It looks like I can pick them up for about $20. He was instrumental in the design of the Koss Model One, the Acoustech and the Dennesen speakers. Classic, Vintage Home Audio / Stereo Speakers for sale / Loudspeakers: Fully Certified by Qualified personnel decades of combined experience! Roger West, the chief designer of the Janszen Corporation, became the president of Sound Lab. The ESR-15s sat atop the 280-DRs and rediated high frequency sound in a soundfield similar to the soundfield of the lower speaker. RTR Model HPR-12 Magnum The HPR series of transducer systems was designed for the audiophile who does not have an extraordinary amount of power in his amplifier. speakers—eventhoughtheyareall designedtoexhibita flatresponse curve. If you want to start a new topic, click here. Using a conventional cone woofer and midrange, and electrostatic tweeters, the 2000 A is actually a very nice speaker in a more compact package. Infinity was obviously experimenting a lot on this design, as I have seen versions with both two and four of the RTR electrostatic tweeters, and both with and without whizzer cones on the midranges. Radiotelevisiun Svizra Rumantscha (RTR, English: Radio-Television Romansh Swirzerland or Swiss Romansh Radio-Television), formerly known as Radio e Televisiun Rumantscha (English: Romansh Radio and Television), is a Swiss broadcasting company (part of SRG SSR) which offers programming to Romansh-speakers in Switzerland and around the world. RTRengineersareamongthe fewwhoconsiderall theseessential design phases increatingtheir products, possiblytheonlyoneswho havedoneso formorethana dozen years. Browsing in the local thrift store I came across a pair of speakers which as best I can tell are RTR Model C Series IV speakers. Ready to GO! It requires a unique combination of intellect and charisma to captivate large audiences. Anyone know anything about them spec wise such as whether their 6 ohm or 8 ohm. When Janszen Corporation was sold, the RTR loudspeaker company bought half of the production tooling. The sound of these speakers in pairs was quite remarkable. In the original HPR-12, the Helmholz ConsequentlyRTR speaker systemsarea dozenyearsaheadof mostwhen itcomesto reproducing natural musicandvoices—soundsyou Refurbished, Rebuilt where necessary and Warranted. Janszen continued to develop electrostatic designs. Those speakers (M meaning Magnum) were made between 1973-1976. They appear to be in decent shape but there is no other info I can find on them. Many of today's low-powered amps and receivers are of otherwise excellent quality, and the HPR series was made for these components. RTR web site (January 12, 2010): RTR once made a complete line of high quality speakers running up to some quite large speakers, this back around the late 1960s and 1970s. They were very nice speakers at the time and probably still are. There seemed to be a few online who refurbished them and/or updated them. Audio History Library Company Listings ® ... RTR : US: Speakers: 196_ RTW (Radio Technische Werkstatten) Germany: Meters: RYCOTE Microphone Windshields Ltd. England: Windscreens: SA (Sound Advance) US: Flat Panel Speakers: SA (Stage Accompany) Netherlands: Concert Speakers : … Speakers throughout history have used their influence and public appeal along with some of their greatest speeches to inspire and unite people during times of struggle. The following topics regarding the RTR 280-DR have been found in the forums. Forum topics on the RTR 280-DR. Now owned by BIC and information on RTR and their past products is pretty much non existent.