How to get surround sound into sage?

[tsitalon1]

Hey guys,

Long time Sage user and loving it. I have never played with surrond sound untill now.

I currently have:

2x hauppagge mce 150's
1x hauppagge 500
1 hdhr

My hauppagge units are connected via s-video to the motorola DCT6200recievers and rca audio connections to the motorola recievres. I think I have a good grasp on how to get surrond sound out to my audio reciever.

My question is...I don't believe this will get me surrond sound because, as far as I know, my audio input into sage is stereo. Am I missing something? How do I get 5.1 through this setup?

[Protoman]

The only tv stations that will have Surround Sound are the HD channels. SD channels only have stereo sound. So with your setup you might be able to get Surround sound from the HDHR, provided that the show is in surround sound.

edit: Not sure if the DCT6200 STB has firewire, but I believe if it does you could hook it up via firewire and get HD, and possibly surround sound. (I do not have this STB so I am only going from what I read about it and know about it.

Hope this helps,
Protoman

[stanger89]

First you must define what you mean by "surround sound". In it's truest sense, surround sound is just audio which contains information that is meant to be placed behind you (or around you). There are many ways to represent this information, and many ways to transmit it to other devices.

These days, the first thing that comes to mind when most people think of surround sound is Dolby Digital 5.1. DD 5.1 is a perceptual codec that stores 6 discrete channels of audio in a single bitstream. Usually that bistream is passed from player to processor, where it is decoded and then routed to 6 or more speakers. Of course there are other discrete audio codecs: DTS (5.1, 6.1), Dolby Digital Plus (7.1), DTS-HD (7.1), Dolby TrueHD (7.1), PCM....

However this is not the only way to represent, nor transmit surround audio. Dolby Digital only came into being with Laserdisc (I believe) but we've had surround audio since long before anyone knew of Dolby Digital. How is that? Matrixed audio. In the general sense, matrixed audio stores n logical audio channels in less than n discrete channels. The most common form of this is Dolby Surround. Dolby Surround is an encoding method which stores 4 logical audio channels (Left, Center, Right, Surround) into two discrete channels (stereo). Dolby Surround was used on VHS and many programs are broadcast in Dolby Surround. The way it works is (essentially) sounds that belong in the Center are store equally in both stereo channels in phase, Surround audio is stored equally in both stereo channels but out of phase, and information unique to Left or Right speakers is stored in either the left or right channels.

When you play this back through a 2.0 system, if you're in the sweet spot, the center info with phantom image in front of you, the Left and Right info will come from the Left and Right, and the surround info will seem to come from "around" you.

When you play this back through a 5.1 system with surround processing like Dolby Pro Logic II, the algorithm will "steer" that info to the specific speakers according to the algorithm I outlined above.

Moral of the story is, Surround Sound is most certainly possible with Stereo connections or stereo audio tracks. If you've got Sage connected such that it records stereo, all you need to do is enable Dolby Pro Logic II (or another surround processing algorithm, not DSP modes like "Cathedral") and you'll get the surround sound you want.

Now, to answer the other question, no, there's no way to get discrete, digital 5.1 from a cable box. That has to be recorded as a bitstream with the video, as it is with OTA digital.

[GTwannabe]

You can use AC3Filter to matrix 2-channel audio into 5.1 Dolby Digital for your receiver. However, it won't be true 5.1, just an approximation.

[stanger89]

And I don't believe it's anywhere near as good as DPL. AC3Filter doesn't seem to do "intelligent" matrix processing (ie taking phase into acount).