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Old 09-06-2011, 02:00 PM   #11
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Join Date: Oct 2007
Location: USA
Posts: 1,874

OK. I did some tests on a ADVC-300 (posted in separate thread).

The ADVC has predictable results. If your audio level is low, using the gain adjustment can add about 6 dB, but using AGC will not help the digiral recorded level much (if at all), and may actually make high analog audio levels seem lower when digitized into a DV stream and dumped to DVD.

At default settings the ADVC-300 does a nicve job digitizing analog audio up to 2 VRMS, but will clip above that. This level corresponds to +6 dBV at the input, and 0 dB digital at the output. If AGC is full on it will control the audio to hold the average output level to no more than about -16 dB digital, which corrsponds to about 0.31 VRMS at the input.

IMHO what the ADVC is doing is correct and appropriate. But the net effect in a consumer recording/authoring/playback environment can be what apears to be a low audio level on the DVD because it allows a professional amount of headroom for signal peaks.

If you want a higher average sound level on the DVD, you may want to enable the AGC on the ADCV-300, and then boost the audio by around 10 dB (give or take to taste) in your NLE or authoring program. But listen to the boosted audio first to be sure it is not distorting or clipping to an unacceptable degree.

(Most consumer camcorders, including the older 8mm, VHS, Beta, Hi8, and S-VHS analog formats, have dismal audio performance out of the box.)
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