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Never heard the 12" at its best


Steve F
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Here’s an intriguing thought—I wonder how much “better”—deeper and/or tighter—Classic AR bass would have been if the Classic thru Vertical enclosures were thick-walled, heavily-braced affairs, like the Thiels and Legacy’s of the world? There have been some Thiel models with 3-inch (!) MDF front baffles and Legacy Audio is famous for its overbuilt, heavily-braced cabinets. Many other audiophile speaker companies follow suit (B&W has their Matrix, etc).

It makes perfect sense, logically: The driver produces ‘x’ amount of energy. That energy can either be projected out into the room as clean audible energy or it can be partially absorbed and diffused by a lossy cabinet with flexing panels.

Here’s a great analogy I used to use in my sales training days at BA and Atlantic Technology: Think of Carl Lewis, the great track runner. He’s in top shape, wearing the very best Nike running shoes. He runs the 100-yd dash on the indoor track. World’s record.

Now take the same Carl Lewis, in the same top shape, wearing the same Nike running shoes. Have him run the 100-yd dash at the seashore, in the soft, wet sand. The indoor track is Enclosure #1. The soft, wet sand is Enclosure #2. Lewis (the woofer) is outputting the exact same amount of energy.

Will the end results differ? Yes, obviously.

Before everyone starts howling that the 3a’s enclosure had some bracing, ok, yes it did. Many AR speakers had some bracing. But it was minimal compared to a 1990’s audiophile speaker, one that benefitted from less cost restraints and also had the benefit of computer-aided vibration analysis, accelerometer testing and the like. My Connoisseur 50’s had 1-inch cabinet walls, but virtually every AR 12-inch speaker had only ¾-inch panels, and that was reduced still further where the woofer mounting area was routed out. (And the Connoisseur 50 had a Tonegen 12-inch polypropylene cone woofer with a FAR of around 24Hz--not 17-18Hz like the 3/3a--so the 50’s bass extension was actually inferior to the 3a’s, despite the 50’s greater cabinet volume.)

The Classic AR 12-inch woofer has proven over time to be a remarkable driver. But I’d love to hear it in an enclosure that really enables it to perform to its maximum potential. We hear it now at the “97%” level. For us—the ultimate music/audiophiles—hearing it at “100%” would be sonic nirvana.

Steve F.

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3 hours ago, Steve F said:

I’d love to hear it in an enclosure that really enables it to perform to its maximum potential.

OK. Install some bracing. It's not difficult. Maybe you could try it and report back. I braced my OLAs but they still couldn't hold a candle to the AR-2ax.

-Kent

11 08 24_7330.jpg

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No, merely installing some front-to-back stick bracing is not what I’m talking about. Although judicious stick bracing can be very effective, I’m talking about the “next level” of cabinet inertness. That level can only be achieved by thicker cabinet walls (1-inch minimum for non-woofer panels, 2-inch minimum for woofer-bearing panels), asymmetric windowpane bracing (asymmetric to prevent coincident frequencies from being reinforced as they would be if the bracing was regularly-spaced), and any internal mid enclosures to have walls that are not parallel to the main cabinet interior walls (to prevent any reflections).

Here’s a thought that’s crossed my mind (the mind I had before I lost it, that is!): I own AR9’s. Nicely restored (re-foamed and re-capped by the prior owner, an MIT engineering student). I love ‘em.

I’ve thought of taking the guts and putting them in new custom-designed, custom-built cabinets. Maybe take that opportunity to use beefier bi-amp terminal connections, but leave everything else the way it is. I still know my industrial designer from my AT days and I’d have him design the cabinet. Panel thickness would be as described above (maybe only the lower woofer sections of the side panels need be 2-inches thick, the rest could be 1-inch), bracing as described, internal chamber for the 8-inch LMR as described.

I’d take advantage of the chance to make the 9’s really attractive, with slightly curved sides and a smoked glass insert on top, similar in look to the Atlantic Technology AT-1, which was a truly sharp-looking floorstander in my view. Pic attached. Color TBD, but the AT-1’s dark gray with a very subtle metallic flake was quite nice, like a luxury car’s finish. I’m still in touch with a major vendor that I knew from my BA and AT days, so the whole thing is actually doable. It just may not be sane, and it certainly wouldn’t be cheap!

My suspicion is that the bass would tighten up ever-so-slightly and the speakers would look incomparably better.

When I hit Powerball, I’ll tell you how it goes.

Steve F.

Screen Shot 2018-02-08 at 3.28.26 PM.png

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5 hours ago, Steve F said:

I own AR9’s. Nicely restored (re-foamed and re-capped by the prior owner, an MIT engineering student). I love ‘em.

When your 9's were restored was there any internal bracing added.  I was thinking of adding some criss cross bracing above the woofer chamber and right below the lower mid driver. Another thought I have had is lining the interior cabinet walls with some type of Dynamat material to reduce vibrations. 

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When your 9's were restored was there any internal bracing added.  I was thinking of adding some criss cross bracing above the woofer chamber and right below the lower mid driver. Another thought I have had is lining the interior cabinet walls with some type of Dynamat material to reduce vibrations. 

 

No, no kind of bracing was added. The cabinets are totally stock.

I think some kind of added bracing would help, especially since the 9's dual woofers generates a good deal of internal pressure. There just wasn't the awareness of cabinet stiffness/inertness in 1979 (nor the ability to measure it) as there would be later. And yes, even though the 9 was a TOTL, high-priced speaker, AR still wanted it to be affordable. When the dollars are going into the drivers and crossover, the manufacturer will economize on the cabinet. Happens all the time.

As far as Dynamat, we've played around with it at various speaker companies I've been with. It works, but it's too expensive to use in a mass-market speaker. You also have to be careful about not reducing the interior volume of the cabinet.

Steve F.

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On 2/8/2018 at 11:13 AM, Steve F said:

Here’s an intriguing thought—I wonder how much “better”—deeper and/or tighter—Classic AR bass would have been if the Classic thru Vertical enclosures were thick-walled, heavily-braced affairs, like the Thiels and Legacy’s of the world?

Steve

Thanks. You raise a good question.  At first, I thought I had no opinion on this topic but now I think AR showed us the future in the 1950s with the AR1w and then for some reason, probably having to do with survival and available tech, abandoned the idea in favor all in one boxes.  

I know little about lumber physics but longer runs of lumber do need more bracing.  Smaller boxes need far less lumber than large ones to resist flexing and one solution to achieving rigidity is to use thicker, heavier slabs with bracing but another is to get small and just use sufficiently thick slabs.   

I can’t be certain, but I suspect the ¾” construction of the Classic 12” is sufficient.  Where IMO AR jumped the rails was in not refining the musicality of the connection between the AR1 sub-woofer box and AR 3ts and instead moving on to building all in one systems exclusively.  And maybe, "jump the rails" is harsh because I can't say I would have had vision either.

I can imagine a system of multiple AR  3T pyramids or irregular cubes that could be scaled up and down depending on need and space.  There could be 3t domes and 2t cones as well as 3t arrays.

 Such an approach would yield an AR 4x to beyond an LST, including the dual sub enclosures we saw in the 9 and 90.

Adams

 

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21 hours ago, Steve F said:

I’ve thought of taking the guts and putting them in new custom-designed, custom-built cabinets.

 

4 minutes ago, Aadams said:

I can imagine a system of multiple AR  3T pyramids or irregular cubes that could be scaled up and down depending on need and space. 

Seems like we're getting into the "Mods, Tweaks, and Upgrades" category.

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quit flappin' yer gums, and make a bass bin for the woofer the same internal volume as some 3a's or slightly larger (IIRC Qsys of a 3a is between .8 and 1)....I'd cast it out of 2" thick concrete, personally.... (:

 

 

 

 

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On 2/8/2018 at 11:13 AM, Steve F said:

Here’s an intriguing thought—I wonder how much “better”—deeper and/or tighter—Classic AR bass would have been if the Classic thru Vertical enclosures were thick-walled, heavily-braced affairs, like the Thiels and Legacy’s of the world? There have been some Thiel models with 3-inch (!) MDF front baffles and Legacy Audio is famous for its overbuilt, heavily-braced cabinets. Many other audiophile speaker companies follow suit (B&W has their Matrix, etc).

It makes perfect sense, logically: The driver produces ‘x’ amount of energy. That energy can either be projected out into the room as clean audible energy or it can be partially absorbed and diffused by a lossy cabinet with flexing panels.

Here’s a great analogy I used to use in my sales training days at BA and Atlantic Technology: Think of Carl Lewis, the great track runner. He’s in top shape, wearing the very best Nike running shoes. He runs the 100-yd dash on the indoor track. World’s record.

Now take the same Carl Lewis, in the same top shape, wearing the same Nike running shoes. Have him run the 100-yd dash at the seashore, in the soft, wet sand. The indoor track is Enclosure #1. The soft, wet sand is Enclosure #2. Lewis (the woofer) is outputting the exact same amount of energy.

Will the end results differ? Yes, obviously.

Before everyone starts howling that the 3a’s enclosure had some bracing, ok, yes it did. Many AR speakers had some bracing. But it was minimal compared to a 1990’s audiophile speaker, one that benefitted from less cost restraints and also had the benefit of computer-aided vibration analysis, accelerometer testing and the like. My Connoisseur 50’s had 1-inch cabinet walls, but virtually every AR 12-inch speaker had only ¾-inch panels, and that was reduced still further where the woofer mounting area was routed out. (And the Connoisseur 50 had a Tonegen 12-inch polypropylene cone woofer with a FAR of around 24Hz--not 17-18Hz like the 3/3a--so the 50’s bass extension was actually inferior to the 3a’s, despite the 50’s greater cabinet volume.)

The Classic AR 12-inch woofer has proven over time to be a remarkable driver. But I’d love to hear it in an enclosure that really enables it to perform to its maximum potential. We hear it now at the “97%” level. For us—the ultimate music/audiophiles—hearing it at “100%” would be sonic nirvana.

Steve F.

I own the Connoisseur 50.

2 issues that originally affected Bass as compared to say a 3a.

1. Polypropylene woofer has diff bass output than a Paper woofer.  I have performed swaps and I know there is a difference.   The POLY has an advantage in clearness, but the Lows go to the Paper woofer (most likely its Mass)

 

2  Stuffing.   WAY overstuffed.   I removed the POLYfill and replaced with fiberglass and less of it.....BASS improved.   Its deep, full and enjoyable.

I own all the BIG dog AR's....and the 50's are a Large room speaker.  They need space and can fill it up well.   Very flat response.....clear mids, and strong highs with that tweeter without harshness.   Its a good one.

 

The Ultimate ar9 would be close to what they made, except for me.........1 forward facing 12 inch and 1 side firing 12 inch.    There is benefit to forward facing and side firing......

AS far as Bass is concerned, the AR9lsi hits Harder than the ar9.  yes, I know....I OWN it too.    

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