I still have the piezo's. When I used the one π's in the car, I just laid them on their backs and let them reflect off the rear window up towards the front of the car. Velcro held them in place.I own a pair of one π's, two π's and tower two π's, each with the KSN1038. I've used the KSN1038 tweeter for nearly 30 years in the Studio Series speakers. They're definitely like old familiar friends.
We still have several KSN1038's in stock for new kits sales. We literally bought up all of the remaining KSN1038's in the country when we found out they were being discontinued. I called CTS and spoke to them and found out who had inventory and bought them. I also inquired about the possibilities of second sources and discovered that CTS was actively looking for a company to buy their tooling equipment. So I had guarded optimism that it might be possible to continue to buy these drivers in the future. This may still come to pass, and if so, I'll continue to sell the Studio Series speakers as they always have been.
But at the same time, I began to look into other options. Some would probably find this as a big improvement. I have a tenative arrangement to start purchasing Vifa DX25's in 250 unit orders, so that I can provide the Studio Series kits at a price point that is still very attractive. The efficiency of the tweeters is about the same and it is a very neutral sounding device that many will approve of. It does sound quite good.
DST (the parent company of Vifa) has assured me that I can continue to purchase the tweeters for quite some time, and that supplies won't be sporadic. I was concerned about consistency and availability, but DST informs me that the base model of this tweeter was initially introduced in the 1980s and that the tweeter has evolved since then, but never been out of production. Improvements are evolutionary, so there will be compatible devices for years to come. That is very attractive to me.
I really like the piezo's, both for sentimental reasons and also for technical ones. While it would not be wise for me to disregard what people say, I have tried to not be swayed by opinions about the tweeter and instead judge it by its merits. The KSN1038 has been consistent, reliable and robust. Sound quality is good. Response is flat and extended, distortion is low. Dispersion is good, and off-axis sounds as good as on-axis. The device is very durable and attractive. All this at a price that made it easy to put together a good sounding high-efficiency speaker for very little money.
On the other hand, dome tweeters have very well behaved response characteristics. There is a certain sound to a bookshelf sized cone/dome speaker system and it is an extremely popular format for studio monitors and high-end systems. Most of them are around 90dB/W/M and have complex crossover networks. Taking this same approach but minimizing the crossover and moving it into the high-efficiency realm is magic.
I like them both, the horn tweeter version and dome tweeter version. Both have their strengths that make each of them attractive.