AR 2-ax

[powerglide]

Good Afternoon fellow AR enthusiasts , recently joined the forum (today) looking to gain some info on a recently acquired set of speakers. 

A quick search of the site tells me I have the later model 2-ax's built in Norwood Mass. I have included a photo of the serial No of one but the pair has had the paper been removed however presents the same. 

My goal is to bring these back to their best and pair them with an older Sansui, I have downloaded and printed off the document on restoring the AR - 3a's and will use the front section to diagnose any problems with the drivers. They look to be in OK shape for their age with the foam surrounds showing a few cracks.

A little knowledge is a dangerous thing, and that is what I possess in the field of speaker refurbishment or electronics and why I'm reaching out for a hand. Providing the drivers check out (bit suspect on the tweeters) I'm looking at replacing the following and hoping to get some feedback on the best parts to use and and where to purchase. 

• bass driver surrounds
•  whole crossover with new caps, resistor and induction coil
• speaker terminals 
• control potentiometers 

I value any opinions by people who have perform the same tasks with good results, I like the look of these but flying blind  https://www.ebay.com.au/itm/ACOUSTIC-RESEARCH-SPEAKERS-control-potentiometer-AR-2AX-AR-3-AR-4-AR-5-AR-6/153393576634?hash=item23b6f83aba:g:LkMAAOSwBXhbEGal  

thanks in advance from the South  

looks like my files are too big, will convert and post later, that serial number is 025182 

[powerglide]

H

 

Edited July 31, 2021 by powerglide
Remove downloads

[JKent]

 Welcome Powerglide

Very nice speakers. I believe you have the European ones

The pots you linked are good or use inexpensive L pads. The tweeters may be ok but there’s no sound because of the corroded pots.

Replace the caps with film from PE or Madisound. Coils and resistors don’t go bad. No resistors in there anyway.

Foam surrounds from SpeakerWorks or ebay seller Rick Cobb are good. I strongly recommend kits with white glue.

Sorry for any typos. Typing on my phone

Kent

ps

Just looked at the pics. Your speakers were built in Holland.

I suggest keeping the original speaker terminals.

[Jim Pearce]

Hi,

1. I have what appear to be a Roy C type modded pair of these that have the terminals taped over, rivet-like terminals like the ones shown here  instead of the pus in types. Does that mean my loudspeakers were built in Holland? What's the story on those differences?

2. Also, the white glue for the surrounds you are referring to... Is that the typical white glue that most people use for woodworking projects? I have some Bose 300 ones that I'm going to do as my first ever refoam job as practice for my ARs, ahem, and have been wondering what adhesive to use.

3. I have a pair of 2axs with mismatched woofers...one has a short square magnet with a sticker that says it is a factory replacement and a Masonite ring, the other has a conical taller magnet. Which woofer is preferable?

Thanks!

[ra.ra]

Hello powerglide, and welcome to the forum. You've got a fine-looking pair of 2ax speakers that appear almost brand new. Your photos are very good, but I suspect they are still rather large image files, since it took a few moments for them to load for viewing (for future: 100KB file size is more than adequate).

Kent hit on all of the most salient points with good advice and recommendations. The decision regarding original pot replacement will be based on your own diagnosis of their condition and functionality... and personal priority, of course. Same with capacitors - - the 2ax typically uses one 4uF and one 6uF cap per cabinet, and yours just might employ the colorful Sprague Compulytic can-type caps which may not require replacement. For confirmation, these can be measured with a hand-held meter, if removed from circuit. Replacing speaker terminals is also a personal preference - - I find the original knurled nuts to be very robust and quite good and have been very satisfied by using spade or ring terminals on my speaker wires (see pic). Other members here have documented clever methods for keeping the original terminals yet adapting them for use with banana plugs. 

Your speakers do reflect the "Euro" cabinet styling with thin front edge profile, larger grille area, and brown speckle paint on backside. Also, while AR's main facility had already moved to Norwood, your label suggests these were most likely assembled in the Holland facility. For reference, I've also included a montage pic of speakers nearly identical to yours: these speakers were assembled in the England facility, and the stamp on the woofer magnet indicates it was fabricated in 1974.

With a re-foam, your woofers should be good for many years to come - - - you may want to re-install them at 180° from original position to counteract the possibility of spider sag. The "ugly duckling" mid drivers are extremely reliable and seem to have a very low failure rate and generally require no attention. It is the tweeters in these speakers that are known to degrade over time - - you'll want to make your own assessment of their performance, but from appearance only, the three orange suspension blobs appear to be surprisingly "fresh", which might be an indication of their overall healthy condition. 

[JKent]

.

PG

Good advice from ra ra

Jim

The euro version looks like those pictured with thin frames around the grilles (and the label will show where manufactured).

The white glue is similar to Elmer’s glue but more like Aleene’s Tacky Glue. But the kit should come with glue. I just advise against the solvent based glue that some sellers use

[Jim Pearce]

Aha, thanks. And I shudder to think how many surrounds on various speakers from different makers have been ruined by people using watered-down caulk, watered down Aileen's or Permatex or some other product to seal them. Man am I glad I waited until I listened to all of you guys... Incidentally the proper stuff is only thinnable with tolulene I believe?

[JKent]

Right Jim but let’s not confuse PG. Toluene will thin the sealant on your cloth surrounds but PG has foam, as do your Bose, which will have to be replaced. For that the white water-soluble glue is much more forgiving 

[Jim Pearce]

So the craft store stuff is solvent-based?

[JKent]

Aleene’s is water based.

If you order from SpeakerWorks for example they have Latex or Nitrile adhesive. Use the latex (white) for paper cones

[BAWSME]

I used the kit from Simply Speakers to repair the  foam surrounds on my AR2ax woofers and it comes supplied with small tube of clear adhesive.  I’ve had no issues with the adhesion between the paper cone to surround and the surround to metal basket.  I’ve used their kits in the past for other speakers and have never had an issue.  I didn’t see any reason to doubt the glue supplied since they have been in business a long time.  What is the reason I should have used white glue?

[Aadams]

14 minutes ago, BAWSME said:

What is the reason I should have used white glue

You are ok.  The white glue is way more forgiving. Longer set time allows for fine tuning the fit. 

[BAWSME]

11 minutes ago, Aadams said:

You are ok.  The white glue is way more forgiving. Longer set time allows for fine tuning the fit. 

I see.  Thank you.

[JKent]

...and any goofs can be easily cleaned up 

[powerglide]

Thanks to everyone for their input. I definitely need to replace the pots, they are a bit toasty, I've been recommended L pads but thought I'd see what people think of the ones in my link as the seller bagged out the L pads? 

Good advice on the crossover components. I will start the diagnostic process tomorrow on the drivers and open up the speakers for a look at the voice coils. I'll post some internals and pics of the crossovers for advice on which type of caps to purchase, is there much of a difference if the values of the replacements are the same? 

Once I get a shopping list together I'd prefer to make a purchase from one supplier if possible as the freight charges down to here are OTT, hopefully I don't need new tweeters 

 

[JKent]

Powerglide

That ebay seller’s comments about L pads are total nonsense. L pads will do the job and will last, all for about $4 each. OTOH some members here have said those ebay pots are very nice.

Your capacitor question opens up a whole can of worms. Most but not all folks here would agree that for your speakers the Dayton 5% film caps from Parts Express are a good choice. PE also sells L pads, nice gasket tape and Hi Vi tweets 

[RoyC]

9 hours ago, powerglide said:

Thanks to everyone for their input. I definitely need to replace the pots, they are a bit toasty, I've been recommended L pads but thought I'd see what people think of the ones in my link as the seller bagged out the L pads? 

Good advice on the crossover components. I will start the diagnostic process tomorrow on the drivers and open up the speakers for a look at the voice coils. I'll post some internals and pics of the crossovers for advice on which type of caps to purchase, is there much of a difference if the values of the replacements are the same? 

Once I get a shopping list together I'd prefer to make a purchase from one supplier if possible as the freight charges down to here are OTT, hopefully I don't need new tweeters 

 

-I agree with Kent, L-pads will work just fine. Contrary to the Ebay (Brooklyn, NY) listing description, the new pots are sourced overseas and are not built by the seller. In fact, they can now be acquired for less dollars from forum member chris1this1. The primary drawback, besides expense, is that the shafts are hard to turn and cannot be easily moved without an added knob or flat head screwdriver.

-You will not be able to see "voice coils" by opening up the speakers.

-No, there is not much difference between caps with like values. You are dealing with 40 +/- year old drivers, as well as variable resistors, with greater variations than new caps. Buy your favorite color within your budget.

-Parts Express is in Ohio...currently offers free shipping over $49 and a flat rate of $7-ish under $49.

Roy

[powerglide]

Thanks again 

6 hours ago, RoyC said:

-You will not be able to see "voice coils" by opening up the speakers.

Arrh I was looking at pg5 of the AR-3a guide and thought they must be accessible, Virgin speaker restorer here, I've been doing cabinet making for 35 years so I konw they are, at least, going to look sharp. 

6 hours ago, RoyC said:

-Parts Express is in Ohio...currently offers free shipping over $49 and a flat rate of $7-ish under $49.

I don't think they are going to honor that deal.  I'm from New Zealand Roy, like the America's Cup - But living in Sydney at the moment. The tweeters are the big ticket item (if needed) shipping costs alone are $15USD and $9USD import fee each so it could mount up. I have a brother in Austin and could take advantage of the free post, have him open every thing up re box it then send it down to me as second hand goods, no import fee.  

I'll see what I'm going to need and make an assessment, it's not that bad! 

photos to come  

[powerglide]

Test results 

I had been anticipating a problem with the bass drivers as one of the previous owners had decided to "fix" the pots by butchering holes in the rear Masonite next to the terminals and had left the mess open with the pots hanging on their wires. 

 

I gingerly added some current and all drivers performed nicely, the pots (appart from a broken one), did as they were asked without crackle, two smoothly and the third with a bit of grinding but no transfer to the mid it was regulating 

I selected an acoustic/vocal/track and increased the volume, Wow! I've never heard AR's before and these little gems exceeded all expectations. I think I got a steel.

Removed the bass drivers and found someone had been in one and changed the glass wool for a lower density blanket type insulation.

 

 

Both mid pots had been wired directly, through the butchered hole, to the T terminal.

 

crossovers were sealed in a wax box arrangement 

I'm thinking not to mess with them too much, definitely fix

• bass driver surrounds 
• Replace all pots with 2 duel L Pads and mount them to the rear of the main box
• Remove what's left of the Masonite panels and replace with a circular set of banana terminals, I have seen some on another refurb that went straight in
• change insulation- any recommendations welcomed 
• Wire wool the veneer and re oil 

Any views on keeping the original crossovers and do they need to be removed to test? 

I have found a local retailer that imports AR driver surround kits, they come with Bostic brand of water based glue you guys have been commented on, I don't like their terminals or L pads but sure I will find them locally from another outlet as well 

 

looking forward to hooking these up to a proper source and amp 

 

[ra.ra]

Excellent pics, and it's good to know that all drivers are functioning. Wow, I'm not sure what was intended by hacking away half of that crossover panel, but that obviously now becomes a top priority.

The multi-colored stuffing is fairly typical for AR's assembled in Europe, but it is surprising to see two different materials used in this pair. Your best bet would be to discard both and replace with equal amounts of new fiberglass (27 ounces per cabinet according to the AR factory drawing). New foam surrounds are essential, and woofers would also benefit from new perimeter seals when re-installing. New L-pads are a good idea, but you really should make the effort to replace the old capacitors as Kent originally recommended. 

Clearly you wish to install banana terminals, but I would strongly discourage you from placing the L-pads outside of this original recessed circular cut-out which is intended to fit all of these components. I think you should just fabricate a new closure panel to cover this hole, and arrange your new terminals and L-pads within this circle. Also to this end, you will want the L-pads that have stems which will not protrude beyond the rear panel surface. This will allow the speakers to be placed flat on their backs.   

[JKent]

The holes in the cabinets will give poor bass response

Oops. Just noticed ra ra answered while I was typing. Not much to add. The wax block is the old double capacitor. Just yank it out.

Replacing the fiberglass is optional imho. 

Be sure to seal behind the woofers when you reinstall them

Kent

[powerglide]

@ra.ra my first train of thought was to do as suggested with the destroyed rear panels as this is an easy fix for me. I swayed to segregating when I saw how another member had upgraded the two components. I'm using old Western Electric unterminated cables at the present but  I've used banana's in the past and found them good and it makes sense to me to install the dual function for the future. I'm sure I will fit everything nicely back in its original spot.

 it is possible that this set was not an original pair? observations for this assumption

• the missing serial number paper - could have easily come adrift over the years 
• the rears of the speakers are painted in a different paint - could have been at the can change over in the factory  
• the veneer has aged slightly different - one may have spent more time in the sun, someone has attempted, poorly, to repair a coffee cup mark on the top of one  
• the different types of insulation used 
• the substrate for the cloth trims is different, one is 4.5mm and the other 6mm 
• not sure if valcro was installed in the factory but there are discrepancies there also

too many variations for me. I don't think it's a biggy? All the drivers, internal components and even wires are identical so they cant have been that far apart, does anyone know over what time frame these were assemble in Holland? 

Ordered the surrounds and sent pic's of the cross overs to a guru who owes me a favour  

I'm going to manufacture new boards for the cloth, would tastefully changing the look hurt the value?     

Powerglide     

[ra.ra]

 

 

 

 

[RTally]

20 hours ago, powerglide said:

I'm thinking not to mess with them too much, definitely fix

• Wire wool the veneer and re oil 

Seems like everyone else has covered the rest, but I want to caution you about using wire wool (Steel wool in the United States). If the wire wool is magnetic, you must remove all the drivers from the baffle before using the wire wool. During use, wire wool leaves fines, which are very small metal pieces. The fines will be attracted to the magnets in the drivers. If the drivers are still installed, the fines will be attracted to the front of the drivers. You do not want this to happen. Also, many woodworkers do not like using wire wool because the fines also get caught in the wood grain if not careful.

Instead of wire wool, I suggest using a solvent to remove the grime and old finish. Then use a fine grit sandpaper to touch up the surface. I like to use 180 or 220 wet-dry sandpaper with a sanding block. You can then use oil or other finish that you prefer. 

[Giorgio AR]

9 hours ago, powerglide said:

Hi Powerglide, here's how I solved with a masonite crossover panel that was deformed and useless due to moisture.
The panel belongs to a Heathkit AS-2a, the clone supplied in kit form with the original Acoustic Research AR2a.
The AS-2a speakers are from 1964, and I used the masonite from the bottom of a 1972 Japanese turntable !!
There is only the different shade of brown to differentiate the back of the 2 speakers.
For the writings I used "transferable" letters, then painted to make them stable!
Under the complete phase of the work.

Giorgio

 

 

 

On left original AS-2a masonite panel

Perform all the holes in the same position and diameter

New panel with writings and mounted pots

Back side AS-2a with original masonite

AS-2a back side with reconstructed masonite