Bass Peak Management: Indicates a function of the THX circuit. The loudest part of a movie soundtrack is the bass portion, which is attached to the over the LFE-Channel (Low Frequency Effects) connected Subwoofer is issued. Due to the extremely large dynamics one Dolby Digital soundtracks, it can happen that the subwoofer has to transmit signals that exceed its capabilities.
The result would be significant sound effects due to distortion and punching through of the bass system. Bass peak management limits the bass signal to a peak value so that the performance profile of the subwoofer is not exceeded.