Sony has a big line of ICX recorders, basically for dictation. This is billed as a "voice recorder" for a reason: the low frequency cutoff. A crucial difference in spec from the PCM-M10.
Frequency Range : LPCM 96/24: 40 - 40,000 Hz LPCM 44/16: 40 - 20,000 Hz MP3 320k: 40 - 20,000 Hz MP3 192k: 40 - 18,000 Hz MP3 128k: 40 - 16,000 Hz MP3 48k (Mono): 40 - 14,000 Hz
I'm not a megabass fanatic, but I do want that bottom octave (20-40 Hz) for fidelity. Lowest key on a piano is 27.5 Hz, and concerts rumble lower. 20-20000 Hz for me.