I bought a pair of old JBL 4771A a couple of weeks ago as a learning/spending time-project.
Pulled them apart and replaced the original drivers with a pair of RCF 15" drivers and a BMS 4590 I had left over from another project that haven't left the ground yet. Spent most of today measuring and testing them, initial results are pretty good. They sound a bit "old school", but they certainly have a character you don't find in smaller speakers. Listening to snare drums with a lot of low end in them are fun, they're suddenly hitting you in the chest again
Pulled them apart and replaced the original drivers with a pair of RCF 15" drivers and a BMS 4590 I had left over from another project that haven't left the ground yet. Spent most of today measuring and testing them, initial results are pretty good. They sound a bit "old school", but they certainly have a character you don't find in smaller speakers. Listening to snare drums with a lot of low end in them are fun, they're suddenly hitting you in the chest again