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replacement mids not identical


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I suppose most posters and readers here already know that the "eyeball-type" midrange units with the screens are no longer available.

What I found-out tonight is that the replacement units don't fit in a 10pi cabinet on two counts. First, the replacement units have back posts @ 180 degrees and the originals were closer to 100 degrees. That means that the notches cut in the cabinet to allow the posts to pass through to the interior are not usable, meaning the cabinet must be filed. Second, the mounting holes in the driver's plate are not the same size. A 10pi's screw will not pass through the hole at all. To make matters much worse the screws are counter-sunk to sit flat once tightened. Boring a larger hole in the new driver's plate would not solve the problem. To do it right you need a counter-sinking drill bit and some careful measurements.

While neither of those things presents an insurmountable problem it is a piece of information I shall tuck away.

I thought it strange that Alex at ABTech would tell the purchaser that the new midranges sound "better" than the originals. I would think the loss of the ring and fiberglass "eyeball" would substantially change the distribution of power into the listening room and quite possibly ruin wide dispersion of the speakers in that very audible frequency range. Not so?

Does anyone repair these "eyeball" type speakers?

Has anyone used the "new" 1.5" replacement midrange? What did you think of the sound before and after?

Bret

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Guest lmrosenthal

I'm not familiar with the AR10pi, but I do have a pair of 3a's. On one of the 3a's I had to replace the mid-range unit. The replacement unit did not have the screen or diffusion material. However, in the six or seven months since I've replaced the mid, I have not noticed any difference between it and my original mid on the other 3a. I've played a lot of mono material, specifically to see if I could detect any difference.

So, if the 3a and 10pi use the same mid-range unit, to my ears I couldn't tell any difference.

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>So, if the 3a and 10pi use the same mid-range unit, to my ears I couldn't tell any difference.<

I'm not trying to imply anything. I'm not being rude. I'm not presuming anything. Read my next question with the appropriate "lilt" in my voice so that you aren't offended or get defensive.

Would you consider your ears to be pretty doggone good?

I don't mean to ask if you claim "golden ears" because I sometimes think golden ears hear things that aren't there; or at least have hearing closer to a dog's or cat's. When someone claims to hear the difference between a 4' run of 32 stranded 8 gauge copper wire and a 4' run of 54 non-oxidizing stranded 8 gauge pseudo-copper/silver wire. . . well. . .

Bret

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Guest lmrosenthal

Hi Bret,

You wrote:

"...I'm not trying to imply anything. I'm not being rude. I'm not presuming anything. Read my next question with the appropriate "lilt" in my voice so that you aren't offended or get defensive."

"Would you consider your ears to be pretty doggone good?"

Nope, not offended in any way, nor do I think my response below is defensive, so here goes.......

I'm 52 years old. That should tell you a little something about my hearing. Is it "pretty doggone good?", probably not. Though I've not had my hearing tested in many years, I'm pretty sure I've lost some ability to hear above 12kHz. I have a very old test album by Command Records (Command Stereo Check-Out I think its called), and it has a frequency sweep from 20Hz to 15kHz, in single tones, about 10 seconds each. I can hear the 12kHz tone pretty well, but not the 15kHz tone at all.

All I was trying to say in my original response to you was, to my ears, at this stage in my life, I couldn't tell any difference between the original AR mid and the new AR mid (assuming the mids are the same for the 3a and the 10pi).

Should there be a difference? I don't know. Someone else has to answer that question.

Hope that helps.

Take care

Larry

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>I can hear the 12kHz tone pretty well, but not the 15kHz tone at all.<

Ah, man, that's not your hearing. It's the tweeters!

I am sorry. I'm not far behind you, I'm sure.

But we are well above midrange whatever the case, so you probably hear those midranges just fine.

It is sad that as we age we have to lose our hearing. My dad (73) is who got me interested in audio in the first place. 20 years ago we were listening to something. . . Dance Macabre maybe, with a steady triangle strike. Not only could he not identify it as a triangle, he couldn't hear it at all.

Some 5-6 years ago he got to the point that he couldn't hear you speaking to him in a quiet room at normal volume. At that point we "forced" him to a doctor.

He got some hearing aids and can understand speech now, but his days of enjoying his audio gear are pretty-much over.

I wish I could give you that last few k for Christmas.

Bret

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Guest lmrosenthal

Hi Bret,

Thanks for your wish for a few extra 'k' at the high end for my hearing, I appreciate it! Unfortunately, my wife and I spent the last two days at an extended family Xmas party: our 6 kids, plus 3 grandchildren, plus 16 nieces and nephews, plus my wife's 6 other sisters, plus my......., you get the picture? Very noisy. Wonderfully happy times, but very noisy. I think I may be in the first stages of tintinitus because of how my ears were ringing for the first hour and a half during our drive home. Wouldn't trade the family time for anything, but.....hello? Can anyone hear me?.....What did you say???....and so on.

Knowing you have a 10pi, do you have any other AR speakers? I was wondering if you have compared the 10pi to the 3a, for example. I have a pair of 3a's since new in 1970 and they're my only speakers. Every time I think that I should 'get mainstream' with modern speakers, my wife and I go and listen to some (we have a couple of high-end stores in Omaha and Lincoln), but we invariably come away with the impression that our 3a's sound as good, if not better than most speakers we hear.

There have been a couple of exceptions in the last few years:

1. We heard the Avante Garde Duo w/a pair of VTL Tiny Triode amps, and the sound was superb! No question that we could live with that sound the rest of our lives - but - we're talking about $12 - $14k for the Duo's alone, plus a good tubed pre/amp combo. Way out of our price range.

2. We also have heard a pair of newer version Quads. Extremely nice soundstaging and mids/highs - but not nearly the quality and depth of bass that the 3a's bring to the party.

So, I was just curious of your experiences with the 10pi versus other AR models, and also what other 'modern' type speakers you've compared the 10pi to.

Hope you had a great holiday!

Take care,

Larry

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>So, I was just curious of your experiences with the 10pi versus other AR models, and also what other 'modern' type speakers you've compared the 10pi to.<

You know, that's a terrific question.

I don't own the 10pi. That is a friend of mine down the street who I "directed" to buy those speakers in the late 70s. By the time he bought those there were no 3a's in the store and the only thing I remember comparing them to were the 11s. There is nothing to compare them to at his house. Oh, he has other speakers but they aren't "good ones" and so are entirely outclassed. But there's an interesting thought. I could borrow some 3a's, maybe. . .

And I don't own a pair of 3a's, BTW. That's my dad and several friends. Dad got his in 1971 and I've listened to them as recently as a couple of weeks ago. They still sound terrific (replacement woofers and pots 10 years ago or so). I am negotiating with a friend for his currently unused 3a's.

My uncle had LSTs (which I'm told my aunt donated to MIT when he died)and 90LS and 3a and 1w's.

I have had in my home 2ax's, MSTs, and the AR9 (as well as some of the cheap "partner" and wedge speakers). I have not "bought" anything worthy of comparisons.

The only "testing them against each other" I have ever been able to do was with the 3a, the 9, and the LSTs in the same room, same amplifier, not a quick A/B situation.

Know that I'm talking "impression" here, not "comparison" because I haven't done a comparison. The 10pi has more high-end output than the 3a, but the character of the output doesn't change. The 11 sounds a lot like the 10pi set "flat" (as I remember from the late 70s). Where the 10pi shines is where placement is a problem. But I also remember the 10pi's as being more 3-D. (that's how I remember it, so if I'm not up on the vernacular forgive me)

Here's another "impression" observation. The 10pi has more mid and high power, but without sounding up-in-your-face like brighter speakers. I listened for a few hours last week and there was no fatigue.

It has been a long time since I went speaker-shopping. The last time I tried there were some highly touted direct/reflecting jobs (two models) that were a "big deal" at the time. I hated them from the first note of the first CD to the last note of the third CD I listened-to. I apologize for not remembering the brand. A friend bought some, so I'll ask her and get back to you. I think they were Paradigm-something. Phantom? Oh, speaking of Phantoms, Kendel Phantoms; they are now rear channels.

Way back there were "modern" designs I compared with the 9s. ESS AMT 1b's (Heil air motion transformers) and "monitor" towers. Boston Acoustics large models. A pair of JBLs, I think it was the 150, and that's about what each cabinet weighed. There were KEFs with ribbon tweeters and 10" woofers (the best of the bunch I've mentioned).

But there's a thought. Once the 9s are in good shape again, I ought to see if the local "salon" will let me bring them in and do a little comparison shopping.

>Hope you had a great holiday!<

I did ! Mine was just slightly less noisy with five 10-and-unders underfoot. I ate. Way too much.

Bret

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>On the AB Tech invoice: "11112100103 MR 1.5" AR-3a"

>

>On the new driver: "12100103 / 0232"

>

>Wrong ones? Only ones?

>

>

>Bret

I don't know these midranges.They are probably the ones used in  AR 303 or 302. If so, they can't be used in AR 10Pi, 11, 3a, LST.  Probably the production of the ones labelled 1210010-1A has stopped and they are not available anymore. In any case ask http://www.speakersupply.com/ maybe they Know samething more. You can also try at http://www.dynavox.ch/default.htm (its E-mail is: info@dynavox.ch). They distribute speakers marked ROWEN that use (or used)the same tweeters and midranges as AR 10 Pi. Maybe they still have replacement units labelled 200010-1 or 1210010-1A. If you should try to buy them on Ebay, be carefull becouse even though a speaker sounds that does not guarantee that it is ok. You should also mesure its DC resistance at least. DC resistance of AR 10 Pi midrange is about 3.7 ohm.

In any case as these midranges are the same as AR 3a and LST in my opinion is incredible and unacceptable

that someone has decided to stop their production!!!

Luigi Fedele

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>In any case as these midranges are the same as AR 3a and LST

>in my opinion is incredible and unacceptable

> that someone has decided to stop their production!!!

>

>Luigi Fedele

I guess what you mean here is that it is incredible that the suppliers discontinued supplying the original-style AR drivers? It is interesting that while Villchur was at AR, he demanded that AR maintain replacement parts for all AR products sold by the company, such that those products could always be repaired. Those were perhaps the "good-old days," in which life was simple and there were few permutations, and relatively few replacement parts to think about. And the issue of "support period" was not an issue, nor was it in the vernacular of those early speaker builders. After Teledyne purchased AR in 1967, that system began to change, but the policy was to maintain replacement parts for a pretty long time after end of production. AB Tech, the primary source of replacement parts for AR, is in business to stay in business, and not there for philanthropic reasons. If a driver is moving slowly, they probably can't afford to continue having it made. Also, once AB Tech ran out of drivers supplied by AR, then decisions had to be made as to what replacement drivers would closely resemble or match the original drivers. Hence the mixture of different type drivers, none original.

In addition, a whole different set of standards exist for industry today. Few companies continue to make replacement parts for many years after the obsolescence of a product. At Hewlett-Packard, for instance, the "end-of-support" period was usually 5-7 years after the last date of manufacture of an obsolete product, and this is probably generous compared to many companies. HP could guarantee "uptime" (at huge expense) because they made every component part readily available worldwide for any instrument during its support period; but once the support period elapsed, parts became more difficult to source. Suppliers could not maintain their inventories, and the prices would begin to creep up as the quantities declined from the production-year numbers. Consider, too, that HP (at any given time) was making as many as 10,000 different products -- all highly complex electronic instruments -- so this support period was extremely expensive to maintain. But the guaranteed-support period was very important to customer satisfaction. In the speaker industry, no such standard likely exists that would give assurance of exact replacement parts for a finite time. If it is not economically viable to continue to produce and stock a product, the vendors will simply stop making it, and then the next-best thing has to be used. Sad, but true.

--Tom Tyson

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>Perhaps the production of the ones labelled 1210010-1A has stopped and the midranges you have are the "right" ones.In any case ask http://www.speakersupply.com/ maybe they Know samething more. <

Thank you for the link. Honestly, I found them yesterday and had come here to announce that I had found OEM replacement drivers.

But whoever buys these has to love their speakers as much as I do mine. The price I saw was $149.00 each. Yeaowch.

So all of this made me think, "I'd better find and buy, at any price, a pair of "semi-horn" midranges in case something happens to these in my 9s."

I can't find any anywhere, at any price.

Moreover, the semi-horns in my 9s have the same terminal configuration as on a 10pi; which is to say they are at 100-110 degrees while the replacements are at 180 degrees. The replacements won't fit in this cabinet and the screw holes are going to be too small. The replacements from AB Tech appear to be good drivers, but no semi-horn. If I had several spares I'd experiment with removing and re-applying the semi-horn to others.

As far as I know, only the 9, the 90, and the 91 used this driver. I suppose I'll start scouring the web for a pair of AR91s with good drivers, steal the semi-horns, and replace them with the replacements available from AB Tech. The AR factory midranges from speakersupply would be great if I just had a speaker system that used them.

Bret

"I have had a perfectly wonderful evening, but this wasn't it."

Groucho Marx

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>As far as I know, only the 9, the 90, and the 91 used this

>driver. I suppose I'll start scouring the web for a pair of

>AR91s with good drivers, steal the semi-horns

>

>Bret

The AR-92 (10" woofer version of the 91, like the 5 was to the 3a) used this driver, but I think the 92 was an 8-ohm system.

The very first 58 (not the 58B or BX or BXi) also used this driver and it was a 4-ohm system. The 58 was a bookshelf version of the 91, but those first-generation 58's were VERY short-lived.

So that gives you a few more speakers to look for.

Steve F.

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>I don't know these midranges. Perhaps the production of the ones labelled 1210010-1A has stopped <

There is update news. Alex at ABTech was called. Alex is issuing a call tag for the incorrect 10pi midranges and is sending a pair of the "correct" midrange drivers to my friend.

When those arrive I will see what numbers show-up on them. Thank you for your help.

Bret

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