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AR11 tweeter and mid


Guest dogmeninreno

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Guest dogmeninreno

Are the AR11 tweeters and mids the same as the AR3a's. This probably has been addressed but I cannot find the threads. Thanks, Dale

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Hello Dale

I have on my 79 parts list the mid #1200010-1 for the 10pi,11.3A,LST

the tweeter#1200011-110pi.11 only the 3A is a part# 1200013-1I believe there was somthing about the cutouts for the terminals being diff Tom said alot about this in the past.

JIm

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>Are the AR11 tweeters and mids the same as the AR3a's. This

>probably has been addressed but I cannot find the threads.

>Thanks, Dale

Dale,

The 4-ohm midrange drivers are fundamentally the same on both the AR-3a and the AR-11, and they are interchangeable. However, the original 1-1/2-inch midrange driver on the AR-3a was a front-wired, hard-wired version with leads that soldered to the tweeter terminal strip on the front baffle board. On the AR-11 and the last versions of the Ar-3a (and the European AR-3a Improved), the drivers were wired from the back and used push-on StaKon-type solderless connectors. If you had an early version of the AR-3a, and want to use the later version midrange driver, you can still do this but you have to solder a lead-out from the solder eyelets on the front and then connect in the usual fashion to the terminal strip. The wire is taped to the front baffle the way the original ones were done. Occasionally it is necessary to notch out the midrange cutout hole to allow for the driver to fit properly. Also, the protective aluminum screen covering the driver is recessed flush with the front mounting plate (which also got a bit thicker in the later versions), rather than being glued to the outside of the plate on the original versions. The third iteration of the midrange driver was the AR-10Pi and AR-11 "B" versions, and they used a pink fiberglass with silver screen and black-painted top plate vs. the earlier orange-fiberglass color. This version is also electrically identical to the original versions.

The 3/4-inch, 4-ohm tweeters on the AR-3a and the AR-11 are not the same and are not interchangeable even though they use the same magnetic structure and mounting configuration. These tweeters differ in response and sensitivity characteristics. The AR-11 tweeters were originally orange in color and were back-wired version. Later "B" versions were black, but the same configuration. The AR-3a tweeter -- a treated-paper, hard-dome affair -- was front-wired up until 1974 or 1975. At that point AR eliminated the tweeter terminal strip and the hard-wired connection and used tab connections on the inside of the speaker as with all the other new speakers. Therefore, you can sometimes locate the back-wired AR-3a tweeters, which are characterized by the two solder lugs on the front of the tweeter at the edges (there are actually two versions of this variation), which go through to the back push-on tabs. These can also be adapted to the earlier hard-wired version by soldering a lead to those lugs, and connecting to the terminal strip. The cabinet again usually needs to be notched slightly to allow for the tab connectors on the back.

--Tom Tyson

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The AR-11 and 10Pi were the first AR speakers to have ferrofluid-cooled 3/4" tweeters. Because of this, the 11's tweeter had tremendously increased power handling compared to the 3a's, and thus could accept a significantly higher voltage drive level through the crossover.

This, coupled with the new tweeter's higher sensitivity relative to the older 3/4" dome, resulted in the 11 and 10Pi having a considerably improved high frequency power response compared to the previous "Classic"-era speakers.

The dome midrange and 12" woofer of the 11 were, in fact, identical to the latest production 3a's. Only the tweeter was different among the three drive units. But because of the tweeter, the crossover was completely changed to take advantage of the newly-found high frequency output capability, and that is what made the 11 so fundamentally different from the 3a.

Steve F.

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  • 12 years later...
On 5/15/2004 at 3:51 PM, Steve F said:

The AR-11 and 10Pi were the first AR speakers to have ferrofluid-cooled 3/4" tweeters. Because of this, the 11's tweeter had tremendously increased power handling compared to the 3a's, and thus could accept a significantly higher voltage drive level through the crossover.

This, coupled with the new tweeter's higher sensitivity relative to the older 3/4" dome, resulted in the 11 and 10Pi having a considerably improved high frequency power response compared to the previous "Classic"-era speakers.

The dome midrange and 12" woofer of the 11 were, in fact, identical to the latest production 3a's. Only the tweeter was different among the three drive units. But because of the tweeter, the crossover was completely changed to take advantage of the newly-found high frequency output capability, and that is what made the 11 so fundamentally different from the 3a.

Steve F.

I was wondering if there was a graph comparing the 3a and 11 tweeters. I thought I came across an off axis comparison a while back, but can't find it now.

Thanks!

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On 5/15/2004 at 1:09 PM, tysontom said:

The 4-ohm midrange drivers are fundamentally the same on both the AR-3a and the AR-11, and they are interchangeable. However, the original 1-1/2-inch midrange driver on the AR-3a was a front-wired, hard-wired version with leads that soldered to the tweeter terminal strip on the front baffle board. On the AR-11 and the last versions of the Ar-3a (and the European AR-3a Improved), the drivers were wired from the back and used push-on StaKon-type solderless connectors. If you had an early version of the AR-3a, and want to use the later version midrange driver, you can still do this but you have to solder a lead-out from the solder eyelets on the front and then connect in the usual fashion to the terminal strip.

Or... Do what I did.

My AR-3s had 1 bad mid and 2 bad tweets, so I decided to convert the speakers to AR-3a's. I plan to keep these, so re-sale value was not a consideration.  btw--those originals tweeters are ridiculously heavy! And with brittle front-wired leads, it's an invitation for disaster.The process included:

  • Building a new AR-3a crossover (it's more complex than the AR-3)
  • Replacing the tweeters with Hi-Vi units
  • Replacing the mids with AR-11 units

Since the new drivers are back-wired I just abandoned the terminal strip and used StaKons for back wiring.

The "a" pin wasn't used on AR-3a's but this is sort of a hybrid, so I figured "why not?" The 3rd photo shows an original grille, 4th shot is new Mellotone grille. Only drawback to the AR-11 mid is it can show through the grille.

-Kent

 

originals.JPG

HiVi and AR11 (3).JPG

fronts (2).JPG

new grille.JPG

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