38 replies to this topic

[schen]

I had a pair of 1290s for a number of years and never found them to be difficult to drive either. I had them on a variety of amps ranging from Adcom GFA-555 (run from an a/d/s/ R4), to a Yamaha DSP-A1. Of course their needs were more than the typical bookshelf speakers, but of course, you are talking 2 acoustic suspension woofer in separate chambers, so......

I must say that I remember them fondly!

[tysontom]

My L1530s, the predecessor to the L1590 and very similar except for the cabinet design, are rated at 95dB 1 watt/1 meter, which I think is insanely efficient. I was used to 89 dB or so before I acquired these monsters. I power them with a Nak PA7II and have never seen the overload lights even flicker for an instant.

audiomagnate,

Judging by a previous message, you may no longer be on this site, so we're sorry to see you leave if this is the case.

With regard to the L1530's efficiency (sensitivity), it was rated by ADS at 95 dB (in a 2000 cu. ft. room), about 5-dB more efficient than the later L1590, rated at 90 dB (in an "average-sized" room). ADS recommended a minimum of 10 watts and 300 watts maximum for the 1530, whereas the 1590 recommended 15 watts minimum and 500 watts maximum. However, the principal reason for this high efficiency rating was the 1530's use of the samarium-cobalt magnet in the 1-inch tweeter vs. the standard ceramic magnet used in the later speakers. For some reason, ADS had the spectral level set fairly high (read "bright") for the L1530 1-inch dome tweeter, but this was later changed in the 1590 ¾-inch tweeter. Also, the woofers in the 1530 had less voice-coil "overhang" in the woofers than with the later 1590 system; as a result, 1590 had lower bass distortion and greater power-handling ability than the earlier 1530 system. It is possible that the 95-dB rating for the 1530 was slightly optimistic, but the system was definitely more sensitive than the later 90-series speakers. The 1530 was also rated with a 25-20,000 Hz frequency response, ±3dB, meaning that the 1530's system resonance was very slightly lower than the 1590, rated at 28-27,000 Hz ±3 dB. In any event, both systems are impressive tower speakers of very high quality!

--Tom Tyson

[tysontom]

The L1590 was a 1980's speaker held in high regard for its uniform on-axis output as well as it's relatively flat acoustic-power output, the downfall of so many loudspeakers. The acoustic-power frequency response is basically the integrated power output of a transducer as measured throughout a listening environment, and is a measurement of the speaker's abillity to disperse sound over a wide vertical and horizontal axis. The end result was a speaker that was capable of great accuracy and realism, as well as a speaker with very "spacious" sound characteristics.

The L1590 also had very low distortion and excellent deep-bass capability with its two 10-inch acoustic-suspension woofers mounted in separate chambers within the heavily braced cabinet. The -3 dB point of this speaker was approximately 28 Hz, so the low-frequency extension was also excellent. Power-handling for the woofers was top notch with the 2-inch-diameter voice coils with 1.5-inch high windings, giving greater than .5-inch linear overhang.

--Tom Tyson

Update on the ADS L1590-2 woofers: the following images are details of the construction of the dual-10-inch woofers used in the L1590-2. The voice coil is coated with a special high-temperature coating, and the coil is wound on a special Kapton former for excellent power-handling capability. The coil is 2-inches in diameter. The cone is a special-density pulp mixture engineered by ADS to prevent breakup distortion, and with the very low crossover frequency, the woofer's output is very uniform down to -3dB point of 28 Hz, with natural rolloff below that frequency. There is usable response down to 20 Hz and below at fairly high output levels.


Fig. 1: Inverted view of high-output 10-inch ADS Stifflite Woofer used in the L1590-2

Fig. 2: Detail of the conformal high-temperature coating of the 2-inch diameter, long-throw ADS L1590-2 dual 10-inch Woofers

Fig. 3: 2-inch Diameter Voice Coil used on the ADS L1590-2 dual 10-inch Woofers

Fig. 4: Detail of the cross-section of the special felted cone assembly of the 10-inch ADS L1590-2 Woofers

--Tom Tyson

[Gerry S]

Tom,

I agree--the ADS '90 series were excellent loudspeakers. I came very close to buying a pair of 1290's. I also thought the 1290's somewhat slimmer profile made it a more attractive speaker than the 1590, which was somewhat 'chunky.'

I seem to remember that these speakers had the unusual option of having a power amplifier attached to the rear of the cabinet in a recess that was made to accept an ADS sub amp. So equipped, these ADS speakers had powered 'subwoofers' and passive mids/highs, pre-dating the so-called Powered Towers of Definitive Technology by some 10 or 15 years.

I know I have some lit on these ADS speakers somewhere in my dusty archives, but perhaps you might shed some light on this innovative aspect of their design.

It always struck me as strange that these ADS speakers did not enjoy wider critical acclaim (were any of them reviewed by the Big Three?) or more widespread commercial success.

Steve F

I owned the 910 , which WAS "chunky". Mounted on their optional metal stands, it looked like R2D2 on steroids. On paper , they were pretty impressive. Living with them for many years, I thought their spectral balance to be between the AR3a and the AR10. Build quality was superb and just about indestructable. I purchased them partly because Deutch Grammaphone used them as monitors. My biggest gripe about them was their imaging capabilites compaired to other "studio monitors". I'm presuming the "towers" discussed here was better in this regard.

[tysontom]

I owned the 910 , which WAS "chunky". Mounted on their optional metal stands, it looked like R2D2 on steroids. On paper , they were pretty impressive. Living with them for many years, I thought their spectral balance to be between the AR3a and the AR10. Build quality was superb and just about indestructable. I purchased them partly because Deutch Grammaphone used them as monitors. My biggest gripe about them was their imaging capabilites compaired to other "studio monitors". I'm presuming the "towers" discussed here was better in this regard.

Gerry,

I never owned the ADS 910s, but I was very impressed with their sound on several occasions. At the local ADS dealer close by, I was able to compare the 910s—with levels equalized—with my own AR-3as, and the ADS was marginally more powerful in the deep bass, as expected with its lower system resonance. The 910 also had more "clarity," but it was also more forward-sounding to me; and what it had in "clarity" over the AR-3a, it seemed to give up in spaciousness. So that might have been a wash. Both speakers are such great reproducers, it's difficult to make a true value judgment on them; however, for sure, the ADS 910s could pound out higher SPL levels more effortlessly—perhaps without strain—than the AR-3a, but then the 910 was intended as a monitor speaker. The 910 never seemed muddy at any sound level I could withstand.

That big, broad front baffle board on the ADS 910 seemed to be in vogue briefly during that time (another example was the Andy Kotsatos Boston Acoustics A100 with the wide front face), but I would think there would be interference effects on a grand scale if the speaker were measured in the near field—again, not a big factor in the reverberant field. The later ADS tower speakers—especially the late-80s L Series 2 versions—were narrower and had significant improvements in dispersion and acoustic power over the 910 series. This acoustic power might be unimportant to some such a Speaker Dave, but it seemed to make the newer "L" speakers more three-dimensional. I really don't know if there were changes in the so-called "imaging" of the speakers, but overall the (especially the 1590) towers were considered better performers.

The ADS 910 had a 550 and 4000 Hz network (12 dB/octave, as with the tower speakers), whereas the 1590 had 350- and 5000-Hz crossover frequencies. In this way, the 1590 used the excellent 2-inch dome to handle a great deal of the important middle frequencies, and thus the dispersion at upper bass frequencies was improved. The 1590 also had a lower fc (33 Hz vs. 39 Hz) and much more robust 10-inch woofers than the 910. I also believe the 1590 was a significant improvement over most of the earlier ADS tower speakers, such as the 1230 and the 1530. For one thing, the treble was toned-down with the improved dome drivers in the newer series. The humongous ADS 2030 may have been the best—I don't know—but it was just gargantuan with its multiple mids and tweeters and dual 14-inch woofers, and it was a favorite of the Telarc recording group for a long period of time.

--Tom Tyson

[Gerry S]

Gerry,

That big, broad front baffle board on the ADS 910 seemed to be in vogue briefly during that time (another example was the Andy Kotsatos Boston Acoustics A100 with the wide front face), but I would think there would be interference effects on a grand scale if the speaker were measured in the near field—again, not a big factor in the reverberant field. The later ADS tower speakers—especially the late-80s L Series 2 versions—were narrower and had significant improvements in dispersion and acoustic power over the 910 series. This acoustic power might be unimportant to some such a Speaker Dave, but it seemed to make the newer "L" speakers more three-dimensional. I really don't know if there were changes in the so-called "imaging" of the speakers, but overall the (especially the 1590) towers were considered better performers.

--Tom Tyson

Tom (and former ADS engineers). I always wondered why they never "mirror imaged " them, especilally since they were "studio monitors". I know that they were "reverberant field" speakers, but still !!!!. Other "classical music" monitors of that period (KEF & B&W) did pay attention to imaging in the near field as well as diffraction issues. The grilll that came with them was reminiscent of the AR3a inset driver mounting with a big lip overhanging the baffle. At least the 910 grills were removable.

I must say that the 910's were my biggest "high-end" dissapointment of all the speakers I've owned. Given the superb and expensive "build quality" of this model, a miirror imaged pair shouldn't have been that costly to make. Heavy MDF consruction, well braced,seperate chambers for each woofer, industrial grade printed circuit board and crossover components, fuses for each driver, etc.

I can't help but wonder why they didn't go "alll out" to address my "minor quibbles" like imaging.

[tysontom]

Tom (and former ADS engineers). I always wondered why they never "mirror imaged " them, especilally since they were "studio monitors". I know that they were "reverberant field" speakers, but still !!!!. Other "classical music" monitors of that period (KEF & B&W) did pay attention to imaging in the near field as well as diffraction issues. The grilll that came with them was reminiscent of the AR3a inset driver mounting with a big lip overhanging the baffle. At least the 910 grills were removable.

I must say that the 910's were my biggest "high-end" dissapointment of all the speakers I've owned. Given the superb and expensive "build quality" of this model, a miirror imaged pair shouldn't have been that costly to make. Heavy MDF consruction, well braced,seperate chambers for each woofer, industrial grade printed circuit board and crossover components, fuses for each driver, etc.

I can't help but wonder why they didn't go "alll out" to address my "minor quibbles" like imaging.

Gerry,

At least the 910s (as well as the later 90-series towers) were vertically aligned. Perhaps "mirror-imaging" might have very slightly improved performance, but considering how Dr. Guenther did things back in those days—and being the resourceful German that he was—he likely dismissed a design change that could not be warranted, but this is a total assumption on my part. Guenther did pay great attention to detail, and ADS speakers always reflect those engineering details, but some things weren't necessary. Nevertheless, the 910s were certainly designed for high-output, far-field acoustic power necessary for studio work during that period. With such wide dispersion, especially through the lower midrange, it would be hard to get imaging such as with some other speakers with 4-5" midrange drivers (such as the KEF and B&W designs). Up close, I thought the speakers did seem a bit bright—and perhaps that was what you didn't like about them—but back in the reverberant field, I felt the balance was pretty good, and the speakers had a definite three-dimensional sound from what I remember back several years ago. I do vividly remember that the speakers could pump out a high SPL output, and one day (at a dealership called Soundhaus Stereo in Chapel Hill, North Carolina) I heard them being powered by a McIntosh MC2300 driven to peak output, and I was amazed at how clean and clear the sound was at such a high-output level. There was none of the usual strain you hear with speakers as they begin to compress. Perhaps this was one reason some studios used this speaker as a monitor. As for diffraction, the front panel was pretty flush and clean, and I suspect that studios did not operate the speakers with grills in place. Even so, diffraction was pretty much swamped in the far field anyway.

It is noteworthy that Guenther used separate chambers for dual woofers all the way back to the 30-series in the early 1980s, and this continued with the lower-cost 810 model during the mid-1980s. This had to be considerably more expensive to manufacture, but according to ADS, this design improved bass performance considerably, and it was used in most of the other top-end ADS designs. The quality-of-construction and attention-to-detail of ADS speakers was definitely set to a high standard.

--Tom Tyson

[Gerry S]

Update on the ADS L1590-2 woofers: the following images are details of the construction of the dual-10-inch woofers used in the L1590-2. The voice coil is coated with a special high-temperature coating, and the coil is wound on a special Kapton former for excellent power-handling capability. The coil is 2-inches in diameter. The cone is a special-density pulp mixture engineered by ADS to prevent breakup distortion, and with the very low crossover frequency, the woofer's output is very uniform down to -3dB point of 28 Hz, with natural rolloff below that frequency. There is usable response down to 20 Hz and below at fairly high output levels.


Fig. 1: Inverted view of high-output 10-inch ADS Stifflite Woofer used in the L1590-2

Fig. 2: Detail of the conformal high-temperature coating of the 2-inch diameter, long-throw ADS L1590-2 dual 10-inch Woofers

Fig. 3: 2-inch Diameter Voice Coil used on the ADS L1590-2 dual 10-inch Woofers

Fig. 4: Detail of the cross-section of the special felted cone assembly of the 10-inch ADS L1590-2 Woofers

--Tom Tyson

I actually WOUND these voice coils in their Wilmington ,MA facilities. I distinctty remember that black "goop" coating; a devil to work with. DCR tolerances were extremely tight (at least mine were). When I owned the 910's, never blew a driver despite using them for hard-rock & disco playback @ high SPL. My amp at the time was a Dunlap- Clark Dreanaught 1000 (rated @500 watts/ channel into 4 ohms from 20 -20 Khz CONTINUOUSLY) ! Think my ears became "non-linear" before the speakers did !

[tysontom]

I actually WOUND these voice coils in their Wilmington ,MA facilities. I distinctty remember that black "goop" coating; a devil to work with. DCR tolerances were extremely tight (at least mine were). When I owned the 910's, never blew a driver despite using them for hard-rock & disco playback @ high SPL. My amp at the time was a Dunlap- Clark Dreanaught 1000 (rated @500 watts/ channel into 4 ohms from 20 -20 Khz CONTINUOUSLY) ! Think my ears became "non-linear" before the speakers did !

Gerry,

When I first got my 1590s I hooked them to my McIntosh MC2500 amp (a full 750 watts rms/channel continuous), and drove them quite hard playing some Telarc recordings on numerous occasions -- sometime to maximum peak power (Power Guard clamping the output on several occasions) -- but I never blew a fuse or damaged any drivers. It was so loud as to be uncomfortable, and the fact these speakers survived this ordeal is probably indicative of the high levels that could not be tolerated for too long! Those two big fans on the back of the Mac would light up and run hard on occasions, indicating a lot of current was passing through the outputs! ADS speakers tend to be durable; however, an underpowered amp clipping badly will always cause problems and can easily destroy a tweeter. Ironically, later Type 2 L1590s and L1290s did away with some fuses, as they were deemed unnecessary.

The Dunlap-Clarke Dreadnaught 1000 was a fine amplifier, and it was originally used in the mid-70s AR-10Pi Live-versus-Recorded demonstration with Neil Grover as drummer. Steve F attended some of these concerts. As long as it was not stressed too much, the 1000 could power anything. The peak-power outputs were so high for so long during the AR demonstration (800-1000 watts peak-per-channel into the AR-10Pi speakers) that the event eventually destroyed the amplifier, and AR (Victor Campos) eventually used another similarly powerful amp for the demonstrations. As I sit here now in my office, I'm listening to that exact pair of AR-10s that was used during the LvR demonstration.

--Tom Tyson

[Gerry S]

Tom, I never blew a 910 fuse either. I do remember the Dunlap-CLark "VU" meters "dimming" significanty when I "clpped them". The meters weren't "true" VU meters because their ballistics were a bit slower than what's called for. still good enough though ! At the "-20 db" level meter setting, 0 to +3 db "average" readings would clip the Dreadnaught. Strangely enough, none of the fuses on the amplifier blew either. And if the fans did come on , it was a very rare occurance. I actually owned TWO Dreadnaughts. When they eventually failed , it was an output transistor.

I actually used the Dreanaught to develop the "improved" BA towers and found the Dreadnaught invaluable; revealed some critical performance criteria i wouldn't have noticed if I used the amps BA had in the labs at the time (big Adcom and NAD amps). But that's another story.

[Gerry S]

Gerry,

When I first got my 1590s I hooked them to my McIntosh MC2500 amp (a full 750 watts rms/channel continuous), and drove them quite hard playing some Telarc recordings on numerous occasions -- sometime to maximum peak power (Power Guard clamping the output on several occasions) -- but I never blew a fuse or damaged any drivers. It was so loud as to be uncomfortable, and the fact these speakers survived this ordeal is probably indicative of the high levels that could not be tolerated for too long! Those two big fans on the back of the Mac would light up and run hard on occasions, indicating a lot of current was passing through the outputs! ADS speakers tend to be durable; however, an underpowered amp clipping badly will always cause problems and can easily destroy a tweeter. Ironically, later Type 2 L1590s and L1290s did away with some fuses, as they were deemed unnecessary.

The Dunlap-Clarke Dreadnaught 1000 was a fine amplifier, and it was originally used in the mid-70s AR-10Pi Live-versus-Recorded demonstration with Neil Grover as drummer. Steve F attended some of these concerts. As long as it was not stressed too much, the 1000 could power anything. The peak-power outputs were so high for so long during the AR demonstration (800-1000 watts peak-per-channel into the AR-10Pi speakers) that the event eventually destroyed the amplifier, and AR (Victor Campos) eventually used another similarly powerful amp for the demonstrations. As I sit here now in my office, I'm listening to that exact pair of AR-10s that was used during the LvR demonstration.

--Tom Tyson

Senior moments come and go. While it's still in my head: "another similarly powerful amp for the demonstrations" was (I think) a Luxman M4000. The Dreadnaught cost me $1500....very industrial looking. The Luxman cost several times that....more than the car I owned at the time. It almost weighed as much too..LOL

[tysontom]

Senior moments come and go. While it's still in my head: "another similarly powerful amp for the demonstrations" was (I think) a Luxman M4000. The Dreadnaught cost me $1500....very industrial looking. The Luxman cost several times that....more than the car I owned at the time. It almost weighed as much too..LOL

Gerry,

You were close: it was the Luxman M-6000 dual-mono (monoblock) amplifier that was used with the AR-10Pi speakers in the Neil Grover live-versus-recorded demonstrations. I think that the Dreadnaught was preferred by Victor Campos because it was "manageable," but it failed along the way. The Luxman weighed over 115 lbs. Ironically, the Luxman was rated for 8 ohms and not 4 ohms, yet it could power the 4-ohm AR-10s easily without shutting down. The M-6000 was a also very expensive, limited-production amplifier that was not mass-produced. Just think that if they had amps such as the QSC PLX-3602 or the big Crown Macro pro amps (5002v or whatever it was), doing a high-power LvR would be a breeze!

--Tom Tyson

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[tysontom]

Several questions have been raised about differences between the mid-1980s "Series 1" and late-1980s "Series 2" ADS speaker models. The following information is adapted (and paraphrased) from some internal and generally published ADS material and manuals. It outlines in some detail the changes from "Series 1" to "Series 2" that were made to the ADS models L470 up through the L1590 flagship tower loudspeaker, subject of this topic.

Series 2 Changes:

ADS made a series of significant engineering changes to the "L" series loudspeakers (L470 through the L1590) in the 1987-1988 period that resulted in improvements in smoothness, power-handling capability and lower distortion. Improvements were made to crossover networks and driver components themselves. For example, the new version were called "L1290 Series 2," or "L1590 Series 2." Original series were simply "L1290" or "L1590," but were referred to internally at ADS as "Series 1."

These changes came about as a result of new computer modeling techniques, such as FFT measurements, that allowed ADS engineers to enhance product performance and durability. Another reason for the improvement came about due to concerns about reducing coloration and distortion in the midrange area. Since ADS speakers were already critically acclaimed for excellent performance in smoothness, off-axis response and low distortion, this improvement was further indication that ADS was very serious about making state-of-the-art loudspeakers for the consumer high-fidelity industry.

For the woofer systems in the new Series 2 versions of the L1590 and L980, ADS changed the 2-inch diameter voice coil former from aluminum to Kapton, a material unaffected by heat well beyond temperatures found in loudspeakers. Kapton is more stable than aluminum at high temperatures and is not affected by magnetic flux during wide excursions.* This simple change reduced low-frequency reproduction coloration and distortion, improved damping and increased power-handling capability for this woofer system. This was a subtle but important improvement in an already potent low-frequency system in the L1590.

For the 2-inch fabric-dome midrange driver, Kapton formers were also used in addition to Ferrofluid to stabilize and cool the voice coil. This improved transient response and smoothed the output in the 5kHz region approaching crossover, reducing a 2-3 dB rise at that frequency to 0 dB. The Kapton former further reduced mass, thus improving efficiency and damping of an already nearly ideal reproducer. The actual passband of the 2-inch Kapton midrange driver was widened to allow a lower crossover to the woofer section, allowing a 350 Hz crossover and the elimination of the 2.5 amp protection fuse. Crossover transition was smoother.

The ¾-inch fabric-dome tweeter also benefitted from the new Series 2 improvements. The 1.5 amp fuse was eliminated and a special, solid-state thermal protection device was incorporated into the crossover. A damping pad was placed under the dome that both protected the dome against indentation (fingers) and also improved damping. Ferrofluid added to the voice coil also increased damping and power-handling capability, and because of the lowered mass of the improved tweeter, the high-frequency on-axis response was extended well beyond audible limits. The tweeter's transient response was further improved, yet there was scarcely any evidence of ringing in any of the older tweeters. The clarity and smoothness of this tweeter was an important reason for the L1590's reputation as a superior sound reproducer.

Crossovers were improved in the Series 2 versions. Computer-aided analysis allowed ADS to improve interaction between the drivers and crossover, resulting in smoother response and lower coloration. Phase response was optimized for flat-baffle systems. Larger-diameter gold-plated binding posts were added to allow larger diameter speaker cable (up to 7 gauge). New-generation "slick-film" capacitors with lower dielectric absorption and less heat loss were added along with polyester-film capacitors in the tweeter circuits. Midrange coils were air-core, low-loss types and woofer chokes were ferrite-bobbin designs rated for 0.02% harmonic distortion at up to 500 watts input, just prior to saturation. This is steady-state power rating, whereas peak power inputs go greatly higher than that without saturation. For example, in 1984 Julian Hirsch tested the original version L1290 with peak power pulses of up to 2,500 watts at 10kHz, which was the limit of the testing amplifier, without distress, and up to 1200 watts at 100 Hz into the woofers. These high numbers are significant, but the L1590 has significantly greater power-handling capability than the 1290, particularly in the bass frequencies. With the Series 2 versions, this power-handling would have been even greater.

Therefore, the Series 2 changes were significant. Audible differences were certainly subtle, but when compared side-by-side, improvements could be heard in smoothness and clarity. These were the last of the butyl-rubber treated fabric-dome midrange and tweeter units, and the last of the "old" ADS speakers before the advent of the newer a/d/s/ versions of the CM and M speakers. Whether or not the new versions were better than the earlier Series 2 speakers has been debated at some length, but in terms of measured response smoothness and dispersion and the resultant acoustic power, the Series 2 speakers were probably superior to the later models and certainly among the best loudspeaker ever designed.

*Kapton is a high-temperature, stable polyimide dielectric film material used for critical aircraft wiring insulation, solderless terminals and other special applications requiring a wide range of heat cycles. It has been the material used for insulation in NASA lunar modules and so forth.

--Tom Tyson

[Gerry S]

I remember reading brochures on the Series II. On paper, it seemed to have enough engineering improvements to justify it as a replacement for my 910's. So, I went to listen to them...forgot where. What I saw was impressive: tall, elegant towers with all drivers vertically aligned. Metal grills designed for minumum difraction. Compared to my relatively "squat" 910's, they certainly LOOKED more apealing to me.

But, when I heard them, I wasn't "hit-over-the-head" impressed. If I AB-ed them at length, and at home, I might have thought differently. When I asked about the price, THAT'S when I decided the audible improvements (I did hear some in that showrooom setting) were not large enough to warrant lugging them home for extended listening. I think I would have been impressed if I did.

Having done my share of crossovers at BA, I can attest to how important ADS's improved crossovers can be in determining overall sound quality. At the same time, many improvements can only be heard if the system is properly set up, AND quality recordings are used to reveal these improvements. I believe under normal conditions, many of these improvements would be inaudible or very subtle.

I know that there IS a "night and day difference" between an AR 3a and a AR10 pi. Despite having similar/identical drivers, I could easily and repeatedly distiguish one from the other blindfolded. Probaly not as much between the AR 10pi and the AR 9 as far as tonal balance...probably reasonably similar! However, the AR 9 would have been my speaker of choice (tremendous dynamic capabilities AND "imaging") if I had to own something "vintage". I can't help but wonder if I would feel the same way about the ADS Series II if I had purchased them.

The ADS Series II towers (an idustrial designer's speaker) LOOKED more advanced than the AR 9 (an audiophile/enginner type product). I wonder.... which product sold better?

[Steve F]

I was always amazed that AR was able to "get away with" such an unattractive cosmetic design as the original AR-9. I often wonder if the design was intentionally bad-looking, as if to emphasize the no-nonsense engineering, or if it was ugly simply because they had no good industrial designers working on the project.

 

I won't go into the detail-by-detail aspects of the awful looks of the AR-9. Suffice to say, the ADS towers showed that it was possible to put worthy effort into the appearance of the product, as well as the sound of the product.

 

The AR-9 would not be allowed to exist in its original form were it on the market today. I think that its acoustic performance is still commensurate with a TOTL speaker in 2012, but the requisite cabinetry would likely push the 9's list price into the $10k/pr. range in 2012.

 

But it would be worth it, I'd say.

 

Steve F.

[tysontom]

I was always amazed that AR was able to "get away with" such an unattractive cosmetic design as the original AR-9. I often wonder if the design was intentionally bad-looking, as if to emphasize the no-nonsense engineering, or if it was ugly simply because they had no good industrial designers working on the project.

 

I won't go into the detail-by-detail aspects of the awful looks of the AR-9. Suffice to say, the ADS towers showed that it was possible to put worthy effort into the appearance of the product, as well as the sound of the product.

 

The AR-9 would not be allowed to exist in its original form were it on the market today. I think that its acoustic performance is still commensurate with a TOTL speaker in 2012, but the requisite cabinetry would likely push the 9's list price into the $10k/pr. range in 2012.

 

But it would be worth it, I'd say.

 

Steve F.

 

I agree with Steve on this matter!  The AR9, while a fine performer in every respect, is not a particularly handsome tower speaker.  It lacks that classic beauty of the ADS L1590, yet each can hold its own, sonically, with about any new-design speaker out there today.  I have both the 1590 and the AR9 and have lived with both speakers over the years.  These two have many similarities with regard to powerful and clean acoustic performance, but the ADS 1590 is far more handsome in appearance.

 

--Tom Tyson

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[mccarty350]

Tom, I also have an ADS L1590 newly purchased and a set of AR9's.  In my opinion so far they seem to be similar in sound and performance with a tad more bass going to the AR9's and a tad more tightness in bass going to the L1590's.  However, the L1590's are INFINITELY easier to drive.  It's made me consider (and I never ever thought I would say this) selling the AR9's.  Have you had similar thoughts?  I haven't A/B'd them and put them through the paces due to time constrains but perhaps you have.

 

Also, does anyone here have a crossover schematic for an L1590/2 and know whether or not there is any gain to recapping these?  I have been told that ADS used a lot of poly caps in their xover but I'm not sure how pervasive that was and whether or not an upgrade to some modern film caps for the tweets/mids might give me some palpable gain.

 

Thanks,

 

McCarty350

[tysontom]

Tom, I also have an ADS L1590 newly purchased and a set of AR9's.  In my opinion so far they seem to be similar in sound and performance with a tad more bass going to the AR9's and a tad more tightness in bass going to the L1590's.  However, the L1590's are INFINITELY easier to drive.  It's made me consider (and I never ever thought I would say this) selling the AR9's.  Have you had similar thoughts?  I haven't A/B'd them and put them through the paces due to time constrains but perhaps you have.
 
Also, does anyone here have a crossover schematic for an L1590/2 and know whether or not there is any gain to recapping these?  I have been told that ADS used a lot of poly caps in their xover but I'm not sure how pervasive that was and whether or not an upgrade to some modern film caps for the tweets/mids might give me some palpable gain.
 
Thanks,
 
McCarty350

Hi McCarty350,

Both the AR9 and the ADS L1590 have a very similar and potent low-frequency response; both speakers have the same approximate system-resonance frequency. I think the AR9 has a bit more palpable bass output than the 1590 for a couple of reasons: 1) the 9's two 12-inch woofers are close to the floor, and thus the coupling is better and 2) the balance between the midrange/treble and bass is slightly different in the AR9, and tends to favor the low-frequency response more than in the ADS 1590. In short, the AR9 seems to sound "heavier" than the ADS 1590. I suspect that both speakers are close in overall performance in the deep bass (extension and harmonic distortion), but the two 12-inch woofers in the AR9 can technically move (slightly) more air than the two 10-inch versions in the 1590, plus the floor-wall coupling favors the AR9 woofers. It's been awhile since I've actually compared the two side-by-side, but both are such outstanding speakers that it would be hard to choose between the two. I do recall that the differences in powerful deep bass was actually tiny after both speakers were properly equalized for sensitivity differences. Whereas the AR9 might a slight advantage in the bass, the 1590 at times seemed a bit cleaner and smoother throughout the midrange and treble. One advantage: the ADS 2-inch midrange is extremely smooth from below 400 Hz up through 10 kHz, even though it is crossed over into the 3/4-inch tweeter at 5 KHz, it provides very smooth and linear response throughout the midrange. Therefore, there is one less crossover transition in the ADS than in the AR9and except for power-handling capabilitythis is probably an advantage. The ADS 3/4-inch tweeter has always been considered one of the best tweeters ever made, thus the treble response is excellent. I do know that a great deal of attention was paid to the crossover in the Series II versions, and a lot of tests were done with impulse testing to improve phase response along with improving the already nearly perfect transient-response characteristics of both dome drivers. I do know that both speakers are capable of handling a huge amount of clean amplifier power. Back when new, I was able to put my McIntosh MC2500 into Power-Guard protection mode using both the AR9 and the ADS L1590/2s on several separate occasions, and neither loudspeaker seemed to be over-stressed. Both were very clean and effortless, a hallmark of a premium tower loudspeaker system!

All in all, I'd have a lot of trouble choosing one over the other, I like them both so much! I'm in the slow process of rebuilding my pair of AR9s now, and I haven't been able to spend too much time recently on them, but I'll compare the two in more detail once I finish that restoration. I don't think the crossover capacitors are an issue with this series ADS speaker. The Series II speakers use high quality "slick-film" capacitors, and these are designed to last for many years without changes or degradation, from what I understand. I have not heard of the need to update any of the Series II crossovers, but I don't know that for a fact. The overall construction of the crossover is really top-notch, computer-grade, and unless you have a specific reason to change the crossoveror suspect something is amissI would leave that particular crossover intact. The crossover is a 12 dB/octave LCR type, but I can't locate a schematic. I'll try to locate one.

Tom Tyson

[mccarty350]

Tom thank you so much for the great and lengthy response!  I hadn't checked for a few weeks so I apologize for the late response on my part.  It's getting late but I did open up and look at the crossover as much as I could (it's sandwiched together and it looks like it would be very tough to get it into two pieces without desoldering the binding post leads from the PCB) and noticed what I thought to be quite a few NPE caps.  When I get a few more cycles I'll reply at length.

 

John