I think it's about 10 to 1 in size, .WAV to .WMA. It's hard to say exactly since the compression seems to vary instrument by instrument, looking at a sample of the RealTracks I have.

By the way, Rachael mentioned uncompressing the .WMA files. Although by doing this the quality of the sounds does not change, you do benefit from the same small speed boost that the audiophile version would give you. BIAB looks for a .WAV file and uses it if it finds one; otherwise, it uses the .WMA file, which takes a bit of time to uncompress.


BIAB 2026 Win Audiophile. Software: Fender Studio One 8, Swam horns, Acoustica-7, Notion 6, Song Master Pro, Win 11 Home. Hardware: Intel i9, 32 Gb; Presonus Quantom HD8 & Faderport 8, Royer 121, Adam Sub8 & Neumann 120 monitors.