Hi, New With New To Me AR-2ax Pair

[jessiAV]

When it was necessary last Fall (2017) to refoam my new-to me AR 2ax woofers (1973 vintage?), I also did not want to cut the center cap. I have the ~highest~ regard for Roy and if he says it is the best way to align the AR's former in the VC gap, then it is. Should I do another AR refoam, I would definitely consider shimming. Happily, the VC gap in these woofers seems to be wide enough that my hand-centering has been acceptable.

 

        My reason back then to leave the center cap intact was, before finding CSP, I wasn't sure if I could properly re-adhere it to the cone. I always trust AR for using the best glue and gluing techniques. Unlike my AR4x's, the 2ax's center cap appears capable of producing lower midrange energy, and I was unwilling to mess with those critical frequencies. Maybe I was just being silly with a 40-something year old driver, but I do believe in retaining the manufacturer's original construction whenever possible.

[tysontom]

22 hours ago, bfastr said:

I have a question for the experts. Which grill badges should my 1968 2ax models have?  they are the cloth surround vintage and Alnico woofers. I see what looks like early 2ax's with a large "ARinc" in one corner and a script "a" in another, and then I see 2ax's with the AR-2ax badge.  Personally I like the simplicity of the big ARinc badge. But, I am also a stickler for having them the way they came from the factory. Maybe the big ARinc are on 2a's ? 

 

Bob F

Bob F.: 

AR-2ax 1970 Version:

The badges—simply called "logos" on all AR models—were changed in 1970 to a single brass "logo" with "AR-2a^x" during the changeover to the new ¾-inch, 8-ohm dome tweeter and the new-style, foam-surround, stamped-steel-frame, yoke-magnet woofer!  Wow....  During the first few months, this new woofer was built with the 11-inch diameter, 6-screw, stamped frame to fit into the old-style, recessed, thick (1⅛-inch thick)  front baffle (Sara's woofers are in this category, and her speakers date to around January, 1971). 

At some point in 1971, AR switched to the true 10-inch, 4-screw, stamped-frame woofer (otherwise identical to the 6-screw stamped version), the standard ¾-inch-thick front baffle and the "tweeter terminal strip."  By 1973 or 1974, AR had transitioned to the new, 4-screw, stamped-frame, ferrite magnet for this same woofer (new part number 200004-3).  The damping was slightly different on this new woofer, but it was otherwise almost identical to the yoke-magnet version.  Ferrites were all in 4-screw versions except for special service-part replacement units (part number 207002-0), which had an 11-inch masonite adapter plate attached to the 4-screw frame. 

AR-2ax 1964-1970 Version:

A 1968 version, such as what you have, would have the original-style, 10-inch, 6-screw Alnico-magnet, cast-aluminum woofer (with an 11-inch frame, which probably caused confusion among many that AR had an 11-inch AR-3 woofer!), the 3½-inch midrange but the AR-3-type 1⅜-inch phenolic-dome tweeter.  This speaker would have the "AR-Inc" logo and the "a" brass stick pin.

Hope this doesn't confuse the matter!

—Tom Tyson  

[tysontom]

6 hours ago, RoyC said:

I've been re-foaming drivers for a very long time, and presently do much of the re-foam work for "Vintage AR", and all of it for a local repair shop. Inexperienced re-foamers using test tones, batteries, and eyeballs to center old woofer cones have been good for business. There are some woofers (not AR) that have plugs under, or in lieu of dust caps. These are the only type for which I don't use shims.

The shims are much better at compensating for a less than perfectly aligned, or worn suspension, and allow the height of the cone to be precisely manipulated during the gluing process.

Of all the old woofers, the flat dust cap of the 2ax woofer is the easiest of all to retain. If you don't have one, acquire an exacto knife (and some .007 inch shims).

Roy

I agree 100% with the idea of shimming all woofers—just as Roy has said—but I didn't always do it that way.  You can usually get away without shimming because of the generally wide voice-coil clearances in AR acoustic-suspension woofers, but it is far better to be sure that the voice coil aligns carefully in the gap (not the vertical alignment, as that will occur naturally if the spider hasn't collapsed), and this always requires the use of shims to have assurance against any voice-coil rubbing later on or misalignment, resulting in greater distortion.  If the voice coil is skewed to one side of the top plate and pole piece, the voice coil will not be getting a perfectly uniform magnetic field (though this is extremely minor).  Shims will usually always prevent the voice coil from being misaligned in the gap.  Shims will also hold the cone in place during the re-foam process, too.  Properly shimmed, the voice coil will always tend to stay just as it was glued.  Always use the original dust cap, too, as Roy stated, to preserve the original performance, cone weight and so forth.  Cut it back almost around its periphery and pull it back; then glue it back in place once finished.

One issue with these new foam surrounds: many have a ⅝-inch, half-round diameter shape, whereas the original AR-2ax woofer had a ½-inch diameter shape.  Therefore, the new surrounds (some of them) are not original in that respect.  It shouldn't have any material effect on performance.  The AR-3a 12-inch woofer, however, requires the ⅝-inch diameter surround for top performance; the AR-2ax does not have nearly as much linear excursion as the AR-3a woofer and only needed a ½-inch surround.

—Tom Tyson

[sarals]

9 hours ago, Aadams said:

 

Sarals,

OZ has spoken,  you are now in "we tried to tell you" mode.  

Adams

I always, always, defer to experience!  I'm not too proud to say so, either.  Shims it is.

Questions?  Where do I cut the dustcaps?  On the glue joint?

And finally;

Where can I get some shims?

[Aadams]

8 hours ago, sarals said:

Where can I get some shims?

You can make them from index cards or stiff acetate sheet like used in note binders as section dividers.  Look at the clamped foam photos on the previous page you will see two woofers with home made shims. The cut shims that come in kits are about 1/2" x 3" white plastic.

I cut my dust covers before I knew about the fold back and re-glue method but I knew to keep the knife away from the coil leads.  I made new covers by cutting an exact circle from a cheerios box and it worked great. 

I searched for images of cut and re-glue on this woofer but no luck.

I have done both methods. Shimming allows incremental control of the process. It is the best, most exact, method for these old woofers.

Adams

[sarals]

This video pertains to the woofer in a JBL Jubal.  However, it's the best demonstration I've been able to find about how to cut the dustcap in a way that keeps it reusable.  

 

[sarals]

Okay, before I wreck a vintage woofer.  Looking at the apex of the cone, where it meets the spider, it appears the dust cap diameter is wider than the voicecoil/cone junction.  Where should I cut the dustcap?  The perimeter of the dustcap looks to be wider than that junction, and I risk slicing the cone away from the voicecoil former if I cut too wide.  That would be a disaster!  

[RoyC]

13 minutes ago, sarals said:

Okay, before I wreck a vintage woofer.  Looking at the apex of the cone, where it meets the spider, it appears the dust cap diameter is wider than the voicecoil/cone junction.  Where should I cut the dustcap?  The perimeter of the dustcap looks to be wider than that junction, and I risk slicing the cone away from the voicecoil former if I cut too wide.  That would be a disaster!  

Use a fresh exacto blade and slice on a slight angle inside the glue line.

Roy

[JeffS]

12 minutes ago, sarals said:

Okay, before I wreck a vintage woofer.  Looking at the apex of the cone, where it meets the spider, it appears the dust cap diameter is wider than the voicecoil/cone junction.  Where should I cut the dustcap?  The perimeter of the dustcap looks to be wider than that junction, and I risk slicing the cone away from the voicecoil former if I cut too wide.  That would be a disaster!  

Great question.

I finished refoaming a pair of woofers for my AR-5's a couple of months ago. Not having done an AR 10" flat dust cap woofer in many years, I cut too close to the glue line on the dustcap and cut into some of the cone. The voicecoil diameter is ~1.5" so you should be safe if you scribe a circle of that diameter on your dustcap as a cutting guide.

[sarals]

@RoyC and @JeffS, thanks to you both!  I just lowered the specter of ruining a perfectly happy vintage woofer significantly....

[sarals]

I opened the dustcap.  The 1/1/2 inch circle suggested by @JeffS which I used to cut the hole was just about perfect.  Somehow, though, I nicked the top of the VC bobbin for about 1/5th way around the bobbin, but the wires are safe, the cut got no where near them.  I'll make sure there is a dab of glue on that nick when I glue the dustcap back down.  I used brochure paper to make the shims, and it seems to have done the job.  I pulled the cone up to glue the surround to it, and the gap is even all the way around the VC.  The cone does sag on one side, it's a bit deformed, and that is obvious when the VC is centered.  The surround is now glued to the cone, this evening I'll glue the surround to the basket after the other glue job sets up, and tomorrow morning, I'll glue the dustcap back on.  If all is well with this woofer, if I haven't destroyed it (then I'll be another GOOD customer for Vintage AR! ;-) ), I'll remove the woofer from the other cabinet and get started on it.

Photos!

[sarals]

The refoam on this woofer seems to be successful.  I tested it this morning, and it works perfectly.  Photos below.

I've moved on to the crossover.  I have to say that the attention to detail and the obvious hand made craftsmanship on these speakers speaks to a level of perfection and care that you just don't see any more.  And, the cabinets are made out of plywood, not MDF!  The fiberglass stuffing was REALLY stuffed, too.  It even was pushed under the wires around the crossover.  I am so impressed!

The capacitors.  They're way out of spec, if the Chinese ESR meter I bought is correct (I don't have a reference capacitor to use as a control).  The photos are below.

I've got to open the pots to see how they look.  I'm sure I'll see degradation, I just don't know how much!

The Marantz 2270 should be here today.

 

[bfastr]

On 3/4/2018 at 8:35 PM, tysontom said:

Bob F.: 

Hope this doesn't confuse the matter!

—Tom Tyson  

Thanks Tom.  that answers exactly what I was looking for and then some.  I like knowing the details like that! 

Bob

[bfastr]

10 minutes ago, sarals said:

The refoam on this woofer seems to be successful.  I tested it this morning, and it works perfectly.  Photos below.

I've moved on to the crossover.  I have to say that the attention to detail and the obvious hand made craftsmanship on these speakers speaks to a level of perfection and care that you just don't see any more.  And, the cabinets are made out of plywood, not MDF!  The fiberglass stuffing was REALLY stuffed, too.  It even was pushed under the wires around the crossover.  I am so impressed!

The capacitors.  They're way out of spec, if the Chinese ESR meter I bought is correct (I don't have a reference capacitor to use as a control).  The photos are below.

I've got to open the pots to see how they look.  I'm sure I'll see degradation, I just don't know how much!

The Marantz 2270 should be here today.

 

 

 

 

 

 

Sara,  I am going to guess your pots are green and corroded like mine.  after you open them soak them in vinegar.  then hit them with a brass brush.  HOPEFULLY the wiper isnt worn thru. 

as for the cap's.  those readings are pretty close to what I get on my original cap's.  I ordered ( and already received) new caps from parts express that I will be potting inside the old shell.

other than that the guts of yours look really good

 

Bob

[sarals]

1 minute ago, bfastr said:

Sara,  I am going to guess your pots are green and corroded like mine.  after you open them soak them in vinegar.  then hit them with a brass brush.  HOPEFULLY the wiper isnt worn thru. 

as for the cap's.  those readings are pretty close to what I get on my original cap's.  I ordered ( and already received) new caps from parts express that I will be potting inside the old shell.

other than that the guts of yours look really good

 

Bob

Bob, thank you!  I'm on the Parts Express site right now.

I should have those pots open sometime this morning, if I ever get off this computer! ;-)  I'll post what I find.

~~Sara

[sarals]

Bob!

You'll be pleased (or maybe not ;-) )  to hear that my pots were NOT corroded at all.  They were shiny and nice, except for the wipers, which had tarnish on them.  I cleaned up the tarnish and put them back together.  I'm now waiting on Dayton caps from Parts Express. 

I only want to do one speaker at a time, I don't have that much room, but I may remove the woofer from the other cabinet and get it refoamed today.

My Marantz 2270 arrived yesterday.  It's a little dirty, but all of the lamps work, the velum isn't yellowed, and it sounds beautiful.  I'll get it cleaned up at some point, and then press it into service.  Lovingly!

Here's some photos:

[bfastr]

WOW !!

Sara,  The pot looks pretty good,  mine were full of crud.  I picked up some electronic potting epoxy. I am going to put the new caps in the old "case" and use two part epoxy to seal it all up. 

The Marantz looks fantastic, I can almost hear it now.  I am very jealous.  

 

Bob

[AR55]

All this talk about restoring AR-2ax and AR-2 speakers got me thinking about restoring a mismatched pair of AR speakers that my wife’s uncle left with me when he moved into a retirement home a few years ago.  He had purchased the AR-2 in 1962 and then upgraded to “stereo” in 1971 by adding an AR-2ax.

The AR-2’s only noticeable issue was the veneer on the bottom of the cabinet.  It was cracked and had delaminated in places after sitting on her uncle’s garage floor nearly 20 years.  I removed the old veneer; re-veneered it with 1/16” thick walnut veneer, and finished it with Watco Dark Walnut Danish Oil (wet sanding the first coat).   After the 3^rd coat I had a decent color match to the original cabinet finish.

The AR-2ax’s restoration was not so simple.  Both the midrange and tweeter pots were corroded; the woofer’s surround (it was foam not cloth like the AR-2) had rotted; only one of the lead wires from the front-wired tweeter was visible; the grill cloth was torn & badly stained and the badge was missing. 

I started with the 2ax’s tweeter, and I got lucky.  After carefully pulling back the black tape below the tweeter, I discovered that the lead wire splice had failed.  There was still about 1½” of intact, very fine, voice coil wire extending from the tweeter.  Since I was already using Central Florida Speaker Repair to replace the woofer surround, I just paid them a little extra to solder on a lead wire extension.

The 2ax pots cleaned-up reasonably well.  Not as nicely as Sara's, but I got them both working well enough that I could adjust them to my liking and not have any scratchiness or drop-outs.

I followed Kent’s recommendation and replaced the AR-2ax’s grill with linen fabric from 123Stitch, and picked up a fair-priced, AR-2ax brass emblem from eBay.

Lastly, I cleaned both cabinets and removed most of the scratches by fine sanding with Watco Rejuvenating Oil.

Excluding the cost of the Watco oils, which I already had on hand, my total out-of-pocket expenses came to a very reasonable $18 for the AR-2 and $98 for the AR-2ax. 

So how do they look and sound after over 20 years of neglect?  The AR-2ax looks almost new and sounds very good.  It has a somewhat mellow overall sound when compared to my newer AR’s, but not in an unpleasant way.  Can it compete with range and clarity of my AR-11’s?  No, but it sounds and looks better than any $100 speaker on the market, so it was well worth the effort/cost of restoring.  The AR-2, on the other hand, looks OK cosmetically, but its sound, though not bad, is underwhelming.  I remember my dad’s AR-2 sounding better, but at the time I didn’t have much to compare it to.  It’s quite possible that stiffness in the old cloth surrounds and/or degradation of the crossover components are affecting the sound, but it may also be that the AR-2 is simply a mediocre speaker when compared to later AR’s.

[sarals]

@AR55, those certainly are some pretty speakers!  I hope, down the road, I can get mine to look close to that.  Bringing back the finish and the cleaning the grill cloth is still down the road a ways, so I'm not going to go into speculating on how I'll do it just yet.

I refoamed the second woofer last night.  I was aware that I was confident enough after doing the first one (and fretting about it the whole time) that if I didn't pay attention and get a grip on my cocky self I'd screw it up.  I didn't.  It came out easily as well as the first.  The cone, from the factory, was not centered in the basket.  The glue residue, and "shadow" from it, showed that after I got it all cleaned up.  After shimming the VC and test fitting the new surround, it was apparent that the new surround was going to be slightly offset.  The speaker worked that way for probably 40 years?  So, I glued it all together, manually moved the cone up and down after the glue had set up, and not a single undue noise.  I glued the dustcap back on, and this morning I tried the woofer.  It works perfectly.

I tackled the pots in the second speaker today.  I left them in the cabinet, and took them apart in there to preserve the wiring (I did cut the capacitor wires, at the capacitor).  Aside, I wish I hadn't cut the wires in that first speaker!  Those pots were just as nice as the first set.  I used some emery cloth the clean up the wiper and the center contact, and then put them back together.  Being a small person with little hands pays dividends!

I plan to put the new caps inside the old caps wax paper box.  I got them unfolded and took out that wax blob of a pair of capacitors.  I plan to hot glue the new caps to the bottom of the boxes and then fold the things back up.  I don't care if they're open at the end where the wires emerge.  It will host a little bit of the originality, and it will hide those new Dayton caps.

I have that Marantz 2270 playing right now through my Advents.  That is a lovely sounding piece!  And, it is sure beautiful to look at.  I can NOT wait to hear those 2ax's through that receiver.  I have no allusions as to what they'll sound like.  I know they'll be "New England Romantic", which means different things to different people.  To me, it's "laid back".  I admit I prefer a more forward sound (NOT JBL forward!).  I own neutral speakers, forward speakers, and now, laid back speakers.  Contrast is a good thing.  Besides, Absolute Sound not withstanding, I gave up on the search for "musical truth" ages ago and settled into just enjoying the music.  That's what it's all about, right?

[sarals]

Here's where I am right now (recorded with an iPhone):

So, that's what classic AR speakers sound like!  They're much, much better than my memory serves.  The tweeters do work, but my, they don't have a lot of output.  Unless, that's normal.  The top end is somewhat soft, yes, but they have a very, very neutral midrange.  No forward mids, here.  The lows are punchy, but they do lack that last octave.  They image surprisingly well, just as well as any modern speaker I've heard.  Top to bottom, I classify the overall sound as very smooth, very even.  Warm?  No, not really.  Maybe a little dark.  They're gorgeous sounding things!  They're a nice match for the Marantz 2270.

If you're wondering what that piece of particle board on the floor is, I use it for my bicycle rollers.  They tend to drag on the carpet when I'm riding them, this stops that from happening.

Next - the cabinets!

[bfastr]

Sounds great Sara!   but You are killing me with the 2270.  now I have to find a nice Marantz of my own.   As for the sound I had the same conclusion, my tweeters are not super bright, but they are there. the mid is loud by comparison, and overall the speakers have a nice sound so I concur with your review.  Mine are paired with my AR4-ax's and between them I have a nice balance of highs and lows. But my 4's have replacement tweeters that have always been very bright.   

As for mine, I changed course on the caps,  I bought a kit of potting epoxy and planned to put the caps in the wax box,  but then I decided to leave that alone and mount the new caps on point to point terminals.  I used some new style fake cloth covered wire that is really cloth over pvc that I use in old guitar amp restorations.  I have a bunch on hand and wasn't about to buy more wire just for a few inches.  I cleaned up the original pots and tucked it all back together. I am very pleased with the sound. but I am a little sad the project is done!  I still have a plan to restore the old AR4's next, but for now I am just enjoying the sounds.

Bob F

[ar_pro]

Ah. The famous Jean-Francois Paillard version. Nice.

[sarals]

Bob, beautiful job!  I'll post a photo of how I dealt with the capacitors.  I removed the old wax caps from the cardboard box and hot glued the poly caps inside, running the wires out of the open end.  It would have been tidier to do it the way you did.  I did squirt some Deoxit into the controls for good measure.  I reused all of the fiberglass as well as the paper cloth behind the woofers, used new "duct putty" for the woofers, and buttoned them both back up.  Before putting the woofers in, I made sure the controls worked and that the midrange and tweeters were both working in each cabinet.  I initially hooked them up to the SCS power amp I have which is driving the Advents.  Once I was sure they were (more than) fine, I connected them to the Marantz 2270 and placed them where they are in the video.  After the video, I moved them further apart.  One of the things that strikes me about them, other than their (lack of, a good thing) sound, is how BIG they really are!  I've had larger speakers over the years, but they were floor standers.  These speakers are just plain big for "bookshelf speakers".  I plan to get some short stands to place them on, I'm thinking a foot to eighteen inches tall.  I've noticed already that they like being near a boundary to reinforce their bass.  Oh, I'm using really crappy zip cord for speaker wire.  I need to get my hands on something better, and a bit heavier to boot.

So this thread doesn't die quite yet, I still need to do some sprucing up in the cabinets.  I haven't decided if I'll clean the grill cloth.  I kind of like the patina.  They're not abused/wrecked/damaged, just aged, and it lends them sort of a civility in their old age, and speaks to their long lives and heritage.  Now, only a woman of a certain age would say such a thing, but, hey!

[sarals]

31 minutes ago, ar_pro said:

Ah. The famous Jean-Francois Paillard version. Nice.

Agreed!!

[lakecat]

13 hours ago, sarals said:

Here's where I am right now (recorded with an iPhone):

So, that's what classic AR speakers sound like!  They're much, much better than my memory serves.  The tweeters do work, but my, they don't have a lot of output.  Unless, that's normal.  The top end is somewhat soft, yes, but they have a very, very neutral midrange.  No forward mids, here.  The lows are punchy, but they do lack that last octave.  They image surprisingly well, just as well as any modern speaker I've heard.  Top to bottom, I classify the overall sound as very smooth, very even.  Warm?  No, not really.  Maybe a little dark.  They're gorgeous sounding things!  They're a nice match for the Marantz 2270.

If you're wondering what that piece of particle board on the floor is, I use it for my bicycle rollers.  They tend to drag on the carpet when I'm riding them, this stops that from happening.

Next - the cabinets!

Nice work Sarals...and treating them with respect is awesome. Reading your thread takes me back seven or eight years ago with my first AR. Since then, about thirty or forty pairs of assorted AR's have through here and have learned so much about them...and their personalities as I refinished them...and of course...cursed at them often!..:)

Having the help of Roy and others on this forum fed the interest and they taught me much about the inner workings. I do love the sound of AR's and they are warm to me...and love the bass on the 12" woofers. 

So....welcome to the club and although they are your first...it probably won't be your last!....just a warning...;)