Pioneer PAX 25a

Back in the early 1960’s the Fukuin Electric company of Tokyo Japan built some really incredible speaker drivers for the new Pioneer brand. The PAX and PIM lines are two of the most famous, and the drivers below are a somewhat rare version, a ten inch coaxial driver labeled the PAX-25A.

The build quality on these early Fukuin drivers is really incredible. The large alnico magnets are covered with nicely fitted bell housings, the frames are solid with careful attention to detail, and the speaker connections are heavy duty. Some of these drivers even had chromed handles. But it's the cone material that is really special; a strange mix of heavy dappled paper, fiber, maybe wool? I’m sure it was a trade secret, although likely borrowed from Rudy Bozak's designs, and I'd bet it goes a long way toward the superb sound these drivers are capable of. And all at an efficiency rating of 101 db/wm, putting them well ahead of most modern drivers.

The PAX-25A is interesting in that it is a coaxial design using a paper tweeter. Most of the PAX lineup used horns or electrostatic drivers in the coaxial position. This pair spent 50+ years in a large set of corner cabinets, and are as perfectly preserved as the day they left the factory. They have a very smooth sound, and do well in both a ported box and in the Telefunken open baffles. They are an easy load for most amplifiers, but I found them to sound better with more power, being a very good match to the big 25 watt Decware Torii amplifier.

Notice the roughly textured rear of the cone. This materail makes these drivers so special.