend.
What size capacitor do you suggest? Does it need to be a special type? The ignition lead is just low voltage yeah?
The pop off is a major concern to me and I appreciate the suggestions!
My amps remote wire is connected to the Power Control Wire on my head unit and it still pops when turned on. Would changing it to the Motor Antenna Control wire work even though I don't have a motorized antenna?
Well, there's your problem, both Flyin11 and groover1234. You need to use the remote turn on lead from the head unit to control the remote lead on the amp; the delays inherent to this design are proper, are rarely cause a problem with pop.
Using the power antenna lead may or may not work. In most head units, the power antenna only goes high when the tuner is active. If you put in a CD, the power antenna lead would go low, turning off the amp. So I would say this wouldn't work.
If you don't have a true remote lead on the head unit let me know what you do have to work with. Model numbers help.
Using the power antenna lead may or may not work. In most head units, the power antenna only goes high when the tuner is active. If you put in a CD, the power antenna lead would go low, turning off the amp. So I would say this wouldn't work.
If you don't have a true remote lead on the head unit let me know what you do have to work with. Model numbers help.
All amps don't power on at the same speed. Some come on quickly (many oem amps) and create audio before the aftermarket deck has a chance to power the preamp circuits. Many aftermarket amps have a slight delay to help prevent this issue, but not all have enough delay. Just buy the remote turn on delay box and be done with it for crying out loud. Its cheap and some are even adjustable.
As I have said before, I am concerned about the pop when turning off moreso than turning on. I assume this was directed at Flyin11.
I am using the lead that fires the Blaupunkt CD changer which was factory installed. There doesn't appear to be any other lead that looks like it has this purpose.
Philips CCR 600 from a 1998 Vauxhall/ Opel/ Holden Vectra.
I really want a solution for the pop when turning off. Someone had suggested I possibly need a better earthing. Is that a viable thing to investigate?
Here's a narrowed down list of suspects:
- AudioControl EPIC 150 - ParaBass harmonics + line level converter:MOST LIKELY: Quieter pop switching off even when head unit is not turned on. Loud pop when head unit provides current to it. Didn't own this in my last car and my last car didn't pop with the same amplifier- only difference is that last time I was using an aftermarket deck and therefore was running a low level signal straight from the deck.
- Head Unit popping on power off: NOT THE CASE: If I flick the switch off without turning off the headunit then the amplifier still pops however not as loud.
- Capacitors within the actual amplifier pop when discharging from an input current (as it only occurs when the RCAs are in): NOT THE CASE: simply because I have had this amplifier in previous vehicles without popping.
So, I suppose I'm looking to put something between the output RCA on the AudioControl EPIC 150 and the input RCA on the amplifier.
Could someone please suggest a device or component that would achieve this?
I am trying to see if I can get hold of another amp to test the EPIC with just to be certain.
Thanks
~groover
Your amplifier needs to turn off before your radio does. This can be acheived with a 6 amp diode and a 4700 mic capacitor.
I will draw and post a diagram this evening.
I will draw and post a diagram this evening.
The purpose of the following is to allow your radio to stay on for a fraction of a second after the amp turns off. This will only eliminate the pop when turning the key off. If you turn the radio off you will still get the pop.
The diodes are available at Radio Shack part number 276-1661
The cap also from Radio Shack part number 272-1022
You will need to cut the switched wire going to your radio and insert this circuit.
The diodes are available at Radio Shack part number 276-1661
The cap also from Radio Shack part number 272-1022
You will need to cut the switched wire going to your radio and insert this circuit.
Attachments
Eliminate POP from Speaker Level Converter
Thanks for the circuit diagram.
I narrowed down the source of the problem to be the speaker level input on the parabass unit. Using an external line level converter from the same headunit, without any other circuitry, I was able to turn the amplifier on and off without any loud pop noise.
However, I made this discovery after purchasing the electrical componentry to product this:
I had originally made this circuit from a collection of 470uf capacitors and one 2200uf capicitor.
It reduces the pop to a gentle expected off, however with the side effect of a "squeak" noise.
I was wondering if I am doing anything wrong with this circuit? and should I be concerned about the squeaking?
One thing I noticed was having the capacitor only on the positive still produced the pop. The pop went away when a capacitor was placed on both positive and negative.
This circuit goes between the parabass/ speaker -> line level converter and the amplifier in the boot.
Cheers
~groover
Thanks for the circuit diagram.
I narrowed down the source of the problem to be the speaker level input on the parabass unit. Using an external line level converter from the same headunit, without any other circuitry, I was able to turn the amplifier on and off without any loud pop noise.
However, I made this discovery after purchasing the electrical componentry to product this:
An externally hosted image should be here but it was not working when we last tested it.
I had originally made this circuit from a collection of 470uf capacitors and one 2200uf capicitor.
It reduces the pop to a gentle expected off, however with the side effect of a "squeak" noise.
I was wondering if I am doing anything wrong with this circuit? and should I be concerned about the squeaking?
One thing I noticed was having the capacitor only on the positive still produced the pop. The pop went away when a capacitor was placed on both positive and negative.
This circuit goes between the parabass/ speaker -> line level converter and the amplifier in the boot.
Cheers
~groover
/\ Wouldn't that degrade the signal quality to an extent? Just curious.
Also, the ideal device would turn your amp on a few seconds after the deck and also turn it off a few seconds before the deck. It wouldn't work if you turned the deck off manually though, you'd have to turn the key off.
You'd also have to wire the amp's remote lead to the car's accessorty circuit if you used the cap and diode method because that will just keep the deck on a little longer. And if the deck is still on, the deck's remote is still keeping the amp's remote on.
Also, the ideal device would turn your amp on a few seconds after the deck and also turn it off a few seconds before the deck. It wouldn't work if you turned the deck off manually though, you'd have to turn the key off.
You'd also have to wire the amp's remote lead to the car's accessorty circuit if you used the cap and diode method because that will just keep the deck on a little longer. And if the deck is still on, the deck's remote is still keeping the amp's remote on.
I hear no signal degradation nor audible gain loss however I am talking about a signal that has a lowpass of 80hz.
Just to clarify:
I have 3 devices in this saga.
1. Head unit
2. Parabass/ Line level converter unit
3. Amplifier
I can turn each of these on and off individually. When I turn off the parabass unit and allow the head unit and amplifier to continue, I hear a loud pop.
Based on the above, and that I ran a line level signal through without problems, I can assume that the issue is not the head unit turning off before the amplifier.
Just to clarify:
I have 3 devices in this saga.
1. Head unit
2. Parabass/ Line level converter unit
3. Amplifier
I can turn each of these on and off individually. When I turn off the parabass unit and allow the head unit and amplifier to continue, I hear a loud pop.
Based on the above, and that I ran a line level signal through without problems, I can assume that the issue is not the head unit turning off before the amplifier.
Well apparently the epicenter is turning off before the amp and that is enough. You'll still need to find a way to modify timing so the amp turns on last and turns off first. That way you never hear any noise from the epicenter or even the deck. If you want to get the amp to turn off before the epicenter:
1- connect two regular diodes (non stripe end) to the deck's remote output.
2-run one striped end to the amp, the other striped end to the sound processor/epicenter
3-connect a polarized capacitor between the remote input on the epicenter end to the epicenter's ground wire so it stays on longer than the amp (you'll have to experiment with sizes to get the timing you like, I'd start with a 16v/25 microfarad)
So basically you will have two diodes split coming from the deck's remote output, but the epicenter will have a capacitor on its remote input to ground. It will continue supplying remote power for a little while after the amp turns off and the diodes will prevent voltage from being shared by the amp and epicenter. Then the epicenter will turn off long after the amp so the amp won't produce the "pop".
Figuring out the timing at turn on will be another issue, but with a relay or two you could reverse the sequence. I just don't have the dexterity or patience to type it in an understandable format.
1- connect two regular diodes (non stripe end) to the deck's remote output.
2-run one striped end to the amp, the other striped end to the sound processor/epicenter
3-connect a polarized capacitor between the remote input on the epicenter end to the epicenter's ground wire so it stays on longer than the amp (you'll have to experiment with sizes to get the timing you like, I'd start with a 16v/25 microfarad)
So basically you will have two diodes split coming from the deck's remote output, but the epicenter will have a capacitor on its remote input to ground. It will continue supplying remote power for a little while after the amp turns off and the diodes will prevent voltage from being shared by the amp and epicenter. Then the epicenter will turn off long after the amp so the amp won't produce the "pop".
Figuring out the timing at turn on will be another issue, but with a relay or two you could reverse the sequence. I just don't have the dexterity or patience to type it in an understandable format.
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