acerikk Posted May 1, 2016 Share Posted May 1, 2016 (edited) Hi... Just started using my old pair of RB-35s again after they'd been in the closet for a few years. One sounds as I'd remembered. The other is dull...lifeless. After ruling out the tube amp's output, I swapped tweeters. And that's the problem. One bad tweeter. The stock tweeter is stamped 3Ω K-130-DN. Poking around on the web I'm not able to locate an exact replacement. What I have found is a K137 rated at 8Ω. (Btw I've sent an inquiry to Klipsch about a replacement tweeter but have not heard back.) Since the impedance is different, I have to presume that the K137 isn't a drop-in replacement in spite of what the web stores that sell them say. And I know very little about the math behind speaker loads. So my questions are...... - If I simply replace the 3Ω tweeter with the 8Ω unit, how does that impact the RB-35's impedance? - If direct replacement throws the RB-35's impedance too far off the original overall 8Ω rating, would there be something that can be done elsewhere to maintain the original impedance?? Perhaps via the crossover?? - If somehow direct replacement is mathematically fine, how might the different impedance affect the sound?? Thanks all...... Edited May 1, 2016 by acerikk Quote Link to comment Share on other sites More sharing options...
Deang Posted May 1, 2016 Share Posted May 1, 2016 Resistance and impedance aren't the same, you also have the sensitivity issue to deal with. You can also call Klipch - be sure to have the serial number of the problem speaker on hand. Quote Link to comment Share on other sites More sharing options...
acerikk Posted May 6, 2016 Author Share Posted May 6, 2016 Thanks for checking in. Called Klipsch. Fella there said the 8ohm K137 is the drop-in replacement, regardless of the fact that it's replacing a 3ohm K130....although he was unwilling to put it in writing. So I've installed replacements and hoping for the best. Still don't see how the impedance on the whole RB-35 unit stays within spec. But the output transformers on the power amp aren't getting hot....so I guess it's good?? Quote Link to comment Share on other sites More sharing options...
pzannucci Posted May 6, 2016 Share Posted May 6, 2016 Considering that it is high frequency, you can typically get away with lower impedance since it doesn't use as much power. The only problem I would worry about if the level is reasonable, is that the crossover point has changed. The crossover may have been made for the other impedance which throws this new one way off. 1 Quote Link to comment Share on other sites More sharing options...
mustang guy Posted May 6, 2016 Share Posted May 6, 2016 I hope you are planning on buying a pair of them. Also, get Ti if they are available. 2 Quote Link to comment Share on other sites More sharing options...
jason str Posted May 6, 2016 Share Posted May 6, 2016 Klipsch gave you bad advise, shame on them. Listen to pzannucci. Quote Link to comment Share on other sites More sharing options...
mustang guy Posted May 7, 2016 Share Posted May 7, 2016 Klipsch gave you bad advise Listen to pzannucci. A Klipsch person gave bad advice. Shame on that person. I wouldn't throw the whole company under the bus. Amy Unger will haunt you. I did some calculations, and if you put an 8 Ohm tweeter in place of the 4 Ohm tweeter (let's call it that), you are cutting the high pass filter frequency by more than double. By my calculations that comes to about a 1KHz HP filter on the new tweeter instead of the intended 2500Hz of the stock diaphragm. Have you called Crites? I would. Quote Link to comment Share on other sites More sharing options...
bhendrix Posted May 7, 2016 Share Posted May 7, 2016 (edited) I'm guessing the "3" to be a partial stamp of an "8". You can buy replacement tweeters from Speaker Exchange for $38. http://reconingspeakers.com/product/klipsch-rb-35-rf-35-tweeter/#prettyPhoto According to Speaker Exchange info, it appears you might NOT have received bad advice from Klipsch folks. Edited May 7, 2016 by bhendrix 2 Quote Link to comment Share on other sites More sharing options...
pzannucci Posted May 7, 2016 Share Posted May 7, 2016 I'm guessing the "3" to be a partial stamp of an "8". You can buy replacement tweeters from Speaker Exchange for $38. http://reconingspeakers.com/product/klipsch-rb-35-rf-35-tweeter/#prettyPhoto According to Speaker Exchange info, it appears you might NOT have received bad advice from Klipsch folks. 3 ohm did sound odd. Great detective work! Quote Link to comment Share on other sites More sharing options...
jason str Posted May 7, 2016 Share Posted May 7, 2016 Look anything like >this< Quote Link to comment Share on other sites More sharing options...
bhendrix Posted May 7, 2016 Share Posted May 7, 2016 (edited) Intersting....... The Klipsch parts spreadsheet from September, 2008 shows the K-137 (160744) as the RB-35 tweeter, per the Speaker Exchange site. A search resulted in no finding for the K-130 (160734) application. Edited May 7, 2016 by bhendrix Quote Link to comment Share on other sites More sharing options...
mustang guy Posted May 7, 2016 Share Posted May 7, 2016 Intersting....... The Klipsch parts spreadsheet from September, 2008 shows the K-137 (160744) as the RB-35 tweeter, per the Speaker Exchange site. A search resulted in no finding for the K-130 (160734) application. ...The stock tweeter is stamped 3Ω K-130-DN... Good catch Jason. Quote Link to comment Share on other sites More sharing options...
pzannucci Posted May 9, 2016 Share Posted May 9, 2016 Too bad someone wasn't close so they could run an impedance sweep on the tweeter. Quote Link to comment Share on other sites More sharing options...
willland Posted May 11, 2016 Share Posted May 11, 2016 (edited) When I bought a pair of RB-35's a few years ago, both tweeters were dead. Ordered "replacement" tweeters which were K137's and the RB-35's were back to rocking within a week of ordering. No issues whatsoever with impedance or amp heat, etc. Bill Edited May 12, 2016 by willland Quote Link to comment Share on other sites More sharing options...
pzannucci Posted May 11, 2016 Share Posted May 11, 2016 If they were off, it would likely show itself with changes in the frequency response from the original sound. Very unlikely to make the amp complain. Quote Link to comment Share on other sites More sharing options...
acerikk Posted May 17, 2016 Author Share Posted May 17, 2016 (edited) Thanks again to everyone who's chimed in. Attached a photo of the faulty tweeter. Speakers purchased new in '04 or '05. I installed a pair of K137s and it's certainly a huge improvement over the single bad K130. Are the RB-35s working at the best of their potential?? I don't know. But it ain't bad. And it's a huge improvement. And nothing seems to be overheating.... Edited May 19, 2016 by acerikk Quote Link to comment Share on other sites More sharing options...
mustang guy Posted May 17, 2016 Share Posted May 17, 2016 I'd say you are fine. Your ears are the best judges, and more impedance will not hurt your equipment. You have a slightly different crossover point now, but if the new crossover point seems pleasing it may explain why Klipsch started using the 137's over the 130's. Quote Link to comment Share on other sites More sharing options...
thenewprofessional Posted July 19, 2016 Share Posted July 19, 2016 Help!! I just acquired a set of RF-35's and one of the tweeters is bad. I took a picture of it and it has K-134-DN and 160740 on the back and it is a 3 ohm tweeter. I read your posts and some others and the K-137 was the replacement. Unfurtunately, now the K-137 has been discontinued. One of the speaker parts stores is suggesting to use a K-138 from the synergy series as a direct substitute. Although they seem to be the same in most respects, the K-137 was made of titatium and the K-138 is aluminum. I need help getting a titanium substitute. Any suggestions? What would I need to look at, other than whether it has the correct hole pattern to attach to the plastic bracket to make it work? Quote Link to comment Share on other sites More sharing options...
mustang guy Posted July 20, 2016 Share Posted July 20, 2016 (edited) I have an old pair of JVC SK-S22's. They blew tweeters like crazy, and I found out there was no high pass filter on the tweeters. They were natural roll off. That is crazy, but it explained a lot. LOL Any way, I decided to just change things out so I bought a pair of off the shelf 3 way 2nd order 8 ohm networks and a pair of half way decent tweeters. They weren't a perfect fit, but I made them work. The speakers no longer rely on natural rolloff, and they shouldn't blow these tweets out now. My point being, if you are daring, you can see about getting a Ti tweeter here and making it work. http://www.parts-express.com/cat/tweeters/17?N=19813+4294967118+4294964873&Ne=10166&Nrpp=99999&Nrs=collection%28%29%2Frecord%5Bendeca%3Amatches%28.%2C%22P_PortalID%22%2C%221%22%29+and+endeca%3Amatches%28.%2C%22P_Searchable%22%2C%221%22%29%5D&PortalID=1 Good luck. Edited July 20, 2016 by mustang guy Quote Link to comment Share on other sites More sharing options...
thenewprofessional Posted July 20, 2016 Share Posted July 20, 2016 thanks mustang guy, I appreciate the comment and willingness to help. I was hoping not to have to change the crossovers and maybe pick something from the same brand. I was thinking of attaching something from other reference series. maybe like rf-62's? What should I be looking at when choosing a different tweeter? Quote Link to comment Share on other sites More sharing options...
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