How to tell if EMIM or EmIT drivers are in trouble


Hi all,

I am considering buying a used pair of Infinity Renaissance 90s. But I am concerned about the EMIM and EMIT planar drivers. They sound good, but they are reputed to be fragile and to deteriorate with time, and I notice on both of the EMIM's that the diaphragm is slightly bulging/bubbling (maybe a couple oval spots 2-3mm long). I that a sign? Are they likely to give up sometime in teh near future anyway? I am very reluctant to buy them because of the impossibility of replacing the midrange and tweeters if they go. Any words of wisdom, please, you who know?

Thanks,
rnm4
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I'm thinking of replacing my Emit R tweets with another set...or a modern Morel mdt 29 for half the cost...and recommended at my reputable, regional speaker repair shop...any tt thoughts?