lARrybody

Very nice indeed. Chris has restored some AR3a tweeters for me, and the difference is like night and day. Maybe J Kent has some 3 badges left.

I have been fairly successful in locating matching examples to most of my orphans, but my lone AR18b speaker still sits there.

I have a pair of AR2a's that have sequential serial numbers, but that may be because they are early production examples. I am thinking some of my smaller AR speakers were sold in pairs thus having the same serial number on both.

Brian just want to add a few things to what Aadams and JKent have said. You can discontinue the wax block cap and push it back slightly to make room for the new 20uf cap. That way you wont have to mess with the inductor. You don't really want to mess with the original pots, just install new L-pads. You wont have any problems that way. The 18 ct. lambs wool from 123 stich is some excellent material but a bit pricy. I went another way and used the Charles Craft Irish Linen from Michaels. Less than $5.00 with the 40% off coupon. It is a tea dyed tint so I soaked it in some diluted bleach water to lighten it up a bit. It does look very presentable. Two last recommendations. Use the sealer available from RoyC and Vintage AR on the woofer cloth surrounds. Don't use anything else no matter what you read. Make sure the woofers and tweeters are properly sealed to keep the cabinets air tight. You should really enjoy these speakers.

I went back and reread the post from seventy1 that DavidR referred to. What a interesting thread. I wonder if the addition of ferro fluid to a AR 91,92 midrange would make it have the characteristics of the AR 9,90 midrange.

I found this explanation of the upper midrange differences on the web. AnonymousMarch 10, 2014 at 2:26 PM One area Teledyne-era AR90/AR-90 owners (& AR9/AR-9 owners, too, for that matter) need to exercise caution in, IMO, has to do w/replacement speakers for the AR90/AR-90. Specifically, there has been a increasing tendency for those parting out an AR91/AR92 to claim that the AR91/AR92 midrange driver (OEM PN=200032) is 100% the same as the AR90 upper-midrange driver (OEM PN=200028), as if the factory routinely shipped AR90/AR9's w/PN=200032's installed. Since the factory specs and wiring diagrams for the AR90/AR9 specify only the PN=200028 then this was not the case. Differences : The PN=200028 has a larger volume of Ferro-Fluid (for cooling) than the (OEM PN=200032), which also reduces the PN=200028 air cavity below the dome (via that extra Ferro-Fluid) which also raises it's resonant freq, hence it's dedication to the upper-mid range, while the converse is true for PN=200032. But since PN=200032 has a better low freq response, how does that play out when coupled to a AR9/90 crossover? And what loss of sustained power handling is encountered wrt the lower volume of Ferro-Fluid ? In short, if the Teledyne-era factory felt that anechoic chamber response testing & power-applied-vs-driver-temp testing allowed for one driver to be used in both applications there very likely would never have been a 200032.

Giorgio I notice that the veneer on the backs of your Mk2 10pi's covers the back panel and leaves the case edges natural. My Mk1's have the veneer edge to edge. I wonder if this is correct for that version. The veneer is starting to come loose and some is missing. The veneer on the sides, tops, bottom and fronts are in great shape. I plan on re veneering the backs with quarter sawn walnut and refinishing the cabinets to match as close as possible. Being the backs will be new it is not that critical that the finish is a exact match.

You have good taste my friend.

I believe Frank is right about the one smooth circular piece that covers the screws. It is kind of rare to find a pair of ADD speakers that have not had the woofers re foamed or replaced by now. It does happen though. I found these AR18 speakers that were completely original. If I remember correctly those "external woofer gaskets" were some kind of thin open cell foam. When I re foamed them I cut new gaskets from some thin Creatolgy closed cell foam sheets from Michaels. The pair below is actually a different set of 18's with the same treatment. The proceeding S series and B series had plastic trim rings.

Lots of choices here. Lets start with the caps first. I have three sets of 2ax's that I have restored and kept. Set 1. Two of these parallel wired together for the 6uf cap. https://www.parts-express.com/dayton-audio-pmpc-30-30uf-250v-precision-audio-capacitor--027-220 This for the 4uf cap. https://www.parts-express.com/dayton-audio-pmpc-40-40uf-250v-precision-audio-capacitor--027-226 About 25 dollars plus shipping Set 2. One of these for the 6uf cap. https://www.erseaudio.com/Products/PulseX250v/MPX25-03-6-00 And two of these wired together for the 4uf.cap https://www.erseaudio.com/Products/PulseX250v/MPX25-03-2-00 About 7.5 dollars plus shipping. Set 3. This is my crazy stupid set of 2ax's These wired in parallel for the 6uf. https://www.madisoundspeakerstore.com/supreme-caps/mundorf-2.7-mfd-supreme-caps/ https://www.madisoundspeakerstore.com/supreme-caps/mundorf-3.3-mfd-supreme-caps/ And these wired in parallel for the 4uf.cap https://www.madisoundspeakerstore.com/supreme-caps/mundorf-3.3-mfd-supreme-caps/ https://www.madisoundspeakerstore.com/supreme-caps/mundorf-2.2-mfd-supreme-caps/ About 200 dollars plus shipping They all sound good. The possibilities are plentiful. You could even use electrolytic caps like the originals were, although I prefer polys here. My opinion on the pots. Don't try to clean the originals. I would go with these L-pads. https://www.parts-express.com/speaker-l-pad-attenuator-15w-mono-3-8-shaft-8-ohm--260-248 or get these from the eBay seller hifiaudio . https://www.ebay.com/itm/ACOUSTIC-RESEARCH-SPEAKERS-control-potentiometer-AR-2AX-AR-3-AR-4-AR-5-AR-6/164155405428? hash=item26386cb474:g:85QAAOSw5WReIgWE They both do about the same thing. Big difference in price. I have one set with cleaned original pots, one set with l pads and my crazy stupid set with the replacement pots from hifiaudio. The tweeters area toss up. If your originals are rebuildable I suggest you send them to Roy C or Chris1 and have them rebuilt. This would sound the best. The HiVi Q1R are a good choice, You will need the small inductor coil and possibly a cap value change, but this will work. https://www.parts-express.com/hivi-q1r-1-1-8-textile-dome-tweeter--297-417 The third option is the Midwest speaker replacements. I have no experience with these, but others speak favorably about them. https://www.ebay.com/itm/AR-Acoustic-Research-Replacement-8-ohm-Tweeter-for-AR-2ax-AR5-LST-2-MT-4121-8/162689351715?hash=item25e10a8023:g:k~kAAOSwc8lZzEo4 These are just my opinions and opinions are much like elbows. Most people have at least one. Oh you did not mention the grills. There is really only one option and that is the 18 count lambs wool linen from 123 stitch. It looks and preforms so much like the original it is uncanny. https://www.123stitch.com/item/Wichelt-18-Ct-Lambswool-Linen-Needlework-Fabric-27x36/59-135X

Early last year I found a pair of 8b at a local thrift. I initially bought them for the tweeters, but decided to go ahead and re-foam the woofers. Upon some online research I found out that these woofers originally came with filled fillet surrounds much like Boston Acoustics woofers. Looking around I found that eBay seller Audiodogs had the correct surrounds. I ordered a set and re-foamed them. Larry from Audiodogs was very easy to deal with. I guess you could use the surrounds others are selling for these, but I like to keep things as original as possible.

The glue that holds the outside of your surround to the Masonite spacer and frame may have dried out and became loose. This could put your voice coil out of alignment. There is also the possibility that the glue on the spider has also failed. I know this from experience. Re gluing and realignment fixed mine.

Vee, your 2ax speakers could have up to three different woofers. The early cloth surround woofer in the middle, the large frame transitional foam surround woofer to the left and the later small frame foam surround woofer to right. Lets identify what you have and go from there.

Not my picture, but I keep it around to clarify the wiring of a original pot and a l-pad.

Would real RMS power be stated as "XX wats per channel, 20-20,000Hz with less than 0.XX distortion". I have a Fisher 400 that I have listened to with some AR2a speakers circa 1962 and also some 1963 KLH Model 6 speakers. How about some of the 8 in variants like the AR 18, 18s, and AR 25.

I had the same thing happen to a 2ax woofer. The best bet is to follow Aadams recommendation and look for a replacement. It wasn't hard to find even though there were two sizes for the woofer basket on 2ax's. Mine were the early 6 hole baskets. The later ones were four hole. If you want to get it repaired the two guys Aadams listed are the best I know of.

They are sitting on a hardwood floor now. The backs are 6 in high and the fronts are 7 1/2 in. high.

Just got a set of these JBL JS-120 steel speaker stands yesterday. They were designed for Century 100's, but are a perfect fit for my AR3a's. I think they have a 5 degree rake. Set them up in another room today and have been listening off and on all day. I think they point the tweeters and midranges more toward my listing position than the previous flat stands.

They are brighter. A little too much for me I think. I am currently running my 58S’s at -6 db on the tweeter and flat on the midrange. My 91’s have been out of rotation to long. Currently working on my third pair of 3a’s. I do like their sound.

DAA. Have you ever listened to the AR 91 or the AR58S ? They are basically the same speaker, different cabinets. To me that is the ultimate version of the AR3a 3 way. The AR 11 is very good But the redesigned dome tweeter and midrange really shine on the AR 58S and 91.

After looking at the second woofer on my home computer screen instead of my phone in the daylight, I am not so sure that surround is cloth. It may be foam that is coated over with something yellow. Here are woofers from two different sets of 2a's that I have.

Everything looks right on the first speaker. The second speaker looks right except for the cone and dust cap. Interesting in that my 2a’s have the yellow cloth surround of the second pictured woofer. Was the speaker re-coned and the original surround reused?

I haven't stacked 2ax's yet but have stacked AR5's on top of AR2ax's. While two identical power amps receiving the same signal might be preferable, I just used the speaker A and B outputs on a receiver. Since both speakers are 8 ohm that would be the same as wiring them in parallel. Just make sure the amp has enough power and can handle 4 ohm loads. Not being identical speakers the dome midranges of the 5's were quite prominent, but the overall voicing was close.

I too use a Crown XLS 2502 to drive a pair of 9's. I have used several preamps, but currently use a vintage Yamaha C70. I use a Art CleanBox pro to convert the unbalanced RCA outputs from the Yamaha to XLR balanced inputs to the Crown. There is no noise. I use decent but not expensive interconnect cables. I definitely prefer this combination over my previous Adcom GFA 5500 II and GFP 5500 II setup which wasn't all that bad. Isolate where your noise is coming from and nip it in the bud. Again I ant say enough good things about the Art CleanBox pro.

I have used the acrylic blackboard paint sold at Michaels with no problems. Here is another idea. KLH used to do this. Get some of the sheere black speaker grill cloth from Parts Express. https://www.parts-express.com/parts-express-speaker-grill-cloth-black-yard-70-wide--260-335 it is 100% acoustically transparent. Cover your frames with it first and then cover with your 18 ct lambswool. You will not see any cutouts. I usually glue the black cloth then staple the lambswool.