I had a friend, Robert Allen from Altadena, California, build a beautiful 3-way system employing the 120Fr for the woofer, the 80 fr for the midrange, and I went over to Culver City (this was 1968) and purchased a pair of toroid tweeters. He made a folded corner horn for the woofer and a separate horn enclosure for the midrange with the tweeter at the mouth of the horn. Had those speakers for 20 years and deeply regret loaning them to my twin brother, who managed to trash them.
Robert built a folded horn enclosure for the 15" Trusonic with a JBLcrossover -- the same one used on the Paragon. To this day, this was the finest speaker I have ever heard. Robert knew how to get the most out of those trusonics. I see your request for advice is two years old. I hope you kept those speakers and added a tweeter with a good crossover. You can't go wrong, IMO.
Robert built a folded horn enclosure for the 15" Trusonic with a JBLcrossover -- the same one used on the Paragon. To this day, this was the finest speaker I have ever heard. Robert knew how to get the most out of those trusonics. I see your request for advice is two years old. I hope you kept those speakers and added a tweeter with a good crossover. You can't go wrong, IMO.