More FM Stations Deliver Surround

By Joseph Palenchar -- TWICE, 4/23/2007

KIRKLAND, WASH. — Sixty classical FM stations have begun broadcasting select works in stereo-compatible 5.1-channel Neural-THX Surround over the air and over the Web.

They join Cincinnati-based WGUC-FM, which broadcasts select songs on a daily basis in surround.

The stations that have converted to digital HD Radio are broadcasting Neural-THX Surround over their digital and analog signals.

The surround-encoded programs can be decoded in surround when played back through home A/V receivers equipped with Neural decoders. These A/V receivers, which became available in 2006, also reproduce two Neural-encoded XM Satellite Radio channels in surround when connected to XM connect-and-play antenna/tuners and to transportable plug-and-play XM tuners, THX said.

The 60 classical stations that have begun broadcasting in surround are members of the Classical Public Radio Network (CPRN), which has encoded more than 3,000 classical works from its library in surround sound. For its part, Neural Audio has encoded more than 16,000 musical tracks in surround sound in a variety of genres and is making them available to radio stations.

CPRN was established in 1998 as a limited-liability, non-profit joint venture of KUSC in Los Angeles and Colorado Public Radio. Startup funding came from the Corporation for Public Broadcasting. The stations serve a combined 1 million listeners.

The CPRN member stations, many of which are National Public Radio (NPR) affiliates, include KUSC of Los Angeles; KVOD of Denver; WBHM-FM, Birmingham, Ala.; WFSQ-FM, Tallahassee, Fla.; Boise State Radio, Boise, Idaho; KBYI-FM, Rexburg, Idaho; WNIU-FM, DeKalb, Ill.; Northeast Indiana Public Radio, Fort Wayne, Ind.; High Plains Public Radio, Garden City, Kan.; WOSU-FM, Columbus, Ohio; South Dakota Public Broadcasting, Vermillion, S.D.; Northwest Public Radio, Pullman, Wash.; Vermont Public Radio, Colchester, Vt.; Public Radio Tulsa, Tulsa, Okla.; WSHU-FM, Fairfield, Conn.; Public Radio East, New Bern, N.C.; WFCR-FM, Amherst, Mass.; WJCT-FM, Jacksonville, Fla.; WQED-FM, Pittsburgh, Pa.; KLRE-FM, Little Rock, Ark.; and Wisconsin Public Radio, Madison, Wisc.

Neural-THX Surround provides fully discrete full-range channels over any two-channel analog or digital signal by embedding a continuous watermark in the stereo audio waveform without affecting the sound quality of the two-channel broadcast, Neural said. The watermark is up-mixed to 5.1 channels by the Neural decoder.

The watermark can also be decoded by existing 5.1 matrix-surround Dolby Pro Logic II and Circle Surround II decoders, but a Neural decoder delivers better separation and stability, the company claims.

Neural decoders also up-mix any two-channel material, including CDs, to 5.1 channels, although the best effects are delivered when an encoded program is decoded, Neural said.

Compared to matrix-surround encoding, the company added, the THX-Neural solution enables sound designers and mixers to better pinpoint sound effects, ambient sound and other audio elements in the surround field.

THX recently teamed with Neural to improve on the Neural algorithm, and THX said existing decoders are able to take advantage if the improvements. "Our big thing was making sure the technology could accurately recreate what the mixer or artist was intending in the studio," said a THX spokesman. "We made tweaks to the Neural algorithms to refine the down-mix/up-mix to ensure that this is possible to make sure it accurately represented the mix."