Conrad Johnson Synthesis LM-20 specs?

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arnel
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Conrad Johnson Synthesis LM-20 specs?

Post by arnel »

I just acquired a pair of LM-20's. Built by Conrad Johnson in the 80's. However that is all the info I can find on them. I am looking for the following:

Frequency Response -

Sensitivity -

Suggested Power Req -

Nominal Impedance -

Type of tweeter and woofer -

Type of wood and veneer -

Many thanks.
RichardSynthesis
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Re: Conrad Johnson Synthesis LM-20 specs?

Post by RichardSynthesis »

Arnel -- I bought a paid of LM-20 in 1987; I have the original docs that came with it (typed .. very low-tech hardcopy) and a color- advertisement; Neither give complete specs but glad to send you what I have; Email me at ridebeachbike-audio@yahoo.com and send me an email in case I can scan and send PDF. No charge; happy to share; DO you know if these are 4 or 8 ohm?
--Richard
arnel
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Re: Conrad Johnson Synthesis LM-20 specs?

Post by arnel »

Email sent! Thought I would share for future researchers, I was able to contact David Fokos, the original designer of the CJ Synthesis line of speakers, and he told me the following info:

Here, to the best of my recollection are the answers to your questions...


Frequency Response - I don't really remember this for sure, sorry.


Sensitivity - I want to say 89dB, but again not entirely sure.


Suggested Power Req - 50W or more. It is never bad to have a higher powered amplifier.


Nominal Impedance - nominally, 8 ohms. In practice, probably closer to 6 ohms, with a minimum of 4 ohms.


Type of tweeter and woofer - The woofer was a Vifa P17 series. The tweeter was likely to be a Dynaudio D28. You can check both of these by removing the driver from the cabinet and checking the labels on them.

Type of wood and veneer - The cabinets were made of oak-veneered MDF.


I hope this is of some help.


He is now a photographer. After his stint with CJ he went on to build his own company and sell his own speakers for some time, then I believe worked for various companies such Boston Acoustics. There was also a Sonographe model that looked exactly like LM-20's and several floor standing models. One day, perhaps in my dreams only I will own the Conrad Johnson Synthesis Reference system. 2 Subtowers and 2 floorstanders with a ribbon tweeter that cost 8000$ new back in the day. It was the standard they built are their amps and preamps to in the listening room at the warehouse. It wasn't until they heard a Wilson speaker system that they adopted those into the listening room and the Synthesis line altogether was discontinued.
whnay1
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Re: Conrad Johnson Synthesis LM-20 specs?

Post by whnay1 »

Try contacting CJ via their website. They have a lot of legacy documentation available at no charge they can email to you.
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