I made my own preset, going from 16HZ to 7HZ in a couple of minutes, and then down 5 or 4HZ for about 25 minutes. This is in the middle theta range, which are the waves associated with drowsiness and the period just before falling asleep.
Trying it, I found it to be more powerful than expected. I stayed in the witness, and saw the small self (body/psyche) go into a deeply relaxed state – in a somewhat different way than what I normally experience when relaxing or falling asleep (almost as if it was doing its own thing). It could have been my curiosity which made the difference this time, or the influence of the sound waves – or maybe most likely a combination.
For some minutes afterwards, I had the experience of being in clear space & awareness (distinct from the drowsiness), trying to function with and through this small self – which was in a stupor…! I could perceive and perform tasks with ease, but accessing information was very difficult – as I noticed when I tried to talk coherently with someone who came to the house just as I was wrapping up the 30 minutes.
They say theta wave entrainment can reduce the amount of sleep needed. We’ll see.