Refreshing old AR11's

[r_laski]

Mark, Thanks for the assist with the edit of my first ever post to this fantastic forum. I composed it in MS Word and then cut & pasted to the forum. I didn’t notice that my paragraph indenting didn’t transfer. I will use carriage returns to separate paragraphs.

Rich Laski

[r_laski]

>That is sooooo odd. The woofers always "die" of old age, but honestly I have never, ever, seen the midranges die and leave the tweeters intact. Do you have any recollection of what might have killed them off? Did an audio signal generator or maybe a component gone bad contribute?<

Bret, I wish I could remember, but we are talking about something that happened 20 +/- years ago. I don’t think I ever really figured out exactly what caused the midranges to die. I think Tom’s explanation is probably right on the money as to why it might have happened:

>Also, the AR-11 has relatively low sensitivity (inefficient), and the tendency is for one to elevate the power because of its clean output. As such, amplifiers without sufficient reserve -- or the capability to operate into low impedances -- can get into trouble quickly. It is also for this reason that midrange drivers can be susceptible to burnout. The tweeters are ferro-fluid cooled, and seem able to take a lot of power (compared to the earlier AR-3a-type dome).<

Then again, it could have been one of those times I cranked up the Telarc 1812 Overture. A lot of bass and midrange at the most dynamic passages, not as much high range.

Sorry, I just can’t remember the details back that far. I can only relate something I believe may have contributed to my AR-11 midranges’ demise. When I bought my AR–11s (It was summer of 1978, not 1979 as I stated in my previous posting). I was powering them with a GAS Ampzilla II. I bought it from a different stereo shop in Oklahoma City about the same time I bought the speakers. At 360 WPC into 4 ohms, 1.5K watt (30 lb) power transformer, and 33,600 micro-Farad filter caps, I’m not sure, but I think it had plenty of reserve and stability for the AR-11s. So I don’t think it was a matter of a weak/unstable amp driven into clipping that fried the mid ranges.

However, one thing I later found out about GAS amps, and the Ampzilla in particular, mine included, was a problem with bad solder on the circuit boards. I did have this problem with the Ampzilla. I eventually gave it to my brother with full knowledge of its condition, and the only cost to him was shipping it to Gasworks in Idaho to get it fixed. So, although the power was adequate, it might not have been “clean power.” The Ampzilla has been powering his AR speakers for several years now, and I don’t recall him toasting any other AR drivers with it. He can verify when he gets back from MN, with a pair of mint/new condition AR-9s.

>MAYbe this is a "feature" of the AR11? <

Hard to say. Two cases are little more than anecdotal evidence. However, what Tom says makes perfect sense to me and I guess you could call that a “feature” of the AR-11 and explain why a midrange might fry before a tweeter. If AR/Teledyne did any failure rate analysis of AR-11 tweeter vs. midrange, I’m sure their findings were never published. But they did exchange my dead drivers for “service replacement units,” no questions asked. About the same time or just before I bought the AR-11s, AR introduced the AR-9 series with the “AR-9” midrange. I’m sure changes were made to it to beef it up in addition to replacing the wire cage with the semi-horn.

> As for the Heresy vs AR11 sound test - I don't have any A/B experience with the two, but I suspect this would be a lot like any A/B of an AR and any inherently brighter speaker; the Heresy would sound MUCH better for about 10-20 minutes.<

If you substituted “Advent” for “Heresy” in the statement above, I’d agree with you 100 %. The point I was trying to get across to Buddy was how to make a valid comparison of two acoustic suspension speakers with vastly different efficiency (sensitivity). The AR-11 with a sensitivity of 86db @ 1 watt/1 meter is “significantly” inefficient (this is NOT a measure of the quality of a speaker) as compared to the Heresy with a sensitivity of 97db @ 1 watt/1meter. For example, if you feed 1 watt to both speakers and stand 1 meter from each, the Heresy will be producing more “volume” (it will be “louder”) (97db) than the AR-11 (87db). I hope we can agree, that psychologically (or is it psycho acoustically), to most people, “louder sounds better”. If this is what you mean by “brighter” then I wasn’t clear in my original explanation. To get an honest and valid comparison of these two speakers, or any two speakers of differing efficiency, you have to match the output of both speakers to each other. In my example, you have to feed more power into the AR-11s so that it is producing 97db at 1 meter before you start your comparison. However, your evaluation will only be honest and valid, everything else being equal, if you are blindfolded and someone else switches the speakers you are listening to so you don’t know which pair it is. This eliminates preconceived preferential bias towards one speaker before the test even begins.

I agree with you that, over an extended period of time, the “brighter” of the two speakers will probably cause a phenomenon called “listener fatigue” sooner than the more “neutral” speaker. If I were to make a prediction, it would be that both will sound really good for quite some time. Definitely longer than Advents, which I’ve never been able to listen to for more than about 30 minutes. I’m only guessing that the horns will make the Heresy a little brighter, but the vertical alignment of the drivers will allow it to image a little better. Anyway, neither you nor I will ever allow a pair of Heresy’s in our stables so let’s get Buddy’s AR-11s restored so he can make his own evaluation.

> Something that I find strange enough for it to almost annoy me about the "old" AR speakers is that my hearing seems to improve the longer I listen to them. That is to say, the detail seems to reveal itself slowly, but naturally. To really appreciate them for what they do, it almost requires extended listening. Fortunately, that's an easy thing to do with AR speakers.<

I’ve found that to be the case as well, especially with my brother’s AR-LSTs. (I’ll be writing a listening impression on these very soon to answer an older thread). It has been my experience with my system and any speakers connected to it that it takes 30-45 minutes for everything to “warm up” and settle in. Then the enjoyment of music really begins. I can’t leave my amps or preamp on because they are enclosed in solid maple cabinets with doors that remain closed when not in use, and that do not allow ventilation to keep them cool.

Rich Laski

[r_laski]

>I tested the drivers in cabinet with a receiver, with a DC battery, and with a multimeter. All negative results on the mids and one woofer. I was and still am interested in any other ideas. I talked with Bill Miller and he wasn't very thrilled about the odds of the mids being any good or repairable. You should talk to Bill about your woofers, if you haven't already (215-412-0542 MillerSoundLabs).<

Two dead mids and a dead woofer, sounds familiar. The only other test I can think of and recommend to you is one we used at Compaq when we troubleshot customer’s servers (I don’t there anymore). Use a “known good” part. In your situation, to do this you have to have a “known good” mid and woofer. You have a “known good” woofer. If it works in both cabinets then it and both crossovers are “good.” If the “suspected bad” woofer works in neither cabinet, it’s “dead.” But, unlike midranges, it is probably repairable. Bill Miller can advise you on this. Just curious, is the “moldy” woofer the dead one? My thought is possible corrosion in the voice coil, that may affect repair cost.

Once you obtain at least one “known good” midrange, (confirm good with multimeter, to me its safer than using a battery) test it in both cabinets. If it works in both, your crossovers are “good” and with absolute certainty your current midranges are dead. If it doesn’t work in one cabinet, you have a crossover/wire problem in that cabinet (unlikely). If it doesn’t work in both cabinets both crossovers/wiring are bad (very unlikely). At this point, based on the tests you’ve already done, you’ve convinced us (including Bill Miller) both your mids took a dirt nap just like mine did 20 years ago. I know you want to minimize your cost to restore your AR-11s, but, as Bret posted, AB tech is being generous. Get two midranges and install them in your AR-11s. Just don’t accept a “suitable substitute” from them. P/N on both my mids is 200010-1 and there is a red/white sticker identifying them as “Service Replacement Unit.” Don’t accept non-AR mid; don’t accept AR-303 mids - fried egg with leads at 3 and 9 o’clock, not 4 and 8 o’clock; and don’t accept AR-9 midranges –silver or black semi-horn instead of fried egg/wire cage. I think these are what Layne is listing on their website. Bret’s already related his experience with these in an AR-10pi.

Read Bret’s posts on his experiences with buying replacement drivers and getting woofers repaired. There is a lot of very valuable information there. As Bret said, expect SLOW service anywhere you send your woofers to be repaired or refoamed. My Dad’s AR-9 woofers spent 7 months in a speaker repair shop in Omaha getting new foam surrounds, that’s excessive. I plan on replacing the foam surround on my “replacement” woofer myself.

Thanks for the tip on Bill Miller. I’ve seen his name on another thread and have him in mind when I decide between replacing / rebuilding the reconed woofer. Bret, is this the guy in PA you are referring to?

> There is a man in PA who will rebuild that 12" driver almost to your specs (new, broken-in, whatever) but he's expensive and as slow as everyone else. (I've sent drivers to Simply Speakers, Layne, and this guy in PA and two months later I have no drivers.)<

>For entertainment purposes you might check out www.simplyspeakers.com down in Fla.<

I have SimplySpeakers book marked in my browser, but have not done business with them yet. Same goes for http://www.newfoam.com in NY and http://www.speakerrepair.com (Orange County Speaker) in CA, http://www.speakersupply.com (Layne Audio). And many more.

>I have original hi range drivers, one warranty replacement mid/one original, both woofers original. The 'eyeball' mids (foam appears white-second generation?) appear as new. The hi range drivers have almost all the foam intact on their face. The woofers have the screen wire on the back of the baskets.<

Once you have determined to your satisfaction that your mids are or are not dead, and repair is or is not feasible, please contact me. As I previously stated, I have a need for the “eyeball” / fried egg / wire cages to remedy a stupid thing I did several years age.

Within the AR-11 family, I’m fairly certain the "diffraction foam" around the tweeters (with the white ring) is unique to the AR-11Bs. Neither my Dad’s, (early-production AR-11s) nor my brother’s, (mid/late-production AR-11s, and possible made in Europe, he bought them while stationed in Germany) have the foam. Unfortunately, when I started my restoration, the foam on my tweeters was so dry rotted and brittle it was flaking off and getting all over everything. As much as I hated to, I had to remove it. The only thing I have found so far that I think might work as a substitute is adhesive baked felt tweeter diffraction rings sold by Madisound: http://www.madisound.com/ They also sell this felt by the foot in 32” wide sheets and they have a foam gasket tape I’m thinking of trying to replace the foam gasket between the surround and the outer edge of the woofer, where the mounting screws are. Haven’t located anything like the original gaskets used between the drivers and the cabinet. Even though they are compressed, I’m still using them because the painted cabinet recesses and the backs of the drives are smooth enough, not much gasket is required to seal the gap. One good thing about replacement drivers is they usually include a new gasket.

The replacement woofer I got from AR/Teledyne has a square magnet and no screens on back. P/N 200003 on the original and 200003-1 on the service replacement. Gray fiberglass/vinyl window screen material and gray adhesive caulk from Lowes or Home Depot will remedy the screen situation. I can’t make the square magnet round.

>I have a great appreciation for old audio equipment. It is frustrating to be put in the position of having to decide whether to trash/not trash something of high quality such as the AR11's. It may take awhile, but if I cannot/ do not repair them I will get in touch with you.<

>Thanks again for the post. It was what I came here looking for.<

Your welcome, and I hope you complete your restoration and get to hear what I consider to be a truly great speaker, still one of our family’s favorites (six pair). Take your time, the end result will be worth it. I’ll help you in any way I can, as will anybody in this forum. But, if for any reason you can’t complete your project, you know who to contact.

Rich Laski

[r_laski]

>One more thing Rich. Do your AR11's have the original badges? As stated earlier, one of mine has a solid brass AR11 badge, the other what appears to be an aluminum AR11 badge that is black. What badges do yours have, if any? I'm wondering which is original. Do you have an 'Owner's Instruction Manual'?<

As Tom stated, Both the badges you have are original. My Dad’s AR-11s (early production) have the brass badges (logos). My brother’s and mine (1978) are black/silver. Do both your AR–11s have the AR-11B sticker with the SN beneath the tweeter? If so, the brass logo is authentic, but not “historically correct” for that cabinet.

As far as an Owner’s Instruction Manual, I’ve been looking for mine. I remember seeing both of them recently, but I just can’t find them right now. The receipt and warranty cards were stapled to the inside of the front cover. I’m real anal about things like instruction manuals, I still have many for things I don’t own any more. I will continue to look for them. I’ll let you know if I find them.

>Another thing. I know a guy that has ties to AR from the seventies. I've got to contact him to see if he can help. If he can offer any help, I'll let you know.<

Great! We might all benefit from his knowledge. If he isn't aware of it, introduce him to this forum.

Rich Laski

[r_laski]

>I currently have six of the 12" drivers being refoamed and/or rebuilt. If you are very patient you might get a couple of rebuilt drivers out of the 10pi's from me, or some replacements that are at least partially broken-in.<

Bret, Please post their availability here first so we have a chance at them before you list them on eBay. Does Ken have any of your woofers yet? I’m real interested in his test results.

> Oh, one other thing - the replacement 12" drivers for my AR9's were purchased about 6-8 weeks after the replacement 12" drivers were bought for the 10pi's. They aren't the same. They all came from ABTech, but evidently ABTech has more than one source; or their one source switched parts.<

Can you elaborate on what is different between the two sets of drivers? Cosmetic or something as significant as a poly cone instead of a paper cone?

Rich Laski

[r_laski]

> I found this listing you might be interested in if this number is right for your 11's (I believe it is):

http://www.audioclassics.com/detail.php3?d...2000101&nav=cat

A little higher than ABTech, but then again, this looks to be the correct driver.<

Bret, absolutely correct. Both my service replacement unit mids have that P/N – 200010-1. I haven’t been to Audio classics site in a while. Another of many book marked stereo related websites. Lots of high-end goodies here. Those AR 12” P/Ns don’t look right to me, Mine are 200003 (original) and 200003-1 (service replacement). Just in case you were interested, the tweeter P/N is 200011-1. Both original. On these tweeters, the “diffraction foam” covers the embossed “+” by the front terminal, the P/N sticker is next to the + terminal in the back.

Buddy, it may be only one midrange, but the P/N looks right to me. Might be worth a call or an e-mail to Audio Classics if ABTech can’t deliver the correct driver. Do your driver P/Ns match or come close to mine?

Rich Laski

[Guest bubbas_buddy]

Thanks for the information and the links Bret. I will have to reread your posts again. The drivers I have bubble wrapped in boxes and after checking them, here is what I have.

Both of the woofers have labels with the numbers 200003/ Made in USA/ and ink stamped on the magnets the same number 561-7742.

The mids (which appear to have faded pink eyeball foam) have labels with 200010-1 and ink stamped numbers 561 7834 and 561 7831(service replacement tag).

The labels on the hi ranges apparently fell off while I was removing and replacing them and are more than likely inside the cabinets which are wrapped and stored. I'll see if I can get those numbers for you soon.

While talking with Alex he originally gave these prices: $129.95/99.60/62.50. After explaining to him that I was not sure that I would refurbish the speakers because of the costs involved, he gave me the lower prices. I commented that I more than likely would not buy all new drivers. At the time the tweeters appeared to be OK and I I thought I might have Bill Miller work on the woofers. He said he would sell at the prices I listed if I bought 'multiple drivers'. I took that to mean buying two mids or two or more of the others.

Hope this helps.

[Guest bubbas_buddy]

Thanks again Rich. Your description of your and my AR11's drivers sound the same. I will post the serial numbers when I look for those tweeter tags!

The moldy woofer is the good one. It has several spots on the cone which can probably be cleaned. Right now I am thinking I may just box up all the drivers and send them to Bill Miller. I have only spoken with him one time but he seemed to possess that passion/excitement/ optimism that you like the person to have that is about to work on your prized possesions.

I will not try to repeat his costs for refoaming, reconing, spider replacement here because I did not take any notes, but his prices seemed reasonable. It would be worth the time and cost to talk with him. Assuming the ABTech woofers are exact replacements?, a new woofer at $89 would be hard to beat.

While in the walk-in closet a while ago, with my good glasses and the good lighting, it now appears that there is a slight pink shade to the mid range foam. I can't tell for sure. I am sure that they look to be almost new. One with the red 'replacement' tag.

I'm not looking to sell the speakers. If I cannot/do not repair them, I will donate them to someone that appreciates them for what they are, not someone that is looking to make a buck. You spoke up first so I'll keep you in mind.

About three or four months ago a guy in Atlanta listed on E-Bay many speakers for sale. He had K-Horns, Cornwalls and many others. Among them was a pair of pristine looking AR11's. I meant to watch the auction but forgot about it. At last look they were sitting at the opening price of $150 with no bids. Did you notice them?

Bill Miller

Miller Sound Labs

1422 Taylor Road

Lansdale, PA 19446

215-412-0542

Fax 215-412-0542

[Guest]

>Can you elaborate on what is different between the two sets of drivers? Cosmetic or something as significant as a poly cone instead of a paper cone?<

No, no. Nothing so dire as that. And. . . don't hate me - no, I can't tell you what exactly was different. I know, it sounds like I'm going prematurely senile, but the fact is that I stared into the backs of enough 12" drivers that were different that I've "lost" the details in the fog.

I want to say that I remember the connectors were different, the magnets were slightly different. . . nah, don't quote me. The packaging was VERY different. One set had plastic covering the entire cone-side of the driver, the other had a "stand-off" plastic ring taped to the frame to hold the cone off the cardboard. The packaging details you can quote.

The fella in PA - His name is Dennis McNeil, I think, but I can't find the envelope I jotted all his information down on. I may have to go to shipping records. . . aging is awful and at my age triply so.

Stephen Tidwell told me about him. He sounds like a guy building ships in bottles because he wants to, not 'cause he has to. I'll get the details and post them. But I don't know when. I'm about to get very busy again.

Bret

[Guest]

Thanks for going to the trouble to get those numbers off of your speakers. They were what Luigi indicated they should be for 10pi's, and I think that's right although the first generation 10pi had paper tweeters. The ones I helped rebuild also started life with paper tweeters, but they died early on and were replaced with the ferrofluid filled version.

I've made a note of the numbers. Thank you.

Bret

[r_laski]

>About three or four months ago a guy in Atlanta listed on E-Bay many speakers for sale. He had K-Horns, Cornwalls and many others. Among them was a pair of pristine looking AR11's. I meant to watch the auction but forgot about it. At last look they were sitting at the opening price of $150 with no bids. Did you notice them?<

Yes, I remember those, and that the seller had those Klipsch’s up for auction at the same time also. This was around the same time my brother bought his AR-LSTs. I remember thinking what an odd combination it was. I don’t remember what the winning bid was, but the AR-11s sold. Last 30 seconds of an auction are all that are important on eBay – too many snipers. This was also too close to Christmas, so I couldn’t even consider buying them. But, it helped me to think seriously about “getting around to” restoring my AR-11s.

AR-11s are “rare” on eBay. Classic AR speakers in Atlanta even more so. However, last Spring, my brother bought his AR-90s from a guy here in Atlanta. I picked them up and brought them to him a few weeks later. I watch almost all the “AR speakers with 12” woofer” auctions. This past weekend a pair of AR-58Ss (a very rare model-looks like AR-91 driver array, but different cabinet) ($275) and AR-303s ($500) went for opening bid. Within the past two weeks someone “stole” a pair of AR-9s in pretty good condition for $411. This was the pair BrianD alerted this forum to in one of his postings. Peter and I had to sit on our hands to keep from bidding. He was already committed to the pair he picked up in MN this past Saturday and “She who must be obeyed” did not like the AR-90s when I had them here, (aesthetically unpleasing to her) so my owning AR-9s is out of the question. Guess I have to settle for listening to Peter’s LSTs until I transport them to him. Not a bad alternative at all IMHO.

BTW, on Sunday, I stumbled across someone selling a Scott 222C amp on eBay (It sold yesterday). Seller is also selling a Rega turntable, which, along with AR turntables, I also watch on eBay. Cool looking classic tube amp. No PCBs, all hand wired chassis. Probably good match for your Klipsch speakers, not a good match for the AR-11s. As you said, your Acurus amps should work with the AR-11s. Made in the USA and very good quality vs. price reputation, (like Adcoms) but I think overshadowed by their brothers/cousins the Aragons. Are those power specs for an 8 ohm or 4 ohm load? Just a guess, but, from what little I know/remember about these amps, I’m thinking they might have a little more power into a 4 ohm load than what you stated.

Rich Laski

[Guest bubbas_buddy]

And from what I was told the guy in Atlanta had a nice collection of speakers and was a nice fella to boot.

I have (2) Scott 222-C integrated amps and a Scott 350(A) tuner. The amps sold for $165 in the early sixties, the tuner for $195. They are really something to see and hear. And that's 40 years later. FM stereo sounds better than I've ever heard on the Scott tuner. Its definitely 'different'. A friend has a pair of LaScalas that I can buy for about the cost of drivers for the AR11's. I'll try them out with the Scott amp soon.

Mondial never was too big on giving specs, but I was told by someone there that the 125X5 would easily output 200WPC @ 8ohm. I believe it. I drive 5 large speakers at pretty good SPL's and it never gets warm. After several hours you can't even tell by feel that its been on. I have driven 6 tower speakers with 2 channels of the 125X5. The sound is clean. No compression. The 125X5 amp is absolutely the best buy I have ever made in audio.

After buying Mondial, Klipsch decided to 'shelve' the Acurus nameplate. Duplication I think they said. Spec output @ 4 ohm is 175WPC, according to the web site. The 100X3 I bought in late 1994 or early 1995. The 'second generation' oval faceplate amps are preferable to me, although the earlier A250 was a hoss.

Thanks for you're responses to my questions Rich. I'll try to decide soon if I have the time to devote to them. Sounds like you would appreciate having them more than I.