“I send this mix to Rick Rubin and he says, ‘Anthony sounds old. Make him sound younger.’ And I'm like, ‘Oh, I wish there was a knob for that’”: Red Hot Chili Peppers mix engineer Ryan Hewitt recalls Rick Rubin's unusual request on 2006's Stadium Arcadium

Rick Rubin and Anthony Kiedis during Lost in Translation DVD Launch Party - Inside at Koi Restaurant in Los Angeles, California, United States. ***Exclusive*** (Photo by Jeff Kravitz/FilmMagic).

Mix engineer Ryan Hewitt goes back a long way with the Red Hot Chili Peppers. In fact, he won a Grammy for his work on Stadium Arcadium, the band’s ninth studio album, which was released in 2006 and produced by Rick Rubin.

Hewitt and Rubin must have clicked - they’ve worked together plenty of times since, including on the Chili Peppers’ two most recent albums, 2022’s Return of the Dream Canteen and Unlimited Love - but in an interview with PMC Speakers, Hewitt remembers that, during the making of Stadium Arcadium, the great bearded sage gave him some unorthodox feedback on what he’d done with lead singer Anthony Kiedis’s vocals.