OK, who has drawings of the AR2ax?

[teknofossil]

Ok, after reading JKENT's little "happy ending" story, here is my galloping tail of woe. I let my older brother take my AR2ax systems since he always has been a reliable guy and knew he'd take care of them. Well, as time passed the surrounds rotted and the AR's went into his attic. (a nicely done attic ) Anyway, he pulled the woofers for me to repair and installed some temporary 10" Eminence woofers I had floating about. Well, his wife soon after decided (yes, later we learned she was pissed at him for something) to grab the AR's and either leave them at a thrift store or pitch them into a dumpster (along with a very nice condition Marantz 4300 quad receiver, my old Heath computer from 1977, some older Mac PC's and our dads 1950's Espey mono receiver). All gone. There is the tail of woe.

Well, I have the AR2ax woofers and I want to clone cabinets and hopefully get my paws on some mids and tweeters.

So who has the prints?

Thanks!

-T

[JKent]

That IS a sad tale.

I have some nice Heathkit AS2 cabinets. Those were AR2 clones. They could be modified to accept 2ax drivers if you are at all handy with woodworking. Free for the asking to a CSP member. I'm in NW NJ, near the NY state line.

Kent

[teknofossil]

That IS a sad tale.

I have some nice Heathkit AS2 cabinets. Those were AR2 clones. They could be modified to accept 2ax drivers if you are at all handy with woodworking. Free for the asking to a CSP member. I'm in NW NJ, near the NY state line.

Kent

Really? That would save some work. Let me ask. What was the difference between the AR2ax and the Heath AS2? I snooped the web for nformation about that model and came up empty handed. I do remember the AR based Heath speakers from the early 70's, but that vaguely.

Thanks

Tom

[JKent]

Really? That would save some work. Let me ask. What was the difference between the AR2ax and the Heath AS2? I snooped the web for nformation about that model and came up empty handed. I do remember the AR based Heath speakers from the early 70's, but that vaguely.

Thanks

Tom

Same size, different cutout for speakers. I "think" AR offered a conversion kit back in the day. The rectangular hole would have to be filled, new holes cut for the mid & tweet.

[Guest jlaplante]

Well, I have the AR2ax woofers and I want to clone cabinets and hopefully get my paws on some mids and tweeters.

So who has the prints?

You still looking for prints? I've got my AR-2A's totally ripped apart and could post photos and measurements if you would like.

I'm going through a 2AX conversion now - see thread My AR-2A to AR-2AX Conversion.

[johnieo]

Well, I have the AR2ax woofers and I want to clone cabinets and hopefully get my paws on some mids and tweeters.

So who has the prints?

Thanks!

-T

Greetings Teknofossil:

There used to be a document in the archives on the old BB software that described the differences between the old and new AR-2ax, and at its end was a brief description of the AR-2a. I will attach, if I can remember - a copy of this pdf document written by Brad Evans. It has one error -- that is the impedance of the "super-tweeter" used in the old (early) AR-2ax was 4-Ohms; it was the identical driver used in the 4-Ohm AR-3.

So, you have AR-2a woofers. I would assume, but others might correct me, that these woofers are the same as those used in the old (early) AR-2ax. The old AR-2ax had serial numbers up to 125,000; the new were the higher range number. As Brad describes, both the tweeter and woofer changed from old to later AR-2ax. So which AR-2ax are you trying to reproduce--old/early or new/late design? In addition to the woofer and tweeter change, the stuffing weight was reduced from 30-32 ounces to about 20 ounces, and the woofer inductor was increased from 1.187 mH (AR-#5 coil) to 1.88 mH (AR-#7 coil).

Also attached --memory permitting--is the crossover circuit from a pair of early model AR-2ax that I restored.

From what you say, you have purchased AB-Tech tweeters that probably are intended for the late model 2ax. Brad describes that tweeter - like the AR-3A tweeter, but 8-Ohms instead of 4. You have to decide which model you wish to reconstruct (early and use your current woofers) or late and use your AB-Tech tweeters. One suggestion is to look for a pair of AR-3 tweeters on internet (the 1-3/8-in phenolic dome). However, do you have a pair of original CTS midranges?

Lots of choices here, but first, you might consider reading Brads' well-written summary and noting the differences in woofers and tweeters.

Cheers,

Comparative_AR_2ax.pdf

[dynaco_dan]

Really? That would save some work. Let me ask. What was the difference between the AR2ax and the Heath AS2? I snooped the web for nformation about that model and came up empty handed. I do remember the AR based Heath speakers from the early 70's, but that vaguely.

Thanks

Tom

Hi there;

The AR/Heath AR-2/AS-2 both contained a 10" alnico woofer system and dual 5 1/2" tweeter array.

The AR/Heath AR-2A/AS-2A both contained a 10"alnico woofer system and 1 3/8" tweeter and dual 5 1/2" tweeter array.

The Heathkit's did not go beyond the model AS-2A speaker system for the 10" woofers.

AR replaced the dual array in the AR-2 with an adapter plate for the 3 1/2" CTS tweeter, which became the AR-2X system.

They later went through the woofer changeover and also to a new 2 1/2" tweeter of their own manufacture.

I have no crossover or other more technical information on these speakers.

AR replaced the 1 3/8" tweeter with a 3/4" tweeter, which now made the early AR-2AX speaker system.

AR later replaced the 10" (actually 11") alnico woofer with a steel framed ceramic magnet woofer with an adapter to fit the 11" hole.

AR later replaced the intermediate woofer with an actual 10" - 6 bolt model woofer with ceramic magnet.

If one was to convert the cabinet of an AR-2/Heath AS-102 to a AR-2A/Heath AS-102A, a subplate similar in appearance to early photos of the AR-3 raw tweeter and mids without screens.

There was a photo that showed a recessed plate adapter larger that the two drivers above the woofer.

This can be done with care and a long router bit.

The drivers can even be installed more in-line or more across and closer to the woofers.

To do only minimum carpentry, an adapter plate for the single tweeter would create an AR-2X or Heath AS-2X.

There would need to be a new coil and cap at minimum for the new crossover.

Insulation would need to be adjusted for each different woofer installed as well.

Of recent interest, since it has come to light on this site that the 1 3/8" tweeter was only made in 4 ohms, the number of AR-3 tweeter auctions has increased significantly.

[Guest jlaplante]

Also attached --memory permitting--is the crossover circuit from a pair of early model AR-2ax that I restored.

johnieo - Thanks for the info. Very relevant for the project I have started here.

In Brad's article that you link to, he mentions a crossover change going from the old 2ax to new 2ax where crossover points were dropped from 2k/7k to 1.4k/5k.

I assume your crossover schematic is for the old style 2k/7k crossover points, correct? Do you know what crossover mods are needed for the 1.4k/5k crossover? Is it simply the #5 to #7 inductor switch, with the remaining changes caused by the switch to a new tweeter?

[Guest jlaplante]

johnieo - Could you do me a favor and check over the conclusions in my thread here and compare to your experience? Most notably the section on Crossovers about halfway down. Thanks!

[johnieo]

johnieo - Could you do me a favor and check over the conclusions in my thread here and compare to your experience? Most notably the section on Crossovers about halfway down. Thanks!

Hi again:

Cannot answer all of your Q for sure; never seen and AR-2a.

Woofer: Brad says it is the same as in the early AR-2ax. Glad you could find a second woofer. These are cloth surround woofers and should not need to be restored. When you say "recone" I presume you mean "re-surround," as reconing would alter the speaker - I doubt that Bill LeGall has any OEM cones! But first before you consider replacing the cloth surrounds with foam surrounds, ask why would you do so? Could you post photos of the surrounds for us to view? You may need to add some butyl rubber (very thin and very sparingly) to any areas in which the rubber is missing, but leaks through the surround cannot be determined for sure until the cabinet is sealed properly. (the AR-3a restore paper has all the details for installing and sealing drivers.)

Mid-range: I am told the AR-2a used a dual 5-1/2" midrange. The AR-2ax used a CTS 3.5 inch diam midrange -- both early and late models. I would attempt to purchase two of these from either an internet auction, or Larry at Vintage-AR; perhaps he has some used originals.

Hi-range: Now for the decision: to make a pair of early AR-2ax or late AR-2ax. The differences, physically, I believe are three:

Woofer inductor: #5 (1.187 mH) early, #7(1.88 mH) late.

Stuffing: 30-32 oz of fiberglass (early) ~20 oz fiberglass (late)

Hi-range driver: Early: 3.5" diam phenolic dome tweeter (also used in AR-3). This is a nominal "4-Ohm" driver with ~2-Ohms dc resistance. Late: 3/4" diam dome tweeter. See photos of drivers A.19, A-20 and A.23 in the AR-3a restore paper. You would need the 8-Ohm version of either of these. I agree with Roy C, don't use the AB-Tech tweeters, not the same beast. Either an internet auction or Larry at Vintage AR are potential sources. you could email and enquire. ljlagace at aol dot com. It may be that the AR-3 "super tweeter," the 1-3/8" phenolic dome is easier to acquire than the later version.

Crossover: I believe the only passive component change used to alter the crossover frequencies in the late AR-2ax was the woofer inductor. However someone else who has been inside a later serial numbered model can tell you if the tweeter cap was changed; I think not. For sure, change those capacitors! Chicago Industrial caps from 1962 are likely dried and far from spec. Could damage drivers with those caps!!

Sound:

I find my pair of early model AR-2ax very enjoyable for listening to the BBC [bach, Beethoven and Chopin ]. Some say that the later version sounds more open, but I have no way of comparing the two versions.

As far as the lack of connection to the third terminal in the AR-2a midrange pot, I would not know. It may well have been that a simple series variable resistor was used with the old 5.5-in midrange. However that is a moot issue if you are building an AR-2ax.

Hope this is helping to make some sense of where to go. ... always choices. Drivers will co$t a bit, but when finished, one can compare the total cost to what one would pay today for equivalent sound from new speakers and realize it is not that pricy, relatively!

Cheers,

[johnieo]

One thing I omitted--since you have the old style woofers, it is most sensible to reconstruct the early or old version of the AR-2ax. That means trying to obtain a pair of AR-3 "super-tweeters," the 1-3/8" phenolic dome tweeter--that tweeter as we mentioned was used in both the AR-3 and the early AR-2ax. Sorry for that oversight.

Cheers

[Guest jlaplante]

Thanks johnieo for the excellent response. This confirms what I have been suspecting all along:

• The only xover change is the inductor --> #7
  
• Stuffing - mine has 32oz, will keep the same for older woofers unless the recone seems to be much stiffer.
  
• Midrange - the dual cone 2A design was flawed to begin with, so I want the 2AX configuration, however that may be possible. I may just stick with AB tech and roll the dice for now. Seems to me that even original drivers from 40 years can't really be "original" anymore due to aging.
  
• I will wire the missing lead to the pot as all other 2AX schematics show this connection
  

AFA my woofers, they are in pretty bad shape, the surrounds are pretty deteriorated and both cones are torn. I understand no one can do an original recone. I prefer to just get them reconed and deal with the differences. Again, I feel certain that even an original off eBay will not sound like it did when new.

Just recently I learned of the AR-5- Basically the mid+tweeter+xover of a 3A coupled with a 10" woofer much like those in my 2A's.

Has anyone considered upgrading a 2A or 2AX to a 5?

[johnieo]

Thanks johnieo for the excellent response. This confirms what I have been suspecting all along:

• The only xover change is the inductor --> #7
  that should be correct.
  
• Stuffing - mine has 32oz, will keep the same for older woofers unless the recone seems to be much stiffer.
  Reconing may change mass! Re-FOAMING will change compliance. If your surrounds are intact (even if they look rumpled, please consider retaining them. Bill can replace a cone and keep the cloth surrounds!
  
• Midrange - the dual cone 2A design was flawed to begin with, so I want the 2AX configuration, however that may be possible. I may just stick with AB tech and roll the dice for now. Seems to me that even original drivers from 40 years can't really be "original" anymore due to aging.
  See if you can look for a pair on ebay or from Larry LaGace.
  
• I will wire the missing lead to the pot as all other 2AX schematics show this connection
  

The 2A and 2Ax did not have the same crossovers, Please use the 2ax crossover if you are rebuilding a 2ax.

AFA my woofers, they are in pretty bad shape, the surrounds are pretty deteriorated and both cones are torn. I understand no one can do an original recone. I prefer to just get them reconed and deal with the differences. Again, I feel certain that even an original off eBay will not sound like it did when new.

Try keeping the surrounds and simply coat them with a dilute THIN coating of Permatex.

Just recently I learned of the AR-5- Basically the mid+tweeter+xover of a 3A coupled with a 10" woofer much like those in my 2A's.

Has anyone considered upgrading a 2A or 2AX to a 5?

different woofers

different midranges

different tweeters

different crossovers

different stuffings

different speakers

different isn't upgrade

cheers,

[RoyC]

Has anyone considered upgrading a 2A or 2AX to a 5?

To elaborate on John's post...

The *later* 2ax shares the 3/4" dome tweeter and foam-surround 10" woofer with the *later* 5. The cabinet is the same size and the grilles are interchangeable, and that is it. The AR-3a crossover is NOT the same as that of the AR-5, and the 3/4" AR-2ax/5 tweeter, as well as the AR-5/LST2 midrange used in the AR-5, are higher impedance versions of their AR-3a counterparts..and therefore NOT the same. Further, the rather rare AR-5/LST2 midrange is much larger than the 2ax midrange, necessitating cabinet surgery.

It would be a big project, and certainly not worth the effort based on your description of the drivers currently at your disposal.

Roy

[teknofossil]

You still looking for prints? I've got my AR-2A's totally ripped apart and could post photos and measurements if you would like.

I'm going through a 2AX conversion now - see thread My AR-2A to AR-2AX Conversion.

Hello! I have been offline a while due to a major failure of my main PC at home. So, sorry for the late response. Yes, if you have photo's I would like to see them. Thank you!

-T

[teknofossil]

Greetings Teknofossil:

There used to be a document in the archives on the old BB software that described the differences between the old and new AR-2ax, and at its end was a brief description of the AR-2a. I will attach, if I can remember - a copy of this pdf document written by Brad Evans. It has one error -- that is the impedance of the "super-tweeter" used in the old (early) AR-2ax was 4-Ohms; it was the identical driver used in the 4-Ohm AR-3.

So, you have AR-2a woofers. I would assume, but others might correct me, that these woofers are the same as those used in the old (early) AR-2ax. The old AR-2ax had serial numbers up to 125,000; the new were the higher range number. As Brad describes, both the tweeter and woofer changed from old to later AR-2ax. So which AR-2ax are you trying to reproduce--old/early or new/late design? In addition to the woofer and tweeter change, the stuffing weight was reduced from 30-32 ounces to about 20 ounces, and the woofer inductor was increased from 1.187 mH (AR-#5 coil) to 1.88 mH (AR-#7 coil).

Also attached --memory permitting--is the crossover circuit from a pair of early model AR-2ax that I restored.

From what you say, you have purchased AB-Tech tweeters that probably are intended for the late model 2ax. Brad describes that tweeter - like the AR-3A tweeter, but 8-Ohms instead of 4. You have to decide which model you wish to reconstruct (early and use your current woofers) or late and use your AB-Tech tweeters. One suggestion is to look for a pair of AR-3 tweeters on internet (the 1-3/8-in phenolic dome). However, do you have a pair of original CTS midranges?

Lots of choices here, but first, you might consider reading Brads' well-written summary and noting the differences in woofers and tweeters.

Cheers,

Hello!

the woofers are late model AR 2ax units. I originally bought the systems in 1978 from the local AR dealer (Lechmere). These were left over stock (I think the AR2ax model was discontinued in 1976) from their demo room. These later found their way to my brother who used them until the foam rotted. My brother pulled the woofers so I could refoam them in 2004. His wife tossed the systems along with the other items mentioned in my first post. These woofers have ceramic magnets, wire screening on the baskets, and, oh yes, no cabinets to go in......

So far as AB-Tech tweeters are concerned you must be confusing me with another member of this forum. I would like to find original drive units. Actually, to be honest I'd like to secure the drivers for the AR5 along with the correct crossover components and schematic.

-T

[RoyC]

Hello!

So far as AB-Tech tweeters are concerned you must be confusing me with another member of this forum. I would like to find original drive units. Actually, to be honest I'd like to secure the drivers for the AR5 along with the correct crossover components and schematic.

-T

Teknofossil,

I had you confused with the person who has the AB Tech drivers as well...sorry!

Attached is the AR-5 schematic, and a photo of an AR-5 crossover I recently re-capped. The layout is the same as the 3a but the component values are different.

I have two spare AR-5 midrange drivers. Contact me through the forum if I can be of assistance.

Roy

[Guest jlaplante]

Apologize for the duplicate entry

[Guest jlaplante]

Apologize for the duplicate entry

[Guest jlaplante]

Has anyone considered upgrading a 2A or 2AX to a 5?

different woofers

different midranges

different tweeters

different crossovers

different stuffings

different speakers

different isn't upgrade

Ouch! Oh well, thanks for all the input, much appreciated! I'll talk to MillerSound about those surrounds.

Regarding the stuffing, I have used a technique from one of David Weems speaker building books on tuning the acoustic stuffing in a cabinet. It is done empirically by injecting a simple step voltage and listening for ringing, then adjusting the stuffing by hand. Anyone know of this or a similar technique, and is it worthwhile in an acoustic suspension?

However, everything I am hearing continues to lean me towards some kind of upgrade. I guess I don't have much faith in old drivers because of their unknown aging characteristics. I am starting to like Carlspeak's SuperMod approach, and may just go a similar way with my 2A's, keeping the original woofers in some form, and upgrading with modern mid+tweeter+xover (NOT AB tech which are an unknown quantity, mediocre quality, and require xover changes anyway).

[Guest jlaplante]

Apologize for the duplicate entry

[Guest jlaplante]

To elaborate on John's post...

The *later* 2ax shares the 3/4" dome tweeter and foam-surround 10" woofer with the *later* 5. The cabinet is the same size and the grilles are interchangeable, and that is it. The AR-3a crossover is NOT the same as that of the AR-5, and the 3/4" AR-2ax/5 tweeter, as well as the AR-5/LST2 midrange used in the AR-5, are higher impedance versions of their AR-3a counterparts..and therefore NOT the same. Further, the rather rare AR-5/LST2 midrange is much larger than the 2ax midrange, necessitating cabinet surgery.

It would be a big project, and certainly not worth the effort based on your description of the drivers currently at your disposal.

Roy

Thanks Roy. Well, what would you make of a project to simply upgrade my 2A's with new drivers? I'm not averse to a big project. I am an avid speaker builder, and cabinet surgery, although controversial here, would open up a lot of options.

My thoughts are similar to Carl's 3A SuperMod but in a 2A. Keep the woofers as original as possible, thus retaining all the charms of AR acoustic suspension sound, but use high quality tweeter+mid and redesigned xover. I would choose tweeter+mid with similar design philosophy to original AR3a/AR5 designs, using fabric domes, emphasizing dispersion.

Suggestions?