After leaving SiriusXM, where he spent nine years talking about rock ’n roll, Nik Carter was taking a break. “I had offers, some of them very intriguing, but none of them seemed right,” he told me.

A post on Facebook’s “The Sound LA Radio Family” group page caught my eye; it essentially asked: How do people like KLOS (95.5 FM), which is sounding a lot like ’90s-era KROQ, these days? I had noted ...