Complex sentence: Initially, the audio quality was far too low to make it a promising medium for music-listening, so it seemed to be just another convenient new format for dictation systems and small battery-operated portable units designed for recording speech, not music.
Split into simpler sentences: Initially, the audio quality was too low to recommend it as a promising medium for music-listening. It seemed to be just another convenient new format for dictation systems and small battery-powered portable units designed for recording speech but not music.