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Revision 0.1 of the ORIONMy longtime collaborator and former recording engineer of the US Marine Band, Don Barringer, has over the years helped me to evaluate my designs. I have learned to trust his observations even when I sometimes cannot immediately hear what he noticed. He brings a musician's and performer's background to my concert-goer's experience. It has always been a healthy exchange where we try to keep each other honest. Don revisited the midrange driver and baffle interface and investigated a number of variations of the driver mounting concept that was used for the PHOENIX for possible sonic benefits. I had chosen for the ORION a simple front panel screw mounting scheme for the driver, because I considered magnet mounting unnecessary given the rigid basket of the Seas driver, I wanted to avoid sound blockage from the rear structure, and I wanted to keep cabinet construction and assembly very simple. There are two potential problems with the traditional way of mounting a driver by clamping it with screws to a baffle. One, the magnet/mass and basket/compliance can form together a very high Q resonant structure, where the magnet moves relative to the voice coil at a resonant frequency, which is typically in the 150 Hz to 450 Hz range. Two, structure borne vibration, which is generated by the considerable force that the accelerating cone of the driver exerts on the basket, is transmitted through the mounting scheme into the baffle. There it might be stored and re-radiated unevenly at different frequencies. The dress panel and baffle of the ORION were designed to form a constrained layer system to damp high frequency vibrations.
The mounting scheme that Don arrived at holds the driver by its magnet. The rim of the driver is not screwed to the front baffle. Instead, it floats mechanically and the narrow gap between it and the baffle is sealed with a soft foam strip. No forces are transmitted between driver rim and baffle. The speakers look the same from the front as before, except that there are no screws. What is the sonic benefit? Well, it does not jump out as something you immediately point to. As I go through my selection of familiar material it becomes clear that human voice, soprano, stringed instruments and many other sounds have assumed a degree of naturalness that surpasses what the ORION was capable of before. I find that I play many recordings at even higher volume level and thoroughly enjoy the richness and subtleties of their sonic fabric and dynamism. Surprisingly, I keep pulling CDs out of my box of discarded ones and put them back on the active shelf. What I thought were poor recordings, because they were irritating to listen to, now turn out to be marginal recordings with faults that can be clearly identified, yet I can easily hear through those and still enjoy their musical content. I re-listen to choral works that I knew had difficult passages and now the speaker just sails through them, yet I hear why it was difficult before. Even "The Prairie Home Companion" on FM radio takes on a new aliveness of staging and increased intelligibility. Every sound source benefits, including pop music. In summary, a layer of distortion has been removed and even greater accuracy has been obtained in reproducing what is on the recording.
Conversion Kit 1A
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Magnet
mounted midrange driver
