Can you please point me to some recommended speakers?

[dissonance]

I couldn't find the frequency range for the Logitech speakers you are interested in, so I'm reluctant to tell you to purchase them.

This is what I use http://www.amazon.com/Bose-Companion-III...r+speakers
I connect them to my iPod nano when I travel and stay in a Motel/Hotel room.

Edit to add: Yes, you would get greater results if you separated each speaker... one on each side of the bed if you plan on listening to subliminals in your sleep.

For these Bose ones that you have, do they EVER crackle at all with the ultrasonic, even at high volumes? For my speakers, they crackle the first 5-10 seconds when I start playing them sometimes, and occasionally randomly throughout, maybe every 30-90 minutes, for the same 5-10 seconds.