In the MB STUDIO audio configuration it is possible to choose the base frequency of the MB STUDIO audio engine. It is a choice for the discerning audiophile who wishes to reduce the number of resamples in the audio chain. Most audio files are recorded at 44100Hz while most video files have an audio track at 48000Hz. MB STUDIO automatically resamples the audio to adapt it to the various audio outputs and encoders. Generally an upsample from 44100 to 48000 or a downsample from 48000 to 44100 is imperceptible to the human ear however it would be better to set the MB STUDIO audio clock to the frequency used by most of your files. Therefore, if you mostly play video files (TV and web TV) it is preferable to use a clock at 48000 Hz, if instead you do not use the VIDEO plugin it is preferable to use a clock at 44100. This clock also affects the audio encoders (except MP3 which is always at 44100 hz), for example by setting this clock to 48000 hz you can generate shoutcast or icecast streams in aac+ at 48000 hz (typical frequency for dab receivers), and it also affects the audio of RTMP RTSP video encoders etc that work best at 48000Hz.
Summary: if you don't use video files and you don't need to generate an audio encoder at 48000 hz then use the standard clock of 44100 hz. if you use a lot of video files or need to generate aac+ or opus streams at 48000 hz then use the clock at 48000.
The clock change will take effect only after restarting MB STUDIO.
Note: AudioProc DSP plugins only work with 44100Hz clock
For those who want to learn more about the subject: https://audioviser.com/44100-hz-vs-48000-hz/