Inform the Idiot about 5.1 Surround Audio
by Ron Shook
on
Oct 22, 2007 at 8:21:42 pm
Vegasites,
I could go elsewhere with these questions, but since I'll be using Vegas to experiment with and do this, someone tell me about 5.1 surround audio.
I've been in this biz a long time and should know the answers, but I've never worked with anything but mono and Stereo
I know the tools are there in Vegas to build the multi-channel files in preparation for encoding, but am I correct in believing that I can encode to 5.1 Dolby in Vegas without resorting to 3rd party software? If I do so, does 5.1 work OK in a stereo playback system or is there some distinct advantage to having a separate stereo file. I notice that most commercial DVDs have both 5.1 and stereo Dolby files and sometimes DTS as well, though I'm not looking to encode DTS.
Finally, I'm more than confused about it what it takes to monitor what you are doing as you build an audio space prior to encoding to 5.1 dolby. How do you get the 6 channels out of your editing system discretely and fed to your speakers. A standard home surround receiver can't do that, can it, as it's set to decode the 5.1 Dolby from a 2 channel encoded signal? Do I need powered speakers all around to feed line level from the integrated or separate sound card in the editing computer?
Maybe I'm biting off more than I can chew or at least afford to chew?
Re: Inform the Idiot about 5.1 Surround Audio by Rick Mac on Oct 22, 2007 at 10:59:50 pm
[Ron Shook]"am I correct in believing that I can encode to 5.1 Dolby in Vegas without resorting to 3rd party software?"
That is correct.
[Ron Shook]"If I do so, does 5.1 work OK in a stereo playback system or is there some distinct advantage to having a separate stereo file."
The playback device will downmix your 5.1 to stereo mix. As long as you do a decent 5.1 mix it should downmix well.
Vegas has a downmix button that allows you to listen to your 5.1 mix downmixed to your stero speakers. Work much the same as a stereo to mono switch.
[Ron Shook]"How do you get the 6 channels out of your editing system discretely and fed to your speakers."
A multichannel soundcard with discrete outputs feeding either
powered speakers or poweramps.
Regards, Rick.
Rick Mac
Director of Audio Production
TCT Network - Directv 377
Re: Inform the Idiot about 5.1 Surround Audio by Ron Shook on Oct 23, 2007 at 2:41:46 am
Rick,
Thanks for the succinct answers,
[Rick Mac]"Vegas has a downmix button that allows you to listen to your 5.1 mix downmixed to your stero speakers. Work much the same as a stereo to mono switch."
Re: Inform the Idiot about 5.1 Surround Audio by Charles on Oct 23, 2007 at 5:17:46 pm
Ron,
Just to add a bit of clarification to an important part of the puzzle. The audio connections from your sound card to your amp or speakers should most likely be: 1 mini-RCA plug for the front, 1 mini-RCA plug for the rear, and one for the subwoofer. Then you need to configure your Vegas hardware settings accordingly. Don't try to listen to 5.1 from Vegas with a Toslink digital connection to your speakers.....it won't work.
Re: Inform the Idiot about 5.1 Surround Audio by Rick Mac on Oct 23, 2007 at 6:12:03 pm
[Charles]"The audio connections from your sound card to your amp or speakers should most likely be: 1 mini-RCA plug for the front, 1 mini-RCA plug for the rear"
Just for the record, there is no such thing as a mini-RCA
plug. There are RCA plugs and their are 1/8th mini plugs.
The mini-plugs can be either mono (unbalanced) or stereo (balanced). Be careful, you don't want to plug a stereo mini into an unblanced mono input.
You can use adapters as needed to interface your soundcard outputs to your amp inputs or power speaker inputs.
Regards, Rick.
Rick Mac
Director of Audio Production
TCT Network - Directv 377
Re: Inform the Idiot about 5.1 Surround Audio by Ron Shook on Oct 23, 2007 at 10:19:34 pm
Charles,
[Charles]"Thanks your right,"
Well maybe Rick wasn't completely right, as I don't think that mini-plugs are ever balanced. The stereo ones are simply 2 channel unbalanced. While you will run into 1/4" tip/ring/sleeve connections that are either stereo unbalanced or mono balanced, I've never run into a balanced 1/8" mini-plug connection. I suppose it's possible, but I've never encountered it.
Re: Inform the Idiot about 5.1 Surround Audio by Rick Mac on Oct 24, 2007 at 12:51:57 am
[Ron Shook]"I don't think that mini-plugs are ever balanced. The stereo ones are simply 2 channel unbalanced. While you will run into 1/4" tip/ring/sleeve connections that are either stereo unbalanced or mono balanced, I've never run into a balanced 1/8" mini-plug connection. I suppose it's possible, but I've never encountered it."
Ron,
For the most part you are correct.
However if you build your own cables or use the wrong adapters you can create anything. I've seen it done lots.
Regards, Rick.
Rick Mac
Director of Audio Production
TCT Network - Directv 377
Re: Inform the Idiot about 5.1 Surround Audio by Ron Shook on Oct 24, 2007 at 5:43:16 am
Hi Spot and to Rick as well,
[dse/spot]"Not only that, but there are times when the 3.5mm plugs are intentionally wired as a balanced cable, though usually marked as such."
Hmmm! Learn something everyday! Since audio has been mostly an adjunct to my world and I've never run into such things, out of curiousity and a necessity to be prepared with my kit adapters, what kind of gear might I expect to find balanced mini-plug connections on? Don't wanta get caught with my pants down. (g)
Re: Inform the Idiot about 5.1 Surround Audio by Ron Shook on Oct 23, 2007 at 10:09:29 pm
Charles and Rick,
[Charles]"Just to add a bit of clarification to an important part of the puzzle. The audio connections from your sound card to your amp or speakers should most likely be: 1 mini-RCA plug for the front, 1 mini-RCA plug for the rear, and one for the subwoofer. Then you need to configure your Vegas hardware settings accordingly. Don't try to listen to 5.1 from Vegas with a Toslink digital connection to your speakers.....it won't work."
Oh My! I just start to look forward to lowering my cable count from the rat's nest of component and S cables and surround sound pushes it in the other direction. This is gonna get a little complicated and I'll fantasize how to do it with what I have and you tell me if I'm on the right track.
I currently have available to my system a sort of cobbled together 5.1 surround system that sounds just short of audiofile. It consists of a mid-sized JVC surround receiver, a couple of JBL mid-sized studio speakers for L&R Front, a couple of small mid-sized Polk Audio speakers for L&R surround, a large mid-sized very clean European center channel speaker, and a relatively inexpensive self powered Yamaha 10" subwoofer (I have no interest is rearranging my guts with heavy bass.)
What I contemplate using for monitoring in production/pre-encoding surround sound is using the JVC surround receiver in stereo mode to power the L&R front, my previous but still good Sony stereo receiver to power the L&R surround, and an amp that I have squirreled away somewhere that has at least one good channel left in it for the center channel. (Speaking of the center channel, is that usually doubled with the subwoofer channel on the sound card?)
Good so far, but it leaves a gapping question. I don't want to string dual sets of speaker cable and I'll want to continue using this system to listen to encoded surround as well. Can I simply loop the surround and center channel speaker wire from the two extra amps through the speaker connections on the surround receiver? Will I risk damage to the surround receiver if I do this and thus need to put in A/B switches on the speaker cable? Are there Rat Shack or other A/B switches for speaker cable if this is necessary?
I hope enough others find this informative enough that I'm not overstaying my welcome.
Re: Inform the Idiot about 5.1 Surround Audio by Charles on Oct 23, 2007 at 10:30:42 pm
I was refering to the "RCA" part of the mini plug as being my error.
"(Speaking of the center channel, is that usually doubled with the subwoofer channel on the sound card?)'
Yes, in my system it is.
"I don't want to string dual sets of speaker cable and I'll want to continue using this system to listen to encoded surround as well."
When you have two different sources of "amplified" signal, I believe you better use an A/B speaker switch. You don't want to feed an amplified signal to an input source in a second amp. But, if I'm wrong, I'm sure someone will correct me.
Re: Inform the Idiot about 5.1 Surround Audio by Rick Mac on Oct 24, 2007 at 12:54:16 am
[Charles]"When you have two different sources of "amplified" signal, I believe you better use an A/B speaker switch. You don't want to feed an amplified signal to an input source in a second amp. But, if I'm wrong, I'm sure someone will correct me."
I agree.
Regards, Rick
Rick Mac
Director of Audio Production
TCT Network - Directv 377
