THX Loudness Plus incorporates two THX Technologies. As the user changes the volume with multi-channel source content, THX Multi-channel Spectral Balancing™ and THX Dynamic Ambience Preservation™ automatically and seamlessly apply for the appropriate compensation. This delivers a more accurate listening experience at any volume level. THX Multi-channel Spectral Balancing Adjusts frequency response to counter the perceptual loss of low and high-frequency sound in all channels. It begins with a flat response at Reference Level, and continually adjusts the response as the user selects lower listening levels. The equalization is applied to all channels in a multi-channel listening environment. THX Dynamic Ambience Preservation Adjusts the surround channel processing to preserve the spatial detail that is lost when listening below Reference Level. It automatically shapes the output on surround channels to maintain the perceived balance in the original mix.