Today my 10-inch subwoofer stopped working. I had a close look at the subwoofer and it is stuck, it won't vibrate. It's like it has been sucked in.

What happened? And can I fix this!!
:cry:

LOL :bowrofl: Sorry, couldn't help myself....I think you need a new sub.

That was my new sub! :doh:

Melted voice coil... If you have a multimeter and it's a 4ohm sub it should read about 2.5ohm or so.

I can still get sound from it, but no bass!

Yep, that's one seized voice coil. Bye-bye sub. Sorry mate... :cry:


The cause of a seized voice coil is usually constant over excursion of the driver, so basically you may have been giving it too much power. As teK-- said, you can test it with a multimeter, but if the driver won't go back and forth when you try and move it with your hand then it's gone. To the best of my knowledge you can't fix this problem, and you're better off replacing the sub.

Having said that, if your amp and sub are well matched and it's setup properly, and you haven't been cranking it all the time, and the sub is new and under warranty, then you might be able to get it replaced. However, it's a long shot and could be hard to prove.

I am trying to work out what happend to my sub. So I don't do it again.

The sub has 2.5" ASV. Voice Coil (4 Layers)
Impedance: 4 OHM


The amp is 2 OHM

My friend thinks I simply put the negative and positive wires the wrong way?

For speakers thats not too bad, they usually just sound weird because theyre out of phase...but for subs, thats bad, REAL bad.

I got a second hand sub off a guy at school a while back, I didnt know too much about subs back then. To cut a long story short + to the - and - to the + = dead sub very quickly. Lucky it was only cheap.

Im not too sure why this is so bad for subs and not speakers???

Actually, wiring any speaker out of phase (or more correctly - in inverted polarity) should not damage it - I mean most sub amps have a phase control anyway which will allow you to change the phase by up to 180 degrees, so it doesn't matter. The only thing this does is reverse the motion of the driver so that it pulls back when given a positive phase and moves forward on a negative phase. Therefore you get a compression when you should have a rarefaction and vice versa.

Well, that's my understanding of it anyway. I'll ask my mates who are training under Neville Theile (As in the guy who helped invent the Theile/Small parameters) to find out more.

You said this was your new sub, did you wear it in?

Ive been recomended by many people to slowly let the sub settle in before you start pumping it. Avoids damaging the voice coil and rubber surrounding thing..

There is nothing wrong with reversing the polarities on your sub. And I've never heard of any exceptions. I run my 10 inch clarion sub with reversed polaritys, and no problems what so ever.

I also have sub control on my HU, and there is a setting in the HU that allows you to have polarity to the sub set to either normal or reverse, and I can say from trying this feature out that it does make a difference to bass production, reversed polaritys sounds alot nicer, Im no expert, but Im guessing due to the reversed motion of the driver and, as Damien stated, and maybe also the way the sub itself is facing, and obviously it comes down to the sub itself, trial and error I spose. But by no means has this damaged my sub.

while on this topic, does switching the rca wires which are connecting to the sub amp have the same effect as reversing the positive and negative wiring of the sub. Or does it change the sound at all? I only ask because someone once told me that it did, but i think it may of been a Brisbane Car Sound worker, so its probably wrong!

The RCA preouts are a signal only an not for driving speakers. Do not reverse them otherwise you'll end up grounding the signal at some point (and results in no sound).

I didn't think reversing the polarity of the driver would damage it. Isn't that what happens when you have something like 4 drivers in a iso-baric incolsure? :confused:

as for the rca's what tooslow said

In total, I've had the polaritys reversed on my sub for 18 months, thats in my old TP and my new TF, and no problems at all, sub still kicks away nicely. And if reversed polaritys could damage a driver, then why would HU's come out with a feature that allows your to reverse it? such as my HU for example.

You said this was your new sub, did you wear it in?

Well, to answer that in one word "NO."

I didn't have it up full, but it wasn't really backed off if you get what I mean.

:doubt:

Well, to answer that in one word "NO."

That might be why.. As far as i know from doing basic electronic courses reversing polarity of a speaker does make it move the opposite way, but produces sound the same (slight loss of quality to the trained ear) But shouldnt damage the speaker in any way.


I didn't have it up full, but it wasn't really backed off if you get what I mean. :doubt:

I dont know what you mean... :confused:

hmmm, inverting the connections isnt supposed to hurt eh....might have just been a dodgy sub....or the amp (home not car) was a bit much, I wasnt cranking it though. Ah well doesnt matter.

Today my 10-inch subwoofer stopped working. I had a close look at the subwoofer and it is stuck, it won't vibrate. It's like it has been sucked in.

What happened? And can I fix this!!
:cry:

Sounds to me like you fried the voice coil. Most likely due to overdriving the sub and most commonly caused by a dirty output from your Amp. With this i mean the Amp is unable to keep control of the Sub at high power levels therefore causing distortion and too much excursion ultimatley leading to a damaged voice coil. Nothing you can do here other then to count your losses and buy a new Sub.

Remember you can buy a low powered quality amp which will outperform a much higher powered lower quality amp and at the same time it will drive your speakers correctly.

When you do buy a new sub perhaps get another with 2 x 4ohm voice coils and wire them up in parallel (make sure your amp is 2ohm stable).

Remember the wattage figures on Amps and speakers are genuinley a crock of s**t so just by good quality american made products and you should be fine.

no the sub is alright!
its just seized....
take the sub out of the box...
have it sitting on a bench and push the sub/cone up... but position your hands around the cone so u distribute force evenly....
depepdning on how stuck it is u might need to give abit of force to it

i did it to my crossfire 15 bmf with 1100rms to it about a year ago and it still works fine now

running a sub with reversed polarity does nothing to the sub... instead of pushing outwards it will suck in wards
sometimes it sound sbetter
i have my sub mounted inverted and wire out of phase and no problems with it
allows u to have a smaller box as u have more voluem in the box cos theres no magnet and structural parts in the box