How does it do that?

[polkfan38]

After playing with my Denon AVR 1802, I have it set to "PLII" for watcing TV. It is hooked up to my cable box with just the two audio outs. It is getting surround on some channels. How is surround info transfered through just two "left and right" outputs? I am baffled!

Thanks

[heiney9]

It a digital algorithum built into a decoding chip. It's fake, as in that info isn't really in the original signal content. That technology has been around since the advent of Surround Sound in the late 80's early 90's.

H9

[danger boy]

it's taking your two channel stereo signal and processing it to be DPLII surround sound.


some times it doesn't sound to bad... and often times beats listening to just the front left and rights

[polkfan38]

Interesting. I can call and ask but, is true surround broadcast through cable? We will be upgrading to a "HD" box this summer.

Yes, Danger Boy. It is much more fun than 2 channel TV!

[concealer404]

Interesting. I can call and ask but, is true surround broadcast through cable? We will be upgrading to a "HD" box this summer.

Yes, Danger Boy. It is much more fun than 2 channel TV!

Depends on the channel... I'm pretty sure some of my movie channels do.

[vc69]

Digital cable systems usually transmit basic channels in stereo. The HD and digital tier channels are dolby 2.0 or 5.1 depending on the source and bandwidth allotted for the channel.

[danger boy]

depends on the channel and the program material.

not all programs are dolby digital 5.1

most HD channels I've found are broadcast in 5.1 surround.

[dudeinaroom]

Dolby surround has been around since the early-mid 80's and prologic came out in the mid-late 80's(addition of the center channel). Basicly the decoder take the right and left input puts and separates them based on differences. Left only info from the left front, right only info on the right. Center is derived from the like signals in the left and right channels and the surrounds(which was a frequency limited mono channel with 2 speakers) information comes from the difference in the left and right channel. I not sure how well I remember this, but I'm pretty sure it's pretty close.

[polkfan38]

That is cool stuff! I kind of wish I got into this earlier! I have a 7-8 year old DVD player hooked up with a digital coax line. If I play a movie that was recorded in 5.1, does the same principal apply or is that 5 actual descrete channels coming through the single line?

[dudeinaroom]

It's is actually 6 discrete channels. Your left, right ,center rear right, rear left, and LFE(sub).

[polkfan38]

Awesome! Thanks!

[mdaudioguy]

It a digital algorithum built into a decoding chip. It's fake, as in that info isn't really in the original signal content. That technology has been around since the advent of Surround Sound in the late 80's early 90's.

H9


Dolby surround has been around since the early-mid 80's and prologic came out in the mid-late 80's(addition of the center channel). Basicly the decoder take the right and left input puts and separates them based on differences. Left only info from the left front, right only info on the right. Center is derived from the like signals in the left and right channels and the surrounds(which was a frequency limited mono channel with 2 speakers) information comes from the difference in the left and right channel. I not sure how well I remember this, but I'm pretty sure it's pretty close.

I don't think it's necessarily fake. Dolby Surround, now known as Dolby Pro Logic, is a true multichannel format in its own right, albeit analog. PL can take any 2-channel stereo signal and make it sound surround-like, however, movies with a Dolby Surround or Dolby PL encoded 2-channel soundtrack will be output by a PL decoder in a 4.0 format, essentially as described above. Send the lower frequencies to a sub, ignore the fact that both surround channels are the same, and you have virtual (fake) 5.1! :);)
We've download several movies via PS3 in SD and the 2-channel soundtracks sound pretty good with PLIIx or DTS Neo:6 (DTS's version of PL).

[polkfan38]

On a side note, I know someone who is in the film industry who has won a Grammy for sound mixing. All movies are mixed in 5.1 with only one or two exceptions where he did some in 6.1. My only point to mentioning this is that 7.1 (or beyond) IS fake. Just processed by a reciever.
The PL stuff is neat though!

[polkfan38]

My bad. I meant Oscar. Not Grammy.