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New, Hindsight-Design AR-5 Loudspeaker


tysontom

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As talented an engineer as Roy was, he was a sales/marketing failure of similar proportions. Allison Acoustics failed because of some blip in the European market (France, where they'd done pretty well for a short time), but the line was never exactly a rip-roaring success, anywhere. It was destined for quick failure from Day 1.

OK, let's Etch-a-Sketch things back to a clean slate. The sales/marketing failures of his last years at AR and the corporate failure of Allison are wiped clean.

Roy starts over, with a blank-sheet-of-paper opportunity to do it all again. But right this time, learning from the mistakes and misjudgments of the past, his previous misreadings of the market behind him, lessons well-learned.

This time we'll do speakers that just sound good in an uncomplicated way, that appeal to the heart of the market, that don't have to be explained with an understanding of arcane audio minutia.

RDL. Room Designed Loudspeakers. So much smarter than Advent.

Never mind.

Great post!

It's difficult to know the exact reasons for Allison Acoustics demise (as well as RDL, etc.), but there were some anachronistic defects that seem to run through the entire Allison business model. Roy was not actually an engineer, but he was thoroughly trained in acoustics, physics and mathematics, and he knew how to design excellent speakers! He was also an excellent writer, and he authored several dozen articles and a wonderful book published by AR (and later Dover), High Fidelity Systems.

Roy was also was purist when it came to his designs. He didn't accept compromise, particularly, in his designs. For example, with the original Allison: One, the angular shape of the cabinet almost guaranteed that many housewives would not accept it in a listening room, and I think this was a deterrent from the beginning. Men were fine with it because they could understand what was going on, technically, with the design. I know this personally in that I got complaints at home the entire time I owned my original Allison pair, and I didn't get the same complaints from other tower speakers, even the somewhat unfriendly looking, pillar-like AR9. Allison Acoustics also refused to make conventional "bookshelf" models that could use the Allison: One components in an AR-3a-style bookshelf speaker (I even suggested this at lunch one day while visiting the Natick, Massachusetts company, and my suggestion was politely and quickly rejected by everyone but Abe Hoffman). I thought that this would be a very successful design, considering the excellence of the Allison drivers, but the company officials said it would then violate the company's room-boundary concepts. I felt that the speaker could be flush-mounted in a bookshelf, but the feeling was that most folks would put them on stands out in a room or even on the floor. Even the Allison IC20 was a sort of final attempt (a sort of "swan song") to attain a high status, and the speaker was obviously superb, yet it was quite expensive and costly to design and manufacture, and it was not particularly well-received. Only about 50 pairs (or perhaps 50 speakers) were ever built in that 1989 time-frame.

Finally, I suspect—but this is speculation on my part—that Allison Acoustics was somewhat under-capitalized from the very beginning; and once there's a cash-flow issue, it's never easy to overcome it. There were some recessions and downturns in the general marketplace during those years, too, as well as a general slow-down in popularity of "conventional" high-fidelity components that occurred right at the end of the 1980s.

—Tom Tyson

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Interesting discussion and information about the history.

Have any or many of you taken a look inside a Large Advent woofer?

Top plate height, wind height, Xmech, etc.?

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I thought that this would be a very successful design, considering the excellence of the Allison drivers, but the company officials said it would then violate the company's room-boundary concepts.

Interesting.

My first step up from the AR-4x was a nice pair of Allison: Fours. They were hung on the wall, about a foot from the ceiling so the upward-firing woofers would reflect the sound off the ceiling. I really liked them but the next house had a cathedral ceiling and the Allisons were demoted to function as surround speakers. The third house also has a cathedral ceiling, so I sold the Allisons. Sort of miss them but they would not work here.

Point is, maybe Allison should have followed your advice.

-Kent

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I remember auditioning the large Advents & to me the weak point of the system was the midrange. A 2 way system with a 12" woofer to me compromised the mid & it should have been a 3 way system. Then again that would have raised the price.

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Interesting discussion and information about the history.

Have any or many of you taken a look inside a Large Advent woofer?

Top plate height, wind height, Xmech, etc.?

Pete,

I have the parameters somewhere on the Advent woofer, but I can't put my hands on the information. A few years ago, I also measured the harmonic distortion of my pair of Advents compared with my AR-3as (using my HP-339A analyzer and a Earthworks M30 microphone and Earthworks microphone preamp), and the AR-3a was significantly better at anything approaching a high-output level, when each system was adjusted for identical SPL output. I also have a pair of Small Advents, which have the same low resonance, but that speaker doesn't seem to tolerate high power levels as readily as the Large Advent. I measured down to 20 Hz and up to 20-25 watts/rms equivalent input power, which might not seem like much power, but it is a significant power level at steady-state input loads at such low frequencies. Most testers over the years stuck with 1-watt input for this measurement. This definitely "separates the men from the boys," and the AR-3a woofer handled that power without distress.

I have attached some pictures of the Advent voice coil compared with an AR-3a coil (both speakers had been damaged somewhere along the line). The 3a used a 2-inch coil with 5/8-inch linear overhang; the Advent's coil was 1.5-inches in diameter and much shorter in height. The top plate was not quite as thick as the AR-3a's .5 inch top-plate thickness.

Basically, the Advent speaker's fc is in the 44-45 Hz range, close to the AR-3a, so there is the subjective deep-bass output from the Advent that rivals the AR-3a; also, the Advent magnet is fairly deep and narrow, and the spider is large to allow pretty large physical excursions, so it doesn't tend to bottom. Apparently when the woofer goes into huge excursions out of the magnetic gap, the voice coil is susceptible to scraping the pole piece, something that happened to my dissected sample.

Therefore, I think the maximum linear excursion is somewhat less than the AR-3a, and the power-handling is less as well. However, for all practical purposes, the Advent will play excellent deep bass sounds if the power is kept within reasonable levels. Rock music and jazz, no sweat; synthesizer and organ music, the AR-3a is more potent. The question in many peoples' minds was whether the AR-3a's superiority was worth twice the price (of course, the 3a was a 3-way high-end speaker with dome tweeters vs. the 2-way cone/donut tweeter used in the Advent). The 3a was better, but it came at a price.

—Tom Tyson

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Allison Acoustics also refused to make conventional "bookshelf" models that could use the Allison: One components in an AR-3a-style bookshelf speaker (I even suggested this at lunch one day while visiting the Natick, Massachusetts company, and my suggestion was politely and quickly rejected by everyone but Abe Hoffman). I thought that this would be a very successful design, considering the excellence of the Allison drivers, but the company officials said it would then violate the company's room-boundary concepts.

This, of course, is perfectly in keeping with Roy's self-limiting marketing outlook, where he threw obstacles in front of himself and then wondered why the landscape was so difficult.

Nothing illustrates this better than the VCR market of the 1980's. JVC/Panasonic invented VHS. Sony invented Betamax. Betamax was slightly superior in a few minor technical aspects, but it lost out in the marketplace, primarily because of its 5-hr max recording time vs. VHS's 6 hours.

While Matsushita reaped millions in profits from the sales of their VHS units and their licensing agreements with RCA, Magnavox, Sylvania, etc, Sony stubbornly stuck to their Beta machines and its "superiority," while they languished at around a 2% VCR market share. All because doing VHS would have violated the "company's principles." Isn't corporate ego a great thing?

But someone talked sense into Sony and around 1985 or so, they came out with a line of VHS VCRs. Know what happened? They roared past Panasonic into the Number 1 market share position. Within a year after their introduction! I was working for Panasonic at the time and I remember this like it was yesterday.

Not saying that an Allison "3a" or "2ax" would have become the no. 1 speaker in the market, but corporate ego that stands in the way of good, credible, worthy products is a mis-placed emotion. Any good marketing person could have "squared" Allison's room-dependent models with a line of conventional bookshelf speakers. AR had no trouble selling 18's and 48's when the 9 and 90 were also in the line. It's not rocket science. It's marketing.

Steve F.

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I remember auditioning the large Advents & to me the weak point of the system was the midrange. A 2 way system with a 12" woofer to me compromised the mid & it should have been a 3 way system. Then again that would have raised the price.

The Advent's tweeter had good output, but it was not the smoothest, so what you ("craigh") heard was probably valid. The tweeter was not exhaustively developed in an anechoic chamber (I'm not sure that an anechoic chamber even existed at the Advent Corporation at the time of the Large Advent); on the contrary, the speaker was "voiced" by members of the Advent executive staff, a sort of "seat-of-the-pants" method of speaker development. The Advent did have significant on-axis output energy (and decent off-axis response) well out to 15 kHz -- and significantly more on-axis energy than a comparable Acoustic Research speaker -- yet the response from the Advent tweeter was ragged (see images of tested Advent), and the tweeter/midrange could sound quite harsh at times on certain types of music. Even with ⅓-octave anechoic response tests, the tweeter did not have smooth acoustic-power output at the highest frequencies, an indication of uneven off-axis output. AR speakers, on the other hand, were very smooth and uniform, but "reticent" compared with the Advent, and customers could hear this reticence on first impression. Chalk up a sale for the Advent each time.

For many music-lovers and prospective stereo speaker-purchasers in the 1970s, this response roughness fell by the wayside when considering the excellent bass response and the low price, handsome cabinet, and so forth. Advent showroom salesmen could overcome the shortcomings of the speaker by bragging about its strong bass response, "clear midrange" and bass response like an AR-3a -- at half the price! Besides, most buyers of the Advent were more into popular and rock music, and these generally were less-discerning music listeners, and Henry Kloss knew this strategy well. Therefore, this strategy worked well until Advent finally drove itself into the ground and filed for Chapter 11 in 1981.

—Tom Tyson

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Interesting that the full system Advent curve(s) on the left seems so much smoother than the tweeter-only curve on the right. The left curve seems to correlate pretty well with how the Advents actually sounded: some midrange prominence and a more pronounced HF drop-off off-axis than the AR 3/4" tweeter-equipped models.

Per my comment about conventional Allison bookshelf speakers above, an Allison 10" 2-way with his excellent tweeter would likely have given Advent a real hard time in the market, if Allison could have priced it competitively ($130 ea. or less).

But as I said, Roy was afflicted with SBD (Sony-Betamax Disorder), so we'll never know.

Steve F

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Steve,

The first curve of the Advent was a ⅓-octave sweep anechoic test; the curve on the right was a sine-wave, anechoic frequency-response test of the driver itself, showing detailed anomalies or other discrepancies in the driver's raw performance, through the crossover. Ironically, the Advent tweeter was smoother without the crossover than with it; nevertheless, the driver is uneven and ragged; as a whole, the system produced reasonably flat energy output.

For contrast, i've attached the ⅓-octave sweep of an AR-2ax.

—Tom

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Tom,

I've never seen this 2ax sweep before. it "looks" like my 2ax's always sounded to me: Very smooth, with a gently down-sloping trend with increasing frequency. Very smooth.

My friends would always say the same thing when they came over to my house and heard my 2ax's: "Wow! They didn't sound like that in the store!"

My Dad's 4x's sounded so good to a friend of mine who owned Large Advents that he said, "But they're [the 4x's] half the size and half the price of my Advents and they sound just about as good! It's not fair!"

From then on, my Dad and I called the 4x the "not fair" speaker.

Steve F.

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Tom wrote:

Besides, most buyers of the Advent were more into popular and rock music, and these generally were less-discerning music listeners, and Henry Kloss knew this strategy well.

That's a very interesting point.

Personal story: a musician friend bought a pair of the original Large Advent speakers for his apartment in college.

He played rock music, but was into all sorts of tunes from exposure to his classical-musician father (an AR-2ax owner).

A number of friends were at his place, listening to the Advents, and trying to assess the difference between them, and the various AR-based systems we all owned.

The consensus was that the Advents sounded reasonably good on recordings of unamplified instruments, but were punchier than an AR-2ax on rock recordings.

Here's the thing, though - one of the guys had been gifted with a single, beat-to-hell Altec 601C Duplex speaker in a 614-type plywood utility cabinet - he had intended to use it with his guitar, but also wanted to hear it through our friend's system, just to compare it against the Advents.

The single Altec was subsequently hooked up, and "Smoke On The Water" was cued up.

To say that we all immediately burst into laughter is an understatement - the Altec was in another league than the Advent!

The dynamics were explosive, and the apparent bass extension was enough to make the Advents seem broken in comparison.

This begs the question of why anyone in that era who was interested in blasting rock music would ever buy anything that didn't carry an Altec or JBL label?

My guess is that it's all about price & size. Kloss found a very comfortable location in the fat part of the cost curve, and juiced his compact A-S system just enough to sound more lively than the direct competition (the 2ax), with nearly the apparent bass performance of the A-S benchmark AR-3a.

As a rule, Altec and JBL tended to be harder to find, were not often discounted, and usually had larger, floor-standing cabinets.

Also, although both Altec and JBL offered a number of relatively compact systems, those companies never really seemed to be agressively interested in the sort of "commodity" market that Advent had focused upon.

One exception was the studio monitor-based JBL Century 100, which was a huge success, although at a much higher price than the Large Advent.

If JBL had been able to produce and agressively market a smaller, equally-potent version at the price of the Large Advent, Kloss' market of rock listeners might have gone up in (Deep Purple) smoke.

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My Dad's 4x's sounded so good to a friend of mine who owned Large Advents that he said, "But they're [the 4x's] half the size and half the price of my Advents and they sound just about as good! It's not fair!"

I had a "not fair" experience shortly after moving with my 2ax's to California in 1980. One of my friends noticed that my listening chair was not located precisely in between my speakers, walked across my living room a couple of times and exclaimed, "You get good stereo everywhere in this room! That's not fair!"

I asked him what speakers he had: JBL.

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I had a "not fair" experience shortly after moving with my 2ax's to California in 1980. One of my friends noticed that my listening chair was not located precisely in between my speakers, walked across my living room a couple of times and exclaimed, "You get good stereo everywhere in this room! That's not fair!"

I asked him what speakers he had: JBL.

True, that.

The smaller-box Altecs & JBLs tended to be pretty beamy - especially in the higher frequencies.

Their large, floor-standing systems were a different story, though; but you needed a big space to contain them.

In those days, not many rock fans were into stereo imaging! :)

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Let me say first off that I like some JBL drivers, and their newer models very much but

the L-100s had many, many technical issues in my opinion, far more than the Advents.

The bass tuning and crossover in the L-100s were pathetic:

http://www.troelsgravesen.dk/JBL_L100.htm

I was suspicious of these flaws based on hearing them and seeing the crossover schematic,

that link just confirms what I heard. They play loud and boomy, that's about it.

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Have you guys ever had a party with a lot of people having a good time where the volume

just keeps going up? What happens with your ARs?

I have a friend who had AR-11s in college with big bridged NAD amps, the ones that would

do 4X their rated power for about 500 ms. Yes, he and his friends liked to turn it up on the

weekends.

Interesting pictures Tom, that does not look like the early Large Advent woofer voice coil is

it from a later Jensen version woofer? Mine have solid formers that look like copper or some

copper color alloy.

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Tom wrote:

Besides, most buyers of the Advent were more into popular and rock music, and these generally were less-discerning music listeners, and Henry Kloss knew this strategy well.

That's a very interesting point.

Personal story: a musician friend bought a pair of the original Large Advent speakers for his apartment in college.

He played rock music, but was into all sorts of tunes from exposure to his classical-musician father (an AR-2ax owner).

......If JBL had been able to produce and agressively market a smaller, equally-potent version at the price of the Large Advent, Kloss' market of rock listeners might have gone up in (Deep Purple) smoke.

Funny you mention that. I was introduced to L-100's, four of them to be precise powered by a Marantz 2270 playing the live version of "Smoke on the Water." It was a fairly small room in Germany and the volume was high enough to make my chest pump from the changes in air pressure. The L-100's were good for that.

Drifting away from the topic I listened to a set of Infinity RS-1b towers the other day that were for sale locally. These were powered by Conrad Johnson and Nakamichi amps. Probably could move mountains with these. The seller is planning on parting them out as he couldn't find a buyer and he says he can get twice his asking price for the drivers. They are way above my pay scale and I happened to be there to pick up a Phase Linear 1000 that he hadn't used for ten years.

Back to the topic, I don't think JBL was into cost cutting to produce a mass market speaker in those days anymore than AR was into producing mini-monitors.

Roger

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Roger wrote:

I don't think JBL was into cost cutting to produce a mass market speaker in those days anymore than AR was into producing mini-monitors.

That's a pretty accurate take, Roger. The JBL Century 100 never really captured the sound & effect of their much larger systems.

Altec was exactly the same - you just couldn't get that sledgehammer effect in their smaller systems; although that Altec 601C Duplex in the utility enclosure beat the living daylight out of my friend's Large Advents - at least with rock music!

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although that Altec 601C Duplex in the utility enclosure beat the living daylight out of my friend's Large Advents - at least with rock music!

One man's opinion, they probably did not have enough power for the Advents.

I'll take some Big Reds that use the Altec 604 and the Mastering Labs crossover.

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Have you guys ever had a party with a lot of people having a good time where the volume

just keeps going up? What happens with your ARs?

I have a friend who had AR-11s in college with big bridged NAD amps, the ones that would

do 4X their rated power for about 500 ms. Yes, he and his friends liked to turn it up on the

weekends.

Interesting pictures Tom, that does not look like the early Large Advent woofer voice coil is

it from a later Jensen version woofer? Mine have solid formers that look like copper or some

copper color alloy.

In college, a good friend of mine had AR-4xs stacked, driven by an first-generation AR Amplifier, and he would play Johnny Cash country music at almost painful, punishing sound levels after the hours wore on. The amplifier, to my amazement, would get so hot you couldn't touch it, but it never failed (blew fuses regularly) in the bias circuit, a common problem with the AR Amplifier in some versions. I don't think he ever burned out a tweeter, and I think the "stacked," parallel-connection arrangement saved them. I used to play stacked LSTs using a McIntosh MC2500 amp, and the sound levels got so high, the load would occasionally tripped the circuit breaker until I wired it with a dedicated 20A circuit. The "Power Guard" lights were shining frequently, but later in life I settled down quite a bit.

The Advent woofer voice coil was from a fairly early (1971 or so) model, and the former, or "bobbin," was made from aluminum. You can probably see the scrape marks on the inside of the bobbin. Up by the lead-out point, there is a paper covering to hold the wires in place. It's the early, original version, definitely long before the post-Kloss versions or the Jensen versions (probably the same). Those later versions were quite difference in design and didn't use the original magnet or voice coil. I think they were designed by Andy Kotsatos.

I hope that helps. The last picture is a low-rez picture of the version of the woofer.

Tom Tyson

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One man's opinion, they probably did not have enough power for the Advents.

I'll take some Big Reds that use the Altec 604 and the Mastering Labs crossover.

More like the opinion of the ten musicians in the room, but since you weren't invited, you wouldn't have known that.

Interesting point about having "enough power", though.

What is enough power for the Large Advent?

Since so many Advent customers of that era were budget-minded youngsters, what percentage do you think had enough power?

One of my roommates in law school had a pair of Stonehenge III's with the 604-8G, and I got to play around with an ancient pair of 604B's several years ago, before sending them off to a new home in Japan.

Based upon those experiences, I can only encourage you to go ahead and actually purchase a pair of 604 speakers, construct the crossovers & boxes, and report back as soon as possible.

Godspeed!

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I think I remember one of our members telling us that his initial invitation to visit AR came after he broke some kind of record for the number of dome tweeters blown out under warranty. Aiming speakers out windows for patio parties or something like that.

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More like the opinion of the ten musicians in the room, but since you weren't invited, you wouldn't have known that.

Interesting point about having "enough power", though.

What is enough power for the Large Advent?

Since so many Advent customers of that era were budget-minded youngsters, what percentage do you think had enough power?

One of my roommates in law school had a pair of Stonehenge III's with the 604-8G, and I got to play around with an ancient pair of 604B's several years ago, before sending them off to a new home in Japan.

Based upon those experiences, I can only encourage you to go ahead and actually purchase a pair of 604 speakers, construct the crossovers & boxes, and report back as soon as possible.

Godspeed!

PA speakers for home use are a novelty, the 604s are just a curiosity to me, I have

plenty of much better modern speakers - thanks.

I remember our discussions in the past and you are obviously baiting me, bash

Advent thinking you can start something. So the eternal AR lover, the rebuilder, WHAT

YOU WERE WRONG AND ADMIT IT????? HAHA, "Goodbye, AR-9":

http://www.classicspeakerpages.net/IP.Board/index.php?showtopic=8153

""Sure", I said - I haven't heard Maggies in years, why not? My significant other had already settled into a chair when the needle hit the groove, and for the first time in my life, I actually heard the music, and not the reproduction. Nevermind that I suddenly, and for the first time, noticed that certain notes from Paul Chambers' bass caused the drummer's snare to buzz in resonance, or that my wife (a musician with perfect pitch) assured me afterward that Bill Evans' piano had two flat notes; a sense of envelopment was in that listening space - a transformative, undeniable experience that went beyond the normal method of assessment that I'd always brought to a listening test."

You mean to say that all those years your AR's were not making music? And now you'll tell us that

none of us can possible be hearing the music unless we get your current favorite and blessed speaker.

You are an internet BS artist, that is all.

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I think I remember one of our members telling us that his initial invitation to visit AR came after he broke some kind of record for the number of dome tweeters blown out under warranty. Aiming speakers out windows for patio parties or something like that.

That was Ken Kantor when he was in college, blasting the speaker onto the quad.

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In college, a good friend of mine had AR-4xs stacked, driven by an first-generation AR Amplifier, and he would play Johnny Cash country music at almost painful, punishing sound levels after the hours wore on. The amplifier, to my amazement, would get so hot you couldn't touch it, but it never failed (blew fuses regularly) in the bias circuit, a common problem with the AR Amplifier in some versions. I don't think he ever burned out a tweeter, and I think the "stacked," parallel-connection arrangement saved them. I used to play stacked LSTs using a McIntosh MC2500 amp, and the sound levels got so high, the load would occasionally tripped the circuit breaker until I wired it with a dedicated 20A circuit. The "Power Guard" lights were shining frequently, but later in life I settled down quite a bit.

The Advent woofer voice coil was from a fairly early (1971 or so) model, and the former, or "bobbin," was made from aluminum. You can probably see the scrape marks on the inside of the bobbin. Up by the lead-out point, there is a paper covering to hold the wires in place. It's the early, original version, definitely long before the post-Kloss versions or the Jensen versions (probably the same). Those later versions were quite difference in design and didn't use the original magnet or voice coil. I think they were designed by Andy Kotsatos.

I hope that helps. The last picture is a low-rez picture of the version of the woofer.

Tom Tyson

First, I'll point out that I have an early Large Advent woofer cone and voice coil here in my hand,

and it does not look anything like yours. Copper colored and without vent holes. I've refoamed a

lot of Advent woofers and inspected them for bad glue joints but I don't cut the dust cap so I didn't

see below the spider but I always remember a copper colored former. It is possible that there were

production changes. I've posted a picture here in the past and will look for it but the search here

does not work very well.

I asked the question as a lead into what I think would have been needed to compete with Advent.

Kloss states outright in the Advent literature that he built the OLA woofer on a bigger frame to allow

for more "linear" throw. We had Large Advents when I was a young teen, and I was very impressed

with the excursion capability, _and_ the fact that it was nearly impossible to bottom the woofer in the

way that most others would make a loud crack sound. I was reasonably careful with them but did drive

a single one with an amp that would do 100W into their 5 ish ohm load and by eye it seemed like the

woofer would do far more that .25" one way, seemed to be closer to .5" one way without bottoming.

For years I thought that they must have 1/4 if not 3/8" one way Xmax - I was wrong, it was much less.

Years ago around 2005 I disassembled an OLA woofer and entered the motor dimensions for both the

LA and the late ceramic magnet AR-11 woofer into a spread sheet that gives calculated Xmax, what I

call Xmax50 (Xmax plus half of the top plate), and Xmech where the voice coil bottoms.

Surprised to learn that the OLA only has about 1/8" linear Xmax whereas the AR-11 woofer had about

1/4", they both have thick top plates which give them more Xmax50 than they'd have with a typical top

plate. The OLA woofer is an economical design, it begins to distort much sooner but the distortion is

tolerated well and it has a lot of headroom for overload, 13mm one way from memory just about and

inch peak to peak. The coil is completely out of the gap before it hits the back plate.

The AR woofer still has a small number of windings in the gap when it hits the back plate, and I found

it fairly easy to bottom in the AR-11 with bass heavy material. It needs a raised back plate.

I could tell a lot of stories of everyday people having parties and pushing their systems way, way beyond

anything linear. The AR-11s came to me with one voice coil gone past the pole piece and stuck fully out

due to it skewing with the back of the former resting on top of the pole piece.

A competing product would have needed a woofer with similar capability and a lot of headroom, all of the

AR woofers should have been built with more headroom. A tweeter capable of crossing low, with smooth

response and also rugged would also be needed. The original EPI tweeter comes to mind, in fact they

called it an air spring tweeter. AR should have copied it. What Kloss did was to get the drivers in phase at

the crossover point which provides a much better polar pattern than other types of crossovers. He also

employed a low crossover point which reduces crossover lobing. In contrast the AR-2ax has too many

crossover points and too high of an XO to the upper tweeter - it is a mess in my opinion. They give the

impression of very poor driver integration.

Kloss seems to have designed Advent systems taking human perception into account, how we tolerate distortion,

and with a frequency response balance that pushes the user to turn it down when it is too loud. I don't know if they

would have voiced them differently if showroom sales were not such a driving factor - I have a feeling they would

have voiced them to be more musical.

Here is the later Advent Legacy 10" woofer, this is a Jensen design but you can see the robust design with a

raised back plate:

http://baselaudiolab.com/ADV-LEG-W.jpg

Here is the AR-48s 10" woofer in contrast on the left, Advent OLA woofer on the right:

http://baselaudiolab.com/AR48SW1.jpg

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