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tysontom

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  1. Bin, I think you have 100% authentic AR-3 loudspeakers, no question there. What I do see, however, is that someone has tampered with the labels on the back and altered the serial numbers. I know that those serial numbers are not authentic, mainly because of the supporting evidence we've reported. You've raised yet another question, why weren't these speakers signed-off? I've never seen a pair that got through final inspection without a signature; it was required of the quality-control employees to sign-off on everything that went through the plant, from the anechoic testing of each individual driver down to the final production-line inspection and testing. In the end, however, I suspect that the sellers had two AR-3s that were early models with authentic drivers in good condition. The original, true serial numbers might have been many units apart, for example, one might have been C 04690 and the other might have been C 07201, for example, but still the same driver configuration and style, and the sellers probably thought that they would not bring as much money if left that way. Also, the original labels on the back might have been damaged or worn off, etc., and the sellers simply put on "new" labels. There are some original AR speaker labels floating around that belonged to AR that had not been put on the back panel of the AR speakers itself. I know, because I have one or two that I got from Roy Allison years ago. The grills and original grill panels were obviously damaged or broken, along with the missing original brass logos, etc. So, therefore, the sellers decided that they could get more money for the speakers if they could make them look like "mint-condition," consecutive-number AR-3s and demand a higher price for them. This in no way detracts from the speakers and their original drivers! It is simply a reflection on the sellers who refurbished them. --Tom Tyson
  2. Why does it even matter?
  3. Clearly the serial numbers are incorrect (and the date-stamp font is also incorrect along with the absence of the "C" in the serial number) for some reason, but I don't know why this would be unless the original serial numbers were pretty far apart and the seller felt that this might detract from their value, which it really won't. Consecutive serial numbers in AR speakers really don't mean anything, and it's fairly rare and usually "coincidental" that two have consecutive numbers. Serial numbers far apart do have significance with regard to components, crossovers, etc., but these two appear to have been built pretty close together. Send some pictures of the two speakers with their grills off, side-by-side. Also, pictures of the other crossover, if possible. These AR-3s are definitely early versions, likely dating to 1960-61. If you look at any of the drivers (the midrange or tweeter, particularly but sometimes on the woofer), you can usually find a date stamped on the back plate of the magnet circuit. Try to locate a stamped date. The presence of the oil-filled, mil-spec surplus crossover capacitors (the best kind, actually) clearly proves that these speakers date back to the earliest versions. Someone appears to have changed the level controls, however, as they don't look original to the AR-3. Woofer details are also present that show the orange surround color (before AR added lamp-black to the treatment), the damping ring around the outside of the woofer cone just inside the surround, and that sort of thing. The woofer has the Gen 2 cone annular rings and foam damping rings, which came about a year or so after the introduction of the AR-3, probably late 1960 or early 1961. The terminal strip is early, too, as mentioned before. I'm thinking that the original serial numbers for these speakers would be something in the C 04500 to C 07500 range or so. If both speakers work properly, then you're in fine shape with only the fraudulent "sequential" serial numbers and the wrong grill cloth material and relatively crude "3" pins. It doesn't appear that any drivers have been changed from the pictures you show, but I haven't seen both speakers. Look on the woofer magnet back plate to see if you can find a date stamp. --Tom Tyson
  4. I agree with Gerry 100%. Bi-amping is somewhat of a solution to which there is no problem. Years ago, with under-powered amplifiers, audiophiles often resorted to bi-amping speakers to get higher output levels with lower distortion. However, with the ADS L1590-2 -- as with most modern loudspeaker systems -- the passive crossover is an integral part of the design of the loudspeaker, and to bypass the crossover can be problematic. In fact, ADS spent about two years researching improvements in the design of their tower speakers (the 1090, 1290 and 1590 in the Series II version) to make them even better, and most of the improvements came in the crossover itself with driver enhancements. Therefore, removing or bypassing the crossover altogether can lead to serious spectral-balance issues, when using an outboard active crossover, which could result in some frequencies favoring others along with a serious issue with the shape and slope of the acoustic-power response into a room. Many times, audiophiles feel that they know better than the designers, and they can improve on the original design, but this is usually a false premise. In other words, the engineers at ADS knew very much what they were doing when they designed and improved these speakers; why screw with their professional work? Place the speakers in an acoustically "proper" listening room, large enough to appreciate the bandwidth of the speakers and a room properly damped with furniture and floor treatment. Again, use an appropriately powerful and stable power amplifier. If the crossover is left in place, however, separating the woofer section from the treble section does not accomplish much of anything, and to get the proper balance is sometimes difficult. There is always the issue of getting the two section out of phase along with the relative balance of the output. With an adequately powered amplifier; i.e., an amplifier with 200-300+ watts output, the sound of the 1590 should be fine without the need to bi-amp. I drove my ADS L1590-2s with several different high-powered amplifiers over time, but mostly I used a Threshold 500-watt amp or McIntosh MC2500, and there were times when the Mac "Limit" lights flashed on peaks, meaning that peaks were greater than 1kW into each channel. I did have a good friend with a pair of L1290s, and he chose to biamp his setup with the crossover in place. He struggled to get the sound properly balanced, and ultimately he returned it to a single-amp operation. With my ADS L1590-2 system, I never once detected any weakness, distortion or lack of clarity from these speakers, a hallmark of the excellent design of the ADS speakers. I did mount them back within about a foot of the front short wall and away from the room corners in my large, well-damped listening room of about 15' x 23' or so. I was always amazed at how clean and effortless these speakers sounded, with clear, balanced output and low-distortion deep bass. --Tom Tyson
  5. The serial number stamp doesn't look authentic, and it lacks the "C" as mentioned earlier.
  6. Add to the mix that the grills and the "3" pin are not original.
  7. The serial numbers for this pair of AR-3s are inconsistent with the physical appearance of the speakers themselves, for some reason. SNs 43896 and 43897 would have been manufactured in the 1964-1965 time-frame, yet these speakers look like 1959-1960 models with their early front terminal strip and the treated-cloth surrounds without the later-added lamp-black treatment for the woofers. How are the cabinets different? With consecutive serial numbers, it would indicate that the speakers were built virtually at the same time. Consecutive numbers aren't particularly rare, but AR speaker were never intentionally shipped out from AR as a "pair" with consecutive numbers. The most unusual thing is the lack of the standard oval-shaped, flush terminal strip rather than the earliest version mounted above the baffle. The serial numbers strangely do not have the "C" in front of the serial numbers. This is unusual, and it's hard to determine what's going on. The drivers are also earlier, but in seemingly excellent, unmolested condition from the one image. More pictures would be very helpful. --Tom Tyson
  8. Norman, Welcome to this forum! That is an interesting story about your experience at the AR Music Room on the west balcony in GCT. I had forgotten that the room was air-conditioned, but now that you mention it, I do recall that it felt very comfortable up in the room. I spent quite a lot of time up there in 1966 and again in 1968, two trips I made to the New York High Fidelity Music Show. Those were fun memories that I had there, too, along with attending the hifi show. At the time, my girlfriend lived in Manhattan, so we all had a great time! I got to know Walt Berry quite well during that time and his assistant Barbara. During those years, AR had over 100,000 people a year visit the room, but no sales were ever allowed to be made. In 1994, AR made a return visit to GCT, but this time renting the east balcony. By now, the old AR building was long-gone, but AR rented the east balcony to celebrate "AR's 40th Birthday Party," a celebration and trip down AR memory lane that included most of the "who's who" in high-fidelity audio history at the time. --Tom Tyson
  9. The tweeters are also wired in a series/parallel fashion, so there are some slight variations between even properly working tweeters. If one tweeter is defective, it will affect the output of the others as well.
  10. Notice, too, that the very first AR-10 Pi speakers (the prototypes, that is) were called "AR-Pi-One," and they had slider switches for the environmental control rather than the later toggle switches. By the time of production, the name was changed to AR-10Pi; and in the ad shown in this message string, the AR-10Pi is actually shown with the slider switches, so perhaps serial number 0001 had sliders instead of toggle switches. One of the important contributors to the AR-10 was C. Victor Campos of AR (he recently died, sadly). Victor and I used to talk for hours about AR and KLH, and Victor had actually worked at AR during two different periods, once in the early 1960s and then in the mid-1970s about the time of the new Advanced Development Division speakers (AR-10, AR-11, AR-12, 14, AR-MST, etc.). He worked on the cabinet design of the AR-10 Pi, and during its development, AR technicians were having some difficulty making the access doors, which tended to bind, close properly. Victor was somewhat impatient, and he insisted that the engineers stop screwing around and just install ball-bearing pivots for the door hinges! Of course, this would have cost a fortune and was immediately nixed by management, so the engineers got to work and fixed the existing bearing surface for the solid-walnut door, and it worked fine forever more. Victor was also very interested in the 1978 AR9 "D", an experimental 4-way "powered" AR9 speaker that was sadly never actually put into production! What good did come of the AR9D: the birth of NAD electronics! --Tom Tyson
  11. This is a great tribute to a very knowledgeable AR man! I couldn’t agree more, and I have been dealing with Acoustic Research products nearly all my life, and I would run something by Roy before deciding on it when it comes to the vintage Acoustic Research products! Roy has had such broad experience because he has seen and worked on so many Acoustic Research speakers! Roy is also a fine gentleman, very gracious and thoughtful – and very nice, too! What a huge asset to this forum of AR devotees! --Tom Tyson
  12. The AR-10π with the black face is a very early version (looks like serial No. 0051) of the original model. The first production models of both the AR-10 and AR-11 -- the first models of the "Advanced Development Division" line -- had the face painted black. Subsequently, veneer was used on the front panel of the upscale AR-10.
  13. Great message! Thanks for this further clarification. One note: after the initial 200003 woofer, AR did change the compliance slightly to prevent the often-occurring back-plate voice-coil incursions. This early 1969-1970 ferrite woofer (Roy and I can't determine precisely when the new ferrite woofer appeared in the AR-3a) was extremely compliant and prone to striking the bottom plate of the magnetic structure under very hard low-frequency input power. This took an excursion of a little over an inch, peak-to-peak. Sometime after AR moved to Norwood (1973), AR did revise this woofer to (1) eliminate the butyl-rubber coating on the surround, (2) change the dust cap and (3) slightly stiffen the spider to control excursion beyond the .5-inch linear travel. Perhaps this corresponds to the drawing changes. I did notice that the AR-11 woofer, for example, was slightly stiffer at extremes than the AR-3a ferrite woofer. This did not materially affect the driver resonance or harmonic distortion, but it limited the excursion a bit more at extremes than the first edition in an effort to prevent flattening the voice coils under duress since the woofer did not have an extended back plate ("bumped"). AR also went to the aluminum bobbin for this woofer in the mid-1970s, and most of the later ones were aluminum rather than the earlier DuPont Nomex-treated-paper formers, even though the latter probably dissipated heat better into the magnet structure. --Tom Tyson --Tom
  14. I didn't mean to repeat the details of my first message!
  15. Pete, I don't know the details of how spiders are made other than they are formed under heat and pressure in a mold. I believe the majority of spiders are made from linen or similar materials, then coated for longevity and stability. I saw a YouTube video recently where some guy had a collapsed spider on a large subwoofer driver, and he sprayed water on the material while keeping the cone "centered" with spacers. He used a shrinkable-tubing heat gun to quickly evaporate the water and to hopefully cause the spider to shrink and return to its original shape. It looked to me like it partially worked, but there were definite sags in the spider that never went completely away; and if the surround material was treated, I don't know how the water could penetrate past the coating to get to the fibers. AR once had a recommendation that to get the sags out of a linen grill cloth, the best way to do that was to use a fine mist spray of distilled water on the fabric and then hold a light bulb (back in the incandescent days) close to the fabric to allow it to shrink and thus draw up the slack and sagging. Of course, that did work quite well, but the surround is a different deal altogether. Once badly stretched, it's likely that there would be no fix other than to replace the spider. --Tom
  16. Are my AR9’s getting “old?” Steve F I bought AR9’s in 2010 in Boston from their second owner, a young EE who had graduated from MIT. He had re-surrounded the woofers and LMRs and had re-capped the x-overs. I’ve never opened up the cabinets to check his work, but the speakers sound great and I have no aural reason to doubt the quality of his work. I think the 9’s are remarkable speakers. They do everything at least very well and some things the best I’ve ever heard. I haven’t tired of them in 9 years, nor do I find their performance lacking in comparison to more “modern” speakers. I do a fair number of speaker reviews for the website Audioholics.com and I compare every speaker that comes my way to the 9. There are some very good mid-priced tower speakers out there these days, but even so, none surpasses the 9, in any area. But I am nagged by the suspicion that my 9’s are aging. I fear the aging is gradual and subtle, such that I don’t notice, and the 9’s margin of ascendancy over other speakers I’ve compared it to side-by-side is great enough that a slight diminution in their absolute performance is not enough to significantly affect their competitive standing. ________________________ There is likely more reduction in your hearing acuity in the intervening ten years than reduction in output fidelity in the AR9s, but without actual before-and-after response measurements to verify it, there is no way of knowing whether or not your AR9s have declined in output and fidelity, or if distortion has increased over time, etc. But, intellectually, academically, I can’t help but think there are areas in which my 40+-year-old speakers have slipped, even if just slightly. Specifically: 1. The woofers’ and LMRs’ spiders. Yes, they have been re-surrounded (by all subjective audible and visual measures, correctly), but the spiders are original. 40 years old. Surely, they have stretched and sagged a little over time. Maybe, just maybe, the spiders are not exerting quite the same degree of control over the cones’ motion as was the case when they were brand new. Could be that the woofers and 8” LMR are just ever-so-slightly looser and floppier than before. A tiny amount, but certainly possible. Sagging of the woofer spiders is more a function of gravity, not so much a function of wearing out during operation, in the 200003-0 woofer, although the strength of the spiders has probably diminished over time due to constant movement. If, however, the voice coils don't rub, or that there is no tear or rip in the spider fabric, you should be fine. The only true function of the spider in this woofer is to center the voice coil both longitudinally and vertically—hold it correctly in place—thus to bring the cone back to the center resting position and and prevent it from rubbing the pole piece. It therefore exerts very little force on the woofer cone. The air in the enclosure does most of the restoring of the woofer to the center position; the spider/skiver only do about 10-15% of that anyway. Remember: the electrical signal driving the woofer cone does not provide the necessary restoring force of the cone to keep it centered; that falls on the suspension system. Therefore, if there is no rubbing, banging noises, rattles, obvious distortion, off-center cones or physical rips... I wouldn't worry too much about the spiders. On this woofer, the spiders are loose but fairly durable, but they certainly will sag if the speaker driver (or the speaker enclosure) is stored face-up or face-down for prolonged periods. 2. I’ve never checked the condition and seal of the LMRs’ tubular sub-enclosure. A tube of heavy-duty cardboard is actually quite a strong structure, but I wonder if they’re still properly sealed against the backside of the baffle board. These speakers have been moved around a lot, from location to location. Glue dries out over time and becomes brittle. Wouldn’t surprise me if the glue seal has cracked slightly and there is a small air leak in one or both LMR enclosures. I think the seal for this sub enclosure was carefully crafted when originally designed, so it shouldn't cause an issue. You could always remove the 8-inch LMR driver and check the seal. No problem here. 3. Slight thickening/degradation of the ferrofluid in the UMR and tweeter. Again, they sound ok, but their output may be slightly compromised and/or the distortion/VC travel slightly impeded compared to factory-fresh units if the FF has degraded even a little. This may be a concern, and there is likely some drying out over time. The problem seems to be worse in many other brands than with the AR series, but no one knows how long it will take for the oil to dry out. Removing all of the old Ferrofluid and replacing it with the proper amount of new stuff is extremely problematical. On the other hand, we don't often hear of this problem as a serious concern with this series of AR speakers. 4. Mediocre 1978 crossover component quality and garden-variety internal wiring. This is both a design and an aging consideration. The x-o’s have supposedly been re-capped (by an MIT EE!) and they sound fine, but still, I wonder if there are any age-related issues with the x-overs. The internal wiring and binding posts that AR used were hardly audiophile quality by today’s standards, but does that matter? It could, even if just a little tiny bit. AR9 crossover components were actually of high quality, mostly Sprague capacitors and large-gauge coils and so forth, and the wiring was more than large enough in gauge with high-temperature insulation. The mediocrity might be in the (lack of) "neatness" of wiring, using very few Ty-Raps to bundle cables together and nicer-appearing crossover boards like those done by some boutique manufacturers during the day. The extra cosmetic things only cost money, and no one looks inside anyway. Nevertheless, the wiring is more than adequate for proper electrical performance. Also, most newer crossovers are usually completely board-mounted and circuit-board soldered, so the appearance of "hand-made" wiring is absent in the newer designs. 5. An undistinguished cabinet. These two 12” woofers can and do generate a great deal of internal cabinet pressure and panel vibration in a sealed enclosure. Are the cabinet glue joints still as strong and vital as they were in 1978? The panel thickness is ¾” all around and the internal bracing is minimal. If these speakers were done today by a high-end speaker manufacturer, the side panels where the woofers are mounted would be 2”-thick MDF, the front baffle would be 1” MDF and the inside would have top-to-bottom windowpane bracing. Does that matter? Probably a little. The AR9 cabinet is not heavily braced, but it is adequately braced for the need. AR extensively tested for that during the development stages, and the bracing was used that provided adequate cabinet damping. Oh sure, additional bracing would help to make the cabinet sides more inert, but there is probably negligible audible benefit and very little measureable benefit from doing that; again, it adds cost. The truncated top-back of the cabinet adds huge stiffness, too. As you know, I had a pair of B&W "Matrix" 801 Series II speakers, which I liked very much, and the cabinet was heavily crossed braced with a high-dollar, honeycomb bracing insert. I still had my AR9s at the time, too, and without doubt I felt that the AR9 was cleaner in the deep bass than the 801s, and the 801s were equalized flat to 18 Hz. Did that bracing make that much difference? It no doubt helped this vented enclosure quite a lot, but the cost to build that speaker was very high and the selling cost was exorbitant, more than twice as much as a pair of AR9s. I personally felt that the AR9 was a superior loudspeaker overall. The thought has crossed my mind to send the woofers and LMRs to Bill Legall at Millersound and have them completely rebuilt. I’ve also though about duplicating the x-overs electrically, but with much higher-quality components and having new custom cabinets built with the same internal volume, the same stuffing arrangement and the same dimensions, but with thicker panels and better bracing. This is probably the last thing you should do. If it's not broke, don't fix it. New spiders, cone and new surrounds will most likely raise the resonance frequency of those woofers and likely change their frequency-response characteristics , and this will, for better or worse, affect the sound the speaker. Just my thoughts! Good topic for discussion, though! —Tom
  17. What I've done is to rotate (flip) the woofer from time-to-time, magnet-up or magnet-down, but this is probably not 100% satisfactory. When you store the speaker, "magnet-up," with cone facing downward, always use shims or blocks to raise the basket up off the table to prevent the surround from touching the table. Probably the best way to stabilize the cone is to get small foam or Styrofoam pieces to place under the cone between the cone and each arm of the speaker frame, to hold the cone in the center position. Note that the 200003 stamped-steel woofer cone naturally sits very slightly below the center position anyway, so just stabilizing the cone so that it does not sag is good. It may be necessary to slit the nylon screen that is glued to most of the early woofers (to prevent fiberglass from entering the area under the cone) enough to place the foam under the cone. A small slit about 2-inches or so will probably work. Also, in lieu of foam or Styrofoam pieces, paper towels, cut into small sections and folded over several times to make a section about an inch thick, can be placed under the cone as well. I watched a YouTube video recently where someone raised a sagging cone/spider to a level position with shims, then lightly sprayed the spider with water and quickly dried the spider with a heat gun or hair drier to quickly bring it back. The material used for most spiders is linen, but it is treated with a preservative, so I'm not sure that the water would completely be absorbed by the spray (this is the old trick to make a sagging AR linen grill "tighten" up a bit; i.e., lightly spray water and then use a hair drier to make it bounce back). Getting the moisture down in the voice-coil area is also not a great idea, but it might be worth a try in extreme cases.
  18. The Collapsed Spider We have discussed this in years past, but good advice is that when storing old Alnico #3700 12-inch or 200003-0 Ferrite 12-inch woofers, do no place it magnet-down (or magnet-up) for prolonged periods of time. This is true also of the AR speaker cabinets themselves using this woofer; i.e., when storing (or mounting) the speaker, do not place or store the speaker cabinet face-up or face-down for long periods of time. This can result in a condition known as "collapsed spider." This sounds quite ominous, but the spider fabric is literally stretched somewhat, and the cone doesn't want to center properly, and the woofer will therefore not operate correctly. This condition applies to other AR woofers, too, but to a lesser degree. The suspension system used on these early AR woofers is extremely compliant—more so than about any other similar woofer. Originally, AR designed the "classic" acoustic-suspension woofer to have approximately 85% acoustic restoring force and 15% mechanical restoring force, just enough to center the voice coil in the gap. The result is the very low harmonic distortion exhibited by these woofers when mounted in the AR-3, AR-3a, AR-11, etc. cabinet. For many years the AR woofer had the lowest distortion of any loudspeaker, and today there are precious-few speakers of comparable size and performance than can equal, let alone surpass this performance. By contrast, most competitive and most contemporary drivers with similar parameters have significantly less compliance, probably on the order of 60/40 or even 50/50 acoustical/mechanical, but with other comparable parameters. These stiffer suspensions work fine and are more robust, but these designs actually have higher distortion, all things remaining equal. Insofar as the voice coil/cone assembly is relatively heavy, more than 80-100 gms or so, the compliant spider and surround (skiver) cannot hold the weight of the moving assembly and will tend to settle. Therefore, if you are preparing to re-foam some AR 12-inch woofers or just storing spares, do not store them magnet-down. —Tom Tyson
  19. Yes, I forgot to mention that in that picture, someone had put AR-2a grills on a pair of AR-2s. The grills are the same, but the "a" pin belongs to AR-2as.
  20. By the way, you would need the beige-linen grill and the "AR" logo and the "a" brass stick pin to make the grills correct. Don't use the "AR-2ax" single logo. This picture is of a pre-1965 AR-2 in Birch with the two 5-inch Carbonneau midrange units. Notice the grill material and logos. This is the type grill your speakers came with originally, but when the new 3 1/2-inch CTS midrange was added in the upgrade, new beige grills were also added, but the logos and so forth stayed the same. The AR-2x and 2ax Mid-Adapter panel and speaker with crossover mod included. --Tom Tyson
  21. IARrybody: You are fortunate to have that pair, as Korina is quite rare to find. I thought that these pictures were off eBay; sorry about that! Thanks for your permission to use that picture, after the fact! This pair looks like a pair of AR-2as that were factory-converted to the first version of the AR-2ax; i.e., updated with the $15.00 midrange upgrade to the CTS 3-1/2-inch midrange. I personally wouldn't change them unless you have the original woven grills and logos, etc. The grill that is shown is the the AR-2ax-type 1965-and-later beige-linen grill. The CTS midrange is much better than the original two 5-inch Carbonneau drivers. In other words, you have a rare pair. Period! Korina was available for only a few years, as I think most of the Korina wood was used by guitar-makers and so forth. The wood is really beautiful, but most of the blond-appearing finishes are birch, not Korina! I think that "Korina" is printed on the label of most of the AR speakers in that finish. That grill molding is also solid-stock Korina. I have yet to see a pair of AR-3s in actual Korina. I once had a pair of KLH Fours in Korina, but never an AR speaker. If anyone else has Korina ARs, share the pictures with this forum! --Tom Tyson
  22. It looks as though the wood grill molding is solid-stock Korina in the image I sent earlier. Here is a close-up image of the Korina AR-2ax molding. Not all of the AR-2 series cabinets had cabinet molding, but most of the early models -- especially in exotic woods -- did have the molding. Unfinished-pine cabinets also had moldings out of birch. Solid-stock Korina molding (I think). The edge line is clearly visible. --Tom
  23. You've got a sharp eye, but I think this AR-3 pair you show is in Birch, usually a bit more yellowish, but I am not completely sure. Korina is slightly darker and has a more stripey texture, and I think that most of the Korina cabinets were marked as such, too, but perhaps not all. Here is an example, images taken from eBay: Korina Finish AR-2ax in round-cut Birch: Birch Finish AR-2ax, above. Birch veneer (as with all veneers) can be purchased "cut" in several different flitch configuration, such as round-cut, quarter-cut and so forth, depending on how the cabinet-maker bought the veneer. This will determine the grain, the texture and figure, etc. --Tom Tyson
  24. tysontom

    ADS L1590

    >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
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