Gary sent me a message tonight snipped from the site http://www.hometheaterforum.com:
"DPL II is a decoder only. It works with any 2 channel stereo source whether surround encoded or not, although you will get better channel separation on Dolby Surround encoded material. DPL II works with the same Dolby Surround encoding as the original Pro Logic, but instead of a frequency limited mono surround, you get full range stereo surrounds." To forum members SAM's post here, I asked Gary at RFC about what you said: "If that is the case, wouldn't one achieve the same/similar results from engaging DPL2 on their receiver or pre-amp?" The answer RFC e-mailed to me SAM, and from what I read on the internet tonight about Surround encoding on the Dolby and other manufacturer's web sites is that the audio material (live streamed or not) needs to be encoded into a 5.1, Dolby Pro Logic II, Dolby Live, DTS, etc. format for a true _stereo_ Surround effect and Center channel effect to be achieved. (Dolby is not the only encoder brand type, just the most well known). So, SAM from what I think I now understand is that "engaging DPL2 on their receiver or preamp" as you said, is only half of the pairing. When you engage (you mean turn on?) a certain surround setting on your equipment, you are turning on the _decoder_ portion (one half) of the surround sound encoding equation. RFC is doing their part at the source by providing the _encoding_ portion of the surround sound equation, or the first 1/2 of the equation of the surround encoded stream. Gary said to me what is going on with this new RFC stream is a Surround Sound "Codec" is being used by RFC which is then embedded into the MP3 stream. Codec is a technical jargon abbreviation for "Coder/Decoder". "Encoders" apply math to encode the signal source, then the Encoded signal is followed by or sent to a "Decoder" which applies its own math to decode the encoding. The decoding could be done by a device connected by analog audio cables, a device connected by a Digital audio cable connection, a device connected to a Cable Television receiver or even from a Satellite signal. So, RFC's 5.1 channel stream (or other sound material encoded in a surround format) is the source part of the "Codec", it is the "Coder" part. Or, consider it the 1/2 of the Codec signal that is provided to you. Then, it's up to you to decide what is the most pleasing, compatible or best sounding Decoder setting to use at your end. Activating certain surround decoder settings on your receiver or preamp provides the latter 1/2 of the sources "Codec", the Decoder, meaning your selected Surround Decoder is providing 1/2 of some type of mathematical solution to the "Codec". Essentially the surround encoding by RFC is embedded into their 192 kbps MP3 stream. This is all possible since some current Dolby encoding is packaged, or carried within an AAC stream of varying bandwidth instead of MP3. I think I read somewhere that Cinema quality DTS uses a PCM bitstream. Gary told me the reason Dolby usually packages their surround encoding within an AAC stream instead of MP3, MP2 or WMA has to do with minimizing monetary royalty payments to non-Dolby patent holders. Gary said when he monitors RFC he uses the 5.1 setting on his Home Theater system and prefers the sound that way, but that your results can vary because his Home Theater system uses: "full-range tower speakers for the front left/right speakers and a large center channel JBL dialog speaker. His left/right front speakers are mated to a Velodyne powered subwoofer with its crossover set to a 6 decibels per octive bandpass slope beginning at 200 Hz" (quoted from Gary). When I activate the Surround setting on my Sony Home Theater system, doing an A/B comparison to other radio stations (FM and Internet) and then listening to Radio Free Colorado as the signal source, to me the sound just leaps out and fills the entire room with better surround imaging and clarity. Gary said the Omnia DSP unit and mating software package being used at Radio Free Colorado can and does mathematically derive separate _stereo_, full-range surround for all channels up to 5.1, whether the original source material RFC plays is surround encoded or not. Finally, I asked about 7.1 encoding, etc. and the reply I received is that Gary felt any encoding of Radio Free Colorado's stream beyond 5.1 channels would be overkill. I agree, since I have the "wife" factor to deal with, adding more speakers to the living room would cause marital distress. :( Personally I find what Radio Free Colorado is doing fascinating. RFC is still experimenting with the encoded sound level of the Subwoofer channel. Also I note in my listening to RFC that older songs, or poorly recorded songs are more easily noticed now than before. Songs with better recording quality, some of which I own on Compact Disc, sound much better on RFC than the poorer sounding songs which have a bad mix, tape hiss, etc. I suspect this is because of the RFC stream being at 192 kbps MP3 instead of 128 kbps MP3, the 192 kbps MP3 stream being more revealing and open in clarity. So, if a song sounded OK encoded at 128 kbps MP3 but has noticeable flaws when encoded at 192 kbps MP3 this is an expected occurrence. The lower bitrate streams can mask imperfect song recordings. Mike -- Radio Surfer You Can't Always Get What You Want....unless you buy it first! ------------------------------------------------------------------------ Radio Surfer's Profile: http://forums.slimdevices.com/member.php?userid=31290 View this thread: http://forums.slimdevices.com/showthread.php?t=67535
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