I personally believe that line-in on DVX100 gives much better DR than 67 dB. Unfortunatelly I do not have a DVX100 at hand to test, with XH-A1 with line in from SD302 I can get almost 93 dB of dynamic range, and DVX100 has good audio reputation.
If you have DVX100 or HVX200 it is easy to test the dynamic range available:
Attach a good mixer to camera line-in. Send full level reference tone (+20 dBVU/ 0 dBFS) to cam and set audio levels to clipping point or just under, -1 dB or so. Or use the standard 0 dBVU tone setting it to -20 dBFS on cam. Attach a microphone to mixer, set correct level for dialog.
Start taping, first some full level test signal to get the top, then normal dialog to make this exercise more natural, then be quet and turn down the mixer pot to record silence.
Capture the video & audio to PC, separate the audio and export as 16/48 WAV. Import the audio clip to a good audio editor ( like Audition I have used). Use "analyze" function on the whole clip, it will tell you what the max peaks are and what is the lowest RMS level.
I would be surpriced if the lowest RMS was not around -90 dB it the peaks are near or at 0 dBFS.
Why rely on hearsay when we have the tools to make simple tests?
