ninohernes Posted November 14, 2003 Report Share Posted November 14, 2003 Hello all, its nice to be back! I have just had the woofers in my AR-2's serviced by Bill Miller, and they sound great, no more loose spiders and maisonite rings where the surround meets the woofer frame! I have also purchaced a new amplifier. An Adcom GFA-5400. It is 125 watts per channel into 8 ohms and 200 into 4 ohms. This thing is a bottomless pit of clean power! It powered my AR-2's and AR-3's with no problem, never once do the distortion lights come on. Anyway, I love the way my AR-2's sound with the Adcom, but just for collectors sake, I would like to find a pair of the super tweeter attachments for them, the AR-3st. They look just like the AR-2, same cloth and everything, except really small. I have only seen them once on ebay, but they were in lousy shape. I also have a question about them. When you connect them to the AR-2's, it has a crossover in it that just sends bass and midrange frequencys to the woofers and tweeters in the AR-2's and the rest to the 3st. What is the crossover frequency, I am guessing that it is the same as the AR-3, about 7200cps. Link to comment Share on other sites More sharing options...
tysontom Posted November 14, 2003 Report Share Posted November 14, 2003 >Hello all, its nice to be back! I have just had the woofers>in my AR-2's serviced by Bill Miller, and they sound great, no>more loose spiders and maisonite rings where the surround>meets the woofer frame! I have also purchaced a new amplifier.>An Adcom GFA-5400. It is 125 watts per channel into 8 ohms and>200 into 4 ohms. This thing is a bottomless pit of clean>power! It powered my AR-2's and AR-3's with no problem, never>once do the distortion lights come on. Anyway, I love the way>my AR-2's sound with the Adcom, but just for collectors sake,>I would like to find a pair of the super tweeter attachments>for them, the AR-3st. They look just like the AR-2, same cloth>and everything, except really small. I have only seen them>once on ebay, but they were in lousy shape. I also have a>question about them. When you connect them to the AR-2's, it>has a crossover in it that just sends bass and midrange>frequencys to the woofers and tweeters in the AR-2's and the>rest to the 3st. What is the crossover frequency, I am>guessing that it is the same as the AR-3, about 7200cps.Hello Joe!The AR-3st ("super tweeter") is actually an AR 1-3/8-inch dome tweeter from the AR-3 or AR-2a (4- or 8-ohm versions, depending on which one you wish to use). It does have the components for the 7500 Hz crossover. They are fairly rare, but quite a few were made during the early 60s. There was also an AR-3t, which was the 2-inch midrange and the 1-3/8-inch tweeter mounted in a small enclosure.--Tom Tyson Link to comment Share on other sites More sharing options...
ninohernes Posted November 14, 2003 Author Report Share Posted November 14, 2003 The AR-2 as is sounds excelent to me. Will the addition of the 3st or 3t drastically change the frequency response from what it is now, or will it just improve stereo imaging? (However, stereo imaging is great now) Link to comment Share on other sites More sharing options...
charger3834 Posted November 15, 2003 Report Share Posted November 15, 2003 Joe,According to the 1961 AR catalog, the AR-3st could be used to convert an AR-2 to the equivalent of an AR-2a. This would of course extend the frequency response and the high frequency dispersion. It does not officially indicate that the AR-3t can be used with an AR-2. However, assuming that you could, you would have the equivalent of an AR-3 with a 10" woofer. Since you own AR-3's, have young ears and you are musically inclined, you would best be able to judge if this is a worthwhile venture. Link to comment Share on other sites More sharing options...
charger3834 Posted November 15, 2003 Report Share Posted November 15, 2003 Joe,I would tend to think that the supertweeter would extend the on axis response from about 15000 cps to about 25000 cps. Link to comment Share on other sites More sharing options...
tysontom Posted November 16, 2003 Report Share Posted November 16, 2003 >The AR-2 as is sounds excelent to me. Will the addition of>the 3st or 3t drastically change the frequency response from>what it is now, or will it just improve stereo imaging?>(However, stereo imaging is great now)Joe,I don't think adding the super tweeter would effect the stereo imaging, per se, but would make the high frequencies "blossom out," as they used to say, for lack of a better expression. Most of the directional clues for imaging reside in the two 5-inch midrange drivers; and because the crossover frequency is so high, the tweeter will just give the speaker more extension and spaciousness to the sound. The two midrange drivers in the AR-2 were OEM drivers that were modified extensivly by AR with butyl rubber around the surround and fiberglass under the cones themselves for damping. The frequency response of these drivers extended only up to about 13 kHz, but the frequency response was uniform.--Tom Tyson Link to comment Share on other sites More sharing options...
ninohernes Posted November 16, 2003 Author Report Share Posted November 16, 2003 >The>frequency response of these drivers extended only up to about>13 kHz, but the frequency response was uniform.>>--Tom TysonWhen I use a tone generator, and a spectrum anayliser, I get response up to 19,000cps. The response drops after that. Link to comment Share on other sites More sharing options...
tysontom Posted November 16, 2003 Report Share Posted November 16, 2003 >>When I use a tone generator, and a spectrum anayliser, I get>response up to 19,000cps. The response drops after that.Joe,That's great that you do get that kind of extended response. When AR published free-field response curves on the original AR-2 tweeters around 1958 (actually they measured only one 5-inch tweeter on axis), the tweeter response was relatively smooth out to around 15 kHz, and then began to fall off after that. Incidentally, I think I was thinking of the AR-1's 8-inch Altec 755A when I said "13 kHz." In any event, the AR-2 tweeters would certainly be "responding" at 19 kHz, but output should be down 8 to 10 dB at the upper frequencies according to AR's original measurements, and that would be consistent with the performance of a 5-inch driver.--Tom Tyson Link to comment Share on other sites More sharing options...
charger3834 Posted November 16, 2003 Report Share Posted November 16, 2003 >>Incidentally, I think I was thinking of the AR-1's>8-inch Altec 755A when I said "13 kHz." >>--Tom Tyson> Is that not a Western Electric tweeter in the AR-1 ? Link to comment Share on other sites More sharing options...
tysontom Posted November 17, 2003 Report Share Posted November 17, 2003 >Incidentally, I think I was thinking of the AR-1's>>8-inch Altec 755A when I said "13 kHz." >>--Tom Tyson>>> Is that not a Western Electric tweeter in the AR-1 ?It is a Western Electric 755A design, but was built under license by Altec-Lansing. I think WE got out of the speaker business quite early on, and sold many of its designs to other speaker companies. You don't often see original WE 755As out there, and all of the AR-1s except possible the very first ones, used Altec-Lansing drivers. Both the WE and the Altec-Lansing 755A 8-inch drivers are virtually identical in every detail except for the builder's decal.Incidentally, the first AR 12-inch acoustic-suspension woofer prototype that was created by Edgar Villchur in 1954 was built using the frame components from a Western Electric 12-inch 728 driver. This was used because all WE drivers were basically bolted together and could be easily disassembled.--Tom Tyson Link to comment Share on other sites More sharing options...
Guest archoi Posted November 24, 2003 Report Share Posted November 24, 2003 HI .ARCHOI is ar collect mania nice too meet you all everyone ar sound is very good style is toomy hobby is repaire of unit sound is one of the greastest the world thanks everyone... Link to comment Share on other sites More sharing options...
tysontom Posted November 25, 2003 Report Share Posted November 25, 2003 >According to the 1961 AR catalog, the AR-3st could be used to>convert an AR-2 to the equivalent of an AR-2a. This would of>course extend the frequency response and the high frequency>dispersion. >>It does not officially indicate that the AR-3t can be used>with an AR-2. However, assuming that you could, you would have>the equivalent of an AR-3 with a 10" woofer. Since you own>AR-3's, have young ears and you are musically inclined, you>would best be able to judge if this is a worthwhile venture. > Brad,I just happened to notice this message again, and thought I would add to it a bit. This is in regard to the AR-3t and the AR-3st "Separate Tweeter Systems."The AR-3t, which used the 4-ohm AR-3 midrange and tweeter, was not compatible with the AR-2 due to impedance mismatch. The 3t was also only offered in the AR-1-style ivory grill cloth for that reason. It was designed to be used with either the AR-1 (woofer portion only) or AR-1W. The AR-3st was designed to be used with the AR-2 or AR-1, and was available in either the AR-2-style grill cloth or the AR-1 ivory grill cloth.--Tom Tyson Link to comment Share on other sites More sharing options...
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