Conception and design of Pi One, 10Pi and ADD/Truth in Listening series

[fedeleluigi]

Hello everybody

If someone knows and remembers it, I'd like to know, as accurately as possible, when AR Pi ONE, 10Pi and the ADD/Truth in Listening series were conceived (and by whom) and who were their real designers.

Moreover, about on June/July 1977, there was an "MKII" series (although AR never mentioned an MKII series, there were some differences both in drivers and sound). Drivers were lightly different: tweeters used ferrofluid, the 10PI and 11 midrange suspension turned from concave (like in the 3a midrange ) into convex (like in AR 9 midrange) and midrange adopted the silver screen and the pale pink fiberglass, woofer had some changes in the paper cone and spider, crossover used a different capacitor trademark, etc . I would also like to know who designed these last driver modifications especially those for AR 10Pi and 11.

Thank you in advance

Luigi

[fedeleluigi]

It's really a pity that  people and engineers who worked at AR when the  Pi One and the ADD/"truth in listening" series were concepted and designed, did not and do not take an active part in this forum. 

 

So, a lot of accurate and precious information about the history of these excellent AR speakers  "will be lost in time like tears in rain"...

 

Personally, I want to thank all people in this forum (Tom Tyson,  Steve Feinstein  etc.) for the historical and technical information given about many AR speakers  all along  these years.

 

In Italy the ADD series has been (and is) considered the AR's swansong by many important audio engineers and reviewers.

 

For example, the AR 10 Pi (more precisely the Pi One) was the only commercial loudspeaker that Renato Giussani bought in all is life. No doubt that Renato Giussani was one of the most important Italian loudspeaker designer. He designed  the 7 series for ESB and many other well sounding speakers. The last company he founded was the "Giussani Research" that is still operating. 

 

Besides being a loudspeaker designer, from 1972 to 1979 he was the laboratory chief technician and loudspeaker reviewer for two of the most important Italian audio magazines: Suono and Stereoplay. Since 1972 he  measured, listened and reviewed  all the vintage AR loudspeakers (and not only) for those magazines. In his opinion, the AR 10 Pi was one of the best designed and sounding loudspeaker ever. Unfortunately Renato Giussani  died before his time on July 25, 2014. A useful link for who wants to know more about him,  is : http://www.giussani-research.it/renato-giussani/?lang=en

 

Someday, I do hope someone can answer my questions about conception and design of Pi ONE, 10 PI and the Add/"truth in listening" series.

 

Luigi