newandold

Hi Jill, Those AL 120’s are in the 32 year plus age range. The woofers (the larger of the two drivers) are installed with one reversed, to smooth the bass with the lowest possible distortion. Allison had 5 models that I know of (I’ve got one of them) that used the same arrangement. The two problems with those speakers are the surrounds on the woofers, and the availability of a tweeter, should one blow out. How far you need to go with those systems right now, depends on “how hard you play”. If you don’t drive them terribly loud, you COULD go for a while yet without having the woofers redone. Bill

Jill, If the sound is “good” as you say just continue to enjoy them, regardless of what you do about the TV ?. One has nothing to do with the other. I’ve replaced my TV 3 times while still keeping the old Allisons. Mine are 33 years old. My “newer” Allisons, similar to yours are babies at a mere 26 years of age! Bill

Glad to hear you were able to isolate the noise issue. Congratulations on your very fine acquisition! (And I like that woodwork in your room also!) Extraordinary....to grab LST’s at that age and be able to just plug and play without issues! (Very cool) Best of luck with them Bill

It’s a methodical process.....going thru each section of these wide dispersion speakers until you get to the source of the noise/ distortion. I’ve had 2 not so distant cousins to the LST’s ....The Allison:One and The Allison IC 20.....6 and 10 driver cabinets respectively. The A1’s I bought new, so nothing to do but play, but the IC 20’s were a 25 year old (at acquisition time) labor of “love”. The short story of how I got them ready to go back into service was to bring one system at a time (with my new hand truck) into my listening room and swapped it with the existing right loudspeaker. With the woofers removed, I evaluated the performance of each midrange and tweeter (all series wired) and isolated any noise/distortion issues. With the aid of Millersound in Pennsylvania, I had the voice coils in 3 midrange drivers realigned, a handful of questionable solder joints redone, and a rebuild of the (4) in my case woofers which included replacing the spiders and the surrounds. Other detail work also done, but without getting totally lost in this since it’s a different system then what you have acquired, the point is, evaluating each section individually is the key (including the crossovers) to isolating the “crackling” noise. Bill

Have to be very careful when removing and reinstalling the woofers. Those nonconducting tabs that secure the leads can easily end up like yours if they bang the cabinet. Bill

"The NAD design principles recognize that the minimum impedance of most speakers is somewhat lower than their nominal ratings. It is not uncommon for the impedance of a "4-ohm" speaker to fall as low as 2.5 ohms at some frequencies. If two sets of such speakers are operated in parallel, an amplifier with limited current capability may produce distorted sound or even overheat and shut down under prolonged or high-level operation. To help deal with this problem, NAD provides a switch in the rear of the Model 7140 receiver to reduce the operating voltage on its output transistors when driving loads of 4 ohms or less (this is designated the "normal" setting). When the switch is set to its "8-ohm" position, the increased power-supply voltage enables the amplifier to deliver its maximum output to nominally 8-ohm speakers." …..Interesting read regarding your receiver. When I first read your post, my suspicions were about the amplifier section of your receiver and how well or not it could handle the load of 2 pair of Allisons over a long period of time. Nothing lasts forever, and my first suspicions are that your amplifier section is getting "tired" sorry to say. In 43 years of dealing with the Allison Loudspeaker, I've never seen the kind of trouble you are experiencing be attributable to a ferrofluid or cap condition. Bill

Congratulations and such an amazing journey for those prizes! I have a soft spot in my heart ❤️ (and my ears) for any and all of those ultra wide dispersion loudspeakers that came out of BOTH acoustic research and Allison Acoustics, of course both of which Roy Allison had his hands in. I never had the opportunity to hear those predecessors to the Allison One (if I may call them that) but after being around the AR drivers for so many years and experiencing RA’s A1 and The IC 20, I’ve got a pretty good idea of how cool they MUST be. Bill

Highly unlikely the capacitors in the Allisons are causing your problems. The resistors in the CD7s are internal, thermal overload protection for the drivers and I’ve heard of instances of them going bad. You could bypass them and be careful of overdrivng the speakers but leave the original caps alone

The Allison 20 was the only 10 speaker (driver) cabinet to ever come from Allison. Plenty of info available here on this site about them. The Allison One was a six driver cabinet. Bill

The original Allison Eight (on the ends) would make for an awesome center channel speaker for the right setup. Bill

That is extraordinary and fun to look at for sure. A number of things come to mind as an experienced Ebayer buyer and seller. A bulk sale such as that is a bust unless the buyer “steals” them (relatively speaking) an resells them individually over time.....either way, a daunting task....putting cabs like that together with individuals who have ALL the drivers, parts and the necessary skills to replicate (as advertised) working systems. Yeah, a few guys (mostly here) could pull it off but a pipe dream essentially. Bill

Hi Tom, I have only used “ear measurements” on that wonderful convex driver, ever since I first owned them in 1977, in the Allison:One. A few guys on the Yahoo forum years ago, talked about “renewing” the fluids, both the silicone grease in the tweeters, (3 way) and the ferrofluid here, but there were never posted completed, before and after test measurement results. I missed them if they are out there. Back in 2012, I sent 3 of the newer midrange units out to Bill Legall to re-center the voice coils (slight rubbing). I never asked him if he touched or did anything with the cooling material. Once you get continuity and sound out of that midrange, there are only two things I’ve noticed that radically impact the sound. A damaged voice coil, which sounds typically like any other blown driver, and the voice coil rub, which is awful when it happens....adding distortion that kills the show. Actually, there is one other, and that is over tightening, or unevenly securing the midrange into the cabinet. This problem, I believe, is unique to the midrange with the newer plastic bezels. Over tightening that one stresses the voice coil and reduces the drivers normal output volume. Bill

You bought the wrong tweeters, unfortunately. You CAN, get away with using them in the 9, but you bought 2 way tweeters designed to operate to spec. In models 4, 5, 6, and 7. They look identical, but use ferrofluid, rather than silicone grease cooling material. These days, you’re lucky to come up with anything at all. Bill

Admittedly, I'm too lucky in that regard. Not long ago, someone saw my living room and said it looks like a bachelor's pad. My bride is a huge fan of the Home Theater, and that has given me creative license in that room. A 115 lb. subwoofer sits in the corner, and I think it was at least a year before she even asked me what that was.

Then, the Ebay advertisement photos, must make you cringe just a bit. The distance from the side walls is good but too much gear in the corners choking off the reflective effects of the systems. I started with the Allison:One in 1977 and have had the opportunity to test every placement option of the non box, prism (or semi) within reason and the design parameters. I found 3 to 4 feet away from an unobstructed corner is cruicial to get the best out of them. Optimization of the bass is much different, when comparing the LST to the A1, or IC20, as the latter are floor standing systems. Bill

You said it! If you wanted to go the quasi surround (quad) mode and stay vintage, the Phase Linear 4000 is still not too hard to come up with.

I think that’s the right number for LST’s in such fine condition. That number is right about where I was back in 2012, when bidding on a pair of Roy Allison’s IC 20’s. Always I compare the values of those two systems that RA had his hands on. I’ve yet to have the chance to hear the LST and be able to judge the differences for myself. Bill

Hi Lou, Yes I agree it should be an excellent paring. I made use of that “Ambience” circuitry, continually and kept it around 2 o’clock or so....opened up the soundstage nicely. Some purists have a tendency to dismiss that kind of embellishment, but my ears liked it! Years later when I made one serious system for both film and music, I was back to Carver (Sunfire) with his Theater Grand Processor that has an evolved version of that circuitry. Bill

Seen this one...….? Miles Davis with the 2ax

I had an 11 year plus run with the Phase Linear 2000 preamp that I bought new, around 1978. Very clean and neutral sound. It’s not as dead quiet as other preamps between source material, but a minimal issue. It should pair nicely with the Hafler, but I ran mine with the Phase 400. I also had a pair of the 2ax, but they were long gone by the time I got to that point. I think you’ll have a great combination on your hands with that setup. Very Spartan inside that 2000, When you take off the cover, there’s almost nothing in there! (Compared to a modern component) Bill

Turns out I don’t have hard copy on the THREE crossover....however I forgot about saved files on another computer of mine that has a good size Allison File. I’ll check that in a few days and won’t post on this again unless there’s a file attached! Bill

I’m pretty sure I have a copy of the original 3 schematic. Away for a few days but will post it when I get back.

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The sound of the Allison Acoustics loudspeaker is superlative in, or out of the Home Theater ? environment. Automated room correction can be helpful when a particular room presents certain challenges but isn’t absolutely essential....powerful manual calibration can handle the job fine and sometimes better especially with Subwoofer integration. I use my 29 driver Allison system for both music and film and rely on an individual base line set up calibration for each. Bill

I have seen 10 inch 4ohm woofs that looked like these also come from Allison. I bought 1, guessing around 1994. Only difference from your pictures was that the cone had a protective coating painted on it. It sounded fine, mixed in one cabinet with an original, unlike the eminence. Those last years of Allison saw many changes as they were going out of business, transitioning to Stanford Acoustics among other things, that I know only bits and pieces of. Outsourcing woofers was definitely one of those things, so it’s very possible the woofers you show, though not originals may very well have once shipped from the company. Bill