Originally Posted by JCarls
What exactly is intended by "discreet". Does the processor extract all the left-only and right-only stereo info, throw it away, and send only the "centered" information to the center channel?
What you're describing is how the old Dolby Pro-Logic processing system extracted the center channel information from a simple 2 channel stereo signal. In a similar fashion, the surround channel info was extracted from a simple 2-channel stereo signal by the Dolby Pro-Logic processor. But multichannel
proccessing today is done by DolbyDigital 5.1 or DTS 5.1 processors. The digital
5.1 channel audio soundtrack of DD/DTS 5.1 material really is, unlike the simple 2-channel stereo soundtrack of old, specifically engineered to have 6 completely different, unique, and discreet channels of information; front L/R, center, surround L/R, and subwoofer. This is what the whole party is about!
Recording, transmitting, and decoding 6 channels of discreet and unique information is only possible in the digital realm. Simple 2-channel stereo obviously cannot contain 6 full channels of discreet and unique information. This is why a digital connection between a DVD player and an AV receiver is necessary. A digital processor, capable of DD/DTS 5.1 processing, processes the 5.1 channel digital soundtrack into the number of channels for which you have speakers. If you have 5 speakers and a subwoofer, the processor is capable of "teasing" out all 6 channels of discreet and unique information from the digital soundtrack, providing for a truly immersive surround sound experience. But a DD/DTS processor is actually capable of doing the opposite of what you described. Instead of extracting info from only 2 stereo channels, if you do NOT have a full compliment of 5 speakers and a subwoofer, it can actually reroute the info from those channels for which you have no speaker to other channels where you DO have a speaker. For example, if you only have 2 front channel speakers, the AV receiver's processor will split the discreet center channel information evenly across the front 2 channels. The 2 surround channels' info will also be distributed appropriately to the front 2 speakers in this situation. The subwoofer channel (0.1) information is also distributed to the 2 front speakers in a 2-channel setup if you do not have a subwoofer. If you have a 3 channel setup, with a center channel speaker, then the center channel information IS maintained as discreet center channel info, but the surround info is still rerouted appropriately to the front 2 channels, and the subwoofer channel info is rerouted to the front 2 speakers if you do not have a subwoofer.
In much the same way that a 2-channel stereo soundtrack from a CD (or LP) contains information unique to the left and right channels only, so too does a 5.1 soundtrack contain information that is unique to all of the 6 channels.
Join the party!