ve9, you made some excellent points, but in actuality, from what I have read, it is the sound level, measured in decibels (db) which is used as a guide to determine how loud sounds are and how they can affect hearing. Though midrange and high frequencies can sound much more 'ear-splitting' than those boomy lows associated with powered subwoofers, the actual db level produced by a sub can cause hearing damage as well under certain conditions. For example, in an article about hearing in Sound and Vision magazine, an account was related in which two guys were setting up a subwoofer, and one guy was close while the other guy accidently cranked up the sound of the 1812 Overture's cannon blasts. The guy near the sub experienced pain that could be the precursor to hearing damage. Granted, these were cannon blasts and not ordinary music, but nonethless a subwoofer produces low frequencies and damage can result if the sound is too loud.