Diamonds&Rust Posted December 1, 2007 Report Share Posted December 1, 2007 Years ago I decided not to replace the 2500uF capacitors in my AR-10pi's when I replaced the other capacitors. The idea was that a 2500uF capacitor would "filter" at so low a frequency that it shouldn't be heard, so why bother with it? It was put there for amplifier protection in the AR-10pi and LST speakers (later used in an AR-9 in a slightly different way), and wasn't put in these crossovers to have any sonic effect.After listening to my 10pi's with everything except the 2500uF capacitor replaced, I felt sure that I was right and that the 2500uF capacitor had no effect on anything. But, still, goofing-around with these is a hobby. I enthusiastically participated when Klaus offered to send some Jensen 2750uF (NPE electrolytic) capacitors from Denmark to me. He sent them quickly and then I put them aside. I really wasn't that ready to get *back* into the speakers. I thought, "It can't make any real difference."Last night I decided to take a few minutes and do some tweeter-swapping in a pair of AR-14s. I was going back to original "made in USA" parts from later tweeters. That got more involved than it should have and so I thought that while I was at-it, with the tools pulled out, I might as well quickly change these 2500uF capacitors in my 10pi's just to satisfy myself that it really wouldn't make a difference.I was wrong.Again.How do I accurately describe the difference? I really can't. It's too involved. An inaccurate, or at least incomplete, description might go something like this:The entire "sound" of the speaker is affected in a very positive way when this capacitor is replaced, but it's hard to know if the midrange actually improved, or if the mud from the woofer abated so I could hear the midrange detail better, or if I'm hearing my amplifier having an easier time with the load. The general impression is that a slight speaking-into-cupped-hands effect (that I didn't realize I even had) went away. The bass became much more articulate and less prone to being blatty and one-noted. Congestion has cleared and instruments seem to stay separate instead of forming a mash of noise. (again, I didn't think I had a problem - until I heard the speakers without the problem)I've been up essentially all night listening to them because I'm finding the difference in them hard to come to terms with. I can't explain it. I don't even have a good theory. I guess any failing component in the path, no matter where it is, is going to have an effect. BTW - I tested the capacitors that came out of the speakers. They were about 2700uF and 2900uF; both within their 20% tolerance from 2500uF. So they were failing in some other way. What do we expect after 30 years, right? A lot of me has aged in the past 30 years, too.Just as an example, one track I was listening-to has two male voices singing a baritone line. It is much easier to hear the differences in their voices now. Bass guitar has more string to it. Bass pedals have more obvious harmonics. But it's the improvement through the midrange (particularly that portion of piano notes and large stringed instruments <cello, upright bass>) that doesn't make much sense - unless the woofer (which gets up into those frequencies) is just behaving better.I'm so encouraged, I'm going to replace the 2500uF capacitors in my AR-9s. I don't do that without trepidation, but if the 9s are suffering problems like the 10pi's were, I expect my 9s to show immediate improvement in bass clarity (not amount).I'm sorry it took me so long to be able to post this. On the other hand, had I recapped the speakers all at once without listening to them for years with bad 2500uF caps in them, I wouldn't have known that this capacitor has a fairly major impact on the entire cabinet even if you have already replaced all the other capacitors. I finally decided I had to install these (thanks again Klaus) and can report that the 2500uF capacitors also need to be replaced.It was worth the time, money, and trouble. Bret Link to comment Share on other sites More sharing options...
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