Sonographe SL-21 speakers


I am not really asking a question on these speakers, since I may have had the only pair in the whole country. I just want to make a few comments on these fantastic little speakers.

I purchased these speakers by chance, I heard about them and drooled over them in the late 80's, but I could not afford any high end gear at that time.

After spending hours searching up and down on the internet, I couldn't find diddly-squat on these speakers, but there are no shortage of info for the Sonographe SA-120 and the SP-1, even the SG-3 is mentioned quite a bit on the net, that really makes me sick.

Anyway, the SL-21 has very attractive real oak veneer, the front and back are sloped, hence involved some time-align design, but like I said, I could not find anything on them. Even when I called C-J, the guy named Ed who handled vintage C-J equipment couldn't tell me a whole lot about them, at least Sota could tell me quite a bit about the SG-3 for crying out loud.

The SL-21 has very wide soundstage and solid bass for it's size, 6.5" woofer and 1" soft dome tweeter, and a 1" port in the front baffle, they also have very nice midrange. The speakers virtally disappear from the room while playing, that proves these speaker are well designed. During the knuckle test, I heard no cabinet echo or resonance, very solidly built, that tells me they are well damped inside.

If anyone who know about them, please charm in. These may be the only pair that left in the country, and they are not for sale.
sovtek6922
all cj speakers (synthesis and later sonographe) were well kept secrets) As as the case with motiff and other cj branded experiments, they ere ambitious, among the best values in audio, and for a variety of reasons, abandoned....go figure.
You may have one of two pairs in the US and I'm sure there are others. I bought mine from a dealer in Tucson many years ago. The dealer quit bringing them in because everytime someone heard them compared to his big expensive speakers they ended up buying the CJ's. a great little speaker.
I have never heard of the synthesis speaker by CJ, but as far as CJ's keeping their speakers a secret that's very interesting.

I would very much like to learn more about the technical aspect of the SL-21, like who were the designers, were the folks at Sonographe, or the folks at CJ? What components did they use, and the crossover design?

My SL-21s front grills are long gone, however, my 1988 Audio magazine advertisment with the picture of the SL-21 didn't show any front grill, the Audio Annual Buyers Guide said the SL-21 grills were optional.

Can anyone tell me if your SL-21 came with front grills? If so, what do they look like, and are they easy to make?

I'm guessing that c-j's direct involvement with the "synthesis" line might have been some what limited.
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Sota made similar looking speaker once upon a time. I am wondering if they had a hand in the Sonographe SL-21, after all I think they designed the Sonographe SG-3 turntable.
the gentleman(can't remember the name) that designed cj's speakers left and started his own line, which failed too. they all ere outstanding. sota's panorama line were incredible as well. two unit sats and subs thats outwattpuppied the watt-puppy...once again they didn't last.
I believe Dave Fokos designed speakers for C-J . I do not know if he designed SL-21.
I own other speaker of his design Icon Acoustics model Parsec. They sound great. Icon Acoustics was his own company. After IA went out of business Fokos worked for Boston Acoustics and Bay Audio. Do a search for Dave or David Fokos.
Quote from inc.com :

“In June 1984 (Dave )Fokos, fresh out of college, landed a job as a loudspeaker designer for Conrad-Johnson, a high-end audio-equipment maker in Fairfax, Va. In the next four years Fokos would be the principal designer of 13 speaker models for C-J, an experience he calls "an invaluable apprenticeship" for running his own show. Fokos founded Icon Acoustics in April 1989, believing the niche he sought had scarcely been explored.”
I have had a pair of the SL-21s since the mid 80's and people who come to visit are still astounded by the sound quality. They're paired with Yamaha separates from the same era (C20 pre-am and M20 amplifier). Unfortunately the grills have both "disintigrated" and, when I called Conrad Johnson I was told they could not find any in the warehouse. Doesn't matter..the speakers look great without the grills. I remember the first time I heard them. I was in an upscale stereo store in Cleveland (no longer in business) and I heard all of this great sound and I couldn't quite locate the source. It turns out all that sound was coming from two little boxes sitting on the floor of the store. They have wonderful musicality and a great sound stage...even better than my B&W's which are much newer.
I recently aquired a pair speakers that sound similar to these. A metal tag on back states manufactured by Conrad Johnson of Fairfax, Virginia Model Number LM20 Serial Number 0200268. The other speaker's tag is missing. They sound good. The cabinets are clean without moajor blemish. They are heavy and well constructed. The foam grill covers are good but not perfect. I am in Atlanta. I would like to know more about them if anyone can shed some light.
Does anyone know the exact Vifa Woofer model # used in these as well as the Tweeter model?

Also, does anyone know if the woofers were shielded or un-shielded as original?

Thanks :)
Sonographe seems to have been c-j's 'budget' line. The models were similar to Synthesis, but were less expensive and had less impressive cabinets. Synthesis speakers were designed by Dave Fokos, who later founded his own mail order company, Icon Acoustics, worked as a designer for another company or two, and went into photography. A local store in Charlottesville Va handled all the c-j stuff and I got to listen to several models of Synthesis speaker: the 2-way LM-210, LM-260, LM-260i, and 3-way LM-300. I also heard the Sonographes. I believe the Synthesis speakers used Bessel filter crossovers, which Jon Bau had popularized with the Spica TC 50. The imaging was outstanding on all of them, though the bass of the 210 was a bit underdamped, while the 260 was overdamped, but to very nice effect. Deep organ notes produced silence but tympani sounded wonderful - you could hear the decay clearly separate from the sound of the mallet striking the head. The 260i extended the bass. Lewis Lipnick was quoted as liking Synthesis speakers in a NYT article, though of course he went on to praise other brands.
I couldn't afford the speakers at the time, but I'd love to have a used pair of 260s or even 210s. The 260s had uncanny imaging if not a lot of depth. The 210s had more depth if not quite as much specificity, and had a really ballsy midrange with solid state, but with cj tubes they sounded extremely liquid and sweet. Great dynamics made them great for either rock or classical. A pair of CM-205s sold just recently on Audiogon. These are similar to the 210s only standmounts with less low end than the 210, which is a tower, like the 260 and above. The seller said they use the same drivers as the 210, in which case they should be pretty capable speakers. All the Synthesis designs got excellent reviews in Sphile. Now I know that nearly everything else does too, but the reviews were good enough that taken together with cj's reputation they should have been able to move some wood. I don't know why these speakers are not more common. They are scarce as hen's teeth. I get the feeling that c-j didn't place the line in a lot of stores. I can't imagine customers were disappointed with them. Also, Synthesis made too many different models given the volume of business. They had silly variations: for example the 300 was just a 310 in a clunky cabinet. I think there was a 200 that was a 210 in a clunky cabinet. Very bad marketing. Dave Fokos is still around and from time to time the idea occurs to me of asking if he has the specs for a DIY project. I would welcome any news or stories anyone has to share. I hope to pick up a pair of one of these models sooner or later, though locating a pair is not trivial.
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Old thread, but..."A local store in Charlottesville..." I spent many hours in that local store, heard a lot and bought some. Heard the full CJ SRS Synthesis system. Spicas. Early Meridian active speakers... I bought and still have the CJ SG3 turntable, although SOTA supplies my belts as the bought the design from CJ. The wood for the SG3 was constructed here in Charlottesville.I just found a pair of the LMS-210 speakers and I will probably buy them to maybe replace my little Madisound SEAS kit speakers. I run all tubes- CJ pre-amp and Assemblage/Sonic Frontiers amp- and am curious what I will find, but when the bug hit a few months ago it was started by me thinking about CJ speakers, migrated through looking at kits, old smaller Snell (I used to have a pair of original type A but once kids came along I needed the space in my house for other things), and even Bud Fried speakers. But then these LM 210s came along, so we will see.
Uh, now it looks like LM-260s will be my choice instead. I didn't think I could find them but a very little effort yielded results. I wonder if my 40W tube amp will be up to the challenge. Assemblage ST040 (Sonic Frontiers kit).
The Sonograph SG3 turntable was originally produced in Oregon in the early 80s. Was bought out by CJ in 1984 I believe. CJ then started making electronics under the Sonograph name. I did not remember about the speakers.

I own a original Sonograph with a Sumiko MMT tonearm. Purchased in 1983.
As I do. I have bought a couple of belts for it from SOTA, new hinges for the dust cover, and recently cleaned out the bearing after too many years and lubricated it with oil from George Merrill. I can afford his oil if not his turntables!

Does anybody know what the DB rating of the CJ

sl21is I’m looking to purchase a set and I’m running at 6 W per channel tube app so obviously I need a speaker of at least 90 DP or above

I would appreciate any help I can’t seem to find specs on these particular speakers anywhere

thanx chaos124

Hello Chaos. I am attempting to attach a pdf of the CJ Synthesis brochure but I don't think this forum will let me do that. Here is some relevant information: IF the SL-21 morphed into the Synthesis LM-20, sensitivity of the (LM-20) is 90db.

 

From the brochure: LM20 uses a 6.5 inch polypropylene woofer and a 1 inch soft polymer dome tweeter with crossover at 1500 Hz.  Is this similar to the SL-21?

 

 

Good luck.

 
 
 
 
 
 

 

 

Synthesis Speaker Brochure.pdf

I did end up finding some information on them and I made the purchase and I’m so happy I did. They are absolutely beautiful. I’m running them on a 6watt per channel tube amp playing  primarily albums and the sound is absolutely phenomenal!