"Listening to the sound difference, I would also say after several listens that the 3D1 appears to have a higher frequency response but it is not smooth and the appearance of the higher frequencies than the Sony is more that the 3D1 captures a peak response in the 1200-2Khz range giving it a more tinny quality. The Sony appears to be smoother and has smooth sound extending into the higher harmonics. I would liken it to comparing a cheap Radio Shack Microphone to a Sennheiser(Sony)."
Don, I m afraid I have to disagree with you on this. I record sound semi-professionally. I think there is something wrong with the Sony sound in the *particular video*; it is completely dull and also sounds processed. My experience with the Sony in use is the sound is normally ok. I am happy with the sound of the TD10 (leaving aside the inability to turn off AGC).
I also think the 3D1 sound is fine, and not peaked. I just recorded extensively (not semi-professionally!) piano playing (see my posted video, which has excerpts). Thus I know what the actual, live sound was, and what the recording contains. That is the only test (without frequency sweeps) - live vs. recorded. The 3D1 recording captured the sound perfectly fine, with no obvious peaks. I listen using Sennheiser HD650 headphones, one of the finest headphones ever made. I also listen using B&W 801 speakers.