Petri Kaipiainen
December 3rd, 2007, 12:51 PM
We all know HX-A1 has a bit funny line in levels, with a standard line in levels (like from SD302) you have to set the potentiometers to full open, or just a hair from full to get decent levels. Some people have sounded concern that this can not be right and they rather use attenuation on the mixer and use mic levels in to be able to use the midrange area with the level pots on camera.
Test setup: Loud pink noise from a good stereo system, quiet room, Rode NT-1A super-quiet studio condenser microphone. First pink noise via SD302 to line in, camera pots open, level on SD302 just starting to hit the limiter set at +17 dBVU, then the mixer pot turned down to kill the input (to get the system noise floor). On the second sample the output levels pulled down on the SD302 so that when using mic in the camera pots are at midrange (optimum?). Same pink noise at same levels, also "quiet" recorded after the noise.
Result: The line level gave max peaks at -4.60 dBFS and minimum average RMS at -93.93 dBFS. An amazing dynamic range for a camera, approaching the theoretical limits of a 16 bit system. Almost 90 dB!
With mic levels the peaks were at -3,17 dBFS and with no signal average RMS at -79.21 dBFS. Thus the mic in was 10 dB noisier than the line level even with the pots all the way open with the later.
I will continue to use the line level in, and turn the potentiometers all the way south.
Both results are good, better than you can get with any Nagra...
Addandum: shot with SD, which uses uncompressed PCM audio.
Test setup: Loud pink noise from a good stereo system, quiet room, Rode NT-1A super-quiet studio condenser microphone. First pink noise via SD302 to line in, camera pots open, level on SD302 just starting to hit the limiter set at +17 dBVU, then the mixer pot turned down to kill the input (to get the system noise floor). On the second sample the output levels pulled down on the SD302 so that when using mic in the camera pots are at midrange (optimum?). Same pink noise at same levels, also "quiet" recorded after the noise.
Result: The line level gave max peaks at -4.60 dBFS and minimum average RMS at -93.93 dBFS. An amazing dynamic range for a camera, approaching the theoretical limits of a 16 bit system. Almost 90 dB!
With mic levels the peaks were at -3,17 dBFS and with no signal average RMS at -79.21 dBFS. Thus the mic in was 10 dB noisier than the line level even with the pots all the way open with the later.
I will continue to use the line level in, and turn the potentiometers all the way south.
Both results are good, better than you can get with any Nagra...
Addandum: shot with SD, which uses uncompressed PCM audio.