Two notes at 2.041256:1 sound really annoying together. You can try by putting 250 and 510 into the boxes here: http://onlinetonegenerator.com/binauralbeats.ht

Two notes at 2.041256:1 sound really annoying together. You can try by putting 250 and 510 into the boxes here: http://onlinetonegenerator.com/binauralbeats.html http://onlinetonegenerator.com/binauralbeats.html and revert to a nice-sounding octave with 250 and 500.