# Noise coming from subwoofer



## MichaelKnight (Nov 20, 2015)

I have two floorstanding speakers,a JL Audio E112 subwoofer and a Pioneer VSX-519V_K a/v receiver which is connected to my desktop Pc via optical cable.Subwoofer is connected to receiver via a RCA cable plus Y adapter.

Subwoofer's master volume control is at the middle(0).Subwoofer's channel volume is set to "+4" on the receiver.
Now,when I turn the volume(using receiver's master volume) up to a loud level, I hear a noise/sound coming from subwoofer.When I put my ear on the subwoofer, I hear it's coming from the back of the subwoofer.It's like a cabinet resonance but I am not sure. I think it happens especially if the source material is bassy and the volume is a bit loud. When I turn the volume level down, it goes away.

What may be the cause of the problem?


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## Tonto (Jun 30, 2007)

Hey MK, welcome to the shack. Can you tell us what kind of subwoofer it is?

Try setting the AVR's subwoofer channel back to (0) & increase the volume control on the amp for loudness. It will get louder as you increase the volume on the AVR. Does that make any difference?


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## Todd Anderson (Jul 24, 2009)

I'd have to agree with Tonto. Get the setting on the AVR to zero and then use the gain on the sub to increase or decrease sub impact when the volume is increased.


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## MichaelKnight (Nov 20, 2015)

Thanks for your answers.

I tried setting subwoofer's channel level on receiver to 0 and subwoofer's gain control to 2 o'clock way but I still hear that noise/sound/cabinet resonance(sometimes it's very low,I can hear only if I bend myself towards subwoofer's back).I even tried setting both of them to "0" but still I can hear it.


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## MichaelKnight (Nov 20, 2015)

Tonto said:


> Hey MK, welcome to the shack. Can you tell us what kind of subwoofer it is?


Thanks.It is a Class D amp,1500W RMS(short term) ,12 inches subwoofer.


I think the sound is like caused by a loose screw or something like a (possibly metal) part rattling at the back of the subwoofer or cabinet resonance but I am not sure.


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## Todd Anderson (Jul 24, 2009)

Can you record the sound? Perhaps take a video, post to YouTube, and put link here?


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## MichaelKnight (Nov 20, 2015)

I tried recording the noise using phone but loud bass totally overshadowed the noise, it is not hearable inside the recording.


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## Todd Anderson (Jul 24, 2009)

NP.

What kind of surface is the sub sitting on?


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## MichaelKnight (Nov 20, 2015)

Thanks for your answer.The subwoofer is on hardwood.I also tried running it on carpet, no difference.


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## asere (Dec 7, 2011)

Change the sub cable and see. I had a hum that went away when I changed the cable.


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## Tonto (Jun 30, 2007)

The first thing I would do is make sure all the screws are tight. Where the amp is attached as well as the woofer itself. If all that is ok, and you think it is cabinet resonance, place your hand on the box while it is happening & try to tell where it is the strongest. Pull the woofer & put a dowel across there to beef it up. Dowels are easy to place. If you have good wood working skills, you can get more creative. Let us know if that works.


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## morca (Aug 26, 2011)

Do you own the movie Pulse,plat the famous 10-20 hz piece and you will hear better where the sound come,s from.
I have a old trance cd i used in the car,there is no bass only infrasound.
That would be a good song.

This is not the first E112 whit this problem i read off.


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## Todd Anderson (Jul 24, 2009)

This is a sealed model, correct? So it's not chuffing from a port. 

Run with Tonto's advice...check all screws.. I'd also inspect the rubber surround on the woofer.
Morca has a good suggestion, too... try playing strictly low bass (maybe use REW to play a 40Hz tone). See if that helps you to better identify where it's coming from.

Have you tried unscrewing the woofer and carefully removing it to see if anything has become dislodged inside of the cabinet?


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## MichaelKnight (Nov 20, 2015)

Thanks for your answers.

I was listening to music while paying attention to that noise, in the last days.I have the impression that noise limited to a few songs.I think maybe setting gain control from the subwoofer instead of increasing the channel level from receiver (like you recommended) helped as well.

I will continue testing and if I have that noise problem more, I will try some of your suggestions(but for example, I can't unscrew the woofer and pull it, I think it's risky to do it for a non-technical person like me  ).


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## theJman (Mar 3, 2012)

MichaelKnight said:


> I was listening to music while paying attention to that noise, in the last days.I have the impression that noise limited to a few songs.I think maybe setting gain control from the subwoofer instead of increasing the channel level from receiver (like you recommended) helped as well.


That wouldn't have helped if there truly is something loose. By turning the trim down 2dB and the gain up 2dB that's basically a net zero outcome, so you're essentially back to where you started with regards to overall output. Unless it was a placebo affect, the noise may not be associated to anything loose if that made a discernible impact.




MichaelKnight said:


> I will continue testing and if I have that noise problem more, I will try some of your suggestions(but for example, I can't unscrew the woofer and pull it, I think it's risky to do it for a non-technical person like me.


I reviewed the E112 and removed the driver to take some pictures, so I know what's involved. With that in mind... if you're the least bit uncomfortable it's probably a good idea for you not to do that. The JL Audio driver is quite heavy for it's size, and the amount of room you have to work with is pretty minimal. That makes it a bit of a challenge.

If you haven't already tightened down the driver and amplifier screws I suggest you go that route first. Don't torque them down, just nice and snug is all. In order to function correctly the E112 needs to remain hermetically sealed. Even a slight air leak can cause a noise, one which would be far more pronounced during times of heavy usage.


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## Todd Anderson (Jul 24, 2009)

Are you sure that this noise isn't coming from something else in your room? A floor board, wall...some other object?


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## MichaelKnight (Nov 20, 2015)

Thanks for your answers.I haven't had time to test the subwoofer for a while so this is a bit late post...



> Todd Anderson:
> 
> Are you sure that this noise isn't coming from something else in your room? A floor board, wall...some other object?


Noise comes from other objects like windows, but I am sure with some songs it also comes from subwoofer's back.

Should I turn the screws toward left or right to make them thight?


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## Tonto (Jun 30, 2007)

To the right.


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## MichaelKnight (Nov 20, 2015)

Thank you Tonto.


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## RLouis (Jan 20, 2010)

My guess>> Sounds like one of the components came loose from the plate amp.


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