tysontom

>OK, I'll bite - you have me curious. My impressions are from owning both, although some of the arguments are moot as at extended levels either box will drive the tweeters into protection - the limiting factor. I'd be doing A/B listening comparisons right now to confirm (I am actually wired for that), but my wife is home ;). In my system, if I were running only the 1590s, I would want a subwoofer. With the 980s, I run a sub only for protection... Jeff, I think you are confusing deeper bass with "more" bass, as in the 40-80 Hz range, such as double bass or guitar bass or what have you, and it sounds to me like you are getting a peak output in the 980 in that region above resonance, and likely you are not getting this same bump in output in the 1590. And by the way, you would never need a subwoofer with a properly working 1590, not with its bass extension. That said, I think the 1590 has a lower "Q" (more damping) at resonance than the 980, thus making the bass seem to you to be a bit weaker when compared to the 980 side-by-side. This is the only explanation I can give you for you feeling that the 980 is stronger in the bass than the 1590. If you carefully matched the output level from both the 980 and 1590 speakers (only one channel at a time) at around 300 Hz, and then swept frequency downward with a audio oscillator (a high-quality one such as a Hewlett-Packard instrument), you would see that output continues further into the deep bass with greater linear output in the 1590 than with the 980; it's that simple. If you are driving the tweeters into protection with a 200-watt amplifier, you are likely clipping the amplifier, causing excessive output into the tweeters; you are essentially over-driving the amplifier. The 1590/2 can easily handle 500-watt peaks, and the 980 can handle 300-watt peaks, so there is no reason to think the speakers are in protection mode with this amplifier setup unless the amp is over-driving. You might also have your bi-amp setup incorrectly wired; in any event, there are more opportunities for problem with bi-amping something like this than by simply using a larger single amplifier through a single input connection. Most importantly, bi-amping does not improve sound quality; it simply allows more power to be applied to the speaker. Bi-amping also increases the opportunity for mistakes and out-of-phase wiring issues. >I had attributed the difference to excursion, curious to hear they're similarly spec'ed. Always appeared visually different to my eye, and recall the 980 as readily able to blow out a match ;). Yes, the voice coils on both of these systems are very similar, and both have about the same excursion. To keep efficiency at decent levels, ADS would never have gone overboard on the excursion travel on the 12-inch woofer in the 980. If they had used a longer voice coil to increase the excursion to 1-inch, for example, the efficiency of the system would have dropped by half, and the midrange and tweeter drivers would not properly match the efficiency of the woofer. It would make no sense whatsoever to design a speaker in that fashion. >As to the ear, the other aspect is cabinet volume vs driver area - 980 has the advantage there: L980 = cabinet volume 3838in^3, driver area 113in^2 = ~34in^3 per driver in^2 L1590 = cabinet volume 4227in^3, driver area 157in^2 = ~27in^3 per driver in^2 This argument isn't valid because it does not take into account the individual speakers' parameters, such as damping, free-air resonance, and so forth. Remember, the two 10-inch 1590 woofers have the approximate radiation area of a single 15-inch woofer vs. the 12-inch woofer in the 980, and with similar excursion, the displacement-volume numbers are in favor of the 1590 >I presumed the dimensions of the cabinet should matter too, as there is wave action (and reaction) inside the box as well. Also please realize the power handling for the 1590 was across two drivers, same rating on L980 for *one*. Granted, it's probably commonality in the crossovers that lead to the consistent rating, if you are sure the voice coils are that similar... >Granted frequency specification is similar (I recall a modest edge to L980 LowF) and I do not have matching A/B documentation, but the L1590 spec's down to 28db at +/-3dB. Attached is a sweep from an L980... I don't understand what you mean by "wave action and reaction inside the box." That is a new one on me. The power-handling on the L1590/II is 500 watts, and the 980 is 300 watts, peak. The earlier spec for the first 1590, using slightly different woofers, was also 300-350 watts peak, but the later series II version is 500 watts. The 980 has always been 300 watts peak maximum power. Note, again, that the low-frequency edge is clearly in the 1590's favor with its lower bass resonance! This is the physics of what is happening; it's not my conjecture. By the way, the response graph you attached is not the (acoustical) output of an ADS L980. It is the electrical current or voltage across the crossover. It shows the energy path through the crossover, but not the acoustical output of the speaker itself. It therefore does not show you anything about the low-frequency output of the speaker itself. >As to pricing, I think the market was not really seeking office-fridge sized bookshelves ;), and the stands added some to the equation. I believe studio reference was the big target for the L980s. The real market was towers, and buying new then the 1290 would have been the value leader with the wifely acceptability thrown in. The ADS 980 was designed to be a competitor with the likes of Acoustic Research's AR-3a, AR10Pi, AR-11, Large Advent and so forth, but it was marketed to be a "studio monitor," to enhance its place in the speaker market place, and insofar as it was priced slightly above those speakers. It was somewhat larger to get a low bass resonance, which was set a around 40-42 Hz, similar to the AR-3a/AR-11. The 980 was also priced much lower than the 1590 as well, so you would expect it to not perform quite as well. Let me finish my comments by saying that I don't doubt your admiration for the 980. It is a wonderful loudspeaker, but you should understand that the 980 is not equal to the 1590 in low-bass output, extension or low distortion. I have always liked the sound of the 980, and I think it is one of ADS's better efforts. Compared with the 1590, it might be close, of course, but not equal and certainly not superior. I have spent this time simply to try to set the facts straight in this discussion about these two speakers. I am not trying to criticize or dispute your impressions, but I wanted to be sure that anyone else reading this would realize that the L1590 is a more potent system over a wider range, for good reasons, than the L980. --Tom Tyson

What you are saying isn't possible. Maybe it feels like more bass to you, and perhaps the 980 is more efficient or has a lower impedance (making it louder for the same volume control setting) but the two 10-inch woofers in the 1590 can move as much air as a single 15-inch woofer, and we both know that a 15-inch woofer is larger and can move more air than a 12-inch woofer, all things being equal (voice coil excursion, etc). The 980 may also have a bass rise down close to resonance, and this would make it seem to have more bass output, but this is not like ADS to have this problem. The 1590 woofers also have a lower resonance than the 980, so the 1590s can also get lower in bass. Both the 1590 woofers and the 980 woofers use a 2-inch-diameter voice coils with about the same linear excursion. So do the math: the 1590 is inherently more potent in the bass than the 980. I'm not saying that for one reason or another, you are not actually hearing more bass from the 980; I'm just saying that technically, the 980 cannot move as much air as the 1590. The 980 is more akin to the Acoustic Research AR-3a in bass output; both of those speakers are closer in performance with about the same resonance, same woofer size, etc. More importantly, why would ADS have ever designed a large bookshelf-type speaker (studio-type) in their product line that costs significantly less than the 1590 to have better bass output? That doesn't make sense, and ADS would have been ridiculed in the industry if this were the case. --Tom

Additional thoughts on Tmc's AR-2axs: Tweeters: · Measure tweeters for dc resistance with voltmeter to determine if they are the correct impedance (i.e., ≈2-4-ohm dcr would be 4-ohm version for AR-11, 10Pi; ≈5-6ohm dcr would be correct 8-ohm impedance for AR-2, AR-5, AR-12). · If you intend to keep the black-fabric-dome tweeters, check with Roy C about any changes made to crossover or changes that need to be made to crossover to make tweeters compatible. The tweeter level control will need to be somewhat lower with this tweeter compared with the original, as it is about 3 dB more efficient. Take a close-up picture of the tweeters for us to study the detail of the dome; Roy is probably correct about this being an AB Tech replacement tweeter. I have an old, but comprehensive AB Tech part-number list on file, and I can cross-reference the tweeter if you also can find the part number on the back of it. · To keep the original AR-2ax "tonal balance," try to locate two original-style AR-2ax (AR-5 and AR-LST/2) 8-ohm tweeters, either front-wired or back-wired. If the crossover had been changed by the service company in the 90s to accommodate the new black-cloth dome tweeters, be sure to return to the original crossover values. Midrange Drivers: · There do not appear to be any issues with these original 3½-inch midrange drivers, and you probably don't need to do anything to them. These were great midrange drivers, and this is one reason why the AR-2ax has such good focused-imaging properties when compared with the AR-5 or AR-3a, etc. Much voice and music intelligibility in the AR-2ax is due to these drivers. They don't disperse the sound as well as the AR-5 or AR-3a 1½-inch dome, and thus the AR-2ax is definitely not as 3-dimensional as the other two, but in terms of clarity and image stability, the 2ax is great. Woofers: · It is possible that these woofers were the last of the yoke-magnet versions, but these could have the larger ferrite-magnet assembly. Sometime during the 1973-1975 time frame, AR updated the earlier AR-2ax woofer (and the 8-inch woofers as well) to the new magnet assembly Either way, the voice coils, cone materials, acoustical parameters and so forth should be very close, and the bass performance should be nearly identical. · The woofers will have a free-air resonance of ≈26Hz, plus-or-minus, and the AR-2ax system should have a system resonance of ≈58 Hz, plus-or-minus. It is possible that the "refoam" job done by your service company was botched, and that the surrounds are a bit too stiff. Remove the woofers and gently push them in to check for compliance to see if they move freely, which they should. If they feel stiff and resistant to movement, you may have an issue with compliance; however, that is very unlikely. Normal AR-2ax bass response will be about 3 dB down at 48 Hz, which means that you should sense relatively strong bass output down into nearly any frequency where there is music. Bass drum and double-bass sounds come through quite clearly with the AR-2ax system, and you should be able to slightly "feel" the bass on this low-frequency output—not as strongly as with the AR-3a, of course, but not too far from it. · Proper bass performance is completely dependent on where the speakers are mounted in a listening room. The AR-2ax speakers should be mounted, either vertically or horizontally, on a shelf or stand at least one foot above the floor, against a wall. The speaker should not be located adjacent to a large opening into another room, such as a large archway. One speaker can be mounted in a corner. That is, the proper flatness and extension in bass will be determined by the speakers' placement in the room, particularly when mounted up off the floor but snugly against the wall (the front wall or facing wall into your room), and better yet with perhaps one AR-2ax mounted in a corner if the room simply doesn't support bass very well. If you pull the speakers out from the wall into the room, bass response will definitely get weaker, leaner and suffer accordingly. It is probably best to mount the speakers along the "short" wall rather than the "long" wall of a room, as this supports bass better as well. · Woofer polarity is also of paramount importance. If one woofer in one speaker is wired out of phase with the speaker in the other cabinet for some reason (service technicians sometimes don't realize this mistake), the bass will have a disjointed, diffuse sound, and low frequencies won't be properly reproduced. To quickly check polarity of the woofers in the speaker cabinet, you should enlist the help of your husband to do the following: solder a short length of wire to each end of a type-D flashlight battery. Remove the grill panel from the speaker, and have one person observe and the woofer. Then, take the stripped ends of the wires and touch the positive (+) terminal battery wire to the No. 2 terminal (this is the positive input terminal) on the back of the speaker. Observing the woofer cone, it should move out away from the cabinet. Then do the same thing to the other speaker, and it should also do the same thing. This way you know that the speakers have the same woofer polarity. It is also possible that something is miswired in the crossover or the woofer leads were reversed when the tech re-foamed the woofers, but check this first. Also, be certain that the speaker wires from the amplifier are in the proper polarity, too, such as the positive amplifier terminal is the same on both speakers. It makes no difference if the negative connects to the No. 1 or No. 3 terminal as long as both speakers are wired the same way; however, it's always best to try to keep the positive to the positive and the negative to the negative just for neatness and clarity. · Be certain that the woofer is sealed properly in the cabinet. If gaskets are used and are in good shape, you are likely sealed well for the proper acoustic-suspension seal. Air leaks can occur at the midrange and tweeter, too, so check everything for a good acoustical seal. The box does not have to be air-tight; this is an "acoustical seal" for the frequencies in use, not a hermitic seal, so if you gently push in on the woofer cone, it should not immediately return to the center position. It should slowly return to the center position within about a half-second or a second. This effect is not as pronounced on this speaker as with the larger AR-3, AR-3a, etc., but you can tell if the woofer has a good seal. · The fiberglass material in the speaker is likely fiberglass, not rock wool, in your version of this speaker. You will recognize the material once you open the speaker. Rock wool was used back in the middle 60s due to a shortage of fiberglass, and it works equally well for the purpose, but it is harder to handle. Be certain that you have the same amount of fiberglass in both speakers, and that it is distributed pretty much the same way in both speakers. Hopefully, the service people didn't change any of this. Speaker Grills: · The replacement grill material you use appears to be dense and somewhat thick, and it may not be acoustically transparent. The original linen grill material was dense enough to block the appearance of the drivers behind the grill, but open enough to allow sound energy to emerge without too much degradation. If you take your grill panel and hold it up to the light, such as window light or the sun, etc., you should see at least 50% light through the grill when compared with pure light. If it looks like the grill is blocking more than this, you should probably consider an original grill material. AR ran out of the original beige-linen grill that was used for all AR speakers in the Cambridge era from around 1965 until 1972, and then AR went to a thicker, white-linen material that was okay but not nearly as transparent as the original. Crossovers and Level Controls: · It is possible that your crossover networks are still within spec. There is no way to know for sure other than by disconnecting one lead of each capacitor and measuring the capacitance of each capacitor and determining if it is over 15% out of spec. The chokes (coils) are rarely out of spec, of course, unless thermally damaged somehow, and you would know this immediately. You could, of course, go in and change all of the capacitors to be sure, but that is overreacting. I have found many old AR speakers that had crossovers still fairly close to spec. Also listen to your speakers to see if you detect any distortion or anything unusual in the output of the drivers. Again, Roy C is a great resource in helping you determine what you may need to know here. · Level controls are the primary source of headaches in these old AR speakers. By the time your speakers were made, AR had adopted an improved version of the Aetna-Pollock level control that had been used for so many years, and the wiper-spring tension was significantly increased. This control is characterized by the aluminum shaft end on the back side of the speaker, and I suspect that you have this version, and that is has not been removed and replaced. Even the improved control did not completely stop the contact issue. If the controls still work, even if scratchy, the best thing to do would be to get some contact-cleaner spray and try to get it on the wiper surface. To some degree, you can let it run down the shaft from the outside, but getting inside is the better way to do this. You can also turn the control back and forth repeatedly to "clean" the contact surface if you still have fairly good electrical contact. As a last resort, you could remove the controls and manually burnish and polish the surfaces to improve the contact. This usually always works as long as the controls haven't been badly corroded over time due to moisture, etc. --Tom Tyson

TMC, your AR-2axs were made after 1973, likely in '74, so the invoice you have would be "1975." If you look as the clerk's sloppy handwriting, you can see that it is a "5." AR moved from Cambridge to Norwood, Massachusetts in 1973, and your speakers are definitely Norwood models. The label on the back does show 10 American Drive, and this would be Norwood. Anytime you see the blue label on the back, you also know it is a Norwood-built version. Norwood versions also had Velcro-attached grills, and your's have that feature. These also still have the "tweeter terminal strip" (adjacent to the incorrect tweeter), and these attachment points were present on a lot of the early Norwood AR speakers. In this case, AR had moved to back-wired tweeters, but they probably had a lot of baffle boards (the front panel that holds the speakers) with the earlier front-wired terminal strips. This strip would not have actually been used unless these had some left-over front-wired tweeters. In any event, it has nothing to do with the quality of the speaker! I am pretty sure that the tweeters are the later AR-12 (or possibly AR-11) tweeters; i.e., these tweeters were used in the 1976 AR-12 if they are the 8-ohm version, or they are the AR-11/AR-10Pi versions if they are 4 ohms. In any event, they are not correct unless a crossover adjustment has been made for them. You should first determine the impedance, and you will need to remove one or both of them and measure the dc resistance ("dcr"). The proper dcr measurement should be in the 6-ohm range; if they measure 2.5-3.0 ohms, they are the AR-11/10Pi versions. All of these 3/4-inch tweeters will mount in the same cutout, so it is very easy to interchange tweeters. It is likely that these black tweeters are significantly brighter in output than the original versions, and this isn't always better. If you can attach a close-up picture of one of the tweeters, that would be helpful. Anyway, you have a wonderful pair of speakers, and you should definitely rebuild them as close to original as possible. Properly working, a pair of AR-2ax speakers is very accurate and natural-sounding, and except for the last 1/3-octave of bass, they are the equal of the bigger AR bookshelf speakers in smoothness and overall sound. Because of the 3-1/2-inch midrange cone driver, the 2ax actually images slightly better than the AR-3a and AR-5, but lacks a little of the spaciousness of the latter! Anyway, if you do stay with the retrofitted tweeters, contact Roy C. on this site for advice on the best way to correct the crossover for the tweeters. For the best acoustical (or "spectral") balance, you might want to try to locate some original 8-ohm AR-2ax 3/4-inch dome tweeters. You can find either an early set of AR-2ax (or AR-5 or AR-LST/2) front-wired tweeters or a pair of later-model back-wired tweeters, and you can make them work with your cabinet either way. Quite frankly, the early front-wired tweeters were somewhat better built, but either type will work. Roy C can also help you get these old tweeters re-wired with new voice coils and suspensions. We will all help you in any way possible to get these back to their original sound! --Tom Tyson

Huh? Are you saying that the L980, with its higher-resonance enclosure and single 12-inch woofer, has great power-handling, etc than the L1590? That does not make sense, but it's entirely possible that I didn't understand what you were trying to say. --Tom

Frank, the speaker stand, shown in my picture, was the first such AR speaker-mounting device and was priced at $30 per stand, not particularly cheap at the time ($30 in 1959 would be $256.45 in 2018, multiplied by 2). This was shipped directly from AR to customers as a kit with the two veneered plywood shelves and four wrought-iron legs with attachment point underneath, hardware and tool. The legs were solid wrought-iron one-piece legs in black, and the bottom of the legs had a plastic protective piece added. This stand was actually quite handsome and was very sturdy and capable of supporting the weight of any of the AR bookshelf speakers mounted horizontally. It was designed to be placed back against the wall. Following the stand was the first speaker base, a solid-walnut, 2-piece design, also quite handsome. Later, an inexpensive vinyl-covered MDF "speaker base" was offered to allow the AR speakers to be brought up off the floor at least a minimum of ten inches. This base was inexpensive, and it looked inexpensive, available only in walnut-grained or ebony vinyl. It was always important to get any of the AR "bookshelf" speakers up off the floor to prevent them from sounding boomy. In the mid-1970s, AR brought out a welded-steel stand that was powder-coated in black, and this was designed to fit primarily the Advanced Development Speakers (AR-10Pi, AR-11, AR-12 and AR-14). --Tom Tyson

The 1960 mounting of the AR-3s on speaker stands on the roof of the Music Room:

I think this ADS L1590 thread has become the most widely read topic in all of the Classic Speaker Pages! Up above 76,000 reads, and that is amazing. Says a lot about this remarkably fine loudspeaker, at or near the top of ADS's engineering efforts. The 1590 woofer loafing along at relatively low power at 20 Hz. Much more excursion left to go! One of the hallmarks of the ADS 1590A was the robust pair of 10-inch woofers -- each with 2-inch voice coils and lots (5/8") voice-coil overhang -- was deep bass with very low harmonic distortion. This speaker was one of the best at reproducing clean deep bass with low distortion. --Tom Tyson

"I was there in 1974 also and the sound did not by any means fill that huge place up with sound. In fact the sound level emanating from that far corner was a faint output which sounded like a small high fidelity system playing in the far corner of a huge room. The AR speakers were mounted on top of a temporary looking room which was and housed AR’s demo room. If standing in the center of the huge hall, one had to get very close to that corner that AR was using in order to hear any sort of high quality sound coming out of two speakers into that huge hall where they were lost if in any attempt to fill the hall. If anything it was a teaser and beckoned a person who may have been interested in hi-fi (me) to walk closer as I did and I was met with a somewhat faint audible ‘hi-fi’ sound. That huge hall had to be thousands and thousands of cubic feet in size. There was no way two or even multiples of AR-3’s would ever fill that space." --FM ________________________________ Frank, First of all, I am almost certain that the AR-3s were not still mounted on the ceiling of the AR Music Room at the end of the room's existence, which was in fact 1974. They were actually placed up there near the beginning of the room's existence in 1959-1960, and they were later removed, so what you heard was almost certainly not the AR-3s playing Christmas Music, the only time of the year that they were used. Consider, too, that the AR-3a was the main attraction in the Music Room by the fall of 1967, and the AR Amplifier was added to the room in 1968, so it would not have made sense to continue with the AR-3/Dyna Mark III combination fifteen years later anyway. Why would AR even consider keeping the AR-3 on the roof of the building at that time? Most likely what you heard in Grand Central Terminal was music from some other location. The AR-3s were mounted horizontally. splayed outwardly, on AR Stands on top of the building on the West Balcony of the terminal and connected to two Dynaco Mark III amplifiers. The sound output was fairly high, causing the Mark IIIs to nearly clip (>140 watts peak/channel) at times, and the AR-3s could definitely be heard throughout the station (I've heard it during those early years), but it was very diffuse and could only be heard clearly when there was not a rush of passengers and people milling throughout the huge main concourse. Listening to the AR-2a, AR-3 and AR-1 during the early years in the AR Music Room. --Tom Tyson

I believe the serial number for this one is C 23638, not 438. You got a great find, particularly if all drivers are functional, which is very likely. Those cabinets are rough, but the drivers look good and have not been removed, which is a definite plus. --Tom Tyson

Two types of AR-LST stands I have used in the past, one a wall mount and the other a floor mount to get the LST up approximately 36" or so from the floor: Tom Tyson

The Bose 901 may not have been the best-selling loudspeaker of all time; that honor probably goes to the Dynaco A25 or perhaps even The Advent Loudspeaker (original version), but the Bose 901 was—with the exception of the low-production Klipschorn—in production longer than any other commercial system, nearly 50 years. It’s interesting that the 901 was extremely maligned over time; for one thing, it could make some other speakers in a showroom seem very anemic, and many dealers “bad-mouthed” the speaker unmercifully. The 901 had equalized deep bass down to nearly 30 Hz, albeit accompanied by an increase in 2nd order (generally less objectionable) harmonic distortion, and few speakers could reach down that low. With an appropriately huge power amplifier such as Bose’s own 1801, the 901 could play at volume levels approaching ear-bleed, and few other speakers could come close without damage. But in terms of generally good overall sound quality and unsurpassed “spaciousness” in the sound field, the Bose 901 was a fine loudspeaker, and it was more than good enough for most high-fidelity audiophiles. It always sounded effortless playing classical music. It was certainly the product that energized the great Bose Corporation to become one of the very largest, and most-successful, consumer-electronics firms in the world. Bose revised the 901 over time to make it easier to mass-produce to improve quality, up the efficiency (one major problem with the early sealed systems) and improve profitability by eliminating much of the hand-labor involved with the original versions. —Tom Tyson

Yes, better late than never! I didn't realize that I could edit the actual subject line itself, but the originator has some slight latitude. What files do you need? I think I dropped some files after my file load approached maximum. I can replace any that are needed for download. --Tom

Also, check the number of "views" on this one topic! More than 72,000! There are very few topics that have been viewed this often. This shows the popularity of ADS' L-series tower speakers, especially the L1590. --Tom Tyson

Notice any difference in this topic? I corrected my early logo mistake: "a/d/s/ L1590 to the correct version, ADS L1590!" ADS didn't change to the more avant garde "a/d/s/" until the late 1980s with the M-series. --Tom Tyson

Hi Mike, Thanks for your message! Any information (particularly images) would be great as I plod along with my project. I would love to see what you have collected. I notice a couple Hewlett-Packard instruments stacked together in the background. Send me a message offline, too. Thanks, --Tom

lakecat, I think your comments about the ADS L980 do reflect a common sentiment about the spectral balance of the ADS woofer, midrange and tweeter. These are accurate and analytical dome drivers, but they have a lot of output, and this sometimes comes across as being a bit forward-sounding. Also, some ADS woofers tend to be slightly over-damped in some instances in an effort to avoid "warmth" in the sound, and this makes the speakers seem dry and lacking in bass in some respects. I don't sense this dryness when I listen to my 1290s, but it may be that the 980 is that way since it was intended to be used in recording studios and high-end installations. Also, you are going to be hard-pressed to find a woofer that can surpass the AR-3a in the region from 500 Hz down to 30 Hz or so; it is nearly perfect in this range with very uniform output and extremely low harmonic distortion. I would love to see the measurement curves on the L980, but I'm sure it is excellent, nonetheless. I don't know the Q of that system or its actual bass resonance (fc) frequency, but I think the latter is around 41 Hz or so, similar to the AR-3a. I suspect that the Q is somewhere between 0.7 and 0.5 judging by the "dry" sound. The AR-3a is 0.7 to 1.0, approximately. I have found that the best place to listen to ADS speakers (in general) is in a large, well-padded living room with little slap echo. A "live" room can be difficult sometimes, but in the right room these speakers can sound great! In any event, ADS always tried to get the most accuracy from their products, and their design and production-control methods for the dome tweeters was outstanding, and there is rarely any variation in the sound. It is unfortunate that most of the ADS (and later a/d/s/) models did not get widespread critical acclaim and reviews in the way that AR speakers did through the years. Julian Hirsch did give the 1290 very high marks, and Julian was basically very fond of Acoustic Research products through the years. Overall, AR received many glowing reviews and tests, and ADS was not tested as much for some reason, yet each design was superb in its own way. Consider this interesting tidbit: ADS manufactured (for the most part) their drivers for the 1090, 1290 and 1590 in-house in the Wilmington, MA facility; the cabinets were made in Germany and shipped to the US! It's amazing that this could be considered economical, but somehow it worked for ADS at the time. --Tom Tyson

Glitch, Thanks for your interesting comments and for the part numbers as listed. The L980 and AR-3a are very similar, of course, in layout and function. Both are low-resonance acoustic-suspension designs with dome midrange and dome tweeters (both ¾-inch) and similar crossover characteristics. A direct A-B comparison would be very interesting. I've never read a report on a comparison between these two fine speakers, but I think there were far fewer L980s out there than AR-3as or its later iterations (AR-10, AR-58, AR98Ls, etc). On the other hand, I did compare my L1290/2 and AR-3a speakers, and I can comment a bit on that comparison. It was difficult to compare them, as the optimal spot for the 3a is flush in a bookshelf, and the 1290 has to be out slightly from the front wall, toed-in a bit, to be positioned optimally. I am fond of both the 1290/2 and the AR-3a; unfortunately, the 50-year-old AR-3a dome tweeters are beginning to deteriorate, causing lower output from the domes. Perhaps a better comparison for the L980 would be an AR-10π, AR58 or AR78 with their cloth-dome tweeters. In the bass, the AR-3a has a slight advantage in low-frequency extension, but the differences are subtle and only noticeable on organ or electronic music or jazz with prominent kick drum or orchestral bass drum. The 1290 isn't deficient, but it's slightly less prominent and less "warm." Part of this difference, too, is the relative balance between the woofers and high-range drivers in the ADS vs. AR speakers. AR's midrange and treble are more reticent, on-axis, and the output is slightly downward-sloping in the higher frequencies; this is not the case with the 1290, as it is quite uniform throughout the midrange and treble. Therefore, the 1290 is more "forward" and brighter-sounding than the AR-3a; however, well back in the reverberant listening area, where the predominant sound is reflected, there are fewer differences in the balance of the sound between these two systems, mainly because the dispersion of the 3a's hard-dome tweeter is somewhat wider than that of the soft-dome ADS tweeter. Therefore, the excellent power response of the AR-3a makes up for its on-axis reticence. The AR-3a's 1½-inch dome midrange also has better dispersion than the 2-inch dome in 1290, but the clarity of the output from the ADS tweeters is just about unsurpassed. Both of these speaker systems are so good that it would be hard to find too much fault with either system. Therefore, I never found a favorite. The ADS seems to bring you a bit closer to the music and there is that outstanding midrange and treble clarity. The AR-3a is more laid-back, but it has a smooth, very natural reproduction of midrange and treble. In the bass, the AR-3a is more solid, but the differences are subtle. Perhaps a draw. —Tom Tyson

Hi Glitch, Great message. Regarding the L980s, I wonder how it would compare, ultimately, with the AR-3a? There would be a fairly close resemblance in terms of bandwidth and spectral balance, except that the ADS speakers would have noticeably greater upper-midrange and treble output in comparison with the AR-3a. As for accuracy, it would be a close call, with both speakers representing a very high level of smoothness and low distortion. I am quite surprised that at least one of ADS's later designs didn't make it to Stereophile magazine's "Best Top Speakers of the Past 40 Years." You just never know how these things will go, but there were several ADS speaker that could easily have outmatched several of the magazine's top picks. Of course, Stereophile magazine (much like TAS) reviews and articles were heavily weighed on subjective evaluation and judgment, and the results were usually more emotional than objective. https://www.stereophile.com/content/40-years-istereophilei-hot-100-products-page-7 By the way, you are exactly right about the different part numbers for the ADS 1590 and 1290! For some reason I thought the tweeters were identical, but it's not the case. According to what I found in my files: L1290: tweeter 206-0117, mid 206-0211, woofer 206-0349 L1590: tweeter 206-0119, mid 206-0213, woofer 206-0350. I'm not positive that these are the Series 2 part numbers or the original series, but I think so. You may know for sure. --Tom

Hi Glitch, These were very interesting comments, especially the contrast between the L1590 and L1290. Sorry I'm so late in commenting on them, over a year later! I think the different crossovers and slight differences between the 2-inch dome midrange drivers between the two speakers probably accounts somewhat for the difference in perceived transient performance. Except for the more robust L1590 woofers, I don't understand why the L1590 has greater overall power-handling capability than the L1290, especially since the 2-inch dome is driven to a lower crossover frequency in the big speaker. How this could represent greater power-handling, I don't know! The upper end should be equal across the board. Thoughts? Also, do you have any copies of your measurements on these speakers? I would love to see them if you have saved any. If you could do some impulse tests—even the old transient-response tests—it would be interesting to see if there are any differences in the two speakers' midrange performance. I would not think so, as both use the same magnet and voice-coil assemblies. Did you actually find the Ferrofluid dried up in the 1290s? Was it partially dry or what was the case? Also, as for imaging, I would think that the L1290 and L890 speakers, with their higher midrange crossover, might image slightly better than the 1590, but the latter would have somewhat greater "spaciousness" in the reverberant field. More three-dimensional in the far field. These were all great speakers! Do you also have a pair of L980s? —Tom Tyson

AR speakers and Dynaco electronics were frequently paired, and David Hafler of Dynaco (founder) was good friends with AR founder Ed Villchur. AR usually recommended Dynaco amps for use with their speakers up until the late 1960s, at which time the AR Amplifier was introduced. AR used Dynaco Mark IIIs and Stereo 70s, as well as PAS-3x preamps, to drive most of the equipment in the AR Music Rooms. During the Live vs. Recorded concerts with the Fine Arts Quartet and so forth, Dynaco Mark III amps were used as well. The Mark III could hit undistorted peaks of 120+ watts, so it provided ample power for most uses. On the other hand, there were many McIntosh MC 60s and MC 275s, as well as Marantz 9Bs and 8s used to drive AR speakers, too. The AR-3 sounded great with the Marantz 9B amplifier at high-output levels! --Tom Tyson

Michele, Klaus and Roy, When the fuse is blown in an AR-LST, rather than have a "totally silent" speaker as you might expect, there remains a high-impedance path through the autotransformer causing a 30 dB drop in system output, but the speaker is not completely shut off. The older Buss Fusetron FNM fuses do sometimes deteriorate over time and can open partially or completely, causing this sensation. --Tom

We've talked about the AR Music Rooms several times in the past. AR had two "permanent" music rooms, one in New York City on the west balcony of Grand Central Terminal and the other room was located on Brattle Street in Cambridge, Massachusetts. A third room was temporarily located at the World's Fair one year. The New York location was, by far, the most-visited of the rooms with over 100,000 visitors each year. No sales were ever allowed at any of the music rooms, but any and all questions about high-fidelity sound equipment were answered objectively, and the equipment was demonstrated for any visitor. The main AR employee in the New York Music Room was Walter Berry, but prior to that many AR executives began their careers working in these music rooms. Gerald Landau, marketing director, and Victor Campos, customer services, started their careers in those rooms. On the roof of the building was a pair of AR-3s, originally driven by two Dynaco Mark III amplfiers, to provide music throughout the huge railroad station! At times, the amplifiers were driven to near-clipping levels, but there were never any damaged AR-3s to my knowledge. The AR Music Room was a fabled venue for high-fidelity music. The New York room was opened in July, 1959 and was closed in 1974 about a year after AR moved its plant to Norwood. --Tom Tyson

Adams your last sentence was not necessarily an incorrect assumption (as I hurriedly stated) except to say that AR knew from the beginning that driving the 12-inch woofer too high represented a slight compromise. However, with the AR-3a, that compromise was reduced significantly, because the 12-inch woofer works well on- and off-axis up into the 500 Hz region. The cone is not terribly directional in that region, but around 1000 Hz, it is becoming more directional. Obviously, 200 Hz is better yet with the main consideration of the 8-inch LMR handling much of the lower midrange, protecting the midrange dome and increasing power-handling capability.

>The point has been made, that the AR9 side firing woofer configuration may have forced a 4way design to keep the LMR in the front. [incorrect assumption]. >The AR9LS, LSi and 98 all had forward firing woofers but AR kept the crossover at 200hz. I am speculating here with no help from Google---------- in tall columns with large spatial separation between drivers a high crossed woofer at the bottom of the column will make some human voices and instruments seem to move up and down the column. The same should be true today. Even though an 8 or 6" speaker can carry a large band of frequencies, when they are used in multiples as woofers in tall columns with a port, the crossover must be placed low enough to prevent this illusion of relocation. The same applies to powered sub-woofers and satellites. [incorrect assumption]. >Apparently AR felt the big 12" was in its best range when cut at 200hz, which implies that anything much higher represented compromise. [This, too, is an incorrect assumption]. >Adams ____________________________________________ AR did not design the tower speakers with those things in mind. It just doesn't work that way. The two 12-inch woofers needed to be placed close to the floor-wall intersection to reduce the possibility of out-of-phase cancellations. The existing 8-inch Lower-Midrange driver was an existing in-house driver, for the most part, used in numerous other AR systems, and it could easily get down well below 200 Hz. Also, AR wanted to improve the lower-midrange power-handling capability of the dome midrange and tweeter units, so the 8-inch LMR helped with that as well. The "art" in the AR9 design is the almost seamless integration between the two 12-inch woofers and this 8-inch lower-midrange unit—working together as though one single unit. There are no clues that there is any transition from the woofers to the LMR, and AR was most proud of this and considered it to be one of the great achievements in the design of the 9's crossover. Unless you are listing to your speakers about a foot away, you will never sense that "human voices and instruments seem to move up and down the column." This just doesn't happen unless you had all large cone drivers operating into the midrange and treble, and thus you might sense a wandering image with highly directional speakers that are projecting to you predominantly first-arrival sound, but these speaker systems are generally objectionable to listen to anyway. —Tom