While we’re on the subject of AM HD Radio, I was talking to Cox Radio Orlando DOE Steve Fluker about cleaning up AM audio before it hits the transmission system.
He says: “The end product of an AM HD station can be anywhere from a disappointment to something that will blow you away. A station needs to pay attention not only to the tuning of the antenna system, but also to the source program material.
“Because AM HD has a lower bit rate than FM, it’s important to try to feed the system with as pure of a program source as possible. Avoid playing audio that has already been compressed such as e-mailed MP3 files, or files delivered over some of the satellite systems.
“Also avoid STL systems that incorporate data compression. Keep the audio linear wherever you have full control from recording, to storage, to transmission, and you’ll get the best sound possible.”
Fluker says he’s heard AM HD stations where he preferred to listen to the analog signal, and on the other side of the coin, also listened to stations that sounded so good that he can “easily forget that I’m not listening to FM.”