I heard Joseph Audio speakers when Jeff first started, very impressive. Haven’t heard his speakers for a long time, but based on other people’s experiences, he is making both high quality cabinets that sound superb.
AND, among other things a unique crossover, and dual magnet woofers.
He worked at Harvey Electronics, when JSE Infinite Slope speakers were added to Harvey’s line. He became friendly with Richard Modafferi, designer of those speakers with 2 unique patents:
1. Infinte Slope Crossover 120db/octave
2. Bass Shift ..., (unique way to blend the 10" and 12" woofers, including the use of dual magnet 12" woofer.
My friend at Harvey’s was Steve, who called me and said " You have got to hear these" Doctors, Lawyers, they were selling like hotcakes, until:
JSE decided to make their own cabinets (decent but nowhere near Jeff’s quality),
AND, they couldn’t deliver on time, many clients quite annoyed, so much so that Harvey’s dropped them from their line.
Jeff bought the rights to the Infinite Slope Crossover in 1992. I checked today, every speaker he makes has a version of Infinite Slope Crossovers, no doubt modified by him as needed for each model. He also uses woofers with dual magnets.
I had no money, but Phil, my friend at Leonard Radio knew I loved the Model 2’s, and Ray had taken a pair in trade with blown tweeters (the Dynaudio D21’s burnt out easily). I made a deal with Ray, replaced the tweeters, absolutely loved them.
Point is, Jeff is the only maker that is using the unique Infinite Slope Crossover, and I suspect a key reason his speakers sound so darn good, as well as his work with his driver supplier and continued use of dual magnet woofers.
two part interview with Jeff