Very different situations. Beyond the ethnic makeup of the market being more receptive to that format (in the Bay Area, the largest single group is non-Hispanic white at 39.2%---in the L.A. metro, that number is 28.7%) , Live 105 is being positioned as a comeback of an old friend. KROQ's glory days are further back and fewer people (in an attractive demo) remember.
What a lesser number of people note is that LA has gone through an immense outward migration of middle income educated non-Hispanic whites in the last several decades. Texas, Nashville, Atlanta, Florida, Nevada, Arizona are some of the primary destinations, but not the only ones.
The end result is an increasing percentage of both Asians and Hispanics, no growth among Blacks and a poorly documented expansion of people from the Middle East, Iran, Armenia and the former Soviet block.
The biggest effect of this is a huge set of listeners who do not know the musical history of LA or LA radio and may like other kinds of songs and not even know of many past hits from LA Radio.
More of this will happen. in my case,, I just contacted my Realtor about selling before it is too late. The "straw that broke the camel's back" is the legislation that will charge higher income residents more for the kwh of electricity. I am in an area with about 120 days a year over 100° and many over 120°. I can't "conserve" electricity and I calculate my bill at nearly $2000 a month, average, with this new absurdity.
I'm limited to some extent as to destinations as a market that is not at least 25% Hispanic will not be my choice. So we are, for the first time considering Monterrey, Mexico or San José, Costa Rica or Mendoza, Argentina.
I mention these items, despite them seeming to be remotely related to radio because changes in market cultures will affect radio programming, entertainment options. Historically successful formats and fun DJs may not work at all in the new environment in markets that are now mostly a mix of people from other states and countries and cultures.
For format research, I'm concerned as to whether stations are thinking beyond age and gender and, maybe, the "big three" race/ethnicity groups of (non-Hispanic)white, Hispanic and Black. To start, perceptual and music research should measure things like time in the metro, prior residential zone, distance (in generations) between the family's arrival in the USA and today, gender identity and education of both respondents and their parents.
We have "a bunch" of participants on this board of different national heritage as well as interesting rural vs. urban contrasts, religious affiliations, gender identities and education levels. I'd love to hear some perspectives