My infinity rs 3b speakers have been fine for 5 years. Suddenly last week after a power surge then failure while listening to music my left channel speaker has lost all sound from the woofer besides an occasional crackle then the speaker plays fine for about five minutes then shuts back off with a crackle. My emit tweeter also quit functioning at the same time but won't make any sounds I switched the speakers with the speakers from the other channel and the speakers are fine. What could be wrong with the crossover. That's where my problems are I'm guessing and I can't find any other rs3b crossovers anywhere. I also can't get the crossover to come out of the cabinet even with all the screws removed.
Infinity rs 3b problems
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avguytx
Lunatic Member
I assume you're talking about the RS-IIIb with the dual 10" woofers, polydome mid and EMIT per cabinet, right? It's rather odd that one crossover got messed up and you're not mentioning that an amp was damaged as well. Crossover wise, the IIIb's are mounted differently than the a's. I have a pair of IIIa's and they unscrew then separate from the back wall which makes them easier to work with. The IIIb's I believe are glued in and you will probably have to remove both woofers then maybe get a wide "chisel", or something similar, and separate the glue that is holding them in place. You'd have to re-glue them back in but that's nothing major. Those speakers are 40 years old and electrolytic caps don't age well plus they have L-pads (or rheostats) that will need to be cleaned. Also check the fuse(s) and fuseholder(s). You'll have to do some troubleshooting.
StimpyWan
Addicted Member
The IIIA/B crossover schematic can be found on Infinity-Classics.de. It may not be 100% accurate, as Infinity often did running changes to speakers, without documenting the updates.
IIIA/B Schematic
IIIA/B Schematic
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StimpyWan
Addicted Member
In looking at the schematic, the woofers have a 600uF series capacitor. That may have been blown, to where it charges and then discharges, resulting in the volume fluctuations. Two of these in parallel, should work as replacements.
300uF NPE
I'd replace the caps in both speakers, just in case. A total recap would be a bad idea either.
Also, the tweeters have a 1A-30 circuit breaker, that may have blown. Parts Express sells replacement breakers. This should work:
1.5A 100W
Good luck.
300uF NPE
I'd replace the caps in both speakers, just in case. A total recap would be a bad idea either.
Also, the tweeters have a 1A-30 circuit breaker, that may have blown. Parts Express sells replacement breakers. This should work:
1.5A 100W
Good luck.
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thirdicomplx
Member
You mentioned a power surge. Have you tested to make sure the left channel of your amplifier/receiver is working correctly?
Even revision update documents themselves may not be accurate. This schematic shows a couple of obvious labeling errors:
Seen another copy of this same revision where tweeter is labeled "TWEETERS" and woofers labeled "WOOFER."
Maybe they cranked out revisions too frequently to thoroughly proof the docs ...
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I figure I have to recap the crossover figure I was going to use some real good caps looking at getting the polypropylene caps and redoing both speakers at the same time. The rheostats seem to work just fine don't think I need to mess with them. There is a noticeable change when they are turned.
Thank you I needed to find the schematic just got the crossover out this afternoon and some of the caps look burnt I mean they are so black they are illegible.
Definitely thank you do you have any preference between polyethylene caps and polystyrene was looking for the best I can get. I fine with spending a couple hundred bucks on capacitors to rebuild both crossovers
The funny thing I did not mention is the poly dome mid speaker plays just fine no issues at all. The amp survived and the other speaker survived. I went ahead and switched my infinity speakers out for some technics by pioneer speakers. sorry about the mess my mother in law got sick and moved in with us and everything is jam-packed in my house
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StimpyWan
Addicted Member
For loudspeaker crossovers, many use polypropylene capacitors. Widely available and not too expensive, you can find poly caps at Parts Express, Parts Connexion, and Madisound. Personally, I like Mundorf and ClarityCap brands. But, Parts Express sells their Dayton brand, plus Audyn, Jantzen, and Solen. Parts Connexion and Madisound have ClarityCap and Mundorf. Obbligato caps get good reviews too, but I haven't tried those. Oh, Sonic Craft sells SoniCaps, another well respected brand.
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