Dynaudio 24W-75 problem

[diymax62]

Hello to all, during a reconditioning of a pair of Dynaudio 24W-75 (substitution of the rotten foam surround with a rubber one) I encountered a strange problem of rattling voice coil.

I was sure that the coil was in good mechanical and electrical order, so I started to search the reason of this defect analyzing other possibilities.

Guided by the nature of the scratch sound, I found the source: it is a piece of self-adhesive paper tape placed to protect the coil wire from the attachement to the coil; it tends to separate itself from the aluminium support, causing this particular kind of scratching.

I found this defect on both speakers, here's the solution:
in the bottom of the speaker there is a protective cloth splitted in six part placed to avoid dust from magnetic gap: just remove (by pressing) only the part near the paper tape; you can easily see wich part it is, because the paper tape go through the spider, so you can find it while rotating the speaker placed in profile.
You'll find this (nasty) piece of paper tape with his little (nasty) wings just scratching while entering into the gap: take a toothpick, place a LITTLE drop of cyanoacrylate glue and gently glue the paper to the aluminium support of the voice coil... no more scratching!! Done with success in both speakers.

In attachement you'll find the photo of the speaker with a yellow ring around the described piece of nasty self-adhesive tape.

Good work to all the Dynaudio lovers (and a great new year to all the community)!!!!!

Max