AR55

I use the gasketing tape sold by Parts Express: https://www.parts-express.com/parts-express-speaker-gasketing-tape

If you want foam grills to match the original look, http://foamspeakergrilles.com/ can make them for you. Below is a link to my AR-17 restoration post that has pictures of the finished speakers & grilles that Foam Speaker Grills made for me. https://community.classicspeakerpages.net/topic/11600-ar-17-restoration/?tab=comments#comment-129612 Another option is to build a wood frame out of 1x2's with a 1/2" beveled edge, and cover the frame with black cloth. Attached is a copy of the sketch that I sent Foam Speaker Grills to use as a guide when they made my grills. AR-17 Grille Round Recess.pdf

My first choice is my pair of AR-9Lsi’s powered by a McIntosh MC7270 power amp. Both the amp and the speakers are over 30 years old, but as I have said in previous posts that there are few speakers on the market today that can compete with them. My wife on the other hand prefers listening to our AR-11’s that are in our small theater room. I think that her opinion is influenced buy the La-Z-Boy rocker centered between the speakers.

Those readings look fine. It isn't an exact number. I have a total of (4) AR-11 tweeters and their measurements range between of 3.4 ohms to 3.7 ohms, and my (4) AR-11 midranges range between 3.3 ohms and 3.5 ohms. Your slightly higher readings are just as likely due to the differences in the calibration our multimeters. It's true that you can probably make more money parting out the speakers. There are aftermarket options for the tweeters, which could keep the price down on for those, but I am not aware of a good aftermarket 1-1/2" dome midrange option.

The biggest killer of speakers is distortion. Most AR speakers with 8 inch woofers are rated at "100 watts continuous power per channel being driven to clipping 10 percent of the time, on normal music source". You can probably handle 200wpc peaks, as long as it comes with less than 1% distortion. Even with your 20ft x 40ft space you probably will never draw that much. My 9Lsi speakers are powered by a 270wpc amp in a 17ft x 30ft space, and even with the most demanding music the amp's meters seldom peak above 27wpc. Have I ever pushed the amp to peak at 270w? Yes, a few of times, but that was with stuff like a jet taking off on a demonstration disc or the cannon fire on Telarc's 1812 Overture. Nothing that I would recommend pushing a 8 inch woofer to try to play at high volume.

I couple of months ago I posted the results of research that I conducted on the 9 models of 8” woofers that were manufactured by AR with ferrite/ceramic magnets prior to the poly-cones of the Connoisseur & TSW series. I decided to follow up with one on the 4 models of 10” woofers manufactured during the same period. The attached pdf includes a matchup of woofer model number to speaker model, and a table with details of each woofer assembly for comparison. Per request I expanded this table to include a column with the woofer/surround info. An index of the AR archive drawings (https://community.classicspeakerpages.net AR Drawings Index) is available thanks to dxho, if you want to find additional info on each woofer assembly and/or subassembly. AR 10-inch Woofers 1973-1986.pdf

Before you give up, check to see if the tweeters and midranges are blown or not. If you don’t have a multimeter, find a friend who does, and have them measure the resistance of each driver. If you get no reading, they are probably blown, and the others right. The speakers aren't worth much. However, if you get a resistance reading of around 3.5 ohms for each, then there is a good chance that the drivers are OK, and the value of the speakers probably goes up to at least $400/pair. I wouldn’t worry about the pealing veneer on the back of the cabinet. It’s a rectangular flat surface making the veneer easy enough to replace. Besides it’s the back of the speaker. Who really cares if it’s veneered? The rest of each cabinet doesn’t look that bad. I have restored far worse. The crossovers on the other hand look like a lot of work, but they wouldn't be a deal breaker.

I think what you have is a pair of AR-11B's with AR-11A replacement badges. I have a pair of AR-11A's and a pair of AR-11B's. Everything you describe is just like my AR-11B's with the exception of the badges. My AR-11A's that are still waiting to be restored have tan tweeters, black screens over the midrange domes, crossovers mounted in the bottom of the speaker, brass badges, and strips of Velcro instead of dots to grab the foam grill. Unfortunately the tweeters are blown and the cabinets have significant water damage, which will require some veneer work. I got them cheap, so I can't complain.

The original model numbers for the AR-93 woofer, midrange and tweeters are: 200035 - woofer 200036 - midrange 200034 - tweeter The 210035, 210036 & 210034 are the same as the above, but manufactured by Tonegen for AR. Note that the AR made a 200038 tweeter that has the same specs as the 200034, but with different metal work. I would note recommend mixing the two, but it looks like either model will work.

I agree. Attached is a photo of a pair of AR-8bxi's, which are virtually identical to the 8bx.x's.

I have an AR-2ax from 1971 with the wider 11” diameter frame, 6 screws and a foam surround. The bass response is reasonably good. About the same as my AR-14. I noticed in your photo that the particle board in the cabinet recess looks pretty rough. When I removed the woofer from my 2ax to replace the surround, the sealing putty that AR used pulled some of particle board with it, leaving a pitted surface. Before I reinstalled the woofer, I patched (DAP plastic wood) and sanded the particle board in the recess to give me a fairly non-pitted surface. Also, I made sure all residue was removed from the back of the woofer frame, before I applied the foam tape. I got my foam tape from Parts Express (https://www.parts-express.com/speaker gasketing tape).

Basically it looks like AR used the same cone/surround specification (203039 - AR archive drawings 350, 356, 403, ...) for all 8" woofers and midranges with 205018 metal work, although it appears that they made minor changes to the spec over the years. The 200001, 200035 & 200037 woofer, and the 200027 & 200036 midranges all reference the 203039 spec. The cone/surround specification was changed for the 200050 woofer & 200045 midrange, which have the 205091 metal work. I would always recommend trying to use the woofer and/or midrange model originally intended for your speaker. That said, while you didn't feel that the 200045 midrange sounded just right in your AR-9's, it was probably closer than anything else you could find as a substitute for the original 200027 midrange. That was all that I was attempting to show, i.e. if you can't find your original midrange and/or woofer, was there anything that was a reasonably close match? In my case, if I can't find a pair of 200001 woofers, a pair of 200037 woofers would be the best alternate match for my AR-17's, since they share almost all the same parts. Still, If I run across a bargain priced pair of 200050's, I might give them a try.

Recently I restored a pair of AR-17’s and wanted to replace the aftermarket woofers. I had a spare pair of 8” midranges (model 200045) meant for my AR-9Lsi/98Ls/98Lsi. They visually compare well with the 200001 woofers in my AR-15’s & have the same measured DC resistance, so I thought that they might be a good match. They sounded alright, but the bass response wasn’t quite what I thought it should be. That led me to start searching for additional information on the 200001 woofer & 200045 midrange. It ultimately grew into a lot more. It became a study of which AR 8” woofer/midrange was original equipment in what AR speaker, and secondarily which of these is a good substitute for the often hard to find 200001 model. A copy of that research is attached as a pdf. AR 8-inch Woofer-Midrange Research.pdf

Part of the reason I went with the Vintage AR fabric was that it is actually slightly more elastic than the original AR fabric. Even with that the last corner ended up with some wrinkles on the top (see photo below). My wife thinks I too much of a perfectionist, pointing out that you can't see it unless you are nearly standing next to the speaker. I also rethought about only relying on glue to hold fabric in the corners. I still didn't want to risk a staple, but I wanted to add a little insurance. Using an existing pin hole in the plastic frame, I drove a small (5/8" x 18 gauge) nail into each corner. The corners have a stiffening rib, so there was little danger of cracking the plastic flange.

I don't remember what version of the fabric that I purchased from Parts Express, but it was cheaper than the Vintage AR fabric, so it may have been their house brand. I have never tried Fabri-Tac, and I agree Goop is a little messy, but it has great holding strength. I was OK with stapling into the face of the frame, but I would recommend against stapling into the frame flanges. You have to use a fairly high setting on the staple gun to get the 1/4" staples to penetrate the 3/16" thick plastic frame. The flanges cantilever off the main frame, and I felt that there was too great of risk that stapling could crack the flange, or worse break a piece off. Also, if you use staples, they would interfere with reattaching the trim. Not critical, but I wanted the grill to look as original as possible. It's been 10 years and the fabric is still fully attached on the 98Ls'.

Briodo if you decide to replace the fabric, definitely start with the 98Ls. I don't think I would have ever tried to replace the fabric on the 9Lsi, if I hadn't had success with the 98Ls. Note that one package of cloth from Vintage AR will cover both 98Ls grilles. I actually purchased the black fabric from Parts Express. The weave is a little closer to the coarseness of the original AR fabric, but it is not quite as elastic as the Vintage AR fabric. I was going to replace the grille fabric on a pair of 48b's for my daughter, and she wanted the cloth to be black. It never happened. Before I started the work, I landed the pair of 98Ls' that I restored and gave her my original 98Ls' that she really wanted all along. She gave the 48b's and the black fabric to her father-in-law, but to date he has not tried to replace the fabric on the grilles.

For anyone who is interested, I have attached a write up on how I removed & replaced the fabric on AR-9Ls & AR-9Lsi grilles. About 10 years ago, when I restored a pair of AR-98Ls speakers, I replaced the torn & stained grille cloth with fabric that I got from Vintage AR (eBay store). It was a little tedious, but not too difficult. I also bought enough matching cloth to recover my AR-9Lsi’s grilles, but knowing it would not be as easy, I put if off for another day. Just recently, I picked up a pair of bargain priced 9Ls grilles with torn/stained fabric & decided to go ahead and recover them instead. If it didn’t work out, I would still have my original 9Lsi grilles. Recovering the 9Ls grilles was definitely a lot more challenging, particularly having to severely stretch the fabric at the corners, but the finished project turned out OK with only a little wave in the fabric at one corner. The fabric that Vintage AR sells is a little pricey @ $47/speaker, but the color is good and it is very elastic, which is a must, if you want to stretch in over the corners without tearing the fabric. Vintage AR also provides their own instructions for replacing the fabric, but they are geared more toward the AR-9 & AR-90, for which they also sell fabric. Photos of completed grille below: AR-9Lsi new grille fabric Installation.pdf

If you bought your AR-17's in 1978, they are the ADD series version and have simpler lower crossover. The resistor should be fine. The 6uF capacitor should be probably be replaced.

I did a little research in the AR archive drawings, and it looks like the voice coil from an AR-48b’s tweeter may not be an exact match for your AR-9Lsi’s blown tweeter. The 2 tweeters have different voice coil part numbers. The .75-inch dome tweeter found in the 38b, 48b, 58b, etc., shares its voice coil (AR Part Number 202012) with tweeters in the AR-10pi, AR-11, AR-58s, AR-9, AR-90, AR-91and AR-92. The .75-inch dome tweeter in your AR-9Lsi has a voice coil part number of 202029 which, from what I can tell, only appears in the dual dome assembly 200048/210048 of the AR9Ls, AR-78Ls, AR-98Ls, AR-9Lsi, AR-98Lsi and the MGC-1. AR often gave parts new numbers, even when only slight changes were made, so it is possible that the coils are the same. I have measured the DC resistance of the tweeters in my AR-11's, 9Lsi's, 98Ls' & 98Lsi's and they all read between 3.2 & 3.7 ohms, so its possible that the coils are the same. I just can’t confirm it, since I was only able to find a detailed drawing of the one of the voice coils (202029) in the AR archives.

I would be very careful disassembling your dual dome. The lead wires are glued in place and can stick to plastic cover, and snap off when you take the cover off. Unfortunately, I know this from experience. Giorgio may be correct, but I was not aware that the tweeter in the 48b is related to the tweeter in the 9Lsi's dual dome. If it is, then you should have a lot of options - the 38b, 38bx, 38bxi, 48b, 48bx, 48bxi, 58b, 58bx & 58bxi all have the same dome tweeter/cone midrange assembly.

Vintage AR (eBay store) used to offer a repair service for the tweeters in the dual dome 200048 (78Ls, 98Ls & 9Ls) & 210048 (98Lsi & 9Lsi). I haven't seen them advertise this service recently, but you might want to check to see if they still offer it. The 210048 & 200048 are the same unit. The 200048 was made by AR & the 210048 was made for AR by Tonegen. There is a pair of the 200048 dual domes for sale on eBay by recycled_josh: https://www.ebay.com/itm/Acoustic-Research-AR-9LS-9LSi-98LS-98LSi-Tweeter-Midrange-Pair He wants $475 for the pair, which is bit above the going rate. Usually they can be found for around $150 each. The post is been up for awhile, so he may be willing to deal for one.

I assume that you are well on your way to making your cloth/wood frame grilles, but I thought you might find it interesting that someone is selling AR-11 reproduction grilles on eBay - https://www.ebay.com/itm/ACOUSTIC-RESEARCH-AR-11-10PI-ETC-NEW-FOAM-GRILLES-PAIR I can't tell from the photos if they are any good. The foam itself looks similar to porous foam that http://foamspeakergrilles.com/ uses to make their grilles.

I agree with you that the reasoning behind the various 8-inch AR woofer models is confusing. The 200001, 200037 & 200050 are all 8-inch woofers used in 2-way systems with nearly the same specs. If you look at the AR spec test drawing for the 200037, you will find that the test was performed with the woofer in an AR-17 cabinet. My guess is that the 300037 & 200050 were slightly modified/improved models of the original 200001. The 200045 was never used in a 2-way system, but since it was all that I had available and its specs appeared to be similar to the 200001, I thought why not try it out. If I ever come across a pair of 200001 woofers, I may change them out, but for right now, I am happy with how these turned out.

My bad! You are correct. I just opened up one of my 28b's and checked. The capacitor in my 28b's is a 5uF. They are buried in glue and I thought the 5 was a 6. By the way, the capacitors in the 17's were the black and red ones everyone seems to dislike. Surprisingly, after I cut them out and measured them, I found that they were not far off spec. One was nearly right on at 6.15uF and the other one measured 7.2uF.

The capacitor value in the 17's is 6uF, which is the same as the capacitor found in the 28b's. The woofer was actually intended for the LMR of the 9Ls/9Lsi & 98Ls/98Lsi. I had picked them up very cheaply when someone was selling the carcasses of a pair of 98Ls' (I got 2 trashed cabinets, the (2) 8" lower midranges, (1) 12" woofer and 2 crossovers for $150. As far as the 200045's performance goes, they mimicked the performance of the 200050, 8" woofer of the 28b very well. Also, I put one of the 200001 woofers from my AR-15's in one of the 17's cabinets and the 200045 woofer in the other and compared them with a mono source. Again, the differences were small. I did feel that the 200001 may have achieved a little deeper base response, but my wife said that she couldn't hear any difference. Below is a picture of the 28b next to the 17. The 28b is a little taller, but the 17 is deeper, so they have about the same internal volume.