#Bohlender graebener bg radia r18i drivers
#Bohlender graebener bg radia r18i driver

The other side of the driver would face a larger baffle made essentially from a 12″-radius curve mating with a 4″-radius curve and then returning to the back side on a straight line. Based on Rudi’s prototype, I decided on a baffle with a very short distance from one side of the driver to a small-radius curve on one side. Then he showed me a new design that was still in prototype stage, using multiple curved sections of plywood. On my way back to the airport, I stopped by and heard his implementation of the baffle. As luck would have it, I was going to LA on business, so I called Rudy to arrange a visit. Visions of curved asymmetric baffles began floating around in my head.

#Bohlender graebener bg radia r18i drivers

Their results confirmed that the best response with the RD-75s was obtained by using curved, asymmetrical baffles, a configuration which reduces the tendency for these drivers to have a bump around 300Hz. But how would I mount them? Would the baffle be flat, curved, symmetric, asymmetric, or what?īack to Rudi, at Audio-XStream’s website, he provided not only a lot of information on the drivers, but also links to work done by John Whittaker and himself in 1997, testing various baffles with the RD-75 and other planars. Being a dipole lover, the first part of the equation was easy. The question now was not whether RD-75s were going to be in my future, but only how. Rudi mentioned that he had a pair of RD-75s with a custom-designed baffle at his house not far from the Los Angeles airport, and that I should visit him if I were in the area. To say that he believes in these drivers is an understatement. Attending that meeting was Audio-XStream’s Rudi Blondia, (at the time) the distributor of BG products to the DIY market, and also a very knowledgeable and helpful guy. The basic character of the driver was still wonderful. Although the sound was different, it was a case of same church, different pew. Shortly after that, one of the Prairie State Audio Construction Society meetings was held at the home of a member who had a pair of RD-75s in a monopole configuration. I knew that things were about to change for me. To top it off, I’m a real sucker for dipoles, and here was a pair of dipoles that could rock. Detail and spaciousness were wed with dynamic range. Here were drivers that had the best of both worlds. I asked him what they were, and he proceeded to explain that they were planar magnetics manufactured by a company called Bohlender Graebener (BG).Īs soon as the music started, it all became clear. They were mounted in baffles and operated in dipole fashion. As I walked into his listening room, I saw these large, thin drivers standing next to his huge subs. I stopped in to visit a member of the Boston Audio Society with whom I had been discussing subwoofers. It happened while I was in Boston on a business trip. I kept asking myself why there were no speakers that could produce this detail while also having the frequency range of classical dynamic speakers.Įnter, stage left, the Bohlender Graebener RD-75 driver. The desire persisted to have the detailed sound that electrostatics and planar magnetics can produce. My dynamic speakers were capable of reproducing a better physical sense of the performance, although the romance was missing. Over time, after listening to a broad range of source material, those shortcomings became all too apparent. The sound was so glorious that it blanked out the fact that the frequency response and dynamic range of the sound was limited. Nothing before had ever sounded so utterly detailed or spacious. I remember that happening to me the first time I heard an electrostatic speaker. You’ve all probably had the sensation of something visual or audible literally grabbing your attention because the effect it produces in your mind is so striking.