catalysis - I totally agree about Benchmark. I run a full BM setup and couldn't be happier. Some folks quibble about BM's lack of lower harmonic distortion. BM intentionally practically eliminates it, while many users like the added 'warmth' and 'fullness' that the HD adds to the signal. I agree that Jim would have loved this gear. It brings truth without costing a fortune.
To your question about progress and kits. The question is valid and the answer is complex. I am working every day on upgrades, and making real progress. A somewhat unexpected twist (which should have been obvious) is that Jim's mastery of value engineering was phenomenal. It takes quite a bit of money to break through to a higher performance/cost level, which turns the idea of upgrading on its head.
Several folks here have upgraded their speakers, and all have been satisfied . . . at considerable cost - which was OEM special buy with no mark-up. Looking at real costs with overhead, the cost/performance equation gets murky. Other interesting developments include that every (?) rebuilder chose to use 'better' internal wire - and were pleased. I have tested all of those wires and plenty more. I am not satisfied with any of them as preserving the unaltered, pure signal. So, i went down a very deep and wide rabbit hole. The result is a proprietary wiring harness that breaks new ground and settles some subtle but persistent sonic issues.
There are other solutions being brought to bear. Analog layout, field effects, thermal management and wavelaunch propagation are all being advanced. All in, I am achieving up to 20dB lower harmonic distortion and other background 'noise' (collectively referred to as 'computational irreducibles') caused by dynamic interactions in the complex speaker system. There really is too much to itemize and summarize, and much of the work is proprietary. I can assure you that we will achieve significant performance improvements while changing nothing of Jim's work, and in fact extending his approach and methods toward qualitatively greater fidelity. Much like the Benhmark gear sounds so good by getting it so right.
The vision has shifted from 'upgrade kits' toward development of novel technologies which do 'it' better for less. The goal is to offer these technologies and finance driver redevelopment and improvements - for a very long life horizon for these heirloom speakers. This autumn I plan to exhibit these technologies to a group of invited guests in a purpose-built playback room, and court more team formation.
FWIW: I'm picking up a pair of CS5i on this trip. I now have 5 pairs of CS3/3.5s. I'm concentrating on early / older models because their drivers are unavailable and aging. Their replacements will be a new iteration of the UltraTweeter (used in the CS5, 3.6 and 2.2) along with a new iteration of the CS3.6 midrange to retrofit into the CS3/3.5. We have a good working relationship with ScanSpeak which has all the working drawings from our development partnership with them. The equalizer has been expertly and impressively upgraded, but the finalization of that job was on Bill Thalmann's plate as he succumbed to illness. We're scouting another electronics designer for that project. The workhorse model shared with my collaborators is the SCS4. If any of you want a Small Coherent Bookshelf / Monitor, that will be the first speaker to be available at various upgrade levels. I am truly encouraged by our improvements.
I recognize that you all expected more progress sooner. I'm playing the hand I'm dealt the best I can. Progress is slow, but I am encouraged by the results to date.
