Aufwuchs Posted February 23, 2007 Share Posted February 23, 2007 Hi, if you have read my other posts recently, I have just recently obtained a pair of EV Aristocrat spekaers. These are a 16 ohm system, with 16 ohms clearly marked on the X36 crossover and T35 tweeter. I recently recapped the crossover, and while I had the cabinet apart I measured the resistance on each of the drivers, after disconnecting them. The two T35's measured 4.8 and 6.1 ohms, the two SP12 full range speakers measured 8.3 and 10.1 ohms, and the terminal measurment (with drivers reconnected and new caps) measured 9.1 and 10.8 ohs. I had thought that 16 ohm T35 tweeters should read closer to 13? Whats the deal here? Damaged coils? Replaced with incorrect diaphragms? Nothing to worry about? Thanks for any help......The world of compression drivers is new to me (except in my Forte II's which were new enough that I never had them apart). Quote Link to comment Share on other sites More sharing options...
BEC Posted February 23, 2007 Share Posted February 23, 2007 The T-35s have probably had the diaphragms replaced at some time with 8 ohm. The 16 ohm diaphragms were out of production for 20 or more years until I had them placed back into production a few years ago. Bob Crites Quote Link to comment Share on other sites More sharing options...
Aufwuchs Posted February 23, 2007 Author Share Posted February 23, 2007 Thanks, Bob. Would I be better off having the diaphragms replaced with 16 ohm, adding resistance, or leaving them as is? Quote Link to comment Share on other sites More sharing options...
BEC Posted February 23, 2007 Share Posted February 23, 2007 If the crossover is meant to have 16 ohm tweeters, 16 ohm would be better. Of course replacing the diaphragms on those T-35s if they are the very old ones, is a real ordeal. Bob Crites Quote Link to comment Share on other sites More sharing options...
Aufwuchs Posted February 23, 2007 Author Share Posted February 23, 2007 They are the older models, I think. White with chrome horn. How do you feel about autoformers (these were recommended to me in another post regarding a different problem). If autoformers are not a good option here, could you PM me about having the diaphragms replaced? Quote Link to comment Share on other sites More sharing options...
BEC Posted February 23, 2007 Share Posted February 23, 2007 If the readings you took are correct, you need to do something anyway. The readings should be very close to each other to have about the same output. Then again, if the T-35 are very old, because of the possible loss of magnetism and the difficulties getting a new diaphragm installed and centered properly, it is pretty much a crap shoot on how well they would match. You can look at this link on rebuilding a T-350. The procedure is pretty much the same for the very old T-35s. http://forums.klipsch.com/forums/thread/872129.aspx Bob Crites bobcrites@mac.com Quote Link to comment Share on other sites More sharing options...
Aufwuchs Posted February 23, 2007 Author Share Posted February 23, 2007 Wow, that diaphragm replacement job takes much more skill than I have. Its funny that the readings for both the SP12 and T35 were lower in one speaker than in the other. Quote Link to comment Share on other sites More sharing options...
Aufwuchs Posted February 23, 2007 Author Share Posted February 23, 2007 Well, I just spoke with the original owner who said that the cabinet had not been opened since he built them...so no new diaphragms. Perhaps I didn't get the measurment right. Quote Link to comment Share on other sites More sharing options...
BEC Posted February 23, 2007 Share Posted February 23, 2007 Do those tweeters actually say that they are 16 ohm on the back of them? Could be meant to be 8 ohm. Bob Quote Link to comment Share on other sites More sharing options...
Aufwuchs Posted February 23, 2007 Author Share Posted February 23, 2007 They actually do say 16 ohm on the back of them. I have been reading about the difference between measuring DC resistance(which is what I did) and actual impedance, but this still doesn't seem to account for the large difference I found. Luckily they seem balanced to my ear with the l-pad set on 3 or 4 (out of 10). Quote Link to comment Share on other sites More sharing options...
BEC Posted February 23, 2007 Share Posted February 23, 2007 8 ohm diaphragms read around 6 ohm DCR. 16 ohm diaprhagm read usually 9 to 10 ohms if they are fairly new. Some of the really old ones should read perhaps 12 ohms because the voice coil back in the old days was aluminum. Bob Quote Link to comment Share on other sites More sharing options...
Aufwuchs Posted February 23, 2007 Author Share Posted February 23, 2007 Well, thanks for all of your input, Bob. I suppose that as long as I can get the sound of the 2 tweeter to match using the l-pads I will live with it. They actually sound quite nice and I never would have guessed that there could be a potential problem if I hadn't broken out the multimeter. (you know what they say about a little bit of knowledge) Maybe I should order a pair of the 16 ohm diaphragms for the future, before they become unobtanium again. Quote Link to comment Share on other sites More sharing options...
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