Mixing 5.1 audio
- — 16 July, 2003 09:00
In previous audio columns we have detailed how to use a variety of tools to help create music, and exclusively in the Digital Music section of our Web site are tutorials for making a video clip in Vegas 3 and remixing songs in ACID Pro 4.
Continuing these themes, this time we'll be using the new version 4 of Vegas+DVD (which includes a Dolby Digital 5.1 AC-3 encoder and DVD architect) to expand on previous tutorials and investigate producing our own 5.1 surround sound mixes. Recently bought by Sony, both Vegas and ACID hail from Sonic Foundry (www.sonicfoundry.com).
Before you begin, you'll need to double-check that your speakers are set up and positioned correctly. To do this in Windows XP, navigate to Start-Control Panel-Sounds and Audio Devices then click on the Advanced button at lower right. Click on the speaker setup list box and choose 5.1 surround sound speakers. Now use the software that came with your speakers or sound card to test them. You might also want to read a guide from Microsoft that features a 556KB, six-channel test file you can download (www.microsoft.com/windowsxp/windowsmediaplayer/51audio.asp).
If you've used any version of ACID, especially version 4 or even ACID XPress (see tutorial in January 2003, page 128 or search online at http://pcworld.idg.com.au), you'll feel at home in Vegas.
The program uses the standard multi-track layout - separate tracks go downwards and begin at the left and move right towards their end (see FIGURE 1). Both version 4.0 of Vegas and ACID Pro use this approach to sequence/edit/lay out both audio and video. You can use the zoom controls at the bottom right of the multi-track area (or your scroll mouse) to zoom in and out for detail.
TIP: if you are not quite sure what a toolbar button or slider in Vegas does, just let your mouse hover over it and the item's name (and therefore its use) will pop up in a small yellow balloon-help style box.
At this point, you need to decide which type of 5.1 mix you wish to create: perhaps you want to give your home movie 5.1 audio, or pan a single song around in 5.1 space. Alternatively, you could have recorded your band using separate microphones for each instrument. You may have used a four- or eight-track tape recorder or even recorded (preferably as mono) directly into multi-track software such as Vegas, and want to try sending the different instruments to different speakers in 5.1 space.
In the following example, we'll look at working with this latter scenario, specifically mixing the different instruments from a song recording and panning each around in 5.1 space.
Step 1. In Vegas 4, go to File-New. Under the Video tab, change the template to PAL DV. Under the Audio tab, change the Master bus mode from Stereo to 5.1 Surround. Click Apply, then OK. Next, pull down the Options menu and select Preferences. Under the Audio Device tab, change your audio device type to your sound card's ASIO driver if available. Click OK. Close the large Preview window at bottom right by clicking on its cross in the top left of that window. You now have a much better view of your surround master mixer.
Step 2. Use the file browser at Vegas's bottom left and browse to where the AIFF or WAV recording files of the different instruments playing the same song are located. Drag each to the multi-track area. Clicking and dragging on each waveform will allow you to finely move each instrument to make sure everything is in time.
Step 3. Look at the surround pan area (a red dot surrounded by blue dots signifying speaker layout) located at the left of each waveform/track (see FIGURE 1). Moving the red dot controls that channel/instrument's panning in 5.1 space.
Step 4. You could now simply pan each channel in 5.1 space and leave it there for the entire song. You can access a more detailed surround panner interface by double-clicking on the small interface. If you're happy with what you hear and don't want to have the instruments move in space during the song, skip Step 5.
Step 5. If you do want the sounds to move in 5.1 space, you'll need to automate them. Do this by selecting a channel to automate and pressing
TIP: if you right-click on a keyframe, you can select how that keyframe will transition into the next - smooth, fast, linear and so on.
- Dolby Digital 5.1 compatible sound card such as those available from Terratec and Creative as well as many more suppliers
- Dolby Digital 5.1-compatible speaker system such as those available from Creative, Altec Lansing and Logitech
- 5.1 mixing software such as Vegas 4 or Acid Pro 4 with 5.1 encoding add-on
Vegas 4 minimum system:
400MHz processor; CD burner; 128MB RAM, 30GB hard disk