Hi there,
I figured this topic is too important to be left out.
As we all know, there are currently two sampling rates that are used most frequently. It's 44.1kHz and 48kHz.
Every library is developed with something in mind. Libraries sampled at 44.1 are considered to be great for general usage, while 48 is used mainly for cinematic setting, due to direct compatibility with DVD audio tracks. However in general, you may find 48 where you least expected it.

As Kontakt resampling algorithm needs to resample every single sample that is played and does not conform with project settings, this add loads of additional CPU usage that can be used for anything else, and also real-time resampling may result in deteriorated quality and ringing artefacts.

For this purpose, I thought of making a list of developers and their most preferred sampling rate. Depending on your project requirements and the libraries used, you can select the most suitable one.

44100Hz (44.1kHz) is used by:
8dio
9V Audio
Audiobro
Bela D Media
Best Service
Embertone
Orange Tree Samples
HollowSun
ProjectSAM
Soniccouture
Sample Logic
Sample Modeling
Tonehammer
Wavesfactory
Westgate Studios

48000Hz (48kHz) is used by:

8dio (certain libraries, 1969 Steinway Piano)
Cinesamples
Cinematic Strings
FT Samples
Native Instruments
Galaxy
SONiVOX
Spitfire Audio

This list is subject to periodical revisions.
For me, 48kHz is a way to go, as I am a big fan of Spitfire, also 48kHz has many advantages over 44.1kHz like less aggressive curve for ATH noise-shaping and nearly-lossless upconversion to 96kHz. Resampling sample content of a single library is not that of a problem. I'll probably write separate tutorial for that *yes*
Cheers!

 

What you're confusing here is sample rate and pitch. Human hearing has an upper limit of ~20kHz in pitch as you point out, but pitch is not the same thing as sample rate. The sample rate is how many times per second any source material (analog waveform) is 'read' and approximated by a digital number; the higher the sample rate the more accurate digital reproduction of the original waveform.

 

Sample rate does not equal just to frequency response.
Higher sample rates are also used to push quantization errors and artefacts outside the audible spectrum. Also many audiophiles agreed, that the reproduction is more faithful. Simply put, it's higher precision.
The size difference between 44.1 and 48 is rather small, but indeed noticeable, with 50GB library the difference would be around 4-5GB.

I'd recommend processing at 48 instead of 44, as there is more room for noise-shaping and the conversion to higher rates like 96kHz, 192kHz or 384kHz is almost lossless (minimum rounding errors).

As for discerning frequencies, that's for another discussion, but as one work put it, "There's life above 20kHz" *yes*

 

From the article:
Given the existence of musical-instrument energy above 20 kilohertz, it is natural to ask whether the energy matters to human perception or music recording. The common view is that energy above 20 kHz does not matter, but AES preprint 3207 by Oohashi et al. claims that reproduced sound above 26 kHz "induces activation of alpha-EEG (electroencephalogram) rhythms that persist in the absence of high frequency stimulation, and can affect perception of sound quality."

Yet I have to agree, 192kHz (96kHz response as per nyquist theory) sample rate for libraries is a bit overkill, 96kHz (48kHz response) is well enough. *yes*