My mid 1980s Pioneer DSS9D speakers have current-driven Beryllium ribbon tweeters inherited from the PT-R series. A USA market re-style of the japanese S-1800DV, itself an evolution of the original S-180 from 1979.
I think of them as the ultimate conventional 3-way old-style box rock loudspeaker. The tweeters and mids are a bit more refined sounding than most and way louder. It a little hard to explain the sound because it came out of trying to one up the JBL L100 and Pioneer HPM-100 but somewhere along the design process, they made a bit of a detour into a more flexible, as I say, refined sound that works OK with classcal, folk, and acoustic as well as power rock and combo jazz.
And they do have a different sound. It’s less distorted, more etched without losing any of the guilty pleasure of rock blasters. Though I have to say they are not nearly so clean, refined or flexible as the Thiel CS3.5 I recently rebuilt with about $1500 of completely conventional drivers, just very high quality. And they do not really compare to my Apogee Stages with enough power thrown at them.
I suppose the difference and what makes these Pioneers so special is that a 35 watt tube amp can achieve orbital velocity with Zeppelin’s "Whole Lotta Love" and there is simply no more distortion than if one were making them whisper. So a lot of popular Japanese hifi makers were playing around with exotic materials, beryllium, tungston, carbon fibers, since the late 1970s to good effect.
A few years ago one could pick these 80’s experiments up for free. But I had to pay $500 for mine last year crumbling foam surrounds and all. And I expect the prices will keep climbing till they might as well be coated with vaporized unobtainium.
Specifications for the DSS9 wich was the DSS9D’s lower powered version: Type: 3 way, 3 driver loudspeaker system, Frequency Response: 30Hz to 50kHz, Power Handling: 240W, Impedance: 6Ω, Sensitivity: 91dB, Bass: 1 x 12" dual voice coil, dual crossover carbon fiber cone, Midrange: 1 x 4-3/4" tungston cone, Tweeter: 1 x beryllium ribbon, Enclosure: bass reflex, Dimensions: 15-3/8 x 26-3/4 x 13-7/8 inches, Weight: 57.3lbs, Year: 1986
