lrsky, Thiel has used air core inductors since the very beginning. And since the development of the 03 in 1978 and going forward, we used six 9s copper in all chokes and internal wiring. At the time we were an innovator with film capacitors and even in the woofer section we used or bypassed with film types. If Jim were redesigning that product today with its same cabinet configuration, I believe he would use six nines copper in the voice coils or replace the drivers with 3.7 type updates, but add titanium to the tweeter alloy and extend the response past 30K. He would source the best modern caps, not available or affordable then, and (I believe I would and he might) take the crossovers outboard. Jim wanted to have powered woofers in the CS5, if cost were no object and development resources were available. Jim wanted
to make powered speakers from the beginning (our early pre-market prototypes were
powered, more on that another time). By the way, that cast marble baffle requiring abrasive diamond
machining could have been kept at a higher price, probably adding some damping component to the casting process. The CS5 bass drivers (first and third from
the ground) could benefit from SmartSub technology, with an outboard amp and crossover to clean up EMF interference for higher pristinity (how's that?)
As an aside I would explore a 6 ohm nominal system impedance (rather than 4) so that more people could get better performance from less than stellar amplification, which was the biggest limitation to that product. I would add some cabinet damping material to the wood panels where identified via Chladni Pattern testing which I now use in guitar design. Stuff like that. Do you still have those speakers Larry? Weren't they Brazilian Rosewood?
Tom