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ar 10pi versus ar 9


fred

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i'm the proud owner of a pair of 10 pi's.

in holland ,where i live ,the ar 9 is a very rare speaker so i never had the chance to hear a pair.

i'm interested to hear the opinion of people who know both speakers; how do they compare, what are the differences and the (perhaps) similarities.

greetings from the netherlands!

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Greetings from Pennsylvania!

In my opinion, the 10PI was AR's best 3-way bookshelf or stand-mounted system.

The 10pi was an evolutionary development from their previous TOTL systems (1, 3, 3a,) with equivalent bass-performance, and improved midrange and highs.

The 10pi also attempted to solve some of the placement problems that are practical considerations for many people who try to fit their loudspeakers into rooms that are not dedicated listening spaces.

Sound-wise, the result is very much like the AR-11, or the last-model AR-3a (American versions) - they can sound particularly impressive on their free-standing welded steel bases, which may be hard to find, but are worth it.

The AR-9 uses completely different upper-range drivers and physical alignment, as well two equivalent woofers per speaker that utilize a unique crossover configuration to reproduce the most extended LF response of any AR system before, or since.

After the 10 Pi, everything changed for the top-end systems, and their sonic relationship to the 3-way, bookshelf systems that had preceeded them grew tenuous.

Even the 3-way AR-91 system (from the same development series as the AR-9) sounds very little like the 3AR-3, 3a, 11, or 10Pi, appearing to indicate that the 10Pi might be the last TOTL system to have 100% of AR's original "House Sound"

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Even the 3-way AR-91 system (from the same development series as the AR-9) sounds very little like the 3AR-3, 3a, 11, or 10Pi, appearing to indicate that the 10Pi might be the last TOTL system to have 100% of AR's original "House Sound"

The timing on this makes sense. Villchur left the company in 67, having secured five-year contracts for his principal team, and they started their exodus in the 72-74 period when the ADDs were being developed. After that a new generation of designers took over, and followed Teledyne's directive to make the product line more appealing to contemporary mass-market preferences.

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i'm the proud owner of a pair of 10 pi's.

in holland ,where i live ,the ar 9 is a very rare speaker so i never had the chance to hear a pair.

i'm interested to hear the opinion of people who know both speakers; how do they compare, what are the differences and the (perhaps) similarities.

greetings from the netherlands!

As far as I can tell, AR 10pi is a modified AR3a. It was developed in an era prior to the widespread availability of graphic frequency equalizers to consumers at low cost. It was intended to make it possible to place it flexibly in a variety of types of locations such as against a wall, away from a wall, on a shelf etc and still maintain reasonable frequency response balance using controls in the speaker system. AR3a should be able to do the same and more using an equalizer. I am not aware that the tweeter or midrange drivers are different from AR3a but I may be wrong about that, they may be further improved versions of them.

AR9 is an entirely different animal. With two 12" woofers instead of one and an enclosure about twice as large, the speaker can handle twice as much bass power and its F3 is substantially lower 28hz instead of 42. The woofer's high end is also restricted to 200 hz making them true subwoofers where AR10 pi probably crosses over at 575 or 525 hz (I never could quite get which it is straight.) AR9 adds an 8" lower midrange which has a major impact on overall sound. First it is a concession to the difficulty of coupling a 2" midrange to a 12" woofer. This fills in this important and difficult range. This restircts the upper midrange to a frequency region above 1.5 khz where it works best. It is also ingeniously integrated with the woofers. Read Tim Holl's technical paper explaining how that works and how the woofer crossover network keeps two 4 ohm woofers connected in parallel from producing an unacceptably low impedence to an amplifier. The tweeter is crossed over I think at 7khz instead of 5 which also allows it to function at frequencies it is better suited for. The semi horn around the upper midrange and the notch between the dome and the front baffle plate in the tweeter act to limit angular dispersion and direct those speaker's energy more in a forward direction than laterally compared to AR 10pi or AR3a. Dispersion is still very good compared to other manufacturer's speakers however. The speaker is very critical of where it is placed. The manufacturer recommends that it be placed no more than 2" from a wall behind it and sufficient space is required laterally on both sides for the bass to propagate. Experience shows exact placement is critical and moving it slightly one way or the other can have a substantial effect on bass response.

AR9 has many outstanding aspects to its sound but one which strikes me as peculiar and unique is its tendency to dominate most rooms acoustically. You get the feeling that the speaker can project a huge amount of acoustic power effortlessly even from modest amplifiers like an excellent 60 wpc amplifier mine are connected to. My listening room is about 4000 cubic feet and on the live side. It will give a mid sized Steinway piano in the same room a run for its money. It can also literally shake the walls, the floor, the ceiling, rattle (and once by accident almost shatter) the windows, produce the deepest gut wrenching bass, and can play the most complex sound with outstanding subtle details....and do it all at the same time when needed. Good as 10pi is, AR9 is one extraordinary speaker system. It is small wonder those who own them prize them so highly. 30 years after they were produced, few other manufacturers have offered comparable products to the market and then only at astronomical prices. Is AR9 the best speaker AR ever produced? I think in some ways yes, in some ways no. AR LST has much better lateral dispersion at middle and high frequencies. AR did not build one speaker system that outperformed all of its others in every respect. Perhaps that is why some collectors have so many different models.

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I am not aware that the tweeter or midrange drivers are different from AR3a but I may be wrong about that, they may be further improved versions of them.

The 3/4" dome tweeters used in the ADDs were ferrofluid cooled (I don't remember if the mids were). The ADDs all sounded a bit brighter than their predecessors to my ear, but otherwise still seemed very much members of the family.

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Hi Fred (and others !)

Just like you, I live in Europe (France) and in 78/79 when I was student near Boston; I spent several weeks of comparative testing in order to buy a hifi system WITH speakers from New England! I ended up with 2 in my short list: AR & AR (the 10 pi and the 90). For budget reason, I bought the 10pis (which are great, I confirm : better than the 3A from what my ears remember..). But I have to admit that a few weeks later I brought them back and traded them for a pair of AR90. The 90s being the small sisters of the AR9s as you know, I can tell you that I was entering into a new world after my 10pis ! And I'm enjoying my AR90s daily since then

Later on I bought a pair of AR9 in France (I confirm, it took more than 3 years to find a decent pair in Europe in my budget) and a pair of AR91 (which is "similar" in size than your 10Pis but with the technology of the AR9x series – largely described and documented in this thread)

As you can guess I am a little bit biased and I prefer the "newer" technology so if I had to decide now I think I would go for an AR91 rather than a 10pi

Unfortunately I just sold my AR9 (mint condition) during Xmas time to a French music conductor. I still have my AR90 and AR91 so if you come to Paris, drop me a line and I'll be happy to have you home for listening to these (by the way my AR91 are for sale …)

I'm enclosing a pic of my AR9x just for fun

JP post-100022-1264346688.jpg

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Fred,

I can't speak for the AR10pi or AR11, but can share my experience with my small collection. I purchased my AR9's in 1981 and then purchased a pair of AR48s, AR98LS, AR15, and AR3a just in the last 4 years. I can tell you the AR48s and AR15 are not even close to being in the same league as the other three systems.

The AR9's are my favorite hands down. I have a hard time describing the experience, but what always comes to mind is how the speaker simply disappears into the music. It produces sound in the same way an athlete breathes, no stress or straining.

The AR98LS have been upgraded to the I version of the crossover circuit, and the AR3a had the crossover redone with new caps and wiring. All the surrounds needed to be replaced.

Make no mistake, the AR98LS and AR3a speakers are no slouches, able to recreate any type of music with authority. They just sound like a speaker, a very nice speaker. In the end, I always end up back with the 9's listening to favorite passages with a big grin on my face.

My oldest daughter is a musician with the best ear in the family and has already claimed the 9's when I can no longer enjoy them.

I've attached a picture for the fun of it! My wife was chuckling the whole time I spent lining this shot up.

Brian

post-101813-1264479994.jpg

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  • 4 weeks later...
I am not aware that the tweeter or midrange drivers are different from AR3a but I may be wrong about that, they may be further improved versions of them.

The tweeter was a new beast BEFORE ferrofluid. The 10pi/11 got the first of the ferrofluid tweeters, but there was a "new" tweeter in them before the introduction of the ferrofluid models.

Yes, the tweeters were of different material and different construction, *before* the ferrofluid.

Ferrofluid tweeters were black. The original "new" tweeters for the 10pi / 11 were "cream colored" and can be seen in the literature in the library.

The midranges got a new number and a new case, but I don't know how much different they were electrically or sonically from the 3a.

The woofer was new. The cone was of a new, fuzzy-feeling, material and was different than anything before or since.

The second generation of the 10pi / 11 got the ferrofluid tweeters and a more rigidly coned, stiffer-compliance woofer treatment.

The second generation 10pi / 11 did not have the extended top or bottom frequency response of the first generation (which was short-lived).

I won't pretend to know why, but the 10pi and the 11 sounded much the same, but not exactly the same. If I had to guess I would say the additional crossover components in the 10pi either caused or prevented something.

I found the 10pi to be pleasant, but I don't pretend to know if it was technically better or worse (from a lab measurement perspective).

The 11 and 10pi sound almost nothing like a pair of 3as. The octave-to-octave "balance" (voice) being noticeably skewed upward in the 10pi / 11 compared to a 3a.

You can't force a 3a to "get in your face" and you can force a 10pi / 11 to do that trick. I get the sense you'd burn a 3a tweeter up very quickly if you forced this new "voice" with an EQ.

As you say, and for the benefit of others, the 9 and 10pi share very little except for ARs exceptionally clean and extended bass response which the 9s have in spades.

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The 11 and 10pi sound almost nothing like a pair of 3as. The octave-to-octave "balance" (voice) being noticeably skewed upward in the 10pi / 11 compared to a 3a.

You can't force a 3a to "get in your face" and you can force a 10pi / 11 to do that trick. I get the sense you'd burn a 3a tweeter up very quickly if you forced this new "voice" with an EQ.

As you say, and for the benefit of others, the 9 and 10pi share very little except for ARs exceptionally clean and extended bass response which the 9s have in spades.

I think you bring up some very good points. We should also bring the LST into the conversation. My understanding is that for the LST and 9-10-11, the objective was to deliver flat in room response and better low end room integration. Essentially these speakers were designed to be the next generation from the 3a.

The LST was the first attempt by AR to get flat in room response, with realistic power handling and natural dispersion characteristics. By all accounts, it was a technological success if not a consumer success. Autotransformer coupling of the woofer greatly improved in room bass response and multiple mid and tweeter domes increased the output level and maintained dispersion characteristics. It needed gobs of power, but it was flat from 30hz-15khz in room. However, AR realised that the LST was not an ideal solution and was not consumer friendly.

The 10pie / 11 that most of us are familiar with used a new generation of mid and tweeter domes that were more efficient, could handle more power and deliver more extended HF response, but at the expense of dispersion. This was a simpler solution to the desire for flat in room response. The autoformer in the 10pie allowed for adjustment of the bass response to assist room integration, while the increased output of the new domes greatly improved the HF response. The objective of flat in room response had been achieved in a box of the approximately the same size as the 3a. These speakers should have been an unqualified success. Unfortunately the market had changed and many competitors had caught up to AR.

With the 9, AR launched an all out assult on the state of the art. In many ways the 9 was as much of a leap forward as the 3 had been in 1960. The 9 delivered flat in room response from 30hz-20khz, outstanding power handling, excellent dispersion and could play louder than any previous AR speaker. Objective achieved.

Was the 9 a success ? Yes and it served as the basis for much of the high end speakers that AR produced in the 80's and early 90's.

Did it have the impact in the market that the 3 and 3a had ? Probably not. By the time of the 9, the marketplace had expanded greatly and many of the competitors were just as technologically advanced as AR- and in some cases more so. In addition, the 9 series was still voiced for the "serious" listener rather than the rock oriented buyer that had come to dominate the marketplace. While AR could compete in the high end, a less than superlative review in TAS did not help.

We understand and appreciate the legacy of the 9 and to a certain extent so does the market (with 30-35yr of hindsight).

Best,

Ross

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  • 4 weeks later...
Greetings from Pennsylvania!

In my opinion, the 10PI was AR's best 3-way bookshelf or stand-mounted system.

The 10pi was an evolutionary development from their previous TOTL systems (1, 3, 3a,) with equivalent bass-performance, and improved midrange and highs.

The 10pi also attempted to solve some of the placement problems that are practical considerations for many people who try to fit their loudspeakers into rooms that are not dedicated listening spaces.

Sound-wise, the result is very much like the AR-11, or the last-model AR-3a (American versions) - they can sound particularly impressive on their free-standing welded steel bases, which may be hard to find, but are worth it.

The AR-9 uses completely different upper-range drivers and physical alignment, as well two equivalent woofers per speaker that utilize a unique crossover configuration to reproduce the most extended LF response of any AR system before, or since.

After the 10 Pi, everything changed for the top-end systems, and their sonic relationship to the 3-way, bookshelf systems that had preceeded them grew tenuous.

Even the 3-way AR-91 system (from the same development series as the AR-9) sounds very little like the 3AR-3, 3a, 11, or 10Pi, appearing to indicate that the 10Pi might be the last TOTL system to have 100% of AR's original "House Sound"

ar_pro,

Sorry that my message is about three months after-the-fact, but I just happened to see this and thought I would comment on it.

The tweeter and midrange used in the AR-9 were fundamentally the same as used in the AR-10 and AR-11; that is, there were no differences in the voice coils, dome materials and so forth, but the design of the driver top plate was different in each case, and certainly the crossover was different. With the AR-9 tweeter, there was a recessed top-plate assembly that was used to enhance the high-frequency efficiency. It was a sort of tiny "horn." The midrange also used a "semi-horn" on the top plate that enhanced efficiency at the top of the operating range, somewhat at the expense of dispersion, but not by much. The AR-9 did use Ferrofluid in the midrange dome (the AR-10 and AR-11 did not), and the suspension was slightly different, but otherwise the mechanical structure was identical to the AR-10 midrange. The tweeter used in the 1977 and 1978 AR-10, AR-11 and AR-12 used Ferrofluid; the midranges in the AR-10 and AR-11 never had Ferrofluid.

So... to say that the AR-9 used completely different drivers, etc., is probably a stretch. There is a very noticeable family resemblance in the sound of the AR-10/11 and the Tower series, with the latter being brighter, more extended and more forward-sounding.

--Tom Tyson

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I think that Roy Allison had pretty much indicated this same scenario in a couple of his interviews. Roy developed, or helped to develop, several new speakers after Villchur left (the AR-3a, AR-LST, and AR-6 being notable examples), but Teledyne wanted speakers that catered to a different kind of clientele. Roy also hired Robert Grodinsky to develop the AR Amp, AR Receiver, and AR Tuner. So, the Villchur philosophical fundamentals of the company did hang in there, at least until Roy left in 1974.

The AR-8 was the first speaker they came up with after Roy left, and he has indicated that it was designed to please the Teledyne brass.

Howard Ferstler

Howard,

Roy Allison left AR early in 1973, not 1974. I believe he spent a year of so designing and testing his new Allison boundary-impedance designs during 1973-1974, and then he helped organize Allison Acoustics, Inc. in 1974.

On June 7, 1967, Ed Villchur (President of AR) signed a contract with Henry Singleton (CEO of Teledyne) to sell the assets of Acoustic Research to Teledyne, and this contract also enabled each of the principal, so-called "First Echelon" officers of AR, to have a six-year employment contract at AR that dated retroactively from January 1967 until December 1972. Roy left at the beginning of 1973.

The AR-8 was designed after Roy left AR "to please the Teledyne brass," as you say by introducing a speaker with the "AR sound" yet with a more prominent treble and mid-bass reproduction to be able to compete with the likes of The Advent Loudspeaker, which was pretty much eating AR's lunch about this time. The AR-8 was not a bad speaker, necessarily, but it was not up to the accuracy standards of most of the other AR speakers of that day.

--Tom Tyson

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Thanks for your input, Tom, it's much appreciated.

It's certainly true that the upper-range drivers on the AR-9 have a strong connection to those from the evolutionary run of the AR-3 to AR-10pi top-of-the-line systems, but I do feel that the "semi-horn" that you mention in the midrange driver, and the recesssed nature of the tweeter's dome were means toward an end whose effect was the more focused directivity of the AR-9, relative to its wide-dispersion bookshelf predecessors (or the LST, for that matter). The AR-9's foam driver baffles and Acoustic Blanket were additional techniques used to achieve this result.

Also, from listening experience, I'd say that after factoring out the more extended LF response of the bigger systems, the 3-way AR-91 sounds considerably closer to the AR-9 or AR-90 in "voicing" and room-effect than it does to all of the earlier 3-way bookshelf systems

Perhaps it is an overstatement to suggest that the AR-9 drivers and their earlier versions don't share a common thread, but (to me) they just don't sound the same, and I always had the impression that they weren't meant too, either.

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Thanks for your input, Tom, it's much appreciated.

It's certainly true that the upper-range drivers on the AR-9 have a strong connection to those from the evolutionary run of the AR-3 to AR-10pi top-of-the-line systems, but I do feel that the "semi-horn" that you mention in the midrange driver, and the recesssed nature of the tweeter's dome were means toward an end whose effect was the more focused directivity of the AR-9, relative to its wide-dispersion bookshelf predecessors (or the LST, for that matter). The AR-9's foam driver baffles and Acoustic Blanket were additional techniques used to achieve this result.

Also, from listening experience, I'd say that after factoring out the more extended LF response of the bigger systems, the 3-way AR-91 sounds considerably closer to the AR-9 or AR-90 in "voicing" and room-effect than it does to all of the earlier 3-way bookshelf systems

Perhaps it is an overstatement to suggest that the AR-9 drivers and their earlier versions don't share a common thread, but (to me) they just don't sound the same, and I always had the impression that they weren't meant too, either.

ar_pro,

We're in basic agreement here. I only wanted to point out that the drivers used in AR-9 and AR-10Pi had a common family thread. There were enough differences in the top plates, crossovers, etc., to make the two systems have different personalities -- a different "spectral balance." Also, the AR-9 midrange has a slightly different half-round surround suspension (inverted from the AR-3a/AR-10 version). However, anyone familiar with AR speaker sound characteristics would immediately recognize that both speaker are very similar on the top end.

--Tom Tyson

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Hi, Tom,

I did some digging and he actually left AR in 1972, probably late in that year. He may also have had a contractual obligation to not compete with the company for a while (I am fuzzy on that), which gave him time to do his research. The result of that research was the beginning of Allison Acoustics in 1974. The interesting thing is that unlike many other speaker designers he actually did "research" on speaker/room interactions, which resulted in some genuine advances in the way of bass-range speaker coupling to the room. Additional research also involved those interesting tweeter and midrange designs of his, with the goal being to get as much broad-bandwidth, wide-dispersion energy into a listening room as possible, particularly in the two upper octaves.

Howard Ferstler

Hi, Howard,

Yeah, you might be right, as I know that Abe Hoffman left in December of 1972, but I read in the Allison introduction piece, About Our Company, the following: "Yes, there really is a Mr. Allison. He is Roy F. Allison, President. From 1959 to 1973 he served as Chief Engineer, then Vice President/Engineering and Manufacturing for Acoustic Research."

I would not think that he was hamstrung from going back into loudspeaker design work in the form of a non-compete agreement, but it is possible. Ed Villchur was, however, and he was contractually precluded from doing such work for five years, even though he had no interest in going further in high-fidelity design. His interest by this time was with hearing-aid researh.

--Tom Tyson

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You know, I've always wondered what the AR-9 upper-range drivers would sound like with the AR-3 cloth-surround woofer, an upgraded crossover, and a cabinet built to modern high-end standards.

Relative to the AR-91, I think the cabinet build-quality was superior in the original AR-3, but the 91's vertical driver alignment which enabled floor placement offers (to my ears, anyway) a more desirable outcome when placed on stands that bring the domes up to a seated level. I think the 3-way AR-91 actually benefits from coming off of the floor, as its woofer sounds a little plump - especially when compared to the dual-woofer AR-9 and AR-90 systems, which seem to disappear until called upon.

Might be an interesting experiment.

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I think the 3-way AR-91 actually benefits from coming off of the floor, as its woofer sounds a little plump - especially when compared to the dual-woofer AR-9 and AR-90 systems, which seem to disappear until called upon.

I owned 91's from 1980-1987. I remember liking them very much, although at this point, I'd be be lying if I told you for certain that it sounded "a little plump." I just don't remember for absolutely sure.

Your comments on the 9 however--"disappear until called upon"-- is spot on. I recently purchased a near-mint set of re-foamed, re-capped 9's, and it is amazing how incredible their low bass capability is; it's similarly incredible how 'thin' they can sound if the program material contains no real bass.

Steve F.

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Hi, Howard,

Yeah, you might be right, as I know that Abe Hoffman left in December of 1972, but I read in the Allison introduction piece, About Our Company, the following: "Yes, there really is a Mr. Allison. He is Roy F. Allison, President. From 1959 to 1973 he served as Chief Engineer, then Vice President/Engineering and Manufacturing for Acoustic Research."

I would not think that he was hamstrung from going back into loudspeaker design work in the form of a non-compete agreement, but it is possible. Ed Villchur was, however, and he was contractually precluded from doing such work for five years, even though he had no interest in going further in high-fidelity design. His interest by this time was with hearing-aid researh.

--Tom Tyson

BTW, the 'late 1972' time frame seems to be correct for Roy Allison's departure from AR.

In the "AR letters to Steve F." section of the library, a letter dated March 12, 1973 from John J. Bubbers, Dir. of Eng. to me contains the phrase, ".....your letter of Feb 2nd (1973) has been passed along to me, since Mr. Allison has retired."

http://www.classicspeakerpages.net/library..._ar_to_steve_f/

Steve F.

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Relative to the AR-91, I think the cabinet build-quality was superior in the original AR-3, but the 91's vertical driver alignment which enabled floor placement offers (to my ears, anyway) a more desirable outcome when placed on stands that bring the domes up to a seated level. I think the 3-way AR-91 actually benefits from coming off of the floor

So does that mean the 91 is heavier than the 3/3a, or just that the finish quality was better? I nearly ruptured something lifting a pair of 3a's up onto their stands. ;)

I think most ARs that aren't floor towers like the 9's produce better results when lifted off the floor. But I'm not about to try putting my 3a's back on the floor to do any comparisons...

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Both speakers weigh in at about 53 lbs, but the AR-91 has a bigger cabinet - approx. 31.5" High x 14" wide x 11.5" deep, vs. the AR-3 at 25" x 14" x 11.5".

Both cabinets are well constructed, but the AR-3 really seems to be very well-braced, and more acoustically dead.

I do wonder what effect a more inert cabinet would have on the performance of my own AR-9 system (I'm not complaining, though).

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