Sony has upgraded its MiniDisc-based ATRAC3 codec to double the compression without degrading sound quality, and it has applied the revised codec, called ATRAC3plus, to seven headphone CD players that play back MP3- and ATRAC3-encoded CDs.
Sony uses ATRAC3 compression in its MiniDisc-based NetMD Walkman player/recorders and in its flash-memory-based Network Walkman. ATRAC is also used in Sony portable, home , and car MiniDisc players and recorders.
The new CD Walkman players are Sony's first two-codec headphone CD players, and they're priced at expected everyday retails of $70 to $200. They ship in April and May. Previous models played MP3 CDs and uncompressed CDs.
The battery life of six of the new players is 50 hours on two AA batteries. The top-end model offers 80 hours of battery life with the two supplied gumstick rechargeable batteries.
ATRAC3plus offers bitrates of 48, 64, 66, 105, and 132kbps. The 66kbps rate offers near-CD quality, as did ATRAC3's 132kbps rate, the company said. Compared to 64kbps Windows Media Audio files, ATRAC3plus occupies the same amount of disc space but offers more natural trebles, more spacious midrange, and more defined bass, the company contended.
About 300 four-minute songs will fit on a 700MB CD encoded in 66kbps ATRAC3.