Aftermarket amplifier turn-off pop/click/thump...The Answers

[darkrider01]

Ok. I have some new information.

The length of delay that the Axxess Trigger causes is very amp specific. My Alpine V12 MRV-F357 takes roughly 6 seconds to turn on and produce audio. My older Alpine 3527S takes just over 1 second.

Originally Posted by Agent WD-40

Thanks a ton! That is interesting. I guess I don't use the mute that often so it probably wouldn't be a big deal.

I assume there isn't a delay if you just have the radio turned off? I would guess that the amp stays on and you would hear the turn signal or Bluetooth ring right away?

If the radio is off, the mute is active. So, that means if the phone rings or you use a turn signal, it will have the same delay.

Since the delay is amp specific, it may not be much of a delay.

[Agent WD-40]

Cool. Thanks a ton for the info! I guess I'll just have to try it with my amp and see what happens.

[SuperH]

The reason this happens I just explained in another thread... IF you have a Class AB amplifier:
http://www.camaro5.com/forums/showthread.php?t=257121

From my response in that thread:
That's normal. All that is, are the bootstrap capacitors discharging across the voice coil. The stored energy has to go somewhere.

In a Class AB push-pull design, the bootstrap capacitors have positive feedback to bias the output voltage to levels higher than the supply can provide.

It's normal. It doesn't generally happen with Class D, unless your crossover network causes it.

If you're driving higher frequencies, you'll hear "snaps" through your tweeters in an equivalent fashion to the "thump" you hear in your subwoofer. The same stored energy would dissipate sooner over a tweeter than a woofer, since they require more energy to drive to the same levels (remember, this is logarithmic). So, for the people who have four channel amps wired up to feed tweeters/mids with two channels and (a) sub(s) with two channels, they'll generally hear:
SNAP-SNAP (tweeters)... (slight delay)... THUD (subwoofer).

---
But... home audio systems have Class AB amplifiers quite often. Why doesn't this occur?

Do you hear this "click" sound every time you turn off your home audio system? It sounds like a relay? That's because it is. This relay opens, so you never hear a pop in the speakers. Short across the relay and you can test this - you'll hear the pop at home, too!

[Casper45th]

Originally Posted by SuperH

The reason this happens I just explained in another thread... IF you have a Class AB amplifier:
http://www.camaro5.com/forums/showthread.php?t=257121

From my response in that thread:
That's normal. All that is, are the bootstrap capacitors discharging across the voice coil. The stored energy has to go somewhere.

In a Class AB push-pull design, the bootstrap capacitors have positive feedback to bias the output voltage to levels higher than the supply can provide.

It's normal. It doesn't generally happen with Class D, unless your crossover network causes it.

If you're driving higher frequencies, you'll hear "snaps" through your tweeters in an equivalent fashion to the "thump" you hear in your subwoofer. The same stored energy would dissipate sooner over a tweeter than a woofer, since they require more energy to drive to the same levels (remember, this is logarithmic). So, for the people who have four channel amps wired up to feed tweeters/mids with two channels and (a) sub(s) with two channels, they'll generally hear:
SNAP-SNAP (tweeters)... (slight delay)... THUD (subwoofer).

---
But... home audio systems have Class AB amplifiers quite often. Why doesn't this occur?

Do you hear this "click" sound every time you turn off your home audio system? It sounds like a relay? That's because it is. This relay opens, so you never hear a pop in the speakers. Short across the relay and you can test this - you'll hear the pop at home, too!

As do sound reinforcement systems in auditoriums, churches, etc. The lazy man's work around for many decades has been to simply turn the amps off, waiting about 15 to 30 seconds, and then turn off the mixing console.

Refreshing to see someone that truly understands all of this from an engineering aspect.

[CWI]

Originally Posted by SuperH

The reason this happens I just explained in another thread... IF you have a Class AB amplifier:
http://www.camaro5.com/forums/showthread.php?t=257121

From my response in that thread:
That's normal. All that is, are the bootstrap capacitors discharging across the voice coil. The stored energy has to go somewhere.

In a Class AB push-pull design, the bootstrap capacitors have positive feedback to bias the output voltage to levels higher than the supply can provide.

It's normal. It doesn't generally happen with Class D, unless your crossover network causes it.

If you're driving higher frequencies, you'll hear "snaps" through your tweeters in an equivalent fashion to the "thump" you hear in your subwoofer. The same stored energy would dissipate sooner over a tweeter than a woofer, since they require more energy to drive to the same levels (remember, this is logarithmic). So, for the people who have four channel amps wired up to feed tweeters/mids with two channels and (a) sub(s) with two channels, they'll generally hear:
SNAP-SNAP (tweeters)... (slight delay)... THUD (subwoofer).

---
But... home audio systems have Class AB amplifiers quite often. Why doesn't this occur?

Do you hear this "click" sound every time you turn off your home audio system? It sounds like a relay? That's because it is. This relay opens, so you never hear a pop in the speakers. Short across the relay and you can test this - you'll hear the pop at home, too!

I have it with Alpine PDX (class D) amps. That's a nice explanation of why it happens. What is the fix?

[darkrider01]

Originally Posted by SuperH

The reason this happens I just explained in another thread... IF you have a Class AB amplifier:
http://www.camaro5.com/forums/showthread.php?t=257121

From my response in that thread:
That's normal. All that is, are the bootstrap capacitors discharging across the voice coil. The stored energy has to go somewhere.

In a Class AB push-pull design, the bootstrap capacitors have positive feedback to bias the output voltage to levels higher than the supply can provide.

It's normal. It doesn't generally happen with Class D, unless your crossover network causes it.

If you're driving higher frequencies, you'll hear "snaps" through your tweeters in an equivalent fashion to the "thump" you hear in your subwoofer. The same stored energy would dissipate sooner over a tweeter than a woofer, since they require more energy to drive to the same levels (remember, this is logarithmic). So, for the people who have four channel amps wired up to feed tweeters/mids with two channels and (a) sub(s) with two channels, they'll generally hear:
SNAP-SNAP (tweeters)... (slight delay)... THUD (subwoofer).

---
But... home audio systems have Class AB amplifiers quite often. Why doesn't this occur?

Do you hear this "click" sound every time you turn off your home audio system? It sounds like a relay? That's because it is. This relay opens, so you never hear a pop in the speakers. Short across the relay and you can test this - you'll hear the pop at home, too!

I understand what you are saying, but I don't buy it. The reason I don't buy it is because when I pair the exact same amp and speakers to a different source (like my new headunit), I get a different outcome (i.e. no pops). From your explanation, the source should have zero effect on the p/c/t.

[IDEALG]

Has no one come to a conclusion to this problem yet????
I'm using all Sound Stream speakers except for my subs. I'm running 2 PowerAcoustik 10 inch subs and two PowerAcoustik Amps. I only get the pop after turn off.
i have the gains set where the pop doesn't bother me but i want to crank these amps up and i can't because of this damn pop.

And to add another question to this mess what are you all doing with your onstar? if i crank up my amps when onstar kicks in it blows my ear drums out. Is there anyway around this or do all of you just not use onstar anymore with your new systems?

[jeepguy_1980]

How is your Axxess Trigger wired?

My system never popped until I added an MS-8. Now it pops. The problem is that my radio turns off before the MS-8 turns off. I tried using an Axxess Trigger, but then my amp never turns on.

How is your trigger wired?

Mine is wired as follows:

• Pin 1 (black): ground
• Pin 2 (purple): ground
• Pin 4 (pink): ground
• Pin 8 (blue): Remote input on MS-8
• Pin 9 (brown): Remote output from stock HU
• Pin 10 (gray): Amp mute output from stock HU
• Pin 11 (yellow): +12v

[FRANK121]

So can somebody list what type of amps should not pop, or better yet, list the brand and model that retain all the stock functions of the factory BA radio and do not pop on power off?

To add to the equation. I had the X3 harness hooked up to power My Fosgate Sub amp and had NO pop. When I replace the stock BA amp and fed the Fosgate Sub amp thru the new amp pass thru. I have the NR16 GLI on all the RCA connections and now I get the power off pop thru both amps?

[Steve@Subthump]

Originally Posted by FRANK121

So can somebody list what type of amps should not pop, or better yet, list the brand and model that retain all the stock functions of the factory BA radio and do not pop on power off?

To add to the equation. I had the X3 harness hooked up to power My Fosgate Sub amp and had NO pop. When I replace the stock BA amp and fed the Fosgate Sub amp thru the new amp pass thru. I have the NR16 GLI on all the RCA connections and now I get the power off pop thru both amps?

All amps that can amplify will retain all the functions of the car. In your case the pop is coming thru your 4ch amp and being passed on. This is why I have always recommended the JL amps over anything else because they tend to filter it out by themselves and give off no pop at all. One thing you can do is instead of getting your sub signal from the 1st amp, split the signal before the amp via some "y" adapters. Then it will be hooked up the way you had it before you replaced the amp.

[FRANK121]

does JL make a 4 channel amp that has 100watts x 4 @ 4ohms with a pass thru for the sub amp?

Would these amps work without the pop?

JL Audio XD400/4 (75watts x 4 @ 4ohms) Low wattage?
JL Audio HD600/4 (150watt x 4 @ 4ohms)

[PIPE]

My system still pops when ignition is turned off and I'm using Jl amps.

[Steve@Subthump]

You don't need 100w per channel for the fronts. The more power you send to the front, the louder it will make your chimes and onstar voice. 60-75w is plenty for most of us. The xd amps have rca outs on them.

[FRANK121]

PIPE, Which JL amps are you using that still pop? And are you using the FARK kit with Ground loop isolators?