they use there own PA guy, so no excuse really, a guy I was with asked how he got the JJ bass sound, he said it's not as hard as you think, then proceeded not to get it 😆.
Like @Velarian said the early bass sound had all but disapeared after the Black and White album, my favourite explanation is that the green P bass he was using broke in half (or probably 2/3rds, 1/3rd), he had if repaired but it was never the same again, I saw a quote somewhere where's he played hundreds of P's since but never found one that sounded the same