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tysontom
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Posts posted by tysontom
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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
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4 minutes ago, Aadams said:
It seems improbable that these cabs were consecutive units when receiving serial numbers.
Aadams
Why does it even matter?
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17 hours ago, Bin said:
Hello Tyson
really appriciate for prompt and details reply
i attached here is the link for more picture
I think the series number should be the fake one as per your findings. But i just curiously why people doing this fake?
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
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On 6/20/2019 at 10:53 AM, Gerry S said:
I always felt the "bi-amp" option that ADS offered to consumers was a mistake. There is more opportunity to screw up the sound than to improve it (I once owned a pair of 910's using just the built in passive crossovers).
Effective bi-amping requires pretty detailed knowledge of the raw drivers individual performance. It also requires test equipment to set amplifier gain levels, as well as the crossover frequencies and slopes. Pro's use bi-amping in sound reinforcement for increased output capability and reliability, and when the performance space has been defined. With pro use,the cost and complexity of additional amplifiers and electronic crossovers is justified over the long haul. With consumer use, I don't think it's justified, from either a cost or performance point of view.
Let's assume the ADS passive crossover was properly designed, and yields what is generally acknowledged to be "good sound". With bi-amping, audible changes to the system should be SUBTLE. The primarily benefit should be less audible distortion as the woofer amplifier "clips" (overloaded) with heavy bass content. The distortion generated with this clipping is produced by the woofer(s) only, where it's mostly inaudible. It's inaudible because woofers naturally rolls off highs, and the passive crossover reduces the highs further.
The trouble with bi-amping occurs when any additional filtering created by the electronic crossover upsets the INTENDED "blending" occurring between upper woofer frequencies and midrange lower frequencies. Not to mention any changes in the "radiation pattern" at the crossover frequencies.
I'm not saying that bi-amping isn't a valid way of improving sound. I'm saying that in the hands of the average consumer, it's not likely to do so.
Gerry S
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
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7 minutes ago, tysontom said:
Add to the mix that the grills and the "3" pin are not original.
The serial number stamp doesn't look authentic, and it lacks the "C" as mentioned earlier.
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Add to the mix that the grills and the "3" pin are not original.
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On 7/17/2019 at 8:45 AM, Bin said:
Hello...
I just bought pair of ar3 speakers as the picture as link .https://xfl.jp/xVW1gw Could someone help me some concerns as:?
1. Looking to front side, which possible production year could be?
2. Looking to series number: is it correct one or fake series number to these speakers?
3. As the series number is closed for both speakers? But the cabinets are different, why?
Thank you very much
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
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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
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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.
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On 5/4/2019 at 8:28 AM, Giorgio AR said:
Wonderful, you have a wonderful couple (I am convinced that all the speakers contained in the cabinets C0051/C0081 are perfectly original and correspond to the AR specifications).
After just refoaming, you can enjoy them for another 15 to 20 years.
I wish you a wonderful listening, it will never be tiring, try also to enjoy the speakers at very low volumes, you will find the same sound and all the instruments you hear at higher volumes!Giorgio
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
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23 hours ago, mrbruce4 said:
Just a short post to acknowledge my appreciation for Roy C.'s invaluable assistance with a resurrected pair of AR3s. Roy accurately diagnosed a mismatch in the midranges and was able to get me set up with the correct replacement. He also was able to do an expert repair of a woofer. Without this major assistance, they would still be sitting, gathering dust. Instead, they are singing!
Anyone who has dealt with Roy already knows the above, so I'm posting this as another data point for those not familiar with him.
Thanks again, Roy.
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
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3 hours ago, Scoup said:
Another question...
Both speakers appear original however one has a black painted front baffle and the other is unpainted wood veneer.
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.
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7 hours ago, fedeleluigi said:
Hi Pete,
There is a lot of information on AR Drawings about the spider of the 200003 ferrite woofer . Examining these documents carefully it comes to light that the first drawing of the AR 200003 spider dates back to 22 Jul 1969. So, most likely around this date the production of first 200003 ferrite woofer started.
Revision B dates 1 Jul 1974 and apparently there was no change in spider manufacturing from 22 Jul 1969 to 1 Jul 1974 because Revision B only reports “drawing no. change" but a previous revision (O) dated 12 Sep 1972 reports "Revised Notes, DWG No. was X-3705" and something could have been changed on that occasion.
Revision C (ISS. C) dates 5 Jul 1978 and apparently there is no variation about dimensions, material, treatment, supplier (LCC, Loudspeaker Components Corporation, Lancaster Wisconsin. I think that the same company is still operating nowdays and they could still have the original molds for the 200003 spider www.loudspeakercomponents.com ) in comparison with Rev. B. Differently from the previous drawing, on this last revision it is also reported something about the spider compliance (maybe there was some compliance variation in comparison with the previous spiders) but it's difficult to understand the standard used (where and how must the 50 grams be exactly employed? where do you have to measure the deflection?).
You can find images of higher resolution on AR Drawings. The drawings are the 422th and the 423th but unfortunately there is no numeration. The last drawing is the 492th.
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
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Just now, tysontom said:
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
I didn't mean to repeat the details of my first message!
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22 hours ago, Pete B said:
Thanks for the info Tom, do you know any more details about how spiders are made?
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
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AR also warned against storing speakers face-down:
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11 hours ago, lakecat said:
I have to ask as I am storing an alnico woofer, is how can it be stored? Just rotate the woofer occasionally?
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.
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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
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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.
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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
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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
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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
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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:
.thumb.jpg.0b3ce57702861dec539c9d89c3385de1.jpg)
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
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>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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AR gentina, New Proyect, 1958 AR-2
in Acoustic Research
Posted
It is rare for the original AR-2 cloth surrounds go bad in most cases, and it is best not to replace with urethane-foam, as this was not original. Foam surround may possibly change the free-air resonance slightly as well. Test the woofer first for air leaks, and if the woofer isn't bad, don't modify it. Leave it alone, but be sure that the cabinet does not have air leaks (use a stethoscope and 30Hz to listen for air leaks).
This speaker also has the WWII-surplus, mil-spec (Army-Navy) oil-filled capacitors and the high-quality A-B level control. Therefore, it is rare for the crossover to ever give trouble, and it's probably good for 100+ years of unchanged, reliable service.
This old AR-2 was very early (what was the serial number?), and it is unusual with some excellent pedigree! The 2 was an exceptionally fine old speaker (designed by Edgar Villchur and partially executed by Henry Kloss before he departed AR in February 1957). The first AR-2 went out the door in March, 1957, and the little speaker was, at that time, literally unsurpassed in sonic accuracy by any other loudspeaker at any cost except for the mightier AR-1, quite an accomplishment.
These are rare, perhaps as famous as the AR-2s that belonged to Richard Nixon in the White House (you may not like his politics, but at least he knew good sound), JFK, Buddy Holly, Miles Davis, Nelson Rockefeller or even Ann Margret Olsen! It had been rumored for many years that that Rockefeller -- a notorious philanderer -- died of a massive heart attack (rip) while listening with his AR-3s to the thunderous final movement of Saint-Saëns Organ Symphony No. 3, while in the arms of one of his lovers at his west 54th street town house (not his main residence). We will never know for sure, but Nelson loved his AR speakers (he had various pairs) as much as his extra-marital girlfriends. Nelson could afford anything, but he always chose AR speakers and beautiful women. As a side note, one of Nixon's AR-2a speakers developed a problem and had to be repaired. Because of the nature of this customer, a secret-service agent accompanied the speaker back to Cambridge and witnessed the repair before returning to Washington.
By the way, the Ponderosa Pine cabinets on the utility cabinet were never finished, but rather left in unfinished condition. So, if you want them to be original, don't mess with the woofer unless is is bad and don't apply finish to the cabinet unless it is an opaque finish. After all, these were work horses.
--Tom Tyson