Sonos I / MBL4 was a direct development of the original standalone MBL4 processor.The software has more features when compared to the standalone MBL4.The MBL4 processor that is part of Sonos is version 6.0.2 and judging by comments from users it is the best of the many versions MBL4 went through.However it is more difficult to setup.The major defects are a tendency to 'hole punch' on dynamic source material and it sounds a little dull.
Sonos I / MBL4 is no longer being developed and is released as freeware.
