Subwoofer
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=50150
Printed Date: May 22, 2024 at 9:00 PM
Topic: Subwoofer
Posted By: aaronU
Subject: Subwoofer
Date Posted: February 15, 2005 at 11:54 AM
Ok, a (long) while back I bought an MTX thunder form box. It had a 5000 in it and I sent it back under warranty and they sent me a 6000. I have used that for a number of years.
2 questions.
I have a small pickup. Why does the sub sound so much louder with the window down (it seems that they need to be below ear level).
The speaker seems to be damaged slightly. It works fine almost all of the time. When I turn it up louder is when the problem show up. I dont know exactly the correct way to say it, but if the speaker was at rest it is pushed out farther than normal. When the speaker is playing this causes it to extend out to the maximum and distort. After I am out of the vehicle for a while the speaker returns to normal. It seems that playing it loud makes the cone come loose. What would be wrong with it?
Replies:
Posted By: Steven Kephart
Date Posted: February 15, 2005 at 12:42 PM
So when you turn off your system, the cone is still extended forward for a while? Or are you just saying that when you play the subwoofer the "center" position moves forward a little bit? If it is the latter, then that's called DC rectification. There really isn't anything you can do about it. But if it just started doing this recently then I would be worried. What amplifier are you using? Do you have a friend with a system that you could test the sub on his amplifier and see if it does this? If you could provide more information it would be helpful. Thanks! Steven Kephart Adire Audio -------------
Posted By: aaronU
Date Posted: February 15, 2005 at 1:13 PM
The cone is extened forward even with the system off. It started doing it a while back. I am using a Rockford amp, 2 channel, I can't remember the output on the amp, but it is far more than enough for the 10" sub.
Posted By: DYohn
Date Posted: February 15, 2005 at 2:16 PM
Disconnect the speaker from the amp. If the cone does not return to the normal resting position, I bet you have a partially burned voice coil and it is binding mechanically. Gently press the cone in with your hand and see it it feels or sounds like it is scraping as it moves. Or IF it moves. ------------- Support the12volt.com
Posted By: Steven Kephart
Date Posted: February 15, 2005 at 3:27 PM
Definitely try what DYohn mentioned. However my suspicion is that it is an issue with the amplifier and not the sub. The reason I say this is that if it was a voice coil issue you would hear the distortion at all output levels, not just when you really turn it up. Steven Kephart Adire Audio -------------
Posted By: aaronU
Date Posted: February 15, 2005 at 3:55 PM
Ok, I'll have to give that a try.
Thanks
Posted By: newtone
Date Posted: February 15, 2005 at 4:23 PM
the set up sounds louder when the window is down or door is open because the sub is in an improper enclosure. i think that means the box is to small, not sure though. did you have the same problem with the 5000? also check for bad rcas before trashing your amp. ive had subs pop and make all types of racket because an rca was going out. too, on a side note.
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Posted By: aaronU
Date Posted: February 15, 2005 at 4:34 PM
I think it was the same way with the 5000. I wasn't sure if it was a problem or maybe just the acousitcs of the vehicle or small air space in the vehicle.
My guess would be that it is a problem in the speaker. The amp can be completly off and it still stays in the same position.
Posted By: customsuburb
Date Posted: February 15, 2005 at 4:41 PM
Your sub might sound different because of the change when you roll down the window. It has to do with the sound wave devoloping and it can devolop more if a window or door is open. Sorry I dont really know how to explain it but I know there is a good article that talks about placement of a subwoofer in the vehicle, and how it was louder in different positions.
Posted By: aaronU
Date Posted: February 15, 2005 at 4:46 PM
I thought it was something like that.
Posted By: jeffchilcott
Date Posted: February 15, 2005 at 10:44 PM
here is a odd tid bit. On a term lab meter we hit 140.3 with the windows up. but 141.7 with the drivers window all the way down, if you watch alot of shows, you will see people cracking windows and flapping doors. something about the pressure in the car can fully build if it has room to expand outside of the vehicle
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