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Why No Big-Boy 8" Three-Ways?

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Ya' know...sometimes a 12" woofer is a lot of woofer. And sometimes a 10" woofer is a lot of woofer.

I've been musing over this for awhile, and it seems that AR might have missed out by failing to offer a high quality 3-way stand-mounted system, utilizing their best midrange & tweeter, and an 8" woofer.

During or around the era of The Verticals, Acoustic Research good have produced a hellacious stand-mounted design with the AR-9 series' upper mid & tweeter domes, and one of their well-regarded 8 inch woofers in a cabinet that would be about half the size of the AR-91.

Most modern small form factor systems are 2-way, bass reflex types, usually with a narrow, but tall & deep format that is pretty much the current norm for stand-mounted mini-monitors.

But only in the upper price echelon do these systems use their manufacturer's finest drivers; AR could have beaten just about everyone to market with a SOTA design, using parts that had long since been amortized.

Cleaning our ancient basement has brought forth a pair of slightly rusted AR-9 tweeters (the ones with the narrow silver ring), and what I think are upper mids from an AR-90 system that came through here about 5 years ago.

If one were interested in undertaking this Frankensteinian task, which AR 8" woofer would be a good candidate?

Any suggestions for utilizing "salvaged" crossover components or entire boards as shortcuts?

Is there anyone named Igor in the house?

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Hi AR-Pro

I think AR must have had the same thought.

You will probably remember that while Ken worked at AR he produced the AR 338, it had an 8" woofer and similar looking units to those you mention for the mid and Tweeter but different.

Perhaps that woofer would be a good prospect for the project, if you can obtain two from the remnants of AB Tech demise.

The cabinet dimensions and type/quantity of fill are already specified

The crossover for the 338 might also be a good starting point.

The following is from the CSP archives and provides a review of the unit.

http://www.classicspeakerpages.net/library/acoustic_research/ar_303_series/ar_303_series_other/ar_302_and_338_review_by_da.pdf

I like the 338.

R

Edited by Rlowe

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Classic British BBC oriented 12" x 12 " x 24" 3-way format has lot to offer, if high volume is not needed. However this was actually two way design with super tweeter, as 8" woofer (bexetrene or polyprop cone) was crossed at about 3 kHz. Rogers made many different versions of this one. Spendor saga is still going on and there were others too. I suppose that lack of good mid ranges capable to lower crossover frequency was reason for using Celestion tweeter that was capable only for 3000 Hz crossover. Super tweeters were used from other marques as well.

When ATC introduced SM 150-75 3" soft dome in 1976. This made it possible to make ATC SL50 true 3-way high power monitor in 1980´s with dimensions only slightly more than those classic dimensions. However ATC did not have any 8" woofer in production, so they used their 9" woofer instead. Ruggedness of ATC design is substantial as it can deliver continuous 112dB SPL@1m. It has proved worthy design, as they are in production still after 30 years of continuous production. http://www.atcloudspeakers.co.uk/hi-fi/loudspeakers/classic-series/scm50/

There are other 3-way designs that would fit format ar_pro mentioned, but I think that above mentioned two look best to me. Igorizing 3-way AR with 8" is good idea... and I think also that AR might have lost some sales. But how much is only guess. After all AR5 did not sell too well and it was not too far from AR Igored.

What is interesting in this idea is that there were not too many choices for good mid range unit in 70´s. AR mid had been in production for a while, even one used for 9-series was new design. ATC SM 150-75 arrived in 1976 and I suppose that it was quite expensive even in these days, as new ones sell today for 372,00 GBP ea. ITT produced good 50 mm soft dome mid range also 70´s, but I do not know when it was introduced.

All the best to AR Igored...

Best Regards

Kimmo.

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I have often felt the same way. It would have been very interesting if AR had done an 8-inch “3a” in the Classic era, around 1971, with the AR-6’s 8-inch woofer system (which was markedly superior to the 4x’s) combined with the 5’s dome mid and tweeter.

The problem was cost: The 1 ½” dome mid cost almost as much as the 12” woofer—more than the 10” woofer—so an 8-inch “3a” would have sold for more than a 2ax and only very slightly less than the 5. The 6’s cabinet would probably have to have been increased in size to compensate for the extra internal displacement of the dome mid and tweeter, and no doubt extra bracing would also have been needed to offset the added weight and larger baffle driver cutouts. (I’m not even sure the 6’s cabinet had any bracing at all. It was small enough and shallow enough that it was likely intrinsically stiff enough all on its own.)

Could AR have successfully marketed this line-up?

4x--$63

6--$81

2x--$102

2ax--$128

“8-in 3a”--$160

5--$175

3a--$250

My feeling is that an 8”-dome-dome wouldn’t have sold because of the price involved.

Maybe a 3-way using the 6’s woofer system with the 2ax’s 3 ½” cone mid and ¾” dome tweeter—that could have likely sold for around $110-115 ea. An 8-inch “2ax” in place of the 2x—now you could be talking.

Steve F.

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There is no bracing in AR5 cabinet. But anyway, production cost of AR Igored should not bee too much different to AR5, which was not big success on AR scale. So... only valid reason for choosing AR Igored would be smaller size.

AR2ax with 8" woofer may have been better product... but 2ax in original form was very good product.

Best Regards

Kimmo

..

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The AR-5 failed in the market because instead of seeing it as a sort of lesser AR-3a as AR tried to pitch it, potential buyers just saw it as a more expensive AR-2ax, with the only difference between it and the 2ax being a different mid driver. So in all likelihood, in order to succeed an 8" 3-way would probably have had to be priced at or near the price of the AR-6 (which, btw, didn't really sell all that well either compared to the AR-4 series, as we can see from the much smaller number of them that show up used compared to 4s).

However, my guess is that the biggest reason there was not an 8" classic AR 3-way is that the response of the 8" driver went high enough that a mid driver just wouldn't have added anything in the way of performance. We didn't see any 8" AR 3-ways until well after the Teledyne acquisition and the departure of Roy Allison, at which point AR's original primary focus on audio performance had given way to designing speakers based on mass market preferences, especially at the low end of the market where there were consumers who would pick a 3-way solely because it had more drivers.

BTW, if you browse the library section for Allisons, he only seems to have designed one 3-way with an 8" woofer, the CD8, which does use the same high and mid drivers as its 10" sibling, so that's probably the closest thing you're going to find to an 8" 3-way based on the same design priorities as a classic AR.

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Ya' know...sometimes a 12" woofer is a lot of woofer. And sometimes a 10" woofer is a lot of woofer.

I've been musing over this for awhile, and it seems that AR might have missed out by failing to offer a high quality 3-way stand-mounted system, utilizing their best midrange & tweeter, and an 8" woofer.

During or around the era of The Verticals, Acoustic Research good have produced a hellacious stand-mounted design with the AR-9 series' upper mid & tweeter domes, and one of their well-regarded 8 inch woofers in a cabinet that would be about half the size of the AR-91.

Most modern small form factor systems are 2-way, bass reflex types, usually with a narrow, but tall & deep format that is pretty much the current norm for stand-mounted mini-monitors.

But only in the upper price echelon do these systems use their manufacturer's finest drivers; AR could have beaten just about everyone to market with a SOTA design, using parts that had long since been amortized.

Cleaning our ancient basement has brought forth a pair of slightly rusted AR-9 tweeters (the ones with the narrow silver ring), and what I think are upper mids from an AR-90 system that came through here about 5 years ago.

If one were interested in undertaking this Frankensteinian task, which AR 8" woofer would be a good candidate?

Any suggestions for utilizing "salvaged" crossover components or entire boards as shortcuts?

Is there anyone named Igor in the house?

How about the AR93 and AR94? Both of these speakersfrom 1980—were true 3-way, 8-inch designs, but granted, these were not conventional 3-way designs in the sense of the AR-5/3a, etc. These were floor-standing models with 3-way crossovers, using the updated, Ferrofluid version of the 1¼-inch tweeter. These speakers were "parts-bin" engineered speakers using conventional drivers that took advantage of new thoughts on boundary issues (the "Allison Effect"), giving pretty solid bass down to the low-40Hz range (-3dB of 44 Hz), and these speakers were relatively inexpensive and could sound impressive if placed properly. The crossover frequencies were 350 Hz and 2000 Hz.

—Tom Tyson

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AR made a bold move with their Verticals series; to change the form factor of the top FOUR systems in their line from bookshelf to floorstanding took some moxie, and they certainly made their point.

Among the distinguishing characteristics of the AR-9 and AR-90 is their freedom from a certain (and I hesitate to use this word, but being among like-minded enthusiasts, I will) muddiness that can be present in their 12" 3-way bookshelf systems.

The ultra-low crossover to the woofer systems in the 9 and 90 that frees up that seemingly prosaic 8" driver makes all of the difference.

After carefully listening to our rebuilt AR-91 speakers for several weeks, I can report that their effect is about 90% that of the AR-9, except for a slight loss of detail in the critical upper-bass-lower-midrange.

My hunch is that in setting out to achieve substantial low-frequency reproduction through their use of the 12" woofer in this 3-way system, AR turned away from that which had made their two new top systems so special.

And so, assuming the need for a 12" 3-way to continue to carry the torch of tradition, I'd much rather have seen an 8" 3-way with slightly compromised bass, but with the musical presentation of the 9 and 90, rather than the AR-93 and AR-94 that Tom has written about.

The small British boxes notwithstanding, AR could have established themselves in the high-end mini-monitor business with a stand mounted 8" 3-way (along the line of the AR-338 that Rlowe has mentioned), years ahead of other manufacturers - it might have been their ticket into the '90s and beyond.

Here's a photo of the current-production Classic Three speaker from NHT. It utilizes a 6.5" acoustic suspension woofer, and a combination metal dome tweeter & midrange.

With this sort of form factor, AR could've built an 8" system that wouldn't have been much larger (sigh).

post-100370-0-72988000-1436840974_thumb.

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My memory may be fading with age, but I don't recall a whole lot of speakers on tall, skinny stands during the late 70s and early 80s, though I do recall a lot of aftermarket stands of that sort for bookshelf speakers.

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I don't recall a whole lot of speakers on tall, skinny stands during the late 70s and early 80s

Correct, Gene - certainly not in the U.S.; Britain & Europe were a different story, as small speakers were certainly not unusual.

But recall that AR had offered dedicated steel stands for the 10pi and AR-11, so the concept must have crossed the corporate mind at some juncture.

I believe that Wilson Audio is usually credited as validating - if not establishing - an audiophile market for small, stand-mounted speakers in the U.S. in the early '80s.

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Those were all pretty short, and intended to raise the bigger bookshelf speakers off the floor just enough to avoid undesired bass reinforcement if the user couldn't position them optimally. It wouldn't be until the Holographic series in the 90s when AR produced stands intended to raise speakers all the way up to ear level as a design feature.

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To Steve's question in post #5 - - the AR-6 had no internal bracing.

Using the TOTL tweeter and UMR from the AR-9 and AR-90 in an 8" three-way would have possibly created yet another conundrum, which would be how to arrange these larger diameter drivers on the baffle board (height x width) of a smallish speaker and then balance this arrangement with the third cabinet dimension (depth) in order to arrive at an optimal internal volume for the intended woofer.

Two attempts at creating an 8" three-way bookshelf speaker are shown in pics below. The first shows the Rectilinear Mini-III (18.75" x 11.75" x 9.25") atop an AR-6 (19.5" x 12" x 7.5"). I may be mistaken about this, but I think the Rect. product uses an 8" CTS woofer (which has many similar characteristics to the typical AR-4x woofer) as well as a 5" Phillips mid and a 2" Peerless (super) tweeter. They are very nice speakers but rather inefficient and rated at nominal 4 ohms.

Don't know much about the second pic, which I found on a Korean website with many images of vintage AR speaker products and components. Clearly, this is a one-off custom cabinet enclosure, but it does employ all original AR drivers from the same era - - - I have no idea how this crossover was designed and/or assembled. Unfortunately with these Asian sites, even after using Google translations they still contain a good deal of indecipherable gibberish.

post-112624-0-65927600-1436899751_thumb. post-112624-0-97656700-1436899781_thumb.

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My feeling is that a single 8" does not provide enough bass output to justify the cost and complexity.

A pair of 8" drivers has roughly the area of a 12" and should allow for a smaller box. A small tower

makes a lot more sense than a small speaker on a stand that wastes the potential extra volume.

I always liked the EPI 8" woofer but I think it is actually about 5-6 ohms DCR but I'd prefer something

that reaches lower for a premium 3-way.

Not that familiar with AR's woofers but for serious bass duty it should have a raised back plate, do we

have cone mass and Fs for the AR 8s? Even better all the T&S parameters?

BA T1030 comes to mind, with of course AR mid and tweeter.

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The world market for stand-mounted, small-woofer speakers is pretty well established at this point; and every manufacturer has representative models in this format.

Clearly, there are practical conditions and circumstances that call for less than a 12" woofer, and AR had a lot of success with their budget 8" systems; this begs the original question of why they resisted building what might have been the first audiophile-grade "minimonitor" from a U.S. company.

The NHT Classic Three has had spectacular reviews in the audiophile press, and they're rocking a little 6.5" acoustic-suspension woofer! :)

Very interesting Korean homebrew project, ra.ra - it looks like a combination of AR-4 drivers and a 2ax midrange.

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The world market for stand-mounted, small-woofer speakers is well established because that is

what is being made and hyped in the magazines. Still, it doesn't make any sense to waste

the space. BA T1030 makes sense, modified however you like to make it more like an AR.

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The NHT Classic Three as tested by the NRC, note the significant compression at 95 dB,

more than any other that I remember tested there:

http://www.soundstagenetwork.com/measurements/speakers/nht_classic_three/

If you want small and capable woofers try a pair of 6.5" Anarchy's on each side, the 8 ohm

version would provide a 4 ohm system to help offset the low efficiency:

http://www.diysoundgroup.com/anarchy-woofer.html

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The TSW 410 (and its Connoisseur Series equivalent, the 35) were interesting speakers, and quite good. The 35 actually made it onto Stereophile's Recommended Components list in 1986 and the 410 received a superb review from High Fidelity magazine in 1987, ending with the line, "AR has done it again."

But they weren't actual 3-ways. They were "2 1/2"-ways. Both the 8" and 6 1'2" drivers covered the bass, working in parallel in the enclosure's volume, but the 8" was rolled off around 4-500Hz or so and only the 6 1/2" driver continued up into the midrange, where it crossed over to the tweeter. I worked at BA in the early 90's for about 11 years with an engineer who had been the lead engineer on many of the TSWs and he told me that they were good speakers, well-designed and serious, if a bit conservative.

The AR94 (dual 8" drivers and the 1 1/4" cone tweeter) was also a 2 1/2-way design--both acting as woofers, but only one driver continuing up into the midrange. BA did a floorstander in 1994 (The VR30, the middle model of the three unit VR20, VR30, VR40 family) that was a 2 1/2-way speaker, using dual 7" woofs and their excellent 1" dome tweeter. Great speaker.

Consider this, as an amusing aside: Manufacturers like to make a huge deal in their brochures about their midranges being in separate internal sub-enclosures, so the mid's cone isn't affected by the backwaves from the woofer.

Yet in a 2 1/2-way, the "mid"--which is one of the two parallel woofers--is "exposed" and being affected by the backwaves from the other woofer, yet the midrange sounds fine. Never a complaint about the 410, 35, 94, or VR30's midrange clarity. Another theoretical "rule" shot to h*ll.

Steve F.

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How about something that used the AR-5 mid & tweeter, but with a woofer from the AR-4 series?

Don't give me any ideas B) ...

I guess the KK era 338 wasn't quite the match for those who appreciated the voicing and dispersion characteristics of the classic period speakers. I've read at least one reviewer who was amazed that they could have made the classic era speakers without the benefit of computer modeling software ... ha, ha, ha ...

Roger

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I have a question: why build an AR without the excellent 12" woofer? One of the most important reason to use an old speaker like AR 3 or 3a is the exceptional bass response. In 40 years I 've never heard a complete speaker ( I mean without a subwoofer ) with similar bass response . Incredibly deep, undistorted, rich, powerful, fast and clean .

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I have a question: why build an AR without the excellent 12" woofer? One of the most important reason to use an old speaker like AR 3 or 3a is the exceptional bass response. In 40 years I 've never heard a complete speaker ( I mean without a subwoofer ) with similar bass response . Incredibly deep, undistorted, rich, powerful, fast and clean .

Exactly!

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Sonnar, on 10 Aug 2015 - 8:12 PM, said:

In 40 years I 've never heard a complete speaker ( I mean without a subwoofer ) with similar bass response.

Have you ever listened to an AR-9? ^_^

Just kidding - the dual-woofer, extended LF design of the AR-9 doesn't negate the quality of the AR-3a, or any other AR 12"-woofer system; it's just designed to serve a different need & circumstance.

There are plenty of listening spaces that don't provide an adequate condition to realize the potential of the AR 12" woofer, but a compact system with drivers of equivalent quality, but with a smaller woofer might prove more suitable, and without sacrificing overall sonic character.

Wilson Audio virtually created the market for small, high-quality monitors with the 2-way Wilson Audio Tiny Tot (WATT); a loudspeaker originally designed for superb reproduction in a compact format.

Using their "best-quality" mid & highrange drivers, AR could've established this niche for themselves, and at a price that would've been a fraction of the WATT's.

It's fun to speculate, no?

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