it needs to be exactly where it was, to the mm, or it wont be the same speaker. if you move the VC up or down in the magnetic gap, you will alter xmax. if it has shorting rings you will also alter LE.

 

how to rebuild a subwoofer pt 5 of 5 - YouTube

I typed in rebuilding subwoofer ^^^^

http://www.youtube.com/watch?v=AflJtF_dvh0

Sub recone - YouTube

I typed in reconing subwoofer

G'luck !

 

God, that guys voice is boring!

A drop-in recone is easy, done it many times before. I'm talking about rebuilding the soft parts with individual pieces.

I'm not worried about changing the T/S parameters of the sub, I just want to have a go and learn a bit more in the process. I can't find a coil with the exact same winding height, so it's going to be a different speaker anyway. This will give me more or less xmax depending on if the winding height is bigger or smaller than the original, correct?

Does the VC need to be centred in the top plate?

 

if you are just experimenting, then go for it. yes, xmax will change based on VC height. look up overhung vs underhung vc subs.

no it doesnt need to be centered, but you will have non-linear operation as it will be able to push or pull the cone more in one direction than the other.

 

Thanks man.

 

I would disagree.....it DOES need to be centered, as much as possible. Granted, the magnetic center of the gap might not correspond to the physical center of the top plate, for the average consumer there is no way of knowing this before-hand. You're better off centering the voice coil to the top-plate than not doing so.

Also that reconing video sucks IMO. Some CA glue accelerators work so fast that if you apply both at once (such as on the spider landing before the spider has "sat" on the glue bead and allowed the CA glue to wick up through the spider material), the CA glue may start hardening up before you get a chance to get the drop-in-kit situated on the spider landing.

If you can see the top-plate from the top, then you can easily verify the amount of voice coil over-hang for overhung topologies. I usually purposely offset it only because I know that some spiders tend to sag inward with age. Offsetting it off just a tad lets the voice coil stay "centered" for a lack of better words as the driver gets older and the suspension sags. I won't say how much I offset it, because I'm not recommending it as it is solely my personal preference, and not responsible for un-wanted results.

just a pic of me using a dial caliper to set the voice coil height during a recone