Amplifier turn-on/off "thump" questions

[yitzac1990 1]

So here's a quick overview of my setup as it sits:

amplifier - older Lanzar Vibe 420 (http://www.autotoys.com/x/product.php?productid=2393)

Front components - Polk db6501 (Brand New, http://www.sonicelectronix.com/item_9109_Polk-Audio-db6501.html?SearchClickout[query_id]=10352811&SearchClickout[ignore]=1)

rear subwoofer (bridged on amp channels 3/4) - older Kenwood 10", 150 wRMS, single 4 ohm, in a 1.36 cu ft ported box

remote turn-on module - (http://www.sonicelectronix.com/item_18693_PAC-TR-4.html?SearchClickout[query_id]=10352736&SearchClickout[ignore]=1)

So for some reason, even with the turn on module providing a 2 second delay, I still get a lot of "thump." I put it in quotes because it doesnt thump just once, it seems like it oscillates, starting at a fast rate, and slowing til it stops, all over about 3 seconds. During this time, my sub and mid woofers reach max excursion. I have no idea why it is doing this, but I know it is the amplifier. Any ideas?

Also, lately my amplifier has been hitting thermal cutoff and going into protect mode, but only if the volume is at a certain level or higher. My pioneer radio goes up to volume 62, and every time the volume is set to at least 35, the speakers start crackling, then the amp suddenly goes into protect. Although, this could have been due to my last set of components being blown? I literalyl just installed the Polks, tested them out pretty loud for about 30 sec and they sounded fine. I'll see what happens with these speakers, but if its not the speakers, any ideas?

Last, I bought an in-line noise filter (http://www.sonicelectronix.com/item_26831_Axxess-AX-ANR1000.html) to suppress my alternator whine. Does it get installed in the yellow constant battery wire, or the red ignition wire? I installed it in line of the yellow wire (constant), and the radio wouldnt even turn on. Maybe I just chose the wrong wire? I took it out and am now waiting for an answer here lol

Sorry for the long thread, hope someone can help...

Thanks!!

P.S. - if you need a video of what exactly the turn on sound is like, let me know.

[Tirefryr 1,741]

You have a noise issue somewhere. I'd be willing to bet, the noise filter you bought is inducing the current issue. It's not related to turn on or off issues, this is a signal issue. Remove the noise filter, then find the true root of your alternator noise.

[yitzac1990 1]

well the noise filter IS removed. Like I said, with the noise filter installed per the instructions, the radio wasnt even getting power. Maybe I got a defective filter? But I installed it on the constant 12v line, should it go on the ignition wire instead?

I read this article (http://www.termpro.com/asp/pubs.asp?ID=121) and followed the steps mentioned to pinpoint the source of the noise, and the only option left is good ol' alternator whine that I need a filter for.

[ricksi30 923]

Are your grounds solid? Have you tried grounding elsewhere?

[ricksi30 923]

What head unit do you have?

[sefugi 166]

Are your grounds solid? Have you tried grounding?

Loose or dirty grounds can cause many issues, I would start by checking them.

[Tirefryr 1,741]

well the noise filter IS removed. Like I said, with the noise filter installed per the instructions, the radio wasnt even getting power. Maybe I got a defective filter? But I installed it on the constant 12v line, should it go on the ignition wire instead?

I read this article (http://www.termpro.c...pubs.asp?ID=121) and followed the steps mentioned to pinpoint the source of the noise, and the only option left is good ol' alternator whine that I need a filter for.

You don't need a filter for alt whine. You need to find the reason you are picking up alt whine and alleviate that. Filters do nothing other than add another possible point of interference. Ask yourself how many times you have seen a filter used for noise. I guarantee it will be less than a handful if so, they were used with lower end equipment in a less than ideal install.

[yitzac1990 1]

the HU is a pioneer DEH-P7900BT. it is grounded directly to the chassis. The amp is grounded to a bolt that is within a few inches of it that is used for a grounding point for some other wires (stock on my vehicle).

I havent seen many installs needing a filter, but thats because Im usually just interested in a subwoofer. this is my first time using a 4-channel amp to run components and a sub. After reading that article I posted, I narrowed it down to needing a filter. If im wrong, that's fine, any suggestions on what to do??

Thanks

[Tirefryr 1,741]

I'd start with moving your ground around. Using the same grounding points as other items can induce noise. Even a poorly crimpled terminal can cause an issue.

[yitzac1990 1]

you mean the amp ground right? ok ill try that first, hopefully later today. Some good news though, with the new speakers the amp no longer goes into protect mode

[yitzac1990 1]

So i tried "enhancing" the amplifier ground; soldered the already crimped ends of the ground wire, and sanded down to bare metal the point where the wire attaches on the car. I think the volume of the whine went down a little, but it is definitely still there.

I made these brackets for my amp to suspend it off the floor while its under my seat:

Do you think these could have anything to do with grounding issues? The part of the seat they are attached to is all painted, so no electrical current going through them...

Also, about my turn-on problems, I took a short video of what exactly happens:

http://imageshack.us/clip/my-videos/441/ggk.mp4/

It gets pretty annoying, on top of the constant alternator whine.....any more help is appreciated!!

[Tirefryr 1,741]

I like to isolate my amps, but it's not a necessity. While there is a load of pain there, I guarantee you have continuity to ground through those brackets. I highly doubt that to be the issue.

The issue might be with your HU as well. Pioneer has has an issue the past several years with fused on the RCAs,

[shizzzon 461]

lookup PICO fuse.

[AgentTyler 5]

I've heard grounding your RCAs to your deck works too.

[yitzac1990 1]

we'll that deck is about 5 years old. 4v preouts, if it matters. I've had countless subs run off of it and it has never let me down. IMO, its the last generation of actually well made radios.

[yitzac1990 1]

shizzzon, I took a look and I think that's my solution ill give it a try as soon as I can, thanks!! do you think fixing that would also help the funky turn-on behavior?

[yitzac1990 1]

ok so I tried the RCA grounding fix, and although I couldnt do it "right" and solder the PICO fuse internally, I did manage to ground each negative line of the RCAs externally to the radios chassis. WOW!!! It actually worked, and the only time I can hear any engine whine, is when the volume is all the way to 0, and there is barely any whine at that. And best of all, all my turn-on/off noises are gone, and it turns on and off just like normal. Thanks guys!! I love this site!

[AgentTyler 5]

Glad we helped.

[idlewild 0]

That deck doesn't have a pico fuse. It's only in the avic series(video and nav) units. Check your RCA's fortheir install location. Are they near a power source? Are they good equality shielded RCA?. Try running them outside the car and test. If the wine goes away you know it's the RCA

[Tirefryr 1,741]

That deck doesn't have a pico fuse. It's only in the avic series(video and nav) units. Check your RCA's fortheir install location. Are they near a power source? Are they good equality shielded RCA?. Try running them outside the car and test. If the wine goes away you know it's the RCA

While his deck may or may not have it it, the pico wad used throughout all models, not just the Avic units.