In the past few days, three radio broadcasting companies serving the Bay Area (CBS, Bonneville and Clear Channel) announced plans to flood the airwaves with new HD channels to deliver niche formats to listeners. Most of the additional channels will air music, but CBS Radio said that one of its new FM stations here will have an all-news format. The CBS news release didn’t elaborate on its new all-news station, but it’s likely to be a simulcast of KCBS-AM 740. Bonneville, owner of KOIT, KDFC and MAX-FM in San Francisco, is simulcasting or moving its AM all-news stations to FM in other markets thanks to the new frequencies created by HD. HD radio receivers start at $299, but the price is expected to come down, and new cars will soon have FM HD receivers. Ben Fong-Torres explained the new FM HD system in the Chronicle on Jan. 15. How good is HD radio? MSNBC columnist Gary Krakow says HD radio will provide some real competition to satellite radio and Howard Stern.