Bit depth and Sampling rate - the real story.

[Oren]

My questions:

               Would there be any advantage in changing the internal bit depth and sampling rate in Audacity and Ardour to 24/48?

               Are projects destined for CD, MP3, or Ogg Vorbis files with a sampling rate of 44.1 kilohertz best recorded and mixed in my digital audio workstation at 44.1 kilohertz?             

Back to the origins of the thread, and the conclusions (based on some excellent advice, both here on this thread and via e-mail):

Most modern "digital audio workstations" process sound internally at a 32-bit floating point bit-depth. This is good, and should not be altered.
The internal sampling rate of a "digital audio workstation" will usually default to 44.1KHz. For all but the most demanding and specialized work, 44.1KHz is adequate to produce world-class audio.(I have experimented with sampling rates up to 96KHz, and cannot hear the difference )
___________________________________________________________________________________________________________

An accessory issue which is often confused with my original question is:
           
 What choice of bit-depth and sampling rate is best for the "digital audio files"(wave files) we use? Although many of us who are striving to produce an exceptional audio experience are working with 24bit/48KHz wave files, most listeners and producers(including me) find that 16bit/44.1KHz wave files are entirely adequate to produce big, rich, detailed sound.

Thanks to everyone who contributed information, opinions, and advice 

Oren.

[rharv]

I read once (in a reputable forum) that an audio cable is capable of less dynamic range than 24bit when considering the noise levels..  ie the noise level inherent in an audio cable is above the noise floor of 24bit.. at line levels...

just thought I'd thro a little more mud into it

[folderol]

Ah noise. Now there's an interesting subject

What do you use to measure noise when the measuring equipment generates its own noise?

Same for distortion.

[Oren]

Rharv:"...an audio cable is capable of less dynamic range than 24bit when considering the noise levels..       ie the noise level inherent in an audio cable is above the noise floor of 24bit.. at line levels..."

Folderol:"...What do you use to measure noise when the measuring equipment generates its own noise?
Same for distortion..."

Precisely the purpose of this thread.
How much of this theory, and how many of these numbers, are actually applicable in a real-world situation? How much is pointless conjecture?

The goal is premium audio. My intention is to de-mystify the subject, and answer the question "What works, and what doesn't?".

[Wyatt]

Just so as we can say we really drove this sucker right into the ground:

http://mixonline.com/recording/mixing/audio_emperors_new_sampling/

The Emperor's New Sampling Rate.



Wyatt

[Moon]

Nice article. I you consider yourself an audio purist, read this one and be surprised ! 

Moon

[folderol]

Coming from a highly hands-on electronics background I'm more pleased than surprised 

... almost to the point of being insufferably smug

Interesting that time/phase differences should get a mention. I'm firmly of the opinion that many stereo panning systems are less that ideal simply because the don't make the appropriate phase corrections.

At 1kHz a wavelength is roughly 300mm. In a typical listening triangle the path difference from one speaker to both ears is around 100mm. That will result in a very significant phase shift, and I know from practical headphone tests, people can hear phase difference at that frequency.

[Oren]

.... I'm more pleased than surprised  ... almost to the point of being insufferably smug

I have read this study before, which inspired me to engage in some creative listening situations of my own.

Playback equipment and listening environment had a dramatic effect on the quality of sound. Audio file format, sampling rate, and bit depth made little significant difference.
The care with which the audio file was created, however, rendered astonishing differences. Low bit-rate MP3s and Ogg Vorbis files prepared with extra attention to detail sounded as good to me as many commercially engineered 16/44.1 CD tracks.

My mother told me not admit to such things in public....

[rharv]

I enjoyed it.  Lots to think about in little space.