Philips F9638

Active, superlative, techno-looking and expensive...

This was how to bring MFB to an even better level, a modern 1980s level : with flat membranes and a low-mass Isophase leaf tweeter !
Of course, you guessed it, all this was a necessary minimum to cope with Digital Audio :)

The flat membranes made for most of the modern look because MFB (Motional Feedback) loudspeakers were as old as the hills :

Voigt and Hanna patented an equivalent scheme in 1924, Trouton in 1928, H.F. Olson wrote about it in 1940, after which came Boer and Schenkel (1948), Werner and Carell (RCA labs, 1957), Brette and Perrin (1961), Gogny (1961), Sakamoto (of Matsushita, 1965) and, no doubt, plenty of others.

Matsushita patented such a system in the early 60s but seemingly licensed it to Luxman who already had an audio reputation (Luxman in return built a special version of its SQ5B for Panasonic).

There is one 105W power amplifier inside the F9638 for all three drivers but, despite imposing looks, the enclosure is only 26 L...

Better yet, daisy-chaining a few F9638 in series was possible, and without losing the benefits of the respective MFB circuits ! Automatic power-on is another feature (only 0,5W is drawn when idle) and a L or R selector is present on the back.


Nitty-gritty: the 1983 F9638 had an "electronic three way speaker system" tag on its front lid, a statement modified for the 1984 models : "Active Response Control System, Designed for Digital Audio".
Case in point :)

The F9638 seemingly sold just as poorly as the original 1970s models like the RH545 - pity.


Nudies aplenty here.