In what looks to be an escalating promotional battle between satellite radio rivals XM and Sirius, XM claims that the sound quality of its service is superior to that of Sirius.
XM said it has been employing a new state of the art audio encoding system called CT-aacPlus. Sirius has long claimed that its satellite service offered the best sound quality due to its use of statistical multiplexing technology, which allocates more bandwidth to those channels that require it, such as music stations.
At a news conference here, held by XM to announce the details of it codec, XM executive VP of programming Steve Gavenas said that XM does not need statistical multiplexing because CT-aacPlus encoding is so efficient that there is plenty of bandwidth for all channels. Claiming CT-aacPlus is 30 pecent more efficient that other coding technologies he added, "We believe our sound quality is better than Sirius'."
In addition, Gavenas said XM's two satellites produce a signal that is twice as strong as that of Sirius for improved geographical coverage.
XM had originally planned to use the PAC codec but claimed it launched with CT-aacPlus because of its merits.
Sirius' reaction was simply, "The fact that XM has taken action to improve their sound quality is a reflection of the fact that they needed to do so," a spokesman said. "We're not going to get into a tit-for-tat discussion on the merits of each technology as both are complex and involved, but we are very pleased with the technology we have. It's been validated in the marketplace that is works very well. We have always felt that our system delivers superior quality sound because of they way it allocates bandwidth to the highs and lows."
CT-aacPlus is a combination of Advanced Audio Coding (AAC), which combines audio encoding technology from AT&T, Dolby, Fraunhofer, Neutral Audio and Sony, with Spectral Band Replication (SBR) technology from Coding Technologies.