Speaker boxes. To rebuild or not to rebuild


Morning gang,
I picked up a free set of Technics 3 way SB-2860. I cant get any good sound out of them. No bass and all tinny.
Is there a speaker rebuild kit on a website that I can buy drivers, mids and tweeters as a kit? Any recommendations? These wont be my premier set, so we can go average on the expense. But, I think the cabintes are in very good shape and it would be a waste just to toss  them?
Thoughts?
Thank you
Marty
martygto
Measure the mounting surfaces, and contact these guys: https://www.madisoundspeakerstore.com/   They can provide drivers, crossovers and any components necessary(of various qualities/prices), to complete your system.
Based on most Technics speaker cabinets I've seen over the years,  I can't see how it would be worth the effort or investment.