subwoofer makes pop noise?

Printed From: the12volt.com
Forum Name: Car Audio
Forum Discription: Car Stereos, Amplifiers, Crossovers, Processors, Speakers, Subwoofers, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=102403
Printed Date: June 09, 2024 at 4:03 AM

Topic: subwoofer makes pop noise?

Posted By: neofate
Subject: subwoofer makes pop noise?
Date Posted: February 21, 2008 at 12:45 PM

Hey guys,..

I just got an Alpine CDA-9886 installed in my 1994 LS 400 Lexus. -- Had them wire it to the factory speakers (factory amp that leads to factory 8" sub).

It looks great, sounds great, and overall I love it.

However, the sub 'pops' when you turn the car off. It sounds just like if you were to unplug or plug in an RCA input to say a Powered Floor Subwoofer on your home theater setup. That is the best way I can describe the sound.

The only thing I know the installer did a little different was he wanted to give the factory sub a little more punch because it wasn't hitting as hard as it did with the factory head unit after he put in the Alpine -- So he got this little red (I think red) box and installed in inline to the sub. He said it was like a mini amplifier.. and sure enough it gave the sub woofer a little more punch.

Surely I don't have get that piece removed to take away this 'pop' on the sub when you cut the ignition off? -- is there anything you guys can think of that I could do.. Or take it back to the installer and tell him this is what I've been told is a good thing to try to remove that pop.

When I left I wasn't aware of the pop.. so if I heard it I would have mentioned it then. Hopefully this is a common thing that you experts can say .. yeah thats no big deal this is probably happening.. just change this wire to this.. or add this isolater thingy inline here.. etc.

Again the speakers are factory, and it consists of this:

4 Door speakers, all are 4inch. (These speakers are not amped factory, they are amped by head unit) .

Then there is a 5th speaker, which is the sub woofer (8inches) that is free-air/IB factory that is powered by a factory Pioneer amplifier at about 40watts. (Sub comes up from trunk and sits in front of the third break light on the deck behind the backseat. (Has a cover etc).

Thanks for any help! I will monitor this thread, and hopefully I can get an idea and take it back today and get something quick done to it , to take that *pop* out of it.

I'd prefer not to remove whatever that inline amp red box thing is, because it really makes the factory sub sound better.

the unit, if you are familiar with the Alpine CDA-9886 has independent controls for the sub, and a crossover built in. He wired it up where it actually works on the sub.. (I guess because it already had a factory amp.. ) -- He said he probably wouldn't be able to get that part to work with the factory sub, but it ended up working anyway.

Here's a pic or two if it helps..

posted_image

and we ran the ipod extension and a USB extension to console which is handy:

posted_image

Thanks so much

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-Neofate

Replies:

Posted By: audioman2007
Date Posted: February 21, 2008 at 2:07 PM

Does this ONLY happen when you turn the car off? Does it do it when you turn the headunit off? It could be that the factory amp is keeping a small amount of power inside when the car is turned off thus causing it to make the sub pop. It could be getting a spike when the car is turned off. I get a spike in my speakers when I turn my headunit on. I dont get it when I turn the car on. But if I have the car on, then turn my headunit on, I get a pop. Its a spike. It wont hurt the sub though.

Posted By: DYohn
Date Posted: February 21, 2008 at 2:10 PM

A "mini amplifier"? Not a good idea. The factory sub uses a factory amp and should not have any sort of power booster applied to it. Go back and have them remove the "little red box" thingy. If you insist on using the factory speakers, you will have to live with the quality trade offs that implies. If I was you, I'd replace of them all as soon as you can afford to do so.

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Posted By: neofate
Date Posted: February 21, 2008 at 5:18 PM

audioman2007 wrote:

Does this ONLY happen when you turn the car off? Does it do it when you turn the headunit off? It could be that the factory amp is keeping a small amount of power inside when the car is turned off thus causing it to make the sub pop. It could be getting a spike when the car is turned off. I get a spike in my speakers when I turn my headunit on. I dont get it when I turn the car on. But if I have the car on, then turn my headunit on, I get a pop. Its a spike. It wont hurt the sub though.

Yes only when when I turn the ignition off..

No, it does not occur when I turn the headunit off manually.

I know it isn't hurting the sub,.. was just curiuos if there was a way to stop it. Apparently there isn't with this configuration. Oh well.

Thanks

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-Neofate

Posted By: audioman2007
Date Posted: February 21, 2008 at 5:38 PM

I would first do what Dyohn said about taking it back to get the booster removed. That might be causing the amp to pop. If that isnt the cause, then you simply have a spike caused by the amp staying on for a split second longer than when the vehicle is turned off. The amp gives off that spike through the output of the sub.

Posted By: neofate
Date Posted: February 21, 2008 at 5:39 PM

DYohn] wrote:

"mini amplifier"? Not a good idea. The factory sub uses a factory amp and should not have any sort of power booster applied to it. Go back and have them remove the "little red box" thingy. If you insist on using the factory speakers, you will have to live with the quality trade offs that implies. If I was you, I'd replace of them all as soon as you can afford to do so.

Ok I was being a little 'coy' --

It is a Power Driver to be specific. It slightly increases the voltage on the signal going to the Sub.

I am not removing the Driver for a number of reasons.

The Alpine head unit does not put out the voltage to the pre-out channel for the sub that the factory unit did. Lexus pushes their speakers hard,.. especially the IB subs. The voltage from the Alpine was between 1-2v lower than what the factory unit utilized. So the Power driver was put in place.

You have to understand, with the factory head unit in.. The sub and speakers sounded great, and the sub was powerful.

When the alpine unit went in, the 4 speaker channels were great.. the sub was very underpowered due to this voltage.

With the correct voltage increase the sub, once again, performed to its capability. It of course, sounds better with the alpine unit due to the digital processing and digital content I am able to run through it as opposed to the factory unit.

I do, intend on replacing all of the speakers in the car as time and money allows. For now the headunit was first priority. Which is why I went with a 9886 , a unit very capable of handling a very hefty 'sound system'.. expandable and so on.

You also should realize that not all factory speakers are the same. -- Factory speakers generally equivalate to utter crap. In the case of the LS series with their Pioneer and Nakamichi synergy, the Lexus factory speakers are not bad. They are not two 12's with 800 watts... but they are much better than average. -- Again though, I still intend on replacing them within the next 6months or so, sub/amp first, followed by doors.

I am very happy with the sound I have achieved with this setup. The alpine unit has taken the factory speakers beyond the factory sound. Which, again, was not bad. The sub has independent control and crossover built into the 9886, as such I can adjust the sound to the music and the setup.

The only quality 'trade-off' involved here was the Alpine unit not being designed to run a 'factory amplified sub' at X voltage. This was corrected. However the trade off I will have to live with is in order to correct the voltage difference there is a 'pop' when turning off the ignition... until I replace the factory sub with an aftermarket IB design amped at about 300Watts.

I asked this question mainly because it does not occur when the unit is turned off manually. It also does not occur when the car is turned on. Only when the ignition is turned completely off. So I thought there might be something to adjust this sudden 'power loss/build up' or whatever it might be.

I asked the installer, and he .. said.. mine does the same thing.. nothing you can do about it unless you want to remove the power driver. -- As an aside: he also was rushing on the job using unnecessary force trying to figure out how things came apart, as I was watching him prying part of the console apart he was cracking plastic and he slipped and his little pry rig went up to the side of my leather seat. He ripped about a 3 inch hole into it. I wasn't happy, but just walked away. --He said "Well thats not cool." However they are going to pay the bill on that. I got an estimate and for a 2-3inch slit it is going to be $85 at the cheapest place I could find so far. (Still looking for someone cheaper)--

This was unnecessary because it was in the middle of the day and they had no customers .. no other customers had come in the entire time. As long as they foot the bill for the repair it doesn' t bother me though.. Though essentially they lost on their markup for the sale by the mistake.

I will probably install all pieces from here on out myself,.. it might take me 'longer', but I won't be tearing anything up because I will be 'careful' and it is my property thus it will be , obviously, respected.

I went to Soundsgreat,.. what can I expect? -- Though at a more 'custom' shop they are even worse. It is really hard to find a spot that you can trust the installers to be 'good' and take their time *If you don't have the luxury of knowing anyone personally there. I might have ended up with better luck at bestbuy. :)

Thanks for the replies.

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-Neofate