Royd Audio Speakers

A common fault with Minstrels is the gumming up of their drivers. This also affects other models that share similar drivers (Doublets, Envoy etc). The coating on the driver cone is, intentionally, ever so slightly viscous and can ‘run’ into the voice coil, preventing the free movement of the cone. Often occurs with speakers left unused in storage or in a hot climate. This can often be remedied by carefully cleaning the gum away from the voice coils.

I’d like to thank ‘The Captain’ (PFM) for the details below on how to de-gum the drivers.

Before you begin
* Firstly: have a look at a basic driver internal diagram picture (cross section) so you know more aware of what you’re doing before. i.e. you need the pole piece & the surrounding adjacent aluminium cylinder (which holds the delicate coils around its rear) completely free of one another; this is where the gum collects.
See here and here.

Speaker Cone Cross-section

* Secondly: just be aware of the 2mm gap in the aluminium voice coil cylinder, where you can just see the coils behind:- DON’T poke at these (common sense will kick in re this, I’m sure).

Procedure
Piece of paper, cut a 4 x 1 cm bit. you will GENTLY insert the shorter end in so make it long enough to hold. curve it slightly so it matches as accurately as you can the gap curve. now just gently go in & just prize out a tiny bit at a time the black gum. work round, careful enough not to force the gap anywhere at all.. you can go deep, but remember the diaphragm (rubbery concertina’d affair) is at the bottom so don’t dig in.. and you should be ok.. providing, in my experience the reason its gummed is not because of being turned up too loud and the voice coil is damaged as a result. Once the cone becomes free’er of the pole piece, use a cotton bud (alcohol, or dipped in something sensible) to gently remove gubbins from around the pole piece, gently working the cone in a bit at a time until they become detached from each other.

Further discussion on this subject can be found these Pink Fish Media threads here, here and here.

Disclaimer:
www.roydaudio.com accepts no responsibility or liability for damage incurred as a result of following the above procedure. Use your common sense!