tysontom

Members
  • Content count

    1,580
  • Joined

  • Last visited

Community Reputation

0 Neutral

1 Follower

About tysontom

  • Rank
    Advanced Member

Contact Methods

  • ICQ
    0

Recent Profile Visitors

9,162 profile views
  1. First ADS'S

    audiofreak, it's fine; we all knew what you were trying to say. Just saying that the expression "tight bass," and "bass punch" are frequently used to describe an emotional experience that sometimes doesn't exist in the real world.
  2. First ADS'S

    audiofreak, the expression "bass punch is tight and fast" really doesn't mean anything. It's an old, tired, audiophile expression that's not based in actual science, and it probably originated at Stereophile magazine back many years ago. It's not the woofers that reproduce most low-frequency transients; it's the midrange and treble that reproduce those overtones and harmonics. The woofer reproduces mostly lumbering, steady-state sounds. If the bass sounds extra crisp and "dry," then the woofer could be over-damped. You don't really want this, but what you are trying to describe in the ADS is the clarity of the midrange and treble dome drivers. Bass-drum rim shots sound clear and well-defines, and plucked violin strings would sound crisp, etc. The woofer actually has very little to do with this effect.
  3. First ADS'S

    Just curious, what do you mean by "bass punch is tight and fast?"
  4. AR-LST mounting.............

    Frank, to answer your question about my AR-LSTs, yes, I am thinking about selling them in the near future. I've had such a large collection of AR speakers that the time has come to thin down the collection, and I have begun selling some AR-1s, AR-3s and AR-3as, etc. I might sell the LSTs in the fall or winter, but I haven't decided at this point. I stored the original grills and ordered a second set (the Norwood "white" linen) in the mid-70s to preserve the originals. Note the Norwood "white" linen in the center. The speakers are still 100% original with no modifications whatsoever, and they continue to work well. These AR-LSTs haven't been in regular use for several years and are stored in air-conditioned/humidity-controlled storage. --Tom Tyson
  5. AR-LST mounting.............

    I designed these wall mounts (and they do sort of look like "Frank's Urinals," now that you mention it!), and I sent drawings to AR to see what interest the company might have with them. There was interest -- probably out of politeness -- but due to the size, weight and high cost, nothing materialized as AR inched closer to the new-style ADD speakers later in the mid-70s. The LST was nearing the end of its career by 1974-1975. The important thing to me was providing enough strength to hold them securely to the wall without having to mount brackets on the back of the LST (AR did have the big-speaker "French Cleat" wall-hanging brackets, but it required screwing into the back of the speaker). Also important was the notion to protect the speakers and to have the stand blend in with the wall to make it appear as if the speakers were "built-in." Painted the wall color, the stands were barely noticeable in the presence of the prominently physical appearance of the AR-LST. The LSTs were mounted too high in this picture, but there was no choice because of headroom along a hall to the right side. Because the speakers were so close to the ceiling, the sound quality was compromised somewhat; I later inverted the speakers to put the woofer close to the ceiling, and this was an improvement but not ideal. --Tom Tyson
  6. Edgar Villchur On Multiple AR-3 Speakers

    This letter -- as with many that Ed Villchur wrote over the years to audio-magazine editors -- exemplifies the dry wit and high intelligence of the man. Villchur was nearly always on another level when he was confronted with these sorts of things. If you read Villchur's letter carefully, it's easy to see that he considered the question "of whether three AR-3s 'equal' one E-V Patrician" to be ridiculous in its context. Norman Eisenberg, a bit "off the wall" at times, was was forced to reply with a convoluted rebuttal that was largely meaningless double-talk, probably flying over the heads of most readers. Norman Eisenberg,not surprisingly, got his facts confused regarding AR's live-vs.-recorded concerts and demonstrations. He thought that Acoustic Research used multiple AR speakers for each channel; as Eisenberg said, "as witness the use of more than one AR system per channel to make such demonstrations more effective." That is certainly not so, but what he misunderstood was that multiple AR speakers were used for sound reinforcement in NY's Museum of Modern Art and other venues for background jazz, etc. --Tom Tyson
  7. Wow, we've seen it all! Those "tweeters," more than twice the diameter of the 3.5-inch mid-range drivers, are old WWII University Sound field PM speakers used in jeeps and so forth. They were mil-spec and environmentally sturdy, but there is scarcely any semblance of "high-fidelity" sound emanating from those phenolic cones. Those woofers look like Pioneer or Sansui models with probably a very high fs, resulting in no deep bass but lots and lots of boom. These are the pre-1970 AR-2ax versions that had the 1-3/8-inch tweeter and the six-bolt alnico woofer, but it looks as though a larger hole or recess has been put into play. Nevertheless, if free,what could you lose? These could still be rebuilt back to original specs with a lot of work!
  8. AR-LSTs

    The cabinet on one AR-LST has been seriously damaged (obviously dropped), causing huge damage to the speaker enclosure. There also are no pictures of the woofers. Hard to say what they are worth. The person listing them bragged about a "matched set" when, if fact, there was no such thing as a "matched set."
  9. Lovely set of LST's

    This early AR-LST, #00081, was built in 1971. It is remarkable (to me, at least) that one of the urethane surrounds is original if barely barely intact, even though the other speaker's surround has begun to collapse in on itself! AR coated all of these early (until 1975) 12-inch woofer surrounds with a clear butyl-latex coating, and this one has been a survivor after 45 years, defying the odds. My LST woofer surrounds lasted this way until around 2013. Most of these surrounds were beginning to go south after 17-20 years, so to see them last for this many years is great. This pair of LSTs has great original grills -- and the cabinets look great -- but sadly there appear to be problems with some of the tweeters and/or the crossover network. Still they should do well considering their overall excellent condition. My pair of LSTs are packed away, but they are in similar condition and have no electrical issues. I stored the original beige-linen grills and ordered replacement grills from AR in Norwood, which were the later "white linen" versions, so the original grills are still in nearly new condition. Norwood "white-linen" grills AR-LST No 636, 1972 AR-LST No. 636 Norwood "white-linen" grill in center vs. "beige-linen" original grills behind. The black outline is a result of a black sticky substance the AR Norwood people put on the grill frame before mounting the grill itself, supposedly to keep the grill material from "migrating" or sagging. Instead, the black mastic leached through the grill. This was later corrected, but some grills have the black showing through the grill itself. --Tom Tyson
  10. Is this 3a woofer toast?

    WTF! Never, ever put anything like that on the inside of the voice coil! To add grease to that woofer (one not designed for anything like this) would seriously degrade the performance of the woofer and cause it to be very over-damped. The grease will always be somewhat in contact with the pole piece and coil, and it will drag it down a small amount, just enough to ruin the normally ruler-flat bass response of this woofer. Bass response would seriously suffer and the roll-off in deep bass would be very audible. Someone had the erroneous notion that putting grease in between the voice coil and the pole piece would create a path for heat dissipation and give the woofer greater power-handling capability, much like the addition of Ferrofluid to a tweeter voice coil. It won't work this way with a woofer with such great excursion (greater than one-half inch, peak-to-peak, or more). --Tom Tyson
  11. Probably not many people actually mount their "classic" AR speakers horizontally on shelves anymore, but the speakers definitely sound better mounted that way. For one thing, it eliminates the fairly audible "notch" in the mid-bass response caused by cancellation reflections of bass frequencies bouncing off the wall behind the speaker and joining, out-of-phase, the forward-firing bass frequencies. This causes a "notch," or "suck out" of frequencies in the 200-300 Hz range. If you have one of the tower speakers such as the AR9 or AR90, AR9Ls, etc., the woofer is mounted close to the floor-wall intersection, and the notch is pretty much eliminated. If the woofer in a bookshelf speaker has a low-enough crossover, say below 200 Hz, then the notch is a non-issue, but few bookshelf speakers have such a low crossover. You can also plunk the speaker directly on the floor, but the sound gets pretty boomy and heavy when you do that. Here is the way I had mine mounted at one time. The sound was great.
  12. Are these AR3's?

    Good! First thing to do is to take a knife and scratch off the paint on the three terminals on the tweeter-terminal strip. The "TTS" is the oblong terminal plate located between the midrange and tweeter. Then, take a 1.5 VDC flashlight battery with a wire connected (preferably soldered) to the negative and another wire connected to the positive terminals, and "touch" the wire to first the center terminal and the other wire to each outside terminal and listen for any "crackling" noises from the drivers. Never attempt to directly check voice-coil's continuity of the exposed aluminum lead-in wires. Also, do not hold the battery connections for more than a brief second; this will needlessly heat the aluminum voice coils. In fact, it's best to simply touch the wire on and off to listen for any sound, thus establishing continuity of the midrange and tweeter voice coils. This is just a quick, simple test to be sure you don't have any voice coils that have been burned out by someone over-driving the speakers. By touching these terminals, you are bypassing the crossover by putting small voltage directly to each driver. Do it sparingly. Be very careful when you work around the tweeter's lead-in wires. These wires are aluminum and are fragile; avoid touching them if possible unless you are very careful. That tweeter looks to be in excellent condition, by the way, and the suspension has not "popped" in any way, meaning that it is clearly within the original spec as far as alignment is concerned, and the dome hasn't migrated away from the top plate. The woofers, though ugly looking here, are probably fine. They are very durable and don't often give trouble. You should put all of your fingers around the outside of the center dust cap and gently push the cone "inward" about 1/4 to 1/2-inch, and then immediately release the cone. It should return to the "center" position slowly within 1-3 seconds or so. It should feel like you are pushing the cone through a viscous fluid when you depress the cone. If you don't feel this resistance and the cone bounces back immediately when you depress it, the surround might be leaking air; but frankly, only a few of the 3700-series woofers suffer from this problem. Do not apply any butyl-rubber or other compound to the cloth surround unless you are positive the cone is leaking air through the cloth. Applying anything to the surround can do more damage than good if the surround is not leaking, despite what anyone says. The free-air resonance can be affected by applying substance to the surround, and this is not good. Take a clean paint brush and lightly "dust" the dirt and grime from the cone and surround. It has collected a lot of dust over time. This AR-3 definitely has an AR-3a cabinet, but the drivers are the original-type Alnico #3700 woofer and #4500 2-inch midrange and the #375 1-3/8-inch super tweeter. This was definitely getting to the end of the line for these drivers, so you are fortunate to have the original-style drivers in an AR-3 this far along. --Tom Tyson
  13. Are these AR3's?

    The grills may be attached with Velcro, but likely AR used hot glue to hold them in place. Gently try to pry the grills away from the cabinet, but watch the walnut grill molding. It's easy to scratch the molding. Use a wide putty knife and use care.
  14. Are these AR3's?

    Great work! For sure, man-handling two 52-53 lbs loudspeakers down stairs would be stressful. Hope you didn't hurt your back. Serial number 69923-69935 were definitely manufactured by Acoustic Research at the 24 Thorndike Street, Cambridge, Massachusetts factory in May-July 1972. The AR-3 was produced through 1973 and finally discontinued in early 1974. For nearly ten years after it was introduced in 1958, the AR-3 was considered to be the finest, most accurate loudspeaker available anywhere for any price. To this day, a pair of properly functioning AR-3s is still a wonder to behold! These particular speakers you have likely used AR-3a-type cabinets, and probably have ferrite woofers! Send pictures when you can. Remember, when you first connect them to an amplifier, be sure to gently rotate the level controls back and forth a great deal to get contact. Don't be surprised or dismayed if you hear nothing from the midrange and tweeter drivers at first! You might have to spend ten or twenty minutes turning them back and forth until finally you will begin to hear some light "crackle" of sound through the midrange and tweeter. Sometimes, you can come back later and you will easily find those "contact" points. AR level controls work sometimes in the "paranormal" world, so don't be surprised. Don't apply too much power at first! Congratulations! --Tom Tyson
  15. Is this 3a woofer toast?

    With the surround gone, and spider (inner suspension) will cause the cone to collapse down below the "center" position, and frequently it will be tilted and will rub. This woofer (in question) is the original-type 200003-0 AR-3a version, second iteration short-wire version, likely 1971-1973 or so, and it is actually one of the more desirable versions of this superb woofer. This woofer is extremely compliant, and you must shim this woofer when you re-foam it to be sure of proper voice-coil alignment. Do not cut the dust cap all the way off (see my pictures below), just cut it very carefully with a razor blade or similarly sharp knife blade around a circle (watch carefully for the lead-in wires to the voice coil assembly under the dome) and leave perhaps 10-20 degrees out of 360 degrees (perhaps 10mm) enough to fold the dust cap back away, exposing the voice coil assemble and cone apex. Never replace the dust cap with a new plastic or paper version! This dust cap is slightly porous, and it lets air from under the dust cap escape very slightly. You risk raising the free-air resonance of the woofer if you replace the dust cap; leave the original in place, but you must shim the voice coil. When you use a proper 5/8-inch foam surround (check with RoyC and others to get an idea of the best surrounds available today) and shim it properly, you should end up with a free-air resonance ("fs") of 17-19 Hz, and the speaker will have the proper system resonance of 41-43 Hz. Distortion will be extremely low with this woofer. It is possible that someone over-drove the woofer and caused the voice coil to slam against the back plate and damage the coil assembly; it's also possible that the woofer has been damaged by a defective or inadequately powered amplifier (most properly working amplifiers will do no harm to this woofer under normal music and speech playback) or extreme over-drive or clipping by an amplifier. Some amplifiers go bad and produce excessive dc offset in the output, and this will damage the woofer. AR9Lsi 12-inch woofer, similar to the 200003-0 AR-3a/AR-LST-type woofer. AR9Lsi woofer AR-12-inch voice coil and dust cap shimming. --Tom Tyson