The company had its origins in the 1988 formation of the American Mobile Satellite Corporation (AMSC), a consortium of several organizations originally dedicated to satellite broadcasting of telephone, fax, and data signals.In 1992, AMSC established a unit called the American Mobile Radio Corporation dedicated to developing a satellite-based digital radio service; this was spun off as XM Satellite Radio Holdings, Inc. The satellite service was officially launched on September 25, 2001. While the satellite receiver radio service was its primary product, XM operated several audio and data services, and advertising.But providers have stuck with the plan for more channels instead of better quality.HD terrestrial digital radio, a competitor has always used this difference as a selling point.XM Radio Online (XMRO), XM's Internet radio product, offered many of XM's music stations and could be accessed from any Internet connected Windows or Macintosh computer, or via the i Phone/i Pod Touch SIRIUS XM app.
Best-of-Sirius was available on US accounts for an additional monthly fee. Channel quality was in one of two flavors, stereo music channels at 39 kbit/s and mono talk channels at 16 kbit/s using proprietary compression.
Many subscribers have complained about the low quality of satellite radio sound.