Avalon Acoustics?

Yes, there was trouble with mounting the new mid range in the Isis speaker and it's deeper thickness did break the the silicone ring and also forced the back glue all over the back. Although they have a beautiful looking speaker their prices have become out of control and they are no longer competitive with other great sounding speakers.

@missioncoonery   You're right on the money.  I remember a few years ago the price for Isis speakers which was already substantial jumped 50% in a couple of years for no apparent reason.  Avalon prices now aren't even in the ballpark of being competitive with other speaker manufacturers and so the company has become irrelevant. 

Samgar2 If your replacement mid is 1/4” higher then there would be trouble mounting into the cabinet. 
Note the black goo they use to get the back of the driver to mount flush against the supporting stud inside the cabinet.  If the new mid is indeed thicker it would spread the goo all over the place causing a mess.  

Manufacturers End of life drivers a lot of times. And speaker makers have no choice but to source new ones.  Are you talking about the C90-6-079 (vs the old 078) mid or the D20N6-31 tweeter?
if they use a 12dB per octave crossover I am certain they’d have to reverse the polarity and notate that the red dot.  

I agree with you in regard to their drivers not made to spec. I purchased new mid range drivers from them and they were  at least 1/4 “ higher in overall thickness and the wire attaching device was reversed in terms of polarity compared to the original one it replaced. I think they sold me knock off. 

Call me a skeptic but I am hesitant to believe that the drivers are made to spec.  I do see wood spacers and ferrules which I can understand for mounting purposes.  They addressed the leaking goo syndrome that plagued the Eidolons and Ascendants appropriately I think.  

They make a good speaker, however they use mostly Acuton diamond and ceramic midrange drivers made to their specifications. The bad news is  if you need to replace any drivers  they have to be purchased from Avalon and their pricing is extremely high. Got abused once and will never do that again.

What happened.....they became too over priced.One of my favorite speakers over the years and I've owned a few models but last time I looked which I admit has been a while,their cost are just stupid.Way better speakers available for way less money...thats what happened, IMO.

I seem to recall they showed at the 2017 RMAF , but in a different hotel than where rmaf was held ,. Down the street from rmaf's location.

My last contact with Avalon Acoustics was to replace self inflicted damage to a standard Eidolon tweeter which was handled very smoothly over three years ago.

My second hand news is quite dated that their sales staff has changed somewhat and are prioritizing their efforts in the European and Asian markets. You’re asked to contact Avalon directly for current U.S. marketing.

http://www.avalonacoustics.com/where_to_audition.html