duramax - I'll be happy to ruminate on the CS5 baffle. The CS5 followed our 1987 CS3.5 which was a runaway hit, and our most expensive product to date at $2450/pair. Times were good, the market was hot and many manufacturers were presenting $20,000 statement speakers. Jim was extremely uncomfortable presenting anything over $5000/pair. So the CS5 actually represents quite an internal struggle. Contrary to statements that the CS5 was a 'cost no object' design, it actually carried compromises to keep its sell price well below $10K for a design with a natural price around $15K. Let's talk about the baffle as an example.
The CS3.5 had a machined 2" MDF baffle with braces. We also fastened the drivers with 2" screws through the entire baffle thickness into hardened pilot holes to best distribute reactive loads. An equivalent baffle for the CS5 would have been 4" thick and still fall short on impulse integrity, and add significant size to the enclosure. To develop a relatively thin-wall baffle with significantly higher stiffness and hardness, I engaged a local marble shop (sinks and bathtubs) to make samples from shop-built molds. By using 3 marble grits we reduced the polyester binder resin to half of typical and increased the stiffness by nearly double while nearly eliminating ringing. That baffle was (I think) about 20mm (3/4+") thick providing considerable internal enclosure volume.
We kept the overall size of the CS5 to no larger than an average woman. Jim invented a bass alignment that paralleled two subwoofers with a full range woofer such that all three were producing low bass at a declining impedance to draw additional power, but in a range that rarely has much musical content. It works and I hoped to apply the concept to further products, but we changed course to reflex bass due to its far lower cost and problems.
Riffing on the baffle: we designed the cabinet around the shrink-factor of that 'dry' triple grit baffle pour. We also developed a dye process for the marble so we could use a clear gel-coat showing off the marble grain. A next-generation concept (we always looked well ahead) enhanced the triple-grit concept to include granite, basalt and marble for even lower resin content, higher stiffness, greater internal damping and a more stunning look. But from a more conservative viewpoint, Jim and Kathy re-budgeted the CS5 at $9300 retail, so we had to lose the dry triple-grit x clear nicesity. The 'normal' pour gave the baffle more shrinkage and the cabinet dimensions shrank a little for it to work. Somewhere around the first 50 pair of CS5s had black gelcoat polished directly off the mold. But mold maintenance had also been deleted from the budget and all the rest of the 500 pair model run were cast with a primer gelcoat and sprayed in-house with emron (aircraft epoxy). My production records showed that those 'budget' baffles cost considerably more than the original, superior baffles would have. Such things happen when non-manufacturing executives step in.
As was our habit, we accumulated ideas for the CS5.2, which never came to be. The home theatre market was steam-rolling much of the esoteric high-performance marketplace. Jim wanted to go where he could design / develop more products faster, which was not a CS5.2. To a similar point, the sealed bass with its natural 12dB/octave in-phase and time aligned output was jettisoned for reflex bass in future products more or less because everyone else was getting away with it. That's a discussion for a different day.
Another point is that Jim wanted the CS5 baffle to follow the tilted flat plane of our other products. That necessitated electronic bucket-brigade delay on the upper and lower midrange drivers accounting for nearly half the component count in that huge crossover. Those coils and caps are all in the signal-feed path, which creates most of the sonic reticence experienced in the CS5. Now, close your eyes and imagine an arc-plane baffle that eliminates that electronic delay in favor of proper physical driver placement. Can anyone visualize a CS5.2?
As it stands, the cast marble baffle of the CS5 is enormously effective and beautiful. That product is a testament to a time when people of fairly ordinary circumstance could afford a product that still holds its own 35 years on.
