It was announced at NAB2006 that WZLX in Boston, a CBS station, would transmit its classic rock programming in MPEG Surround beginning in mid-August. We talked to Denny Sanders, general manager of Telos-Omnia-Axia about the idea and what the station has to do to make it happen.
Radio: How much of the station's library has been converted/upgraded to surround?
DS: About 10 to 15 percent of the titles on the WZLX main playlist are available in authentic, discrete surround versions. However, the real amount of airtime that discrete surround music will be heard is probably more than that, since many of the famous hot rotation classics are available in 5.1 surround.
Radio: Where did the surround content come from?
DS: Most music is commonly available and more is released every week. Many longform concert DVDs already have the soundtrack in discrete 5.1 surround, so there is a wealth of material there. Recordings not yet released in discrete 5.1 surround will be heard in an emulated surround version for now, with discrete surround versions to follow as released. The emulation technique that we will use is a Fraunhofer development, and is created for each title separately for maximum integrity. Station imaging, bumpers, promos and some commercials will also be produced in discrete surround as well.
Radio: Who encoded all the music into the MPEG Surround format for storage?
DS: We are doing it for WZLX by duplicating the station's library on a second hard drive, replacing titles with discrete surround (or emulated) versions, and then swapping hard drives. This technique is actually 5.1 + 2. The original two-track version remains intact for stereo playout, sidestepping the challenges of collapsing multi-channel down to stereo or mono.
Radio: There are no radios capable of playing the MPEG Surround format. Why is WZLX undertaking this project?
DS: Paul Donovan (CBS VP engineering) and Joe Soucise (WZLX chief engineer) heard our demonstration some months ago and were intrigued. WZLX was a pioneer in the Classic Rock format, just celebrating 20 years as America's pre-eminent classic rock station, so it is only natural that this anniversary period is marked with another pioneering effort. Also, Boston is a tech center, so it was a fit for us to be able to have Bose, Boston Acoustics, Genelec, Tivoli and others in the region able to access the off-air broadcasts and hopefully give us their feedback. Genelec is providing the speakers for all of the studios at WZLX. There will be a limited amount of specially modified receivers for initial demonstration and evaluation, but it will be a while before off-the-shelf receivers are available. However, if all goes as planned, WZLX will offer the service via a 5.1 surround Internet stream for initial consumption.