Natural Sounds and Sights
 lvl.4
Spain
Offline
|
Finally got some time to test the latest firmware... as before the audio levels being recorded, both internally on the Pocket 3 and also externally on the DJI Mic 2 are incredibly low and do not in any way coincide with what the on-screen meter bar indicates.
Method: I took an industry standard microphone level feed from a Sound Devices Mixpre-D with the 1kHz tone generator switched on. This outputs at precisely 0dB. In fact, it is so reliable and accurate that it is a great tool for calibrating separate recorder and camera audio meters. The resulting waveform from the internal Pocket 3, however, shows that the actual recorded level is around -21dB! This is what Adobe Audition reveals when the WAV file is opened:
Here's the accompanying audio analysis:
I repeated this with the same signal at the same level but this time directly into the MIC 2 and inspected the resulting internal 32-bit WAV file.... not only were the levels similarly extremely low, but the 'continuous' tone was now 'pulsing' on a regular basis, as if some form of limiting or compression was being applied? Here's what that looks like in Final Cut Pro's timeline:
The concern here, of course, is that if - for example - the Mic 2 was being used to record a musical instrument that emits a strong, continuous tone, such as a flute or a bowed instrument such as a 'cello, what happens then? I have not had time to test this, but maybe others could? It definitely looks like some form of limiting to me... 'clamping down' on the already very low signal at precise intervals.
Very strange behaviour, anyway.... would not expect to see a recorder do this.
Should add that the Pocket 3 meters both showed the signal level to be near clipping!
|
|
Administrator
