Avalon ,discoloration of ceramic tweeter

Light weight small diameter underhung voice coils are more easily overdriven. 1/2" is roughly the voice coil diameter (yep it is tiny - considering most tweeters VC are 1 inch).

As you halve the VC diameter then the surface area to radiate heat becomes FOUR times less. You tend to get thermal compression (distortion) and the tweeters blow all too easily. It is a bad design if you like to play music loud or fill a large space with music. Pro equipment nearly always uses larger diameter VC's and/or compression drivers (horns).

Possibly most of the ferrofluid is gone from your tweeter and it may be on it's last legs. Fortunately the tweeter does not do that much (midrange is far more important) it may be hard to hear any added distortion - try listening to piano carefully.

You burnt the living #$%&* out of them, Best to get the exact tweeters from the distributor and pop in two new ones. Just be careful to attach the wires correctly. I did the same thing but no color chage to my JM/Focals. The fix was very easy but not exactly cheap - and I am not a DIY guy, yet anyway.

Do / did you play them very loudly?

I also own the Avalon Opus, and I do not play them loud. My pair have a light ring of discoloration around the center of the tweeter, so I called Avalon. I was told that the discoloration is generally normal and not a problem.

Basically it comes from a small amount of ferrofluid coming in contact with the ceramic through the gap of the voice coil. If you can hear a problem in the tweeter, or you cant hear the tweeter then you can have them replaced, but tech support at Avalon said they have received tweeters back that were almost completely black in the center that still played and measured correctly.

Alan

Thanks for the responces.

I have never played them loud.
Bought the Avalons used , with 6 months warranty (ended in May).
The dutch importer did listen to the tweeter, and it was sounding fine .
His explanation is similar to Aljordan`s.