Mastering

When you export your music, you should keep the sample rate the same as is in your session. It is best that sample rate conversion is left to mastering

Bit depth should be no less than 24 bit

Any level below 0dBFS is ideal, as long as the output isn't clipping and limiters have been bypassed.

Turnaround can vary between 2 to 10 days depending on peak times.  If you have a tight deadline please contact me directly at rumble@rumblemastering.com and I will be happy to accommodate