Kuja Posted September 10, 2005 Report Share Posted September 10, 2005 Hello everybody,Can you help me in identifying these AR 12" woofers?On this site I've read about many versions of this driver.On all posted pictures, no matter what version of the driver, magnets are round.On my drivers they are square. Why they were made this way?Any thoughts on their quality compared to other 12" drivers?http://www.kujucev.com/ar/ar12inch_a.jpghttp://www.kujucev.com/ar/ar12inch_b.jpg Link to comment Share on other sites More sharing options...
ToastedAlmond Posted September 10, 2005 Report Share Posted September 10, 2005 I am almost positive the magnets on the 12"ers inside my AR-9's were also square, and original. Steve F.? Tom T.? Link to comment Share on other sites More sharing options...
soundminded Posted September 10, 2005 Report Share Posted September 10, 2005 My AR9's woofers look just like that. They were demos under warrantee and betewen the dealer and AR they had to replace all of the drivers due to damage on the showroom floor by people poking their fingers in them. The originals had the round magnets though. Link to comment Share on other sites More sharing options...
ToastedAlmond Posted September 10, 2005 Report Share Posted September 10, 2005 So what do you think the chances are that the same thing happened to my woofers? I purchased my AR-9's from the cantor of a synagogue. He told me he was in fact the original owner, and the woofer surrounds were as rotted as they should've been for 23 year olds when I got them. Link to comment Share on other sites More sharing options...
soundminded Posted September 10, 2005 Report Share Posted September 10, 2005 It's strange about the surrounds on the AR9 woofers and lower midranges. Mine are 21 years old. I have just started to notice deterioraton to one small spot on the surround on one of the lower midranges but so far it hasn't affected the sound. I had a pair of McIntosh ML1Cs and after only a couple of years they completely rotted away. I kept them near some potted plants which I kept watered. Maybe the environment they are in can accelerate or decelerate the rate of rot. Link to comment Share on other sites More sharing options...
RoyC Posted September 10, 2005 Report Share Posted September 10, 2005 The serial number indicates that they were manufactured in the 24th week of 1982, so that would put them in the AR-9 era.Roy Link to comment Share on other sites More sharing options...
ToastedAlmond Posted September 10, 2005 Report Share Posted September 10, 2005 Cantor Tillman told me he purchased them around 78-79. I tend to believe his original owner statement as when I went to pick them up he was driving them with his original owner H-K Citation 12 power amp. I got them around 2002. One of the guys I work with has AR-94's I believe. The ones with the dual 8" woofs. When he told me about them I stated that the surrounds were probably rotted. Not knowing how to get the sock type grille cloth off, he brought them into the squadron. I yanked off the socks, and two perfect 8" woof surrounds were present and accounted for. This was last year. I asked him about the atmospheric conditions they were kept in and he stated "Nothing special"! Thank you Roy. Link to comment Share on other sites More sharing options...
soundminded Posted September 11, 2005 Report Share Posted September 11, 2005 Plants give off oxygen. I wonder if that had anything to do with my ML1Cs rotting. I always assumed it was the humidity. Link to comment Share on other sites More sharing options...
ToastedAlmond Posted September 11, 2005 Report Share Posted September 11, 2005 I'm onboard with humidity being a big factor in foam deterioration.I'm heavily into oxygen, and I haven't rotted out yet. Link to comment Share on other sites More sharing options...
Wally Posted November 7, 2005 Report Share Posted November 7, 2005 I just acquired a pair of AR-58s speakers.The magnets are square and the part numbers are 561-8217... otherwise identical. They apper to be original drivers because ther was no evidence of them being opened before.Th woofers need to be refoamed. Anyone who has done their own refoaming, whose surround do you recommend? I remember reading that one was preferable to others because it was deeper??? or what???? I can't find that passage again even with the search.I just missed a pair of AR-3a's in good condition... they went for $450 cdn. I'm pleased with the acquisition of the 58's because they have the inline drivers.Looking for feedback on the sound of 58's vs 3a's and preferences.This dealer is also selling AR48's and AR28's. Are the 48's worth getting? Don't have a price yet.Reason I ask, is way back when , I listened to the AR3a's and the AR5's and I remember preferring the 5's overall even though the 3's were the top of the line. The 5's were punchier if I remember. Link to comment Share on other sites More sharing options...
tysontom Posted November 7, 2005 Report Share Posted November 7, 2005 >Hello everybody,>>Can you help me in identifying these AR 12" woofers?>>On this site I've read about many versions of this driver.>>On all posted pictures, no matter what version of the driver,>magnets are round.>>On my drivers they are square. Why they were made this way?>>Any thoughts on their quality compared to other 12" drivers?>I am pretty sure that most of the 200003 12-inch woofers were round-magnet version up until the early 1980s, and then the square-magnet version appeared for awhile, certainly around the 1982 period, and perhaps longer. Probably a different magnet supplier. I am sure that the magnet structure weight is nearly identical to that of the round-magnet versions; i.e., approximately 10-11 lbs or so for the total structure weight. I rebuilt a friend's AR-58s a few years ago, and it had square magnets; I remember measuring the free-air (fs) resonance, and it was consistent with the round-magnet versions at about 18 Hz. I really don't think there is any appreciable difference in that woofer and the round-magnet versions. Some changes occurred to the skiver stiffness as time went on, but the voice coil and magnet strength remainded relatively constant for all of the 200003-series woofers. The in-box performance would be nearly the same, which is to say extremely linear low-bass response with low distortion.Therefore, I wouldn't worry too much about whether the magnet is round or square. The round magnet might look better, but it really doesn't matter from the standpoint of performance. For example, on the 10-inch woofers used in the AR-2ax and some other models, the magnet type went from a slug-type Alnico to a square-type ceramic-ferrite. Overall, the performance was pretty close to identical.--Tom Tyson Link to comment Share on other sites More sharing options...
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