All - regarding upgrade pricing - there will be multiple plateaus for each model which are self-defining as the project proceeds. You know it is possible to spend more on crossover parts than the entire original speaker system parts cost. I'm not going there. In other words, I will not be putting Duelunds and Paths in a 2.4, even if an individual DIY owner might go that far.
My work is to determine the hard limits of format, cabinet and drivers, and then determine an ultimate cost-feasible implementation of that format considering traditional Thiel values. Beetlemania's CS2.4s are at or close to the highest imagined implementation tier. We must learn whether its $4 figure cost will be sonically justified.
There seems to be a middle plateau upgrade at half the parts cost of that. Brands have been chosen, but much remains to be decided.
The first tier upgrade will be a step up from stock in that sand-cast resistors will be replaced with Mills MRAs and all electrolytics will be replaced with polypropylenes. ERSE MPX caps are an outstanding bargain for that use. In this and all tiers, any questionable wire & coils will be replaced with 6-9s as in Lexington Thiels.
I would like to address design style. Many designers take many approaches to this subtle work - a high level of art is involved. I am honoring Jim's approach of reason-based, experimentally and musically verified choice. In Jim's approach, every element or change or choice must BOTH improve
the sound and align more closely with the measured technical ideal. That might seem obvious, but it is far from common. Many designers mix and match various euphonic anomalies to arrive at a pleasant end result. A corollary of Jim's approach is that each component must be pure. A capacitor is a capacitor, etc. Again, that approach is far from the norm.
An example of Jim's straightforward style is wire. Wire is enormously complex in how it behaves and how it sounds. With the help of Ted and GE aerospace avionics, Jim decided on his wire configuration. That 6-9s, polished surface, teflon jacket twisted pair sounds great and acts predictably like an ideal, engineerable wire. Over the years he investigated other types and brands, but kept our wire because it does what good wire should do and doesn't introduce spurious anomalies (which some folks might prefer.)
Holco- your wire idea is fine. Its identical geometry and jacket will not alter the measured system functioning. Your diameters are similar to my calculations for upgrades. Silver is a better conductor than copper, but coming at a hefty cost. Silver also imparts a different sonic signature, which some people like. I am very interested in your feedback should you choose to make this investment.
From my perspective that departure, both in value engineering and sonic signature, rules it out of consideration. We could make a sonic contributions list, and near the top would be inductors/coils. The short silver hookup runs attach to hundreds of feet of coil conductors. My reason-based choice dictates Thiel copper, same as the coils. My further investigations for hookup wire include litzed, graduated, multi-strand high purity copper - because theoretical considerations suggest its possible superiority. It would also have to improve sonics, and fall in my affordability value plateau structure.
Right now I have 4 wire configurations awaiting evaluation and testing. Tier One upgrade keeps traditional Thiel wire because it withstood decades of testing and comparison. Other tiers may or may not change. Further work. Input welcome.
