How do you tell if you have a blown subwoofer - AVS Forum
Forum Jump: 
 
Thread Tools
post #1 of 23 Old 09-29-2008, 09:15 PM - Thread Starter
AVS Special Member
 
saprano's Avatar
 
Join Date: Oct 2007
Location: Bronx NY
Posts: 3,314
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 41 Post(s)
Liked: 204
I was watching war of the worlds today and the scene where the pod steps out the ground my sub started to rattle. its a very bass strong movie with hz getting down into the teens, so i put somthing heavy on top to make it stop. i played the same scene again and it did stop, but now the weight that i put on there started to rattle.
so i took it off and played the same scene again but this time there was no rattle and i noticed the bass seemed weaker. me being worried i played some other movies, and i still noticed a weaker bass. its strong just as strong as before. did i break something? me playing that scene over, and over was that a bad thing?
Then i tried playing a bass heavy music track with my mains un plugged, i could hear the bass but very very little was coming through. it was like the bass was stuck inside, i dont think its all in my head cause i definitely notice something different......could it be the protection circuitry? damaged coil?
its a definitive technology pro sub 1000 10" 300 watts.

home theater addict
saprano is offline  
Sponsored Links
Advertisement
 
post #2 of 23 Old 09-29-2008, 09:44 PM
Member
 
Hurtful Goat's Avatar
 
Join Date: Jan 2007
Posts: 156
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Protection circuitry generally just shuts the amp off. So that isn't it.

The common symptoms of a blown subwoofer driver:

-Unusually weak output (aka sensitivity goes to crap)

-Rattling sound (almost as if the driver is bottoming out at next to nothing)

-No output at all

-Cone or surround are torn or ripped away from the basket or each other (If you can pull the driver, inspect the spider for the same kinds of damage)


I may have missed a few. A damaged (burnt or maybe scuffed) voice coil is a form of "blowing" the driver, I believe (anyone want to chime in on that one?)

-Jason
Hurtful Goat is offline  
post #3 of 23 Old 09-30-2008, 03:53 AM
 
JBLsound4645's Avatar
 
Join Date: May 2006
Location: Bournemouth, Dorset, United Kingdom
Posts: 5,409
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
The cone will be very stiff as you press your fingers down on the cone it will have scratchy sound as you press it inwards.
JBLsound4645 is offline  
post #4 of 23 Old 09-30-2008, 05:22 AM - Thread Starter
AVS Special Member
 
saprano's Avatar
 
Join Date: Oct 2007
Location: Bronx NY
Posts: 3,314
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 41 Post(s)
Liked: 204
What? come on guys this AVS right? i need more answers.......please!

home theater addict
saprano is offline  
post #5 of 23 Old 09-30-2008, 09:12 AM
AVS Special Member
 
Raymond Leggs's Avatar
 
Join Date: Jul 2006
Posts: 3,612
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 12
The voice coil will be melted into the VC former.

One shall stand... One Shall Fall... - Optimus Prime
Raymond Leggs is offline  
post #6 of 23 Old 09-30-2008, 09:25 AM - Thread Starter
AVS Special Member
 
saprano's Avatar
 
Join Date: Oct 2007
Location: Bronx NY
Posts: 3,314
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 41 Post(s)
Liked: 204
i still dont understand, you want me push the woofer inward? i did that already but i didn't hear anything.

home theater addict
saprano is offline  
post #7 of 23 Old 09-30-2008, 09:38 AM
Senior Member
 
iresq's Avatar
 
Join Date: Nov 2002
Location: Annapolis MD
Posts: 403
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
When you pushed in the driver, did it move freely?

Do you have a sound meter? Did you take measurements?
iresq is offline  
post #8 of 23 Old 09-30-2008, 02:31 PM
AVS Special Member
 
rlj5242's Avatar
 
Join Date: Dec 2000
Location: Southaven, MS
Posts: 3,269
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 17
Quote:
Originally Posted by saprano View Post

i still dont understand, you want me push the woofer inward? i did that already but i didn't hear anything.

Then you didn't deform the voice coil former when it hit the back plate of the magnet. There's a good chance there is nothing wrong and the lower bass output is all in your head. As mentioned, you need to measure it so that it can be confirmed.

-Robert
rlj5242 is offline  
post #9 of 23 Old 09-30-2008, 09:53 PM - Thread Starter
AVS Special Member
 
saprano's Avatar
 
Join Date: Oct 2007
Location: Bronx NY
Posts: 3,314
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 41 Post(s)
Liked: 204
Quote:
Originally Posted by iresq View Post

When you pushed in the driver, did it move freely?

Do you have a sound meter? Did you take measurements?

Yes i pushed the driver and i heard nothing. it did move in and out freely.

home theater addict
saprano is offline  
post #10 of 23 Old 09-30-2008, 10:18 PM - Thread Starter
AVS Special Member
 
saprano's Avatar
 
Join Date: Oct 2007
Location: Bronx NY
Posts: 3,314
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 41 Post(s)
Liked: 204
Quote:
Originally Posted by rlj5242 View Post

Then you didn't deform the voice coil former when it hit the back plate of the magnet. There's a good chance there is nothing wrong and the lower bass output is all in your head. As mentioned, you need to measure it so that it can be confirmed.

-Robert

I noticed a difference though, what could it be? did i get use to the sound?
what to look for when i get the spl meter?

home theater addict
saprano is offline  
post #11 of 23 Old 10-01-2008, 09:36 AM - Thread Starter
AVS Special Member
 
saprano's Avatar
 
Join Date: Oct 2007
Location: Bronx NY
Posts: 3,314
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 41 Post(s)
Liked: 204
Bump.

home theater addict
saprano is offline  
post #12 of 23 Old 10-01-2008, 12:16 PM
AVS Special Member
 
rlj5242's Avatar
 
Join Date: Dec 2000
Location: Southaven, MS
Posts: 3,269
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 17
Quote:
Originally Posted by saprano View Post

I noticed a difference though, what could it be?

It could be that you tore part of the suspension and there is degraded output of your sub or it could all be in your head. They same way that more expensive cables make systems sound better. You heard a noise and now something must be broken somewhere.

Quote:
Originally Posted by saprano View Post

did i get use to the sound?

Or you could have damaged your hearing.

Quote:
Originally Posted by saprano View Post

what to look for when i get the spl meter?

If you don't have a baseline set already from when you originally calibrated then you just need to perform a standard calibration using an SPL meter and a calibration DVD like Avia or VE. If you want to take it a step further, then you can graph your sub's in-room response with the meter and a set of test tones. You put the readings into your favorite spreadsheet along with the correction factors for your meter. Graph the results.

-Robert
rlj5242 is offline  
post #13 of 23 Old 10-01-2008, 04:57 PM
 
JBLsound4645's Avatar
 
Join Date: May 2006
Location: Bournemouth, Dorset, United Kingdom
Posts: 5,409
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Quote:
Originally Posted by Raymond Leggs View Post

The voice coil will be melted into the VC former.

Yeah like arch welding.

Quote:
Originally Posted by saprano View Post

What? come on guys this AVS right? i need more answers.......please!

You’ve got enough good answers on this thread to block up the Merseyside tunnel.



I’d seriously change your signature because I know your taking the piss with all of us and I don’t funny anyone.
JBLsound4645 is offline  
post #14 of 23 Old 10-01-2008, 06:34 PM - Thread Starter
AVS Special Member
 
saprano's Avatar
 
Join Date: Oct 2007
Location: Bronx NY
Posts: 3,314
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 41 Post(s)
Liked: 204
Change it for what? i cant ask questions?
anyway im bringing it to best buy to have them check it out. thanks for all the help guys!

home theater addict
saprano is offline  
post #15 of 23 Old 10-02-2008, 03:51 AM
AVS Special Member
 
rlj5242's Avatar
 
Join Date: Dec 2000
Location: Southaven, MS
Posts: 3,269
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 17
Quote:
Originally Posted by saprano View Post

anyway im bringing it to best buy to have them check it out.

Good luck with that. You already know more than your average BB home theater salesperson.

-Robert
rlj5242 is offline  
post #16 of 23 Old 10-02-2008, 05:53 AM
Senior Member
 
evilbeaver's Avatar
 
Join Date: Feb 2007
Posts: 324
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Play some test tones and make sure your mains are crossed-over above whatever tones you use.
evilbeaver is offline  
post #17 of 23 Old 10-02-2008, 04:26 PM - Thread Starter
AVS Special Member
 
saprano's Avatar
 
Join Date: Oct 2007
Location: Bronx NY
Posts: 3,314
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 41 Post(s)
Liked: 204
Quote:
Originally Posted by rlj5242 View Post

Good luck with that. You already know more than your average BB home theater salesperson.

-Robert

I ment for warranty, magnolia is suppose to service or replace anything under difinitives warranty. i might just get a sub from them.

home theater addict
saprano is offline  
post #18 of 23 Old 10-06-2008, 08:43 PM - Thread Starter
AVS Special Member
 
saprano's Avatar
 
Join Date: Oct 2007
Location: Bronx NY
Posts: 3,314
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 41 Post(s)
Liked: 204
So i took took the sub to bestbuy and i think the magnolia guy has no idea what he's talking about. i told him my problem and all he did was plug it in, heard it rumble and told me theres nothing wrong i tried telling him its probably the amp or something is damaged inside, he said it ether works or it doesn't. he said if they send it out to the service center all there going to do is plug it in like he did, and hear that it rumbles and send it back.....what?
so anyway i took it to another bestbuy, and brought it to the geek squad. this guy understood my problem better, so its been sent out for 2 weeks......do you think there going to really fix it? or do what that guy says and just plug it in? do they even know about this stuff as to actually open it up and check inside instead of just hearing that it rumbles?.

home theater addict
saprano is offline  
post #19 of 23 Old 10-07-2008, 07:59 AM
AVS Special Member
 
rlj5242's Avatar
 
Join Date: Dec 2000
Location: Southaven, MS
Posts: 3,269
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 17
That post just proved my point. As you can see, you will get different responses based on who you run into. So there is a chance your sub will land in the hands of a slacker who will plug it in and listen. Someone else may take it apart and test the impedance of the driver with a DMM (something you could have done) and run other extensive tests. It's a crap shoot. That's why we try to educate you on these things so that you can fix your own problems rather than relying on others. If you want something done right, you have to do it yourself. Or pay someone who will.

-Robert
rlj5242 is offline  
post #20 of 23 Old 10-07-2008, 11:14 AM - Thread Starter
AVS Special Member
 
saprano's Avatar
 
Join Date: Oct 2007
Location: Bronx NY
Posts: 3,314
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 41 Post(s)
Liked: 204
Yea you were right not that i doubted what you said about BB workers, trust me i know they dont know anything. but i wanted to see if hopefully they knew what the hell i was talking about, turns out i did know more about the sub than they did, you were right again
speaking of paying to fix it, if my sub does come back un fixed( witch i think it will) do you know any audio dealer, or any place where i can take it to get the job done? i live in bronx new york.
( i should of done that in the first place)

home theater addict
saprano is offline  
post #21 of 23 Old 10-23-2008, 11:20 PM - Thread Starter
AVS Special Member
 
saprano's Avatar
 
Join Date: Oct 2007
Location: Bronx NY
Posts: 3,314
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 41 Post(s)
Liked: 204
I just got my sub back from repair and they said theres nothing wrong with it
i have a 5 year warranty so it got sent out by geek sqaud.

home theater addict
saprano is offline  
post #22 of 23 Old 10-24-2008, 10:52 PM
Member
 
Playdirty714's Avatar
 
Join Date: Oct 2008
Posts: 69
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
My old Kenwood vr-707 receiver had a bug up its alley once in a while and I would have to reset it by unplugging the power cord and holding the power button on the receiver and plugging the power cord back into the power outlet. What happens is somehow the receiver sends out weak signals and I would have to reset the receiver. Try resetting the receiver.
Playdirty714 is offline  
post #23 of 23 Old 10-25-2008, 08:35 AM - Thread Starter
AVS Special Member
 
saprano's Avatar
 
Join Date: Oct 2007
Location: Bronx NY
Posts: 3,314
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 41 Post(s)
Liked: 204
I'll try that thanks, is resetting it the same way on all receivers? i have a onkyo 705.

home theater addict
saprano is offline  
Reply Subwoofers, Bass, and Transducers

User Tag List

Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page


Forum Jump: 

Posting Rules  
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off