I would love to discuss it more off line. In the case of the Stella it was more an incremental development and a lot of parts and a lot of $$$ in prototyping. I have tested many sound related designs since I did the TM15 and some things work, and some things didn't.
Sometimes the perception is not the DB of the sound but in the type of sound also. The more I study people's perceptions the more I wish I had studied Psychology after I finished my Engineering degree