When there is some 'subtilty' or artistry in the creation and modulation of the DTP, then the trance is compelling and there is an increase in the trance force. A loud, heavy beat is not necessary. Loudness or heavyness is not of itself productive of trance. Repetition produces trance. But it will be the type of repetition which is 'engaging' or which produces an involvement with the inner reality.
Subtle loops tend to bring the attention to a finer focus.
The resulting splitting or dissociation results in trance. But that is not the whole story. What 'subtle' is to one person may be different for another. Again, this can vary between persons listening to the same music. Another consideration is the order in which cognitive functions are disabled, and finally, what additional processes are being encouraged when these cognitive functions are disabled.