All of the surround mode functions in our devices work in different ways, and some might be useful in certain situations. Here is a list of each mode, explained with more details. HVS surround mode: Is the abbreviation for HARMAN Virtual Surround. It will process the signal to simulate a surround effect from a stereo source. DSP Bypass: Surround Off (DSP or Analog Bypass) = 2 CH STEREO. When this mode is selected, the BDS will pass the analog source material directly through to the front left and right speakers, bypassing the digital processing circuitry. Stereo mode: Turns off all surround processing and plays a pure two-channel signal or a downmix of a multichannel signal. The signal is digitized and bass management settings are applied, making it appropriate when a subwoofer is used. Pulse-code modulation (PCM): This method is used to digitally represent sampled analog signals, and two channels (stereo) is the most common format. PCM Stereo is what standard Audio CDs always use. Dynamic Range Control: This setting makes the loud and quiet parts of a movie or music sound closer to the same volume (a process known as compression). Compression lets you turn up the volume so you can hear the quiet parts without the loud parts disturbing other people. NOTE: This feature works only with Dolby Digital programs that have been specially encoded. Three settings are available: •• Off: Never applies compression. Use this setting when the volume may be as loud as you desire. •• On: Always applies compression. Use this setting when you want the volume to be as quiet as possible without making it difficult to hear spoken dialogue. •• Auto: Applies compression based on information encoded within the Dolby Digital bit-stream. The receiver will selectively apply compression only during the most dynamic parts of the soundtrack.