When I try to record something with Audacity 12.2 I can see that it adds a very quiet sound on the maximum recordable frequencies. I would like to know the cause of this, if it’s audible (I don’t think so), how can I remove it (low pass simpy changes the disposition of the dots of the sound) and if it changes the original waveform of a lossless file that reaches those frequencies (e.g.: if I try to record a CD @44.1kHz the new sound will modify the 20-22kHz frequencies?).
2 examples of high sampling rate to show better the situation: http://imgur.com/a/t7Jy0
Audacity 12.2
Is that really correct? I’m pretty sure Audacity doesn’t come in a 12.2.
You can get Audacity 2.1.3 from here:
Koz
Audacity doesn’t add anything but there is always some “analog noise” in anything that’s recorded.
How do we know what’s added and what’s "original sound’?
Or, maybe you’re seeing an artifact of the spectrum analysis algorithm.
Is that really correct? I’m pretty sure Audacity doesn’t come in a 12.2.
Yes, I meant 2.1.2, I downloaded the last version yesterday
How do we know what’s added and what’s "original sound’?
Using a very high sampling rate we are able to record more frequencies. Since the “noise” seems to be added on the highest frequencies (it is 30% high, where 100% is the complete recordable spectrum).
http://imgur.com/a/t7Jy0 Within these screenshots we can recognize 3 areas in the screenshots, from the top:
@384kHz, 192kHz as maximum recordable frequency, one is made by the noise (30%), one is made by silence (55%), and the lowest one made by the sound itself (0-22kHz, 15%)
@96kHz, 48kHz as maximum recordable frequency, the noise keeps the same area (30%), but the silence is reduced to a tighter one (25%) and the sound alone (0-22kHz) reaches a good part (45%)
I would like to know if Audacity add this noise or what can I do to remove it if it ruins the top frequencies of an audio stream
Are you perhaps referring to “dither” which gets added on export?
(See: http://wiki.audacityteam.org/wiki/Dither)