There are a few posts with 2.3, 2.4 and Rob being mentioned. I had the coincident drivers in my 2.3i rebuilt by Rob twice - 2006 and 2017. In 2006 they did came back great. However something remarkable happened in the 2017 rebuild - they came back sounding so much better that I was stunned. Everything we love about Thiels became turbocharged and in addition there was now a body and richness to the sound that makes vocals and violin scarily realistic. I encourage 2.3/2.4 owners who might be thinking about an easy upgrade to give him a call.