First of all thank you for your amazing website, I have a question regarding these matters, I can make both binaural beats and isochronic tones for myself but I doubt for low frequencies states (Theta and Delta) which one is better? Because I searched a lot and saw that binaural beats are better for low frequencies and for high frequencies (Beta Gamma Lambda….) isochronic tones are more effective. Also, for Alpha states some said isochronic and other said binaural.
The phenomena of brainwave entrainment was first described in the scientific literature in 1973 by Gerald Oster in results published in an article in Scientific American entitled, “Auditory Beats in the Brain”. He showed that a specific brainwave could be induced when a person heard two separate, but closely related, sound frequencies, one in each ear. He discovered that when the frequencies heard by each ear differed by about 10 hertz, the brainwave pattern of the person hearing the sound would synchronize to the difference between the two frequencies. For example, if the person heard a 410 hertz sound in one ear and a 400 hertz sound in the other ear, their brainwaves would stabilize at the difference between the two, or 10 hertz. This technique is called binaural beats, and it is a fundamental principle of brainwave entrainment methods.
So using the example track above, the right ear is sent a 20Hz beat, compared to a 10Hz beat in the left ear.  As the right ear receives the higher frequency of beat, this works to increase the speed of the ‘left' brain hemisphere, which can be helpful for people with conditions like ADD, who are often found to have an abundance of slow wave activity in the left brain.
A very pleasurable experience during listening (and often for some time afterwards). As Holosync® changes your brain wave patterns to those of deep meditation, the brain produces several very pleasurable neurochemicals, including endorphins (the same endorphins responsible for “runner’s high”)…as well as several hormones with a profound and positive effect on longevity, aging, stress, and well-being.
Theta waves also have been observed in moments when a person recalls information from the past, and this may be what links them also to improvement in learning ability. We also experience theta waves when we go into automatic pilot mode, such as when doing a repetitive task like driving a familiar route where the mind become disconnected while you still drive safely toward your destination.

The activity of neurons generate electric currents; and the synchronous action of neural ensembles in the cerebral cortex, comprising large numbers of neurons, produce macroscopic oscillations. These phenomena can be monitored and graphically documented by an electroencephalogram (EEG). The electroencephalographic representations of those oscillations are typically denoted by the term 'brainwaves' in common parlance.[4][5]