The newest products tend to have the largest field diameters. But the average field diameter is at least 20 feet. The energy is the strongest within just a few feet from the device. So even though the field diameter tends to be larger, people who happen to be within the outer perimeter of the field will not be adversely affected.
The audio programs feature multiple components, and each component features a different amplitude (i.e. power level) than the other components.
In ascending order: Mild Mandala (weakest amplitude), Regular Mandala (strong amplitude), 20-min Audio (even stronger amplitude than the Regular Mandala), 60-min Audio (even stronger amplitude than the 20-min Audio), Silent Energy Video (even stronger amplitude than the 60-min Audio), 1-min Ultra-Strength Audio (strongest amplitude of all).