A couple of years ago I bought a pair of Yamaha speakers -- NS-1000x's. The NS-1000x is similar to the NS-1000M / NS-1000, with several variations as noted below:

* the drivers in the NS-1000x are aligned in the center of the baffle (like the NS-2000 & NSX-10000) rather than with the tweeter and midrange offset to the side.
* the midrange in the NS-1000x is a JA-0803 instead of the JA-0801 used in the NS-1000M & NS-1000. I'm not sure what differences there are between the JA-0801 and the JA-0803.
* ea. NS-1000x weighs 90.6lbs (ea. NS-1000 weighs 85.8lbs)





When the speakers arrived I discovered that the magnet on one of the woofers had separated from the magnet assembly that is bolted to the basket. There was some breakage of the magnet where the glue held, but overall the magnet appears to be in good condition.

A number of threads on AK describe the repair procedure. It consists of building a jig from a short length of PVC pipe that has been cut lengthwise to allow it to fit over the outer diameter of the magnet assembly and a hose clamp to lock it in place. 6 bolts are spaced around the perimeter and are used to center the delaminated magnet on the main assembly so the voice coil has full excursion without rubbing on the pole piece or the magnet. The delaminated magnet is epoxied in place, taking care not to get epoxy into the gap for the voice coil.

Nice!
Tanx for sharing.

It appears that 6" PVC pipe is not a commonly carried item. It's not available at the local big box home improvement stores like Home Depot and Lowes. I checked a few online sources and the minimum quantity is 8' at about $6 a foot. I only need 4" of the stuff. A possible option is getting a 6" PVC fitting. I saw a short PVC connector for about $20.

The usual process is to apply a slow curing epoxy to the magnet, reassemble the magnet and then connect the jig and then by turning the 6 screws in the jig adjust the magnet so the voice coil is aligned in the voice coil gap without rubbing. That requires removing the dust cap so that clearance can be seen as the adjustment is made.

I decided to do a dry fit since I don't have a jig yet, and then use thin CA to glue the magnet once I have the jig to do the adjustment.

Reassembling the magnet is a somewhat delicate process since the voice coil needs to fit in the gap between the pole piece and the magnet. There is no standard procedure that I know of for doing this. What I did was to take several Sharpie pens and use them as spacers around the perimeter of the magnet and then align the basket by eye. The tricky part is removing the spacers without screwing up the alignment or damaging the voice coil. Getting fingers pinched seems to be unavoidable.

I took photos of this procedure, but for some reason the import wizard doesn't find the pictures on the camera. They are there, and perhaps when Dingus used the camera to take some pics a setting was changed? I'll have to ask him about that.

Got the magnet reassmbled and with the dust cap removed (it's carbon fiber like the cone) visually checked the voice coil gap. Holy chit, there is virtually no gap between the voice coil and the pole piece. I was expecting a small but discernable gap. The voice coil will not move, and I wonder if it will be able to move freely even after adjusting the magnet once I have the jig in place.

This is not going as well as I'd hoped.

Was finally able to upload the pics to the computer.

I was stupid enough to think that you have already done all the job and forget to post all the pics.... Sorry.

I think you need that 6" PVC pipe with urgency, otherwise you could damage something with a bad alignment...you can try find not the whole lengh of pipe but some 6" pipe acessories, like a curve a union or something with the same diameter.
Patience is the key. Keep us posted.

One more thing:
What do you think was the cause of that problem?
I'm asking this because some magnetic materials can lose some of their flux magnetic energy if subjected to shock ( a speaker drop in the floor...).

No apology needed Clint, my initial post wasn't very clear.

I've come to the conclusion that with the banged up pole piece and voice coil the speaker is not repairable as is, and that it's beyond my ability to repair. So I dropped it off this afternoon at a speaker repair shop in Portland called JAMAC to see if they can repair it. When I took it in, the shop owner looked it over and concluded that the voice coil will need to be replaced.

well at least its moving forward. i cant see how anything could be done with it without the help of a professional.

I concur with you guys. A professional help on this matter is a must.
Keep us posted Mark.