XP-15B

Carl's AR-3a Super Mod...how does it sound? Who's done it?

29 posts in this topic

I am seriously considering Carl's Super-Mod for my AR-3a's. I think it makes a lot of sense because it addresses the two biggest problems with the speaker(though, to my knowledge, doesn't address the poor imaging); 1) the crossover point of the woofer and 2) the poor-sounding midrange driver. Carl's website describes it as being a vast improvement and sounding "SWEET!", but I'm wondering how it sounds in actuality. I really love the smooth, laid-back sound of the AR speakers. Does the mod retain that quality? Also, one of my concerns is that lowering the crossover point and introducing a small-ish midrange driver to cover the 300-600Hz region of the music will adversely effect the size, scale, and weight of the sonic presentation; make the speaker sound smaller. I'm also concerned that the midrange basket will be an issue with regard to reducing cabinet size(that woofer is already crowded enough). And finally, I'm wondering if the SEAS paper cone midrange speaker improves the imaging; in other words, is the stock speaker's poor performance in this area the result of the lip around the front of the cabinet and driver orientation, or is it because a sponge is covering the original dome? On paper, it looks like Carl has really done the work here. I'd just like to gather some specific comments on the sound. Thanks!

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I'm a little confused. If you "love the smooth, laid-back sound of the AR speakers", why change them? I have not heard Carl's speakers but here are some thoughts, FWIW:

  • Carl's "super-mod" is not a mod. It's an entirely new speaker of his own design that happens to use vintage AR woofers in an AR box.
  • He uses first-rate components. SEAS drivers are excellent.
  • The new speakers are probably excellent speaker systems but they are NOT AR3a's

So if you love AR 3a's why change? Or, alternatively, if you believe the mid-range is "poor-sounding" why do you love the 3a?

There are some outstanding modern speakers available today, with modern and reliable drivers. Carl's "super mod" may be among that group.

One more thing: I don't believe "imaging" was an issue when the ARs were developed. And for good reason--go to a symphony, jazz performance, rock concert, whatever. Close your eyes and listen to the music. Then think about "pinpoint imaging." There ain't no such thing in a concert hall. The whole point of "surround sound" was to mimic the reflections and reverberations that occur naturally in a live performance.

But, if you are looking for accurate deep bass plus pinpoint imaging it seems to me a honkin' big subwoofer (like these: http://www.vmpsaudio.com/subwoofers.htm ) and some extremely accurate "satellites" might fill the bill.

YMMV

Kent

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I don't like subwoofers. The reason to change the speaker is because although I like it's general tonal balance, I'm not very impressed with the mid-driver. It's extremely listenable compared to most speakers, but an improvement would be welcome. The other problem is that running the woofer up to 575Hz as per the original results in unacceptable vocal coloration. You can hear the woofer smearing it's way into the midrange. Carl addresses this issue. The short answer is that though I've been happy with the AR-3a for a very long time, I can no longer live with them. It's either modify them or move on to something else. I've never heard any other speaker I like, other than the Quad ESL 57. The only alternative is to build something new.

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I asked Carl about the SuperMod a while back, and he said it was designed for someone wanting the bass of the AR with a more modern sound generally. I think it's probably not feasible to build anything else using drivers available today.

A less invasive alternative might be to simply get another pair of smaller speakers whose sound you like and then disconnect the jumper to disable the 3a's mid and tweeter and use it as if it was an AR-1W.

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not to get down on all the great work Carl's done, but if I had a set of good, working AR3's from a value and collectible standpoint, I'd have a very hard time modifying them....at the very least, I'd probably just pull the woofers and build new boxes for them, so I could put them back to original very easily...

other options,

look for some AR58S's or AR91's....basically the same speaker, and the successors of the 3a, with improved mids and tweets, and the drivers are aligned on a vertical axis, so imaging is improved, the boxes are a little bigger, but they aren't as pretty as the classic 3/3a

or the AR303/303a, a modern re-interpretation of the 3/3a built by AR in the early/mid 90's, with improved drivers, and mirror imaged driver orientation, with the mid & tweeet aligned vertically, offset from the woofer axis. these also don't have any "picture frames" around the edge of the cabinet causing diffraction

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If I had a nice AR3a and I didn't like it I'd either sell it and buy another speaker or keep it the way it is and put it in another room. I wouldn't rebuild it with other parts. Sell the 3a and put that money and what it would cost to rebuild them together and buy a $900 set of speakers easily.

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If I had a nice AR3a and I didn't like it I'd either sell it and buy another speaker or keep it the way it is and put it in another room. I wouldn't rebuild it with other parts. Sell the 3a and put that money and what it would cost to rebuild them together and buy a $900 set of speakers easily.

Gene, it's seems to me this thread belongs in the mods/tweaks area. Comments like those above are certainly expected in this forum where the focus is on restoration rather than modifications.

Sorry Kent to disagree. It is a mod simply because the box and woofer are retained in the design. Otherwise, it would become a silly debate as to where a mod ends and where a 'entirely new speaker' begins. With the grilles on, who's to know what's behind them if the sound is pleasant to the listener?

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Gene, it's seems to me this thread belongs in the mods/tweaks area. Comments like those above are certainly expected in this forum where the focus is on restoration rather than modifications.

I've left it where it is for now because the OP asked if the SM would preserve the original "laid back" tone and I wanted to see if anyone would discuss ways to make the SM sound more like the original speaker, but I'll probably move it once it's played out so it'll be in the right place for archival purposes.

One question, though: since we routinely discuss the use of the HiVi tweeter with mods as a replacement for the 3a tweeter, what if someone wanted to "mod the super mod" to bring its tonal balance more in line with that of the original at some setting of its level controls? Since original 3a mids are just as old and hard to get as original tweeters now, maybe we need to expand the concept of "restoration and repair" to cover ways to get close-to-original sound using modern components.

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Let's talk about the subject at hand; how Carl's mod actually performs/sounds. All else is off-topic, though I also welcome discussion of alternatives to Carl's mod. The goal is to have the ultimate 3-way, sealed box system with a 12" woofer. It really doesn't matter to me how I get there. I'm not the least bit interested in keeping my AR-3a's original for collectible value.

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I've left it where it is for now because the OP asked if the SM would preserve the original "laid back" tone and I wanted to see if anyone would discuss ways to make the SM sound more like the original speaker, but I'll probably move it once it's played out so it'll be in the right place for archival purposes.

One question, though: since we routinely discuss the use of the HiVi tweeter with mods as a replacement for the 3a tweeter, what if someone wanted to "mod the super mod" to bring its tonal balance more in line with that of the original at some setting of its level controls? Since original 3a mids are just as old and hard to get as original tweeters now, maybe we need to expand the concept of "restoration and repair" to cover ways to get close-to-original sound using modern components.

Absolutely; an excellent post.

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I have already modified my AR-3a with SEAS T25CF001 tweeters. These were a drop-in replacement, integrate nicely and sound fine with the original crossover, and are a huge improvement over the original units. Changing the midrange driver is not so simple. I could find a replacement dome and install that unit, but that doesn't address the issue of altering the crossover point of the woofer. I don't know enough to design a crossover, so that is why Carl's mod interests me. In terms of his actual driver choice, I may experiment with different alternatives there. I could simply start with another speaker and another cabinet from scratch, of course, but I figure it's better to begin with something I like already. Really, all I'm seeking to do is drop the crossover point of the woofer to around 300Hz and use a larger diameter, cone midrange. That's it. I just don't know how to design that system. Seems like Carl has already done it.

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The goal is to have the ultimate 3-way, sealed box system with a 12" woofer. It really doesn't matter to me how I get there.

"Ultimate" is in the ear of the beholder. Whether your "ultimate" is something resembling the original sound or something completely different is probably what will determine how quickly this discussion ends up getting moved to Mods and Tweaks. :)

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I've left it where it is for now because the OP asked if the SM would preserve the original "laid back" tone and I wanted to see if anyone would discuss ways to make the SM sound more like the original speaker, but I'll probably move it once it's played out so it'll be in the right place for archival purposes.

One question, though: since we routinely discuss the use of the HiVi tweeter with mods as a replacement for the 3a tweeter, what if someone wanted to "mod the super mod" to bring its tonal balance more in line with that of the original at some setting of its level controls? Since original 3a mids are just as old and hard to get as original tweeters now, maybe we need to expand the concept of "restoration and repair" to cover ways to get close-to-original sound using modern components.

I'm glad you at least plan to move it. I'm also hoping some Super-Mod owners spot this thread and contribute their un-solicited (at least from me) comments on the sound. I wasn't planning to add mine personally; simply because they would obviously be viewed as biased. All I'll say is the intent of the SM development was to preserve the original laid back sound of the 3a's but improve on the overall clarity and imaging thru the use of high quality, modern mids and tweeters.

You alude to a mod of the SM to "bring it's tonal balance in line with that of the original". IMHO, I'm not sure that's necessary since I've heard no feedback that the 'tonal balance' was changed with the SM. Let's not speculate on what may or may not have changed. Let the owners of the SM make that call.

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I am in an AR3a restoration based on the guide mentored on this site.....new caps, new pots etc. I have always wanted a pair of AR3a's but after reading some of these posts I suddenly feel I will have a sub standard speaker when I'm done. The modded units in my opinion are not AR3a's anymore.......just a new speaker using some of the AR3a parts. If the AR3a was so good, why is it now so bad. I hope my many hours of tedious work was not a waste of time. This is an AR forum isn't it? What's so bad about the AR3a?

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I am in an AR3a restoration based on the guide mentored on this site.....new caps, new pots etc. I have always wanted a pair of AR3a's but after reading some of these posts I suddenly feel I will have a sub standard speaker when I'm done. The modded units in my opinion are not AR3a's anymore.......just a new speaker using some of the AR3a parts. If the AR3a was so good, why is it now so bad. I hope my many hours of tedious work was not a waste of time. This is an AR forum isn't it? What's so bad about the AR3a?

I can tell you exactly what's wrong with the AR-3a. First, the original tweeter is somewhat spitty and nasty sounding and has to go. Secondly, the midrange driver is not very articulate, nor full-bodied or transparent, and is somewhat hard sounding. The cabinet has a giant frame around it and the drivers are recessed into a cavity, thus introducing a host of diffraction problems. The drivers are not lined up correctly for the purpose of coherent imaging. And lastly, the original crossover design runs the woofer up too high so that there is a chesty, boomy coloration that is most obvious when listening to vocals, particularly female. The woofer clouds the midrange and you end up with a speaker that sounds like mids and highs with a booming, intrusive subwoofer.

The good thing about the AR-3a is that A- the cabinet is extremely well made. B- the woofer is decent. C- the stock midrange unit is extremely well-behaved compared to most drivers in the world and D- the overall picture is a big, warm, smooth..though somewhat opaque...sound. As I mentioned, though. There are some rough spots. They will become more and more obvious over time. The stock AR-3a, in my opinion, is completely unacceptable and will never be a reference quality loudspeaker. The only solution is to attempt something like Carl has done. Carl's mods represent, in my opinion, some very intelligent thinking.

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The stock AR-3a, in my opinion, is completely unacceptable and will never be a reference quality loudspeaker.

Carl's mods represent, in my opinion, some very intelligent thinking.

Hi there

You are about 3 decades too late to say that about the AR-3A.

It was in it's day's, a world class standard, maybe in the top 25 overall, under $10,000.00, that is.

Your tastes are not for the AR-3A, so move on to another model or brand.

Why trash a speaker thought so very highly on this site and by the hifi community in general.

As we will be less able to replace original drivers with original drivers we will need to compromise with different drivers and pots.

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Seriously, why are you even bothering?

Your criticism of the 3a is counterintuitive - a speaker you "love" for its "smooth, laid-back sound" is the sum of its parts.

Mess with the parts, and the sound will be gone - ipso facto!

This whole thing smells of troll.

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Seriously, why are you even bothering?

Your criticism of the 3a is counterintuitive - a speaker you "love" for its "smooth, laid-back sound" is the sum of its parts.

Mess with the parts, and the sound will be gone - ipso facto!

This whole thing smells of troll.

If you want to insult people and make ridiculous statements, maybe you're the one who shouldn't bother. "Mess with the parts, and the sound will be gone." Oh really? Are you sure? How much experimenting have you done with parts swapping and crossover mods on the AR-3a? Please tell us about it.

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Why trash a speaker thought so very highly on this site and by the hifi community in general.

I'm so sorry I expressed my personal opinion and your feelings were hurt. So if I understand correctly, you are wondering why I would dare make unpopular statements about/and question a product that everyone loves as-is? And I assume you also don't understand why I would want to change something that so many people favor? I'm sorry. I really don't know how to begin to answer these questions, nor do I see how this sort of direction pertains to the subject at hand and this thread in general.

Perhaps Carl is correct and the administrators should move this discussion to the alternate section where people are open to modification of existing designs. It's not my mission to offend anyone.

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If you all don't stop taking personal potshots at each other, it's going to get closed and moved into The Kitchen.

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Perhaps Carl is correct and the administrators should move this discussion to the alternate section where people are open to modification of existing designs. It's not my mission to offend anyone.

Like maybe the Kitchen? :lol:

Really--the rhetoric IS getting to be a bit strident.

XP: You need to realize that this forum is dedicated to classic AR speakers and many here view the 3a as the sine qua non of speakers. So when you trash it--both figuratively and, if you go ahead as planned, literally--people get excited.

If the Quad ESL is YOUR idea of the ideal speaker (a fine speaker I'm sure), then maybe the "classic New England" acoustic suspension box is not for you. You may be better off selling the 3a's "unmolested" and using the money to buy something more to your liking.

I recently had the pleasure of auditioning (briefly) the Carver Amazing speakers. Full-range ribbons with 4 big cone woofers for frequencies below (I think) 100 Hz. There are lots of planar and electrostatic speakers that are highly regarded, and they are all quite different from "boxes" like those discussed in these pages.

If you DO like some things about the ARs but not the tweeters, mids, or the "frames" that cause diffraction problems, review michiganpat's very sensible recommendations in post #5. I can tell you I just completed an AR91 restoration and they are fine speakers indeed. And they correct the things you dislike. However, I really like the 3a so maybe my opinion is too slanted. Gene also made a very sensible recommendation: The 3a is designed so you can power just the woofer. Remove the jumper then add a pair of mini monitors that you like.

And you're right: No one has addressed your initial question: How do Carl's speakers sound? We're still waiting for answers to that.

But remember your audience here. Let's put it this way: If I were in a position to collect cars, I'd love to have a '58 Corvette. Now you could argue that it could be "improved" by dropping in a new engine, 6-speed trans, ABS disc brakes, and so on. But it would no longer be a classic car.

Kent

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Let's talk about the subject at hand; how Carl's mod actually performs/sounds. All else is off-topic, though I also welcome discussion of alternatives to Carl's mod. The goal is to have the ultimate 3-way, sealed box system with a 12" woofer. It really doesn't matter to me how I get there. I'm not the least bit interested in keeping my AR-3a's original for collectible value.

if you're looking for that elusive "imaging", at the very least, you'll need to more or less mirror image the mids/tweets. that why I'd suggest maybe new cabs, because it's going to be a lot of pain to re-do the baffles....other than that, without ever hearing them, I'd guess you're going to have a hard time improving on Carl's supermod without a lot of time, measuring equipment, and knowledge of crossover design and simulation software (PCD)...

Carl, have you ever measured the in-box Q of the 3/3a? would it benefit from a slightly larger cabinet? just curious

with the crazy-stupid prices 3's/3a's go for on fleabay, you might be money ahead selling your "originals" (especially if you have the original tweets to go with them), and pick up a pair of AR 12" woofers and build new cabs, or some AR 1's that the altec driver has been removed from, or some 1W's (woofer only, the rest of the baffle is free to cut as you like)

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if you're looking for that elusive "imaging", at the very least, you'll need to more or less mirror image the mids/tweets. that why I'd suggest maybe new cabs, because it's going to be a lot of pain to re-do the baffles....other than that, without ever hearing them, I'd guess you're going to have a hard time improving on Carl's supermod without a lot of time, measuring equipment, and knowledge of crossover design and simulation software (PCD)...

Carl, have you ever measured the in-box Q of the 3/3a? would it benefit from a slightly larger cabinet? just curious

with the crazy-stupid prices 3's/3a's go for on fleabay, you might be money ahead selling your "originals" (especially if you have the original tweets to go with them), and pick up a pair of AR 12" woofers and build new cabs, or some AR 1's that the altec driver has been removed from, or some 1W's (woofer only, the rest of the baffle is free to cut as you like)

Mirror imaging won't help acoustic imaging. Been there, done that with a pair of AR-1W's.

In-box Q will vary with stuffing type and amount. Typically, I get in the range of 0.6 to 0.9 when I measure it. Don't know if a larger box will help. OTOH, IIRC, the whole objective of AS design was smaller boxes. That's what brought E.V. fame and fortune.

I've just finished a new personal 2-way vented mini-monitor project involving some high end drivers in 1/2 cu. ft. box that image great and would look great sitting atop a pair of handsomely refinished 3a cabs with woofers. As they stand now, the 2-ways get down well below 100 hz. and might be too much bass when coupled with the 3a woofers without some minor crossover changes to raise F3 on the MM's. It's doable, but not without some tweaking. In fact, I might try them out with the 3a's I have. I'll just turn off the tweets and mids and see and listen to what happens. Right now, they're sitting atop some KLH-5's awaiting restoration.

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Mirror imaging won't help acoustic imaging. Been there, done that with a pair of AR-1W's.

In-box Q will vary with stuffing type and amount. Typically, I get in the range of 0.6 to 0.9 when I measure it. Don't know if a larger box will help. OTOH, IIRC, the whole objective of AS design was smaller boxes. That's what brought E.V. fame and fortune.

interesting....I always assumed having vertically aligned and mirrored drivers (or at the very least, mirror imaged drivers) for the midrange on up was necessary to get any sort of "imaging", especially nearfield. do they image better if placed on their side, so the mid & tweet are more closely aligned vertically? again, just curious....

just wondering about the Q, as I've heard people who've measured Large Advents even after heavily stuffed only getting them down to ~.8 Q, and complain about the 1.5 decibel bass hump in them....my thinking with the bigger box was also to give more height to allow for the mid/tweet to be aligned on the same vertical axis, to improve imaging, ala the 303/303a....

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interesting....I always assumed having vertically aligned and mirrored drivers (or at the very least, mirror imaged drivers) for the midrange on up was necessary to get any sort of "imaging", especially nearfield. do they image better if placed on their side, so the mid & tweet are more closely aligned vertically? again, just curious....

just wondering about the Q, as I've heard people who've measured Large Advents even after heavily stuffed only getting them down to ~.8 Q, and complain about the 1.5 decibel bass hump in them....my thinking with the bigger box was also to give more height to allow for the mid/tweet to be aligned on the same vertical axis, to improve imaging, ala the 303/303a....

Over 80 posts at this thread on imaging http://www.diyaudio.com/forums/multi-way/137646-how-do-you-get-good-imaging.html and no mention made of driver placement on the BB as being a key contributor. Some heavy hitters posted here (much more so than I, for sure). Geddes, Olson, Bateman, etc...

BTW, thanks Gene for moving the thread.

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