Providing a mix that is ideal for mastering takes in the amount of headroom in consideration. The general idea is: allow 6dB of headroom. Audiobyray Mastering recommends that the loudest part of the mix should be around -3db tot -5 db (below 0level). This encourages generally sane levels throughout the mix, it prevents any risk of inter-sample clipping and you still have masses of signal-to-noise ratio at 24-bit – and, plenty at 16 bits too, assuming you dither correctly.
Here at AudiobyRay we have both Mixing & Mastering experience for over 9 years.We mastered over a 1000 EDM tracks, Stem Mastering sessions, and countless DJ Mixtapes so far