Premiere Pro Preferences , audio hardware settings , latency .....

Preferences in PPro  (and AME and AE) all have the "latency audio settings"  in the Audio Hardware section of Preferences.

I set all 3 programs to 50 ms... but I have no idea why? LOL  other than, 50 is faster than 200... but left room to breath. (it can go as low as 30ms) 

What is the correct latency for the trio of programs? 

btw, I don't think I have any audio out of sync issues... maybe caz 50ms did the trick?

Thanks!

Letty