Pioneer S-F1

preliminary

The S-F1 is a Quadradial Flat-Plane Diaphragmed Speaker - like Sony's APM-8, only sort of... all-in-one !

The pre-production sample was somewhat different, especially the enclosure.
Like Kenwood's LX series or the Diatone and Yamaha flat-diaphragm prototypes, the S-F1 is part of those outlandish items which were planned, made, but not really commercialized after the enthusiasm of the 1979 Japan Audio Fair had vanished into the air.

Of all of these tests or attempts, only the APM-8 was actually made (and it sold very well) and the S-F1 (and it didn't).
Specs and technical descriptions are skimp but the diaphragms are made of extremely thin plates of beryllium ; engineering is beyond what even Sony put forth but, this always has a downside, commercially absolutely not viable...

The later S-F1 Custom version had a less sci-fi look but was the same speaker with only the three tone pots deported to the bottom of the enclosure and the front grille replaced by a much more inviting brownish cloth.

One pair of S-F1 has been spotted in Italy, owned by an ex-Pioneer employee : according to his souvenirs, only FOUR pairs of S-F1 were ever made... More accurately : only four were exported to Italy, an extremely strong market for Pioneer.

One pair of S-F1 Custom with serial numbers #CH00103 and #CH00109 was recently spotted (in Japan) : that's august 1982, numbers 103 and 109, probably one of the last pairs made. One pair is in France, too.