# blown subby amp



## Guest (Sep 6, 2008)

Hello,

Thanks for providing such a great forum.

I'm new here and hope i'm posting in the correct place?

I have a Jensen Subwoofer and recently have noticed a lack of sound from it. However it does make a distinct low booming noise when changing the selector dial on the receiver. I was wondering if that perhaps my subby amp has blown?

Any help would be greatly appreciated.

Thanks


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## salvasol (Oct 31, 2006)

First of all ... Welcome :wave:



metalfossil said:


> I have a Jensen Subwoofer and recently have noticed a lack of sound from it. However it does make a distinct low booming noise *when changing the selector dial on the receiver*. I was wondering if that perhaps my subby amp has blown? ...


What do you mean when you said: "when changing the selector on the receiver" ... Which selector???

The lack of sound could be the movie/program you were watching (some lack bass sound) ... it also could be the setting on the receiver (somebody might have changed) :yes:

Maybe some more details about the problem and you'll get more suggestions ... and an easy fix :bigsmile:


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## Guest (Sep 7, 2008)

Hello Senior Shackster,

Thanks for your reply.

More details: ok. I've a Jensen SPX-17. I'm not sure exactly how long it's been playing up as it hasn't been used for a while. There doesn't seem to be any bass coming from it at all. However, when moving the gain button on the back it makes a sort of low sighing/woofing sound. And when changing the selector button on the receiver/amp it makes a dull booming thump.

Hope this helps?

Thanks again,


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## robbroy (Oct 19, 2006)

metalfossil,

First, go through each of the items on this list:

http://www.robbroy.net/HT/SubwooferErrors.cfm

Jensen's reputation is not that of quality, so a bad component is not out of the question.

-Robb


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## salvasol (Oct 31, 2006)

metalfossil said:


> ... There doesn't seem to be any bass coming from it at all...


Have you played a CD or movie that you know it contains a lot of bass and the sub doesn't play any??? or are you just guessing, because you can't hear the bass??



> when moving the gain button on the back it makes a sort of low sighing/woofing sound. And when changing the selector button on the receiver/amp it makes a dull booming thump...


The woofing sound when you move the gain it could be the famous ground loop (it makes a hummmmmm sound, specially with the gain at maximum) :yes: ... to fix that you need a ground isolator.

The selector button on the receiver, I assume is to select the source (DVD, CD, tuner, etc.), Right??? ... I think that I have the same problem before (I used a Sony AVR) and when I changed channels the sub was making a noise (not loud but you could hear it) ... that sound went away by itself (it could be the sub cable that is not pushed in all the way, or is bad).

What AVR do you use??? ... Does it have the autocalibration feature??? ... Can you play test tones to all speakers??? ... I'm asking this because you can send a test tone to the sub to see if it works or not. :yes:

You can also check the setting on the AVR to see that the setting is correct :bigsmile:.

Hope this helps...


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## Guest (Sep 7, 2008)

Hello again,

Thanks for the great advice and the robroy link. I've gone through all the options. However I'm guessing its one of the subby components as when I undertake the test tone option on the amp there is nothing at all coming out of the subwoofer.

Could it be something as simple as a cable, or does need to be serviced, and is it even worth it?

Thanks again


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## Mike P. (Apr 6, 2007)

First thing would be switching out the cable from the receiver to the subwoofer and see if that makes a difference. Any chance of using another receiver to verify where the problem is? If you get the same results with another receiver then you'll know for sure problem is with the subwoofer. It's a process of elimination.


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## Guest (Sep 7, 2008)

Hello, 

Just to update with a bit of new info. I've just had an exchange of emails from the Jensen tech. He states that the thumping is due to my home wiring (and can be fixed over the phone). However the subby needs to be returned for a service due to 'reduced output'. can anybody shed any light on what this refers to?

Thanks


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## Mike P. (Apr 6, 2007)

A faulty amplifier would be my first guess. Is the unit still under warranty? If not you should ask what the charges will be to get it fixed.


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## thewire (Jun 28, 2007)

I had an amp that I thought quit working. I called to find out what it would cost to repair it and they wanted $50.00 less than it would have cost me to buy another used one. After I had added the cost of gas and shipping cost to and back to the repair center it might have cost more. I left the amp in my car overnight and tried it again the next day and it worked fine. Something in it was loose I think. Anyway I second the idea to call back to find what it might cost for repairs. Those are pretty expensive. They needed $800.00 just to repair a receiver I had once. Again it would it have been cheaper to get a new one, but I just used the money to get something else.


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## tonyvdb (Sep 5, 2007)

To varify that the it is indeed the sub you can attach it directly to an mp3 player or other source like a CD player, by sending it a signal you will be able to hear something if the sub is indeed working. Then I would suspect that the receiver is not sending a signal out of its output.


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## salvasol (Oct 31, 2006)

metalfossil said:


> ... He states that the thumping is due to my home wiring (and can be fixed over the phone)...


:rubeyes: . :scratchhead: . :huh:


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