I am mixing a midi sequence orchestra music which all the samples are from VSL. Is there any benefits to work in 24bit/96KHz audio mixing environment, when all the audio sources are 16bit/44.1KHz? Thanks.
It depends. If you are using a digital reverb, some people swear that the quality is greatly improved at higher sample rates, even if the source material is not recorded at these rates. In fact, I know people who use VSL in 24bit/96kHz sessions for this reason. However, it puts much more CPU strain on your system, especially when using multiple instances of reverb on big arrangements, so its a trade off.
I personally cannot verify these ideas, as my system chokes at such rates. However, if yours can handle it, why not? Just note if you switch from 24bit/96kHz down to 16bit/44kHz in your mixing session, your reverb ratio will be messed up. Best of luck!