Alright, so I was looking for a new computer to turn in to my editing suite and I noticed that 5.1 Surround is practically a common feature now. Well, I was wondering how I could use this to my advantage and started thinking about where in the hell I would begin to edit for Surround Sound. I can't imagine it being too hard, I figure it's just a matter of assigning the correct audio to the correct channels, yet I couldn't think of one program that has channels other than left and right. Anyway, any info on this would be exxxxxxxxtremely helpful.

Thank you,
Elliott

The AC-3 encoder bundled with DVD Studio Pro encodes 5.1... but it sounds like you might have a Windows PC.

best of luck,
joren

Editing in 5.1 is ((EXTREMELY DIFFICULT)), it's not easy or simple. You need to know "how" to mix. Don't kid yourself into thinking it's just "assigning the correct channels", it's much more complex than that.


First of all, you're gonna need to buy a "5.1 monitoring system" (if you don't already have one) if you wanna be able to "hear" what you are doing, otherwise it's like editing with your eyes closed. Don't try to do 5.1 mixes on stereo computer speakers (don't use computer speakers period, unless that's all you have). 5.1 monitors are anywhere from 2.5k on up. (BTW- my 2.1 monitor system was $7,000... just to give you an idea of what good monitors cost. But I'm a composer, so sound is my job)


The 5.1 monitors need to be placed in an exact position. Mathematics are involved. It's physics. Do a search on-line for "5.1 film mixing". There is too much info to be explained in one post.

There's a reason why The Matrix surround sounds amazing, and there's a reason why the mixers get paid good money (cause it's hard). My buddy works for Todd-AO, so he's one of those guys.


BTW... Check out "Blue Sky" monitors for 5.1 mixing, they are fairly inexpensive but sound amazing.


Jayy

Here's a link to the Blue Sky 5.1 system:

BLUE SKY 5.1 MONITORS


What a 5.1 monitor set up looks like


The physical speaker layout is pretty simple. Just put a poll at the mix position and measure the distance from that position to the location of the center-channel speaker. Then cut a piece of string to the same length and tie one end to the poll. Mark the center-speaker position and go 30 degrees to the left and right for the front L/R speaker positions. Next, go 110 degrees to the left and right of the center for the Ls and Rs (surround) channels. This setup is the AES standard for monitor placement.

You'll need to calibrate your speakers too. Here's how:

Grab some limited-band (100 Hz to 2 kHz) pink noise from the mixing-console noise generator, a home-theater receiver, or a test CD and patch it to an input channel. Make sure to set the output gains to unity. Set the channle input strip so that the output level is at -20 dB (below 0). This is the standard reference level for surround mixes.

Feed the pink noise through one speaker at a time and point the SPL meter in the speaker's direction while holding the meter in the mixing location. Trim the gain of the corresponding amplifier channel so the meter reads 85 dB SPL. Repeat this process for each full-bandwidth speaker, one at a time, until you have the same output for each.

Next, run low-frequency pink noise (25 to 80 Hz) to the LFE channel. In theory, the gain of the LFE channel should be set 10 dB higher than that of the main channels (95 dB SPL), as read by a real-time analyzer (RTA). But a Radio Shack meter has a lot of low-frequency rolloff, and you're feeding it less than two octaves of audio information in this case. These factors cause the meter to read lower than the true output level. As a result, when the LFE level is correct, the Radio Shack meter will show approximately 90 dB SPL-4 to 6 dB higher than the level for the five full-bandwidth speakers.

For diffuse surround speakers used in cinema mixes, the rear surround levels are set to 82 dB SPL (-3 dB relative to the other full-bandwidth speakers). For really small mixing rooms where you can literally reach out and touch the speakers, Dolby recommends setting the surround speakers 2 dB down; that is, at 83 dB SPL.


It can be a bit confusing. If you don't get these levels correct, all the mixes you do will have incorrect surround an d center-channel levels, or the LFE level will be out of control. Those problems will force listeners to jump up and adjust the levels on their home systems.


Be sure to use "THX Certified" monitors.


Jayy›

Jay, I have a cheap $70 analog Creative 5.1 speaker system, with an audigy platinum 5.1 sound card. I have a mixing program, and ask if this is good enough for creating a 5.1 track for my video. I know these speakers aren't the best, but if I calibrate them correctly, will they pass? I mean what does the extra $2000 give you when your audience will listen on a completely different system? Also, will I be able to put a 30 minute film on dvd(as minidv is only stereo) without much compression?

Jay is right, 5.1 mixes are very difficult to do well and pro monitoring equipment is very expensive but I suppose that since we are all students here the pro route is not an option.

So the question is what is the minimum you can get by with... right?

The advantage to pro monitoring equipment is that it will provide you with a clean and precise sound representation. But... if you are using a crappy pair of computer speakers (within reason of course) or stereo speakers you can learn to make compensations to the sound in order to counter-act the coloration your equipment adds. I'm not suggesting that you'll be able to solve every problem that a pro monitoring system can solve but you can definitely come out with something pretty good with some hard work.

On the PC side (somebody already talked about the Mac side) Vegas 4 includes a 5.1 mixing plugin and it is easy to use. 5.1 mixing is difficult but so is a good stereo mix.... but then again everything's difficult until you try it.

This is a very interesting topic. I'd love to know more about sound design and acoustics.

I absolutely agree that good, correct equipment makes all the difference. But, as that is sometimes not an option, what if you were able to test your mix for your intended audience? Burn a quick DVD and go to your living room, and see what it sounds like. Of course you won't get Matrix results, and it may not sound perfect on every system, but you should have a rough estimate what it'll sound like. After all, most people don't get their living rooms THX certified.

On the video side, I guarantee 95% of the people on this board aren't using calibrated broadcast TV monitors when editing. They still have useable images--sometimes. So, as a test, I say go for it! Use the best monitor speakers within your means. The worst thing that'll happen is it won't work or it'll sound bad. Please correct me if I'm wrong.

You can always do two audio streams. One Dolby 2 and one Dolby 5.1. Encoding 5.1 takes up relatively little room. Just make sure you're always encoding Dolby AC-3 and not the other, heavier formats. The difference is 273kbs compared with almost 1Mbs (for 2.0 channel). It adds up.

joren

Yes, by all means, do what you can afford!!!


Although I do suggest at least getting a set of inexpensive stereo "powered monitors" to mix stereo, especially if you do everything yourself (a decent stereo mix is a hell of alot better than a bad surround m ix). You can find some cheap powered monitors for around $350 that will be night and day compared to a pair of sh!tty computer speakers (which really should only be used as last resort... no mater how small your budget is).


Don't forget that sound is h alf of the film experience (on the large scale). But even low or micro budgets can not afford to have "bad sound".....


*The easiest trick to make your film(s) sound more professional is to run an "audio compressor" on the dialogue track so that the levels are fairly consistent. Already it would be closer to what is considered "standard".

The first complaint viewers (usually) have upon watching a low budget films is; "the sound sucks... why can't I hear everything.... the volume keeps going up and down"? People tend to notice this before bad cuts, shots, angles, lighting, color-timing, etc.

*** Biggest point: Better sound makes the acting "SEEM" better. It's psychology.... trust me on that!


Directors need to know a lot, but still.... try and hav e fun too!


I'll explain more about the benefit of monitors and sound in a bit.... I'm in the process of a final mix.


Late



Jay

I absolutely agree with you, Jay. Sound to me is way more than half the experience. It is what gives credibility to the picture. It also "tells" you how to feel about what you're watching. Sound is the biggest problem with student films by far, IMHO.

joren