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AR grille cloth variation


stupidhead

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Hello all,

Over the past two weeks I have picked up two different sets of 2ax speakers. One with serials in the four digit range (1035) and the old identifying paper on back. These had a grille frame that is recessed into top and bottom and some sort of masonite frame. Also, the frame has three cutouts, vs. the two cutouts I have seen on almost every other 2ax I have seen. The grille cloth is the standard off white linen. Also the woofer has the cloth surround and the tweeter is what I believe is referenced as the fried egg version.

The second set has the newer style paper on the back with serials like 227733, These have a velcro-ed frame (no recess) and have a different grille cloth than I am familiar with. The woofers have foam surrounds, or at least they used to, and the tweeters are different with a slightly smaller dome and three globs around the dome. So I have a variety of questions before I dig into these for restoring;

1. Mrs. Stupidhead likes the new (pictured below with Genghis) grille cloth over the white linen type. Is there a resource for replacement cloth that matches? My intention is to stack the two sets on the flat side when done and matching cloths would be desirable.

2. What would be the best resource for replacement surrounds for the second set?

3. Will the crossovers be the same on both units, or are the caps going to have different values?

4. The tweeter mount on the older set seems particularly delicate (very thin wires to some baffle front mounted terminal nuts) and if I don't need to remove them I would like to not! Is there any reason to have to remove these from the baffle, for example caps mounted off of the driver terminals.

Both sets cabinets are in very good shape, and I am anxious to get this project started. Thanx for any input. Also, I am anticipating pot corrosion, and will be assessing that once I crack these open. I have a few spares if need be, and I also have some dope left from Roy on my recent 4x restore.

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All good questions, and I find it timely b/c I've been wondering about this cloth myself. In first pic attached, various models include (L to R): AR-7, AR-2x, AR-4x, AR-6 and AR-5, all with the same cloth, and I've never seen this shown in any AR literature. Although I do rather like the dark grille cloth on some other similar-looking speakers of the era (see Rectilinear Mini-III thread), my strong personal preference remains the off-white linen for the AR's. But of course, Mrs. SH and Genghis need to be satisfied, too.

Crossovers should be the same on both pairs, I think. A single 4uF and 6uF cap in each; fix/replace the pots as usual. Schematic is attached.

I learned of this source, M-Sound (see pic), from this site and John is great to work with, but I haven't ordered from him in awhile and I think I've seen some recent chatter about him having new contact info - - others with more current experience will probably chime in.

On the older set, those external wires are indeed tiny and somewhat delicate. It should not be necessary to remove these drivers, but it is often done using great care.

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Thanks anthropologo. I am hoping to find an exact replacement, not just any cloth. The cloth on the newer set is pristine and does not need to be replaced. I know there is a very close replacement from 1-2-3 stitch for the off white version, but have seen no reference to a match (or very close) for the brown tweed looking cloth.

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Thanx ra.ra. Yes, keeping Genghis happy is important. I agree, I personally like the off white as well, but my tastes are often questioned by Mrs. SH. Thanks also for the schematic and the dubious assurance that both xovers will be the same. Hopefully Roy, or someone will have a definite answer on this. Also for the tip on the foam. Yeah, I don't want to dick with those wires if I don't have to!

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MSound is no longer on ebay and his site is down but last I checked he was still in business and is a good guy to do business with. Email him at msound@shentel.net

-Kent

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Thanx ra.ra. Yes, keeping Genghis happy is important. I agree, I personally like the off white as well, but my tastes are often questioned by Mrs. SH. Thanks also for the schematic and the dubious assurance that both xovers will be the same. Hopefully Roy, or someone will have a definite answer on this. Also for the tip on the foam. Yeah, I don't want to dick with those wires if I don't have to!

SH,

-The crossovers all have the same caps (4uf and 6uf), but different inductors (#5 vs #7).

-The best foam to use is the 10 inch foam for Boston Acoustics woofers ("filled fillet"). All decent foam suppliers sell it. Ask for it by name or you are liable to receive a generic replacement. If Msound is still in business, he will know what to send you.

-The original brown cloth is not available, but the 18ct 123 stitch material comes in darker shades (I haven't tried any of 'em).

-The reason the grilles differ is because the early AR-2ax used the AR-2a style grille for awhile.

-Don't touch the leads of the earlier tweeters. They are aluminum, and break easily. They also require special solder if a lead needs to be repaired. With the exception of this issue, these tweeters (shared with the AR-3) have generally held up better than the later small dome tweeter.

Roy

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So first of all, I am not sure what happened to my pic above of Genghis so re-posting here.

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Now to the meat of the matter. Thanx for the guidance on this and I have reached out to John (Msound) and the filled filets are on their way! I am a little disappointed in the apparent non-availability of the brown cloth. I suppose the off white from 123 stitch will be used on the first set. The original cloth is slightly damaged and the way AR did that grille frame is a little sketchy. It didn't even wrap around the long vertical edges and was only wrapped on top and bottom horizontal edges. I am thinking about cutting down

the top and bottom of the masonite frame and velcro-ing the frame in place rather than the tucking in top and bottom edges. The question will become how do I fasten the what would be wrapped around all four edges fabric to the masonite. Too thin to staple, and gluing would be problematic when I try to stretch the material taut, the glue takes time to setup. Maybe I am overthinking and I should just order replacement frame and cloth from vintage AR, well at least the frames.

Trust me Roy, I won't touch those wires!

On the caps, a preliminary search suggests that a 6uf cap is maybe not common. Does anyone know of a resource for good qualty caps with these values?

Thanx,

Geoff

SH,

-The crossovers all have the same caps (4uf and 6uf), but different inductors (#5 vs #7).

-The best foam to use is the 10 inch foam for Boston Acoustics woofers ("filled fillet"). All decent foam suppliers sell it. Ask for it by name or you are liable to receive a generic replacement. If Msound is still in business, he will know what to send you.

-The original brown cloth is not available, but the 18ct 123 stitch material comes in darker shades (I haven't tried any of 'em).

-The reason the grilles differ is because the early AR-2ax used the AR-2a style grille for awhile.

-Don't touch the leads of the earlier tweeters. They are aluminum, and break easily. They also require special solder if a lead needs to be repaired. With the exception of this issue, these tweeters (shared with the AR-3) have generally held up better than the later small dome tweeter.

Roy

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Thanx ra.ra. After doing a little more research, I came across the Solens and will be placing an order for the 4's and 6's from Madisound. Actually, part of my initial concern about 6 value caps being odd was your above schematic. You have 6.2 caps in place of the original 6 value. Is that a matter of being "close enough" or is there more to it? Forgive me if this question seems ignorant, but I am. I strive to gather info from experts so I can achieve the best results leaning on the experience of others.

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Sounds to me like you are doing just fine. I was just about to say that you'll be using the exact same caps I used for my 2ax speakers until I looked back on my notes (can't locate my own x-o pics at the moment) and saw that I used Solen 3.9 and 6.2 values - - which tells me I probably was not familiar with Madisound at that time. I like your selections better.

On file I have four different 2ax schematics, and the one I showed is simply the best graphic version. It is not my drawing, and it represents someone else's project, where they used a 6.2uF cap for the midrange. If you look closely, though, you'll see a note stating that 6uF was the original value. Roy's comment in post #7 regarding the coil revision between old (cloth) and new (foam) versions is revealing, and it made me look at this a bit look closer.

On closer inspection, the first schematic I provided in post #3 now has me somewhat confounded. The notes about the phenolic tweeter and the cloth woofer led me to conclude this was an early version 2ax. However, it shows a #7 coil (which differs from schematic attached below) and the serial nos. noted baffle me. My own 2ax speakers have s/n 209564 and 209657 (which fall between those noted in the first schematic), and have #7 coils and foam alnico woofers (date Sep '72) and later 3/4" tweeters (also '72).

Another very good schematic is attached - - - looks identical except for the #5 coil. These speakers are early version s/n 117xxx speakers. Both schematic drawings make mention of driver polarity - - - take note!

Second pic is a 2ax re-cap (not mine) that used reliable Dayton caps. Third pic shows detail of my woofer re-foam - - if you look closely, you can see that the original dust cap was re-glued after shimming.

Am now curious to know a little more about your pair - - - type (alnico or ceramic) and date of woofer, serial numbers and coil identification?

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Hi ra.ra, et al,

So it is then OK to use caps that are "close" to the manufacturer's prescribed values. I am guessing the tolerance plays into this yes? In my looking for caps I try to find the tightest tolerance and not pay stupid money. Thanx for the other schematic, I definitely will download and save these files for future reference. I am intrigued by your confoundedness over the serial numbers thing. Maybe I can add to the confusion, here is a pic of one of the first set I picked up a few weeks ago. Note the serial number is only four digits, well five really but 0 doesn't count does it?

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and I will add that these speakers were clean. This is a pic of one of the sides and I have done nothing to the finish yet!

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sorry for the sideways pic btw.

So onto the drivers. Here is the tweeter, and don't worry Roy I will not touch those wires!

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and here is the mid

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and finally the woofer!

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and I will close with a couple of observations. Note the masonite is in place in these pics and has the three cutouts like the 2a, but clearly the identifier page with serial calls it out as a 2ax. Also it seems curious to me the badge (peaking through the cloth in the woofer pic) is the AR inc badge and not the 2ax badge.

I have not cracked these open yet, but I will be within the next week or so. I am finishing a pair of JBL L110s first, then onto the four 2ax's. I will be sure to take pics of the inner of these, and will update as I go.

Geoff

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Those are nice speakers! Early 2ax's did use the square "AR INC" badges. The engraved 2ax badge came later. I love the early cloth surround/aluminum frame woofers.

Yes--6.2uF is "close enough." Solens are fine but don't overlook Carli caps from Madisound. Less expensive and according to Roy they have ESR close to the original values. A 3.9uF (also close enough) is $1.35 and a 6uF is $1.80. Cheap! Or to REALLY go cheap, get ten 2.0uF mylar surplus caps @ 0.35 each = $3.50 - 10% for 10 = $3.15 to recap 2 speakers. The leads on these are only 1/2" so you'll have to attach some short wires.

-Kent

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Yep, in many, or maybe even most cases, substituting a cap value very close to original will normally work well enough - - - but what I was also saying is that when you are able to, why not strive to correctly duplicate the manufacturer's original capacitor values? Your plan seems to be doing exactly this (6 and 4, as opposed to my 6.2 and 3.9), which is why I like what you have chosen to do.

About the pics in your most recent post: as Kent has already stated, those speakers look magnificent. Very early serial numbers, cabinets look nearly new, and drivers appear all in great shape. What a great find! Regarding the grille frames, as I stated in an earlier post, these appear to be frames with cut-outs for the 2a speaker. This notion would make some sense since your 2ax's are so early, they possibly overlapped with the latest production of the 2a model. Thanks for these pics but I am still curious about your other 2ax's - - - it was the later pair (brown cloth) that I had the questions about.

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with any luck, I will crack open one of the newer ones tomorrow. Gotta work today and tomorrow is my Dad's 93rd birthday so spending some time with him. I should find enough time to at least take out the woofers as I will be refoaming them later this week. On that note, any tips from you gurus on the filled filet foams? John is sending the full kit with shims. I will pick up an exacto knife for cutting out the old dust cover. I am a little nervous about this, but I will be careful and methodical in my approach, as I tend to be with all my projects.

I will post pics of the drivers once I extract them on this thread, and I still need to go through these and clean them up!

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John will send very thorough step-by-step instructions. They used to be on his website but that's in transition. Just follow them exactly. The white glue he supplies is nice to work with because it's water based and forgiving.

My first re-foam was 2ax's using John's kit. I'll post a link if I can find it.

-Kent

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so again I want to thank all for responses. This forum is great for someone like me with a thirst for knowledge and guidance on this stuff.

I did receive the foams and the instructions are very thorough! Yet another example of good guidance and encouragement by others with a similar interest.

So I did crack open these and didn't find anything alarming. First, here is the serial and inspection sticker.

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and I believe this sticker was printed in June of '74, and speakers got final inspection of Dec. '74.

Here is the woofer mounted as I bought them.

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no surprises yet!

And here is the woofer unmounted and still wired. I expected soldered wires like I found on my 4ax set, but pleasantly surprised to see the connectors! Also, notice the "Z" in red on the side of the magnet. Does it mean anything? Both drivers had the same marking by the way.

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so an observation at this point. The magnet had a film of some sticky something. Almost gooey if it were thicker. Has something leaked out of the magnet or is that normal and of no concern? (I did do both cabs/woofers, and both had same sticky coating!) In the below pic you can see the sticky material on the edges of the magnet, and some of the inner cloth/paper barrier stuck to it.

Here is the info printed on the backside of the driver which seems to confirm the date we saw on the label.

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and finally a pic of what was the worst outer face on this set, the bottom. This pic is before any cleaning of any kind.

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and finally a pic of the same edge after some Howard's walnut restor a finish. A marked improvement, and again this was the worst face on both cabs! I am lucky to have found these as I did!!

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I could sand these a little, but I think I will leave well enough alone. These things are 40 years old and have been on their journey.

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Looks like you found another very nice pair of speakers. So far, these are very similar to the pair I have, with the following exceptions. Mine: 1972, Cambridge production, alnico magnet. Yours: 1974, Norwood production, ceramic magnet. Give us another update when you identify the coil and uncover the crossovers. Not sure if the wax block caps were still in use during 1974, but if so, you should not be surprised to find one of these in each cabinet.

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