I doubt there's any discernable or measureable difference in frequency
response at audio with ANY connector that makes a good,
low impedance connection.
It's good to keep in mind though, that the lowly RCA plug is a BETTER choice
(impedance bump-wise) than the PL-259 ("VHF" connector) is. While they're
not the most rugged, they do work fine up to, and including HF.
73
John wb5oau