AR Timeline & Dating

[Guest Droog]

For years I've a KLH speaker collector, but this now extends to AR since I found a very nice pair of early 2ax

for $10. Im looking for a timeline on production (year introduced and year discontinued) on the model 1,

2, 2a, 2ax 3, 3a and 4x. Also would a serial number of 9600 on a 2ax be a first year speaker.....what year?

[tysontom]

>For years I've a KLH speaker collector, but this now extends

>to AR since I found a very nice pair of early 2ax

>for $10. Im looking for a timeline on production (year

>introduced and year discontinued) on the model 1,

>2, 2a, 2ax 3, 3a and 4x. Also would a serial number of 9600

>on a 2ax be a first year speaker.....what year?

The AR-1 was introduced in 1954 and discontinued in 1966 but available for a period of time after that. The AR-1x was the replacement for the AR-1, and it was introduced in 1966 and discontinued by 1969 or so.

The AR-2 was introduced in 1957 (just about the time that Henry Kloss departed AR) and was replaced by the AR-2x in 1965.

The AR-2a was introduced in 1959; the first AR-2ax (style with the 1-3/8-inch tweeter and Alnico woofer) was introduced in 1964; the second-series AR-2ax (new woofer and 3/4-inch tweeter) in 1970. The AR-2ax series was discontinued around 1975 or 76 (replaced by the AR-14 from the Advanced Development Division).

The AR-3 was introduced in late 1958 (commercially available in early 1959), and it was discontinued in 1973.

The AR-3a was introduced in 1967 and discontinued in 1975.

The AR-4 was introduced in 1964, discontinued in 1965 when the AR-4x was introduced. The AR-4x was discontinued around 1973 or early 1974 when the AR-4xa was introduced. The AR-4xa was replaced in 1976 by the AR-16 from the Advanced Development Division.

AR-2 SN 9600 would be somewhere in the second year of production, I think, but production numbers ramped up quickly after that. The first year, 1957, was a short year from October until December. Also, Acoustic Research was a bit late getting the AR-2 into production due to a woofer "offset" problem (Henry Kloss was not able to solve the problem before he left) and it was left to Edgar Villchur to solve this issue before the speaker could go into full production.

--Tom Tyson

[charger3834]

>AR-2 SN 9600 would be somewhere in the second year of

>production, I think, but production numbers ramped up quickly

>after that. The first year, 1957, was a short year from

>October until December. Also, Acoustic Research was a bit

>late getting the AR-2 into production due to a woofer "offset"

>problem (Henry Kloss was not able to solve the problem before

>he left) and it was left to Edgar Villchur to solve this issue

>before the speaker could go into full production.

>

>--Tom Tyson

Tom, I think he said he had AR-2ax's not AR-2's. Therefore he would have the Pre 1970(SN 125,000) versions. If they made 125,000 AR-2ax's from 1965-1969, I would guess that his would have been built in 1965, since his serial numbers are 9600.

As Tom says, the AR-2ax was revamped in 1970 starting with serial number 125,000. The new, foam surround AR 10" woofer from the AR-5, repaced the original cast frame, cloth surround woofer. The 3/4" Tweeter replaced the original 1 3/8" tweeter. All AR-2ax's had the same 3.5" cone midrange. In the post 1970 version, crossover frequencies were lowered from 2000 HZ to 1400 HZ and from 7500 HZ to 5000 HZ respectively.

We really should build a section on this site dedicated to this 2ax business. We should have photos showing the two different versions.

[Guest Droog]

Thanks Brad and Tom for the fast response and yes, mine are 2ax. I consider myself lucky to find such nice speakers

fo $10., extra clean mahogany cabinets & in perfect working order. I'm just 35 miles from Boston and some interesting AR and KLH items turn up when you least expect it.

[tysontom]

>

>Tom, I think he said he had AR-2ax's not AR-2's. Therefore he

>would have the Pre 1970(SN 125,000) versions. If they made

>125,000 AR-2ax's from 1965-1969, I would guess that his would

>have been built in 1965, since his serial numbers are 9600.

>

>As Tom says, the AR-2ax was revamped in 1970 starting with

>serial number 125,000. The new, foam surround AR 10" woofer

>from the AR-5, repaced the original cast frame, cloth surround

>woofer. The 3/4" Tweeter replaced the original 1 3/8" tweeter.

>All AR-2ax's had the same 3.5" cone midrange. In the post 1970

>version, crossover frequencies were lowered from 2000 HZ to

>1400 HZ and from 7500 HZ to 5000 HZ respectively.

>

>We really should build a section on this site dedicated to

>this 2ax business. We should have photos showing the two

>different versions.

Brad,

You are exactly right, I think, in the AR-2ax timeline for that serial number. I clearly blew over the fact that it was a "AR-2ax" and not an "AR-2."

Incidentally, the 1970-version AR-2ax actually did not use the same woofer as the AR-5. There were some subtle differences in the cones and voice coils between the two and the crossover frequencies, of course, were different. The AR-2ax woofer was #200004-2 and the AR-5 (and LST/2) had #200004-3 (later #1200004-2 and -3). By the mid-80s, however, all the 10-inch woofers for the AR-2ax, AR-5, AR-8, AR-12 and AR-LST/2 were all the same, and all by this time had the ceramic magnet structures.

--Tom Tyson

[charger3834]

>Incidentally, the 1970-version AR-2ax actually did not use the

>same woofer as the AR-5. There were some subtle differences

>in the cones and voice coils between the two and the crossover

>frequencies, of course, were different. The AR-2ax woofer was

>#200004-2 and the AR-5 (and LST/2) had #200004-3 (later

>#1200004-2 and -3). By the mid-80s, however, all the 10-inch

>woofers for the AR-2ax, AR-5, AR-8, AR-12 and AR-LST/2 were

>all the same, and all by this time had the ceramic magnet

>structures.

>

>--Tom Tyson

Interesting subject. As a group, I know we have discussed the evolution of the 12" woofer family on a number of occasions however, we have not quite devoted as much time to the 10" family.

There does seem to be a number of iterations of the so called "new 10" woofer." Early AR-5's seem to have a visually different cone than that of the AR-2ax. They also have a more rounded dust cap. Later AR-5's have a woofer that looks identical to the 2ax. Also, I have seen some early post 1970 2ax's with an oversized 6 bolt variant of the new style woofer. These were most likely made to make use of existing cabinets during the 1970 transition period. I have seen a couple like this on ebay. Layne Audio also documents this in their AR-2ax section, however some of his other facts on the subject are muddled.

[Guest Droog]

I have a follow up question about the 2ax pricing, a 1969 brochure lists a mahogany 2ax for $122 and the

mahogany 3a at $240. , about twice the cost. Did it perform that much better then the 2ax. Also of interest,

a 1969 ad lists a KLH model six at $134. To me, the 2ax seems like much more of a speaker then the KLH

six. The AR 2ax looks to have been a very good buy when compared to other speakers in the $125 range.

AR's of this vintage seem so nicely made, performance appears to be above all the competition, and a

very fair price from a company who set the standard by which other speakers are judged. This leads me to

ask, couldn't AR have charged a bit more for their speakers and still sold a volume amount......consider only $63. for

the 4x, wow!

[Guest rickcee]

Hi except - Advent. large advent was great, both looking and sounding. And, of course, the Dyna 25 and EPI 100 were excel. in the $80.00 ea. range. ( My Mom bought -my pick actually) the AR 6 which was excel at same price, I think it didn't sell much. ? Rick

[tysontom]

>There does seem to be a number of iterations of the so called

>"new 10" woofer." Early AR-5's seem to have a visually

>different cone than that of the AR-2ax. They also have a more

>rounded dust cap. Later AR-5's have a woofer that looks

>identical to the 2ax. Also, I have seen some early post 1970

>2ax's with an oversized 6 bolt variant of the new style

>woofer. These were most likely made to make use of existing

>cabinets during the 1970 transition period. I have seen a

>couple like this on ebay. Layne Audio also documents this in

>their AR-2ax section, however some of his other facts on the

>subject are muddled.

>

The first AR-5 ten-inch woofer, introduced in 1968, was a special design that incorporated one of the first applications (perhaps the first) of the urethane-polymer "foam" surround materials. The AR-3a -- introduced the year before -- used the carry-over AR-3 Alnico woofer with cloth surround, and it did not get the new-style woofer until 1969 or so.

The AR-5 4-bolt woofer, however, was unique in its new surround, and the cone material itself used a new "low-vacuum" process with a compound-curvature cone treated with an asphalt-like material. This cone has the convex dust cap. The voice coil was also longer, and had gone to 1.5-inches in diameter vs. the original AR-2ax's 1.3-inch diameter. The coil length, or "overhang" in the gap, was increased to accomodate longer axial excursions. This early AR-5 woofer was highly compliant.

By 1970, AR introduced the AR-2ax with the 3/4-inch (AR-5) tweeter, new beige-linen grill material, new logo, and a new 4-bolt woofer similar to the AR-5 woofer. It had the larger-diameter voice coil, but the overhang was slightly less (later all were the same), and it also used a urethane-polymer surround. The cone material was less dense, it also has a flat dusc cap, and this woofer was more appropriate for the higher crossover in the AR-2ax vs. the AR-5's 650Hz.

Prior to the 1970 version AR-2ax, the earlier speaker used the original-style AR-2 10-inch, 6-bolt, Alnico, cast-frame (11-inch diameter frame) woofer. A version of the new woofer was made for retrofit of this earlier woofer for service parts, and it used either a special frame with 6 bolt holes or it had an adapter ring with 4-6 adaptation. Is all this clear as mud?

--Tom Tyson

[Steve F]

"I have a follow up question about the 2ax pricing, a 1969 brochure lists a mahogany 2ax for $122 and the mahogany 3a at $240, about twice the cost. Did it perform that much better then the 2ax. Also of interest, a 1969 ad lists a KLH model six at $134. To me, the 2ax seems like much more of a speaker then the KLH six. The AR 2ax looks to have been a very good buy when compared to other speakers in the $125 range. AR's of this vintage seem so nicely made, performance appears to be above all the competition, and a very fair price from a company who set the standard by which other speakers are judged. This leads me to ask, couldn't AR have charged a bit more for their speakers and still sold a volume amount......consider only $63 for the 4x, wow!

Droog"

What an interesting thread. I’ve been very busy lately, but a 2ax/AR timeline thread is just too tempting to ignore.

First, a comment about the AR-8’s 10" woofer: In AR’s 1974 introductory literature for this speaker, they say, "…uses a 10" woofer that is more efficient than some of our other designs…". This statement, coupled with a system resonance listed as 52Hz—compared to 56Hz for the 2ax, 5, and LST-2 in the same volume enclosures—leads to the conclusion that the 8’s woofer was, in fact, slightly different than the other 10-inchers.

There are not too many vintage AR-8’s around (and with good reason, since this model was not their finest hour!), so it may be somewhat difficult to resolve the 2ax/8 woofer question. However, it would seem that they used different woofers.

Now, back to the 2ax, a favorite subject of mine. As I opined in a recent thread, I think the new 2ax represented the high water mark for AR in regards to price/performance ratio. In their most common finishes, oiled walnut, the 2ax was $128.00 ea., and the 3a was $250 ea. Yes, the 3a had obvious sonic advantages, especially in the bass, but the 2ax provided very nearly as good overall performance—well balanced, widely dispersed, with strong, clean bass down to within 10Hz of the lowest usable musical frequencies.

As to its performance vs. its main marketplace competition of the day—the KLH-6 at $134 ea. and the Large Advent at $102 ea. in vinyl, $116 ea. in walnut: the 2ax, like all AR speakers of that era, intentionally sacrificed a bright on-axis response in favor of a smooth (but somewhat downward-sloping) far-field power response. Much has been written in these pages about the merits and design choices of axial vs. power response in loudspeaker design. Suffice to say, very simply, that AR speakers didn’t "show off" as well in a five-minute retail demo as a Large Advent, but could very well be a more satisfying, enjoyable, and musically-accurate speaker to live with for the long haul, day in and day out.

AR’s self-destructive marketing and sales policies also had a lot to do with how many speakers they sold in the late ‘60’s through the mid-‘70’s.

I have dealt with all these topics at great length in previous threads, and I will be happy to point you to them if you are interested.

I never tired of my 2ax’s, and never considered them outdated or needing replacement, even after many years of use. A friend of mine still uses them in his photo studio, 31 years after I first bought them. The surrounds have been replaced, but that’s it. They still sound great.

Steve F.

[Guest Bret]

>Also, I have seen some early post 1970 2ax's with an oversized 6 bolt variant of the new style woofer. These were most likely made to make use of existing cabinets during the 1970 transition period. <

I owned a pair of these! The old cabinet theory might not be correct, though.

My foam deteriorated and I had to have a pair of replacements. I picked these up from AR in Norwood (I think; it was somewhere around Boston, for sure) in February 1987. When I got the replacements home (6-bolt) they would not fit in my cabinets. I called AR and Alex (still working for AR at the time, I believe) told me that I had to cut the cabinets until the drivers would fit, period, no other solution.

And all six bolt-holes lined-up perfectly, so the "replacement" I got was for the old, bigger, 6-bolt woofer, but I was replacing the newer smaller 6-bolt version.

*That* driver (the replacement) was very obviously something: better, more efficient, longer-throw, something. It would thump you right out of a room if you let it.

Bret

[Guest Bret]

>A version of the new woofer was made for retrofit of this earlier woofer for service parts, and it used either a special frame with 6 bolt holes or it had an adapter ring with 4-6 adaptation. Is all this clear as mud?<

I had the 6-bolt service part unit that was just slightly larger than the first foam 6-bolt it replaced. I assume it was the same size as the alnico woofer that I did not have. No adapter ring.

Bret

[ar_pro]

I think your take on the 2ax is on the money, Steve...keeping in mind that its strongest competition (the Large Advent) was a design that came along well after the 2ax had pretty much established the affordable/high-quality loudspeaker niche, it's arguable that the 2ax was never actually bettered by a similarly-priced design - it was that good.

Having owned a pair of 2ax's in college, and having directly compared them against a friend's brand-new Advents, it was never a contest. The 2ax went deeper, it's midrange response was more well-defined, and it sounded (much) better with tube amplification than the Advent ever did. It's possible that much of Advent's orginal success as a company was due to excellent target-group advertising, and the fact that their speaker sounded pretty good with 1st & 2nd generation solid-state equipment, while the 2ax (as well as the 3a and 5) could be a challenge for lesser SS amplifiers.

And although the 2ax stands on its own as a superb design, it's important to remember that it didn't start with a clean piece of paper, but rather was a successful effort to bring most of the 3's capabilities to a lower price-point. I still believe the 3a to be the company's high-water mark, in that it represented (literally) the state-of-the-design & manufacturing-art for Acoustic Research, and it did so at a ridiculously low price when compared to the competition's best. Considering the stratospheric cost of today's top designs, this really serves to put AR's achievement with the 3a into perspective.

Having owned the 2ax, 3a, and original 9 (we listen to our restored 9s every day), though, I'd have to say that the 2ax's were probably the most FUN!

[Guest Bret]

>February 1987<

Wrong. October 1987.

Bret