Doing this for about 30 years now. Hear are some replacement speakers. that may work for some of those nice solid made speaker cabinets. I have 2 way and 3 way True Hi End Kits. you can make new cabinets or rebuild good vintage cabinets into Modern Hi End with what I have and do. Contact 614 470 2356 some are buy out to technicians as a package the others are project kits still available for build. new monitor cabinets available with monitor kit. for now use large tower speakers and modify them into tower bass cabinets. IT WORKS.