Combo of 1950s-70s and modern most is about 50 years old. Have pairs from 1930-40s working wonderfully. Try that with weak chinless modern dynamic designs.
How old are your speakers
I am wondering how many listen to old speakers. I am not looking so much as to how long you owned them but how old are they. Are they your primary speakers? I am listening to a pair of 2003 Verity Parsifal Encores and continue to be pretty pleased with them.