AR surround Posted December 29, 2016 Report Share Posted December 29, 2016 Well, I had been warned by many here that my beloved 38 year old AR-9's would eventually need to have their crossovers recapped. I was listening to a quadraphonic SACD on my system (The AR-90's are the front speakers and the AR-9's are the surrounds) when I noticed reduced output from the right rear AR-9. I immediately stopped playing the music and used a white noise test tone on the speaker. The tweeter not only had reduced output but was crackling away. Miraculously, I was pleased to discover upon re-capping that the tweeter DID NOT BLOW. Perhaps these tweeters are very robust, or perhaps the bass-free rear channels of the quadraphonic SACD saved it, or maybe I just dodged a bullet. Anyway, I replaced all of the upper range capacitors. The three smallest capacitors are Dayton PMPC (1%); the 30uF and 40uF caps are Dayton DMPC (5%); the 24uF cap is a Solen (5%) and the 80uF cap was replaced with a Jantzen 82uF (5%). I used Dayton or Janzen wherever possible as I understand that the Solens sound a bit brighter based on what I've read in these pages. I sent the old Callen capacitors, except for one of the 6uF units, to my cousin for measurement. The results are shown in the attached diagram: - One 6uF cap was off by 400%. This is the one that probably had failed and caused the immediate problem with the tweeter. - Both 30uF caps were way off by over 40%. - All the 4uF and 8uF caps still measured very close to their ratings. - The 24uF, 40uF and 80uF caps were in the range of 20% or less than nameplate. Given that both of the the 80uF caps were very close to each other at +15%, I suspect that they have always been that way. It is interesting to note that the AR-9's now sound somewhat clearer the the AR-90's but the 90's sound a tad sweeter. The AR-90's are a bit more forgiving and sound better with crappy source material while the AR-9's are more revealing and sound better with great sounding source material. Regardless, the upper range crossovers of the AR-90's will get redone next month as doing so is inevitable. Much thanks to all of you who provided input on this site regarding recapping these speakers. It was very helpful. AR Surround Link to comment Share on other sites More sharing options...
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