How do I clean a sticky speaker

Or M1 remover, also available at most hardware stores.

Try Afta - cleans anything!

With all proper precautions when using this flammable agent, lighter fluid often works when all else fails.
I have used in the open air outside of the house for removing the occasional anonymous sticky material that seems to afflict the used components we all buy.
Test a small area to check if the speaker cabinet finish is preserved.
Happy New Year, minus the incendiary display!

Dear Sticky
I have a pair of sl600's, oritinal owner, same problem. I am considering veneering at this point. There is nothing I found that worked, and I started with mild soapy water, then a few over the counter things. Aluminum is a tricky substance to paint, and my guess is that over time, the nextel like finish started to have a reaction to the alum.
good luck.

Any idea what the substance is? You might try some tar remover from an auto parts store. It is safe for car paint, but not sure about your speakers. Like mentioned above, I would try a small inconspicious spot first to see the results.