Guest goughary Posted May 11, 2007 Report Share Posted May 11, 2007 Does anyone know the Thiele-Small parameters for the 8" midrange and the 10" woofers on the AR90?I was going to research good replacement drivers as an upgrade, but I have know idea what the TS parameters are that I am looking for...Any help would be appreciated. Link to comment Share on other sites More sharing options...
Carlspeak Posted May 12, 2007 Report Share Posted May 12, 2007 >Does anyone know the Thiele-Small parameters for the 8">midrange and the 10" woofers on the AR90?>>I was going to research good replacement drivers as an>upgrade, but I have know idea what the TS parameters are that>I am looking for...Any help would be appreciated.I have some of the numbers you seek but not all. Albeit, these are values obtained via testing on freshly refoamed drivers. Values are average of 2 driver tests. Sorry, didn't test Vas10"Fs 26 hzRe 7.4 ohmsQts .7Qes 1.3Qms 1.5Le .47 mH8"Fs 38 hzRe 5.75 ohmsQts .47Qes .7Qms 1.3Le .42 mHIt's all about the musicCarlCarl's Custom Loudspeakers Link to comment Share on other sites More sharing options...
Guest goughary Posted May 12, 2007 Report Share Posted May 12, 2007 Thanks for that - Two questions for you:First - were they well broken in when you tested them? And Second - How close do you think these parameters are to the original drivers before the old surrounds went bad?I just re-foamed mine, and they sound good, but I want to see if I can find good replacement drivers to test with these cabinets...Had you heard these speakers with original drivers? Do they sound as good with re-foamed drivers? Link to comment Share on other sites More sharing options...
Carlspeak Posted May 12, 2007 Report Share Posted May 12, 2007 >Thanks for that - Two questions for you:>>First - were they well broken in when you tested them? NO, THEY WERE NOT BROKEN IN AT ALL. I HAVE FOUND THE Fs IS USUALLY REDUCED A Hz OR TWO AFTER HOURS OF PLAYING AT RESONANT FREQUENCY SO I DON'T THINK 'BREAKING IN' WILL ALTER THINGS MUCH.>>And Second - How close do you think these parameters are to>the original drivers before the old surrounds went bad?WITHOUT KNOWING THE ORIGINAL PAPAMETERS, I CAN SAY WITH ANY CERTANTY HOW CLOSE THEY WERE TO ORIGINALS. HOWEVER, I WILL SPECULATE THAT THEY ARE REASONABLY CLOSE SINCE THE ORIGINAL SPIDER, VC AND CONE ARE STILL THERE. IT IS WELL KNOWN THAT THE SPIDER CONTRIBUTES ABOUT 80% OF THE COMPLIANCE AND THUS MY SPECULATION. I HAVE RAISED THIS PET PEEVE IN THE PAST REGARDING THE LACK OF ORIGINAL T/S DATA AVAILABLE HERE. >>I just re-foamed mine, and they sound good, but I want to see>if I can find good replacement drivers to test with these>cabinets...Had you heard these speakers with original drivers?>Do they sound as good with re-foamed drivers?I DID THESE FOR A CUSTOMER WHO IS QUITE KNOWLEDGEABLE ON AR EQUIPMENT AND HE REPORTED HIS AR 90'S SOUNDED GREAT WHEN HE REINSTALLED ALL 4 DRIVERS. I DIDN'T HAVE THE CABINETS.It's all about the musicCarlCarl's Custom Loudspeakers Link to comment Share on other sites More sharing options...
soundminded Posted May 12, 2007 Report Share Posted May 12, 2007 >Does anyone know the Thiele-Small parameters for the 8">midrange and the 10" woofers on the AR90?>>I was going to research good replacement drivers as an>upgrade, but I have know idea what the TS parameters are that>I am looking for...Any help would be appreciated.I have found it virtually impossible to find currently manufactured drivers comparable to those used in popular AR speakers suitable for drop in replacements. The parameters are invariably way off the mark. In discussions here about reverse engineering AR speakers with modern alternatives, I've come up largely empty handed. For example, there are no tweeters I've found which come even remotely close to the dispersion of the 3/4" tweeter used in AR3a, LST, and 10 pi. You just won't find one which is only down 5 db at 15 khz, 60 degrees off axis. The current popular speaker design philosophy dictates tweeters which beam their high frequencies narrowly to avoid room interactions, the exact opposite of the AR design philosophy. As for woofers, many designs today look to optimise ported enclosures with fairly hi Q drivers. Even the excellent AS driver Tonegen 1259 has a Vas about double that of the AR 12" design. Most subwoofers have Qms and Vas too high. Also the best current woofers usually don't have paper cones making their response at the upper end of range coverd by AR woofers in 3 way systems unsuitable. Personally, If I had to choose an alternate to the 10" woofers for AR90 I'd look at Parts Express 10" high fidelty reference series. As AR90 is a 4 way system, the woofer only has to operate up to 200 hz so its plastic cone may be ok but the crossover network would have to be completely redesigned for its different electrical parameters and the arrangement of the stuffing would have to be adjusted to achieve a 0.7 damping factor. It's level would have to be matched to the rest of the system too. Most high quality woofers today are wired with 4 ohm voice coils not 8 ohms although those with dual voice coils could be wired in series. Parts Express may be able to give you assistance in that regard. An alternative is to use a separate plate amplifier iwth its own built in active crossover and equalizer which will make the project considerably simpler but more expensive.http://www.partsexpress.com/pe/showdetl.cf...tnumber=295-460 Link to comment Share on other sites More sharing options...
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