Turn-off thump....... it won't go away.

[Agent WD-40]

Originally Posted by darkrider01

I PM'd Steve earlier, and he does say he has a solution. I respect Steve and trust his experience in this matter. I kinda feel like his solution is something I have already tried, but I haven't tried his exact solution. I'm going to try his exact solution anyway and buy some stuff from him tomorrow, but I figured I would at least explain further everything I have tried in case someone else is looking for info about this problem.

Please share what you find. I have been living with my turn off thump, but if there is an easy solution I would be interested.

[darkrider01]

I will definitely do a write-up when I am finished with this ordeal. Unfortunately, it may be week after next until I can do it. My car goes into the body shop on Monday (a lady backed into my car last Thursday), so I may not be able to get all the stuff from ********.com in my car until end of next week, that's if they can get my car fixed quickly.....

Also, Steve is a very busy man. The fact that he has taken his personal time (sending me messages at 8PM at night) should be reason enough to do business with him. If more companies were like ********, this world would be a much better place.

[netz]

Would wiring your amp remote to a switch fix your problem. Any system I ever install in my cars I always do this. For me I just like the option of cutting my subs off if I'm not in the mood for a lot of bass, and it also comes in handy when they are full blast and you spot a cop. Just a suggestion though.

[PIPE]

Originally Posted by netz

Would wiring your amp remote to a switch fix your problem. Any system I ever install in my cars I always do this. For me I just like the option of cutting my subs off if I'm not in the mood for a lot of bass, and it also comes in handy when they are full blast and you spot a cop. Just a suggestion though.

I dont think a switch per se will fix the problem. And what your describing is what a bass knob is for.

[darkrider01]

Originally Posted by netz

Would wiring your amp remote to a switch fix your problem. Any system I ever install in my cars I always do this. For me I just like the option of cutting my subs off if I'm not in the mood for a lot of bass, and it also comes in handy when they are full blast and you spot a cop. Just a suggestion though.

Originally Posted by PIPE

I dont think a switch per se will fix the problem. And what your describing is what a bass knob is for.

I don't really want a switch. I have a Punch EQ knob mounted under my dash, so I have the ability to turn the bass down. Also, I don't really want any switches anywhere except for maybe a nitrous button

Anyway, I went to Radio Shack yesterday and bought a Single Pole Double Throw relay. It turns out the amp control doesn't provide enough current to actuate the coil. The coil requires 56mA to actuate, the amp control only produces 1.9mA. I could probably solve that with an IC, but at this point, I think I'm going to discontinue the relay path.

I have some other things I'm working on that may fix it, so I'll try to keep everyone updated.

[jeepguy_1980]

Originally Posted by netz

it also comes in handy when they are full blast and you spot a cop. Just a suggestion though.

I would imagine the mute button is just as handy, and located right on the steering wheel.

[darkrider01]

Ok. I beat it. I now have no thump, pop, or anything. I'm now going to work on a complete write up of everything I have learned. I'll probably do it in a troubleshooting format. Once I get with the person that gave the actual perfect solution, I will get it done so that everyone can have "turn-off-thump-free" audio in their cars.

I have been fighting this issue for months - I am sooooooooo happy!!!!!!!

[thahemp]

Audio issues can be a nuisance to deal with (nice way of putting it , but i would guess coming from a bad ground reference. If your ground reference is bad, then the output stage caps on your amp will pop as they discharge. Since you metion the rca inputs, i assume you started with the input ground as opposed to the amp power ground. I would assume the amp has a resistor to ground to bleed off the charge in the output stage caps. As long as you don't feed it a signal, however inadvertently, it should stay quiet.

[austinjames]

Originally Posted by darkrider01

Ok. I beat it. I now have no thump, pop, or anything. I'm now going to work on a complete write up of everything I have learned. I'll probably do it in a troubleshooting format. Once I get with the person that gave the actual perfect solution, I will get it done so that everyone can have "turn-off-thump-free" audio in their cars.

I have been fighting this issue for months - I am sooooooooo happy!!!!!!!

ill be watching for this one. I get too many thumps

[thahemp]

Mine pops a little too a couple seconds after i turn the car off. I don't have much of an amp in my car though... Smaller power, smaller pop. Pops can be caused by bad caps in an output stage too btw. If they're bulging on top it's not a good sign.

[thahemp]

Probably not a bad cap if everyone's pops though

The battery is in the back and easy to get to. I'll see if i can capture some discharges and input audio ground to power ground noise on our scope. Maybe the factory low level audio ground sucks?

[darkrider01]

Originally Posted by thahemp

Probably not a bad cap if everyone's pops though

The battery is in the back and easy to get to. I'll see if i can capture some discharges and input audio ground to power ground noise on our scope. Maybe the factory low level audio ground sucks?

It's not an issue with the amps. My understanding of the cause is that the low level between the BA amp and the radio has a DC voltage on it. The factory head unit remote turn-on stays active for around 2-3 seconds after the car is turned off. When the radio turns off, it sends a mute signal to the BA amp, which I believe actually grounds the outputs or disconnects the inputs to the BA amp (my theory anyway). Aftermarket amps do not have this feature, so they are left on until the remote turn-on drops. When the remote drops, there is still voltage on the inputs which translates to a pop/thump/click when the amp turns off.

The cause is really a moot point. The solution or solutions (outside of replacing the factory head unit) are what I am exploring. I have explored every avenue I can imagine (even making my own circuit board with a low voltage relay) and I have only found one definite solution so far. Steve at ******** has given me one more avenue of possibility that I will explore in the next day or two and then I'll reveal one definite solution, and maybe 2 solutions if the ******** method works for me. I'm not going to reveal the definite solution until I have spoken with the person who sent me item that fixed it for me. If he wants to try and make a little profit from the solution, I won't stand in his way. I was at the point that if nothing fixed it, I was going to order a Scosche kit and a Pioneer DEH80PRS. I like the factory head unit (bluetooth, ipod control, dash matching contour) but not enough to suffer the pop.

Aside from whether Steve's method works for me, he has been very helpful and supportive. His products (which I paid for) have been wonderful for helping me troubleshoot and will be great for my finished install. Translated: buy stuff from ******** - their products are excellent quality and they are the only ones making the X3 harness. Steve has been trying hard to help me fix this.

[thahemp]

Yep. I bought his harness too. Oem connectors can be very difficult, if not impossible to get in small quantities. Grounding problems can likely be solved without replacing the factory head unit though. The DC voltage is just a bad ground when compared to the battery ground. It's impossible to say much more without actually looking at it on the scope.

[Agent WD-40]

Looking forward to seeing what you present.