LexCiting

What would cause an amp to start "popping'? I have a Sony 1200w amp installed, and whenever I switch a source, the amp starts popping like a gunshot, and then no more bass. It is running a 2 ohm, to a 2 ohm subwoofer. The installer said it is the Pioneer Brain that is defective because it is sending too much voltage to the subwoofer outputs. I don't know if to believe that or not. I have another Pioneer brain on route, so I was wondering what else could be the cause, just in case their explaination isn't the cause of the popping.

Thanks

Lee

~ Man, am I having troubles with my stereo installation!

sktn77a

iTrader: (2)

Well, it could be both. The pioneer brain (?) could be putting out a transient "pop" when changing sources and this is triggering the protection circuits in the amp. If it only happens with the volume turned up, this is the likely explanation. If it happens at any volume level, it could be a ground loop. Of course, it could possibly be a defective component.

Good luck

keith

engin_ear

iTrader: (1)

Could be many, many things, very tough to generalize. Typically the pop comes from a DC voltage being switched in suddenly from part of the circuit, usually some residual charge on a capacitor, etc. If the pop has just started occurring and did not occur earlier, it could be that a component has gone bad in your amp or other electronics, allowing a node to float up in voltage when it is not supposed to. When that node is switched in (either by your amp or otherwise, depending on what's doing the switching in your case), the voltage is discharged thru your speaker(s), causing the pop. One problem in diagnosing this is not knowing whether the unwanted voltage is coming from the source end or the destination end, as there are many possible combinations.
You may want to have someone take a hard look at the device that is doing your input switching, if it is not being done in your amp itself.

LexCiting

Ok here is the deal. We swapped out the 8000R brain, with a new 8000R brain, and the popping became worst. The installer did a voltage reading from my alternator, and he said it is at 13.9, when it should be around 14.5 amps (I think). Anyhow, he said that I am overloading my alternator, and thats what is causing the popping. Someone suggested that I get two 1 farard capacitors (sp ?), to help with the amp (1200watt Sony Xplode going to one 2 ohm 10" sub). They swapped out the amp with 3 other subs, swapped out the subwoofer, same result: Loud popping with any song with bass.

So my question is what the hell is a 1 farad capasitor (sp), what does it do, and does this sound like a good cure to my amp popping? Also are there any aftermarket alternators for the Lex GS4? I don't want to go with an aftermarket altenator, if I don't have to..

thanks

Lee

projectsc

With your problem, a capacitor won't do the trick. I'm not sure how many amps(from the alt) you need but I know you can get your alternator rewound to a higher amperage. If not I would have to think you need a bigger alternator. A capacitor usually only helps for those quick bass hits for dimming lights and such. I'm pretty sure I am correct on this, but Perry and any others please chime in if I'm wrong.

TimDimman

Oh man...that installer is feeding you some bull...

It should read 14.4V at the alt with the car going, probably around 2000RPM...maybe at idle, I'm not sure...but 13.9V is ok.

Is he playing a sine wave through your system, at the resonant frequency of the subs? That's what would test the taxation of your alternator...otherwise music will be too transient to tell if your really taxing your alt.

Caps are a bandaid...they will help with transients in music, but you really shouldn't use them to help make up for a deficiency.

Is the amp shutting down? Overheating? Are all your speakers popping or just your subs?

My best guess would be a loose sub wire, or a bad ground.

Play your music hard and see what the voltage at the amp dips to when bass notes hit. If you're less than 12V then you'll have a hard time charging your system, otherwise, you're probably in the green as far as the alt goes. You'll probably notice that the music is to transient and voltage dips will be instantaneous...

Tim

LexCiting

OK, the popping only happens to the subwoofer in the back, and the is only one 1200w Sony amp powering that subwoofer. My volumn goes to 30. If I play a song with bass passed 19, then the subwoofer starts popping like a firecracker everytime the bass hits. POP..POP....POP...POP Then the amps shuts down, and I don't have any bass from the subwoofer until I cut the car off. The installer said that he swapped out the amp, with another amp, and it still popped. Then he said he swapped the subwoofer, and it still popped. Now I am only guessing if he swapped it or not, but it is blowing me that I can't play any type of music in my car without the popping. Now when I say bass, I am not talking Miami bass, any song of the radio: soft rock, R&B, etc. It doesn't matter. As soon as the bass note comes in: POP. And its not just all bass notes, it seems to be particular bass notes that start the popping.

TimDimman

Oh man...sounds like a good case of clipping to me...

What's your input? Are you using an LOC? Your gains might be turned up way too high...

It sounds like you don't have enough signal for the amp to work with, so you are sending a direct DC current to your sub, probably giving it's voice coil a good slap on one of its plates...(the pop you are hearing)...the clipping is probably sending the amp into protection mode.

The installer may have switched out the amp, but if your input signal is worthless, then more than likely any amp will clip...

Another possibility is the box you used for your sub has a leak, and you are essentially running your sub free air, which could cause the voice coil to tax its suspension.

If you are running an IB sub, then did you get a sub capable of IB? The motor structure might not be strong enough to control its travel...

Anyways, whether or not that's right...that pretty much eliminates the alt as the problem, and more than likely makes a cap absolutely worthless to you.

Any more info you could provide would be helpful.

Tim

TimDimman

Alright...

Just tried looking up your "brain"...

It looks like you aren't using an LOC...

Check your gains, make sure they are properly matched to your input signal.

It really sounds like you are clipping your amp...

What type of Sony amp are you running and are you sure its 2 ohm stable?

Tim

LexCiting

I am using a JL 10W3 as a free air sub. There isn't a box attached. I just swapped out the stock subwoofer and replaced it with the 2ohm JL 10W3. The amp that I am using is the Sony Xplode 1200W Class D, and it says it is stable to 1 ohm. What is clipping, and what is LOC?

Someone told me that I need a box for that subwoofer, and that the manufactor may have said it was a free air, but it needs a box, because it is "bottoming" out. Of course, I don't know what that means.

BananaGS

LOC is the line level converter, the signal comming out of the stock amp is too high (speakers level) you need a line level converter to convert the signal to a lower level.

Clipping meaning, the amp is overloaded, the input signal is too high, if the amp amplify that signal a few thousand time more, then it's too loud, ie draw too much current--> the amp internal circuit is shutting off itself to prevent from being over-heated.

get it. I think sony amp has a LOC built in, make sure you use the LOC, turn down your input gain on the sony amp to the lowest setting for now.

using a non free air sub in an free air application meaning, you need to cut at least 1/2 of the power to the sub, if your sub rate 400W max, then you better not putting more than 200W through that baby, or the center cone will fly off like a rocket. you can use it in free air, but don't put much power through it.

(Power push the speaker cone back and forth-> create sound, if you push a lot of power, then you push the cone back and forth farther and father, until a point where the cone fall apart)

LexCiting

So the signal coming to the amp is too high? So what do I need to do? Just turn down the amp? Is there anyway to prevent this? I also read somewhere about transiet (sp) signals causing popping to subwoofer whenever you switch a source. Thats exactly what is happening. The amp works fine until a output source is switched (Radio to CD changer), or when a song ends, and another songs has more bass. POP POP POP again

Thanks everyone for your input!

BananaGS

LexCiting,
Sony amp input have the input gain setting, turn that down.
if still does not work, look for an LLC from a local audio shop, they all carry it, very popular device.

the LLC may not take care the pop, but it will soften the pop to just a soft click, not loud pop anymore. (or LOC, what ever they call them, the correct name is Line level driver/converter)

I still don't know your set up, your installer should have use the LLC already, if that is the case, turn down the gain on the LLC.

or did you installer use the built in LLC on the Sony amp (don't use the built-in LLC, they are sux, even on good amp), get yourself an LLC, cost around $25


Check out the audio set up on my website. I don't get any pop does not matter what source I change to, turn on or off. No problem, one in a while i head a soft click when I turn on the system, but it barely noticeable. (that is the pay off of using the stock amp/headunit)

DIY#22 stereo upgrade

if that does not work, you may have a messed up stock amp.
I have studied the stock amp, everytime you switch source, there is a 500ms+ mute delay on the stock amp mute signal to ensure soft transition.

Anh

LexCiting

Here is my setup:

Pioneer 7300DVD head unit
Pioneer Navigation 9DVD-AVIC
Pioneer 8000R AV unit
Pioneer TV Tuner
Pioneer 12 CD Changer
Sony Xplode 1200w Amp
JL 10W3 10" Subwoofer

The Sony amp is hooked up to the Subwoofer running at 2 ohms.
All the other speakers in my car are all stock, and running from the Pioneer 8000R brain which is MOSFET and pump 45 watts to 4 channels.

BananaGS

Now I know your setup, you don't need the LLC, because headunit already provides the sub output for the Sony amp.

sorry, can't help much more, I never have this problem when I run all aftermarkets stereo like you.