A-Jax member Jaehyung mentioned Jaejoong in his interview with 10asia.
"[unlike the music I do as a Kpop boy band] Usually, I love rock. Not heavy metal, but the rock Kim Jaejoong sunbae-nim does. I like Kim Jaejoong sunbae-nim, so I always look [his name] up and watch his videos on Youtube."
source: 10asia http://tenasia.hankyung.com/archives/182562