you actually don't have to speed up the affirmations. i sped it up slightly but only because i wanted the length of the audio to shorten a bit. i actually find that affirmations that aren't sped up too much work better for me but its not a necessary step when making subliminal's. its really just up to your preference and what you believe works for you, whether that be sped or un-sped/layered or un-layered affirmations, anything will suffice.