For those mixing in surround, the biggest shortcoming of Digidesign Pro Tools LE and M-Powered is the lack of surround support. Luckily, Neyrinck Mix 51 (neyrinck.com), an RTAS plug-in reviewed in the June 2008 issue (available at emusician.com), brings surround panning and mixing to both. (Digidesign's recently announced Complete Production Toolkit adds surround support to Pro Tools LE.) If you're familiar with Pro Tools|HD's surround panner, you'll feel right at home with the plug-in. If you aren't, I'll have you up and running in no time.
Setting up Mix 51 is a bit convoluted, but everything works as expected (see “Step-by-Step Instructions”). The setup gives you one 5.1 main output and two quad effects returns. That lets you have separate returns for delay and reverb. To create multiple surround subgroups or to mix to separate music, dialog, and effects stems, use the plug-in's three 5.1 main outputs and three quad send outputs.
Spin Me Right Round
FIG. 1: The Mix 51 Surround Panner plug-in''s controls emulate those in the Pro Tools|HD surround panner.
Insert an instance of Mix 51 Surround Panner on each audio, aux, and instrument track you want to pan in surround (see Fig. 1). For most applications, you'll simply grab the little orange widget and drag it within the x-y grid. Drag it all the way to any corner to hard-pan to a specific channel, and Alt-click (Option-click on a Mac) to hard-pan to the center channel.
The Surround Panner plug-in directs the signal to the surround outputs; no signal passes through the assigned track outputs, and their controls are irrelevant. However, if you click on the Bypass button, the signal does pass through the track outputs, allowing you to create an independent stereo mix. Actually, the name Bypass is inapt because the surround panner also continues to operate normally.
Divergence is an often-misunderstood parameter with varying definitions. In Pro Tools, it controls the amount to which a signal bleeds into adjacent channels. With all three Diverge knobs set to 100, when you pan a signal to the center channel, none of the signal comes out of any other speakers. (The surround panner's meters will confirm this.) That makes the sound a point source at the center speaker, giving it maximum isolation at that position.
Lowering the front divergence lets the signal bleed into the left and right channels, spreading the sound wider across the front. At zero, the signal comes equally from all three front speakers. Lower the front-to-rear (F/R) and rear divergences, and the signal comes equally from all five main speakers. At this point, the signal will be centered in the room and will not drift relative to the listening position.
Notice how the outline of the surround panner (blue square) narrows as you lower each divergence control — divergence effectively makes the room smaller. Imagine that you are panning a sound from left to right to follow onscreen movement. If your left and right speakers are placed exactly at the left and right edges of the screen, the motion will track perfectly. If, however, your speakers are placed beyond the edges, the sound will travel farther left and right than the onscreen action. By lowering front divergence, you can narrow the reach of the front speakers to fit the screen. As another example, try panning a sound in a circle as you progressively lower divergence, and you will hear the circle growing smaller.
Journey to the Center
Center percentage (set with the Center % slider) is a bit simpler. It controls the amount of signal coming from the center channel, regardless of pan and divergence. Think of onscreen dialog with street noise behind the actors. The center-panned dialog is isolated in the center channel by setting center percentage on those tracks to 100. The street noise (passing cars, jackhammers, and so forth) is panned between the left and right channels, with center percentage set to 0, so that even when it passes through the center of the soundstage, it remains acoustically separate from the dialog. Use the same technique to obtain some separation between your lead vocal and center-panned instruments.
The one thing still missing is true multichannel effects. Inserting two identical plug-ins (with the same settings) on the front and rear effects returns will get you close. To get true multichannel compression, bus the tracks you want to compress together and use that bus as the key input on stereo compressors on the three auxes that make up the 5.1 subgroup. You'll need to bypass the surround panner for audio to get to the bus. (See Web Clip 1 for an example session that demonstrates this technique.)
All of Mix 51's parameters are compatible with corresponding parameters in Pro Tools|HD's surround mixer. (The online bonus material at emusician.com describes how to migrate your LE/M-Powered surround mix to Pro Tools|HD.) Getting the most out of Mix 51 is a bit laborious, but it's worth it to finally be able to mix in surround in LE.
Brian Smithers is department chair of workstations at Full Sail University and the author of Mixing in Pro Tools: Skill Pack (Cengage Learning, 2006).
STEP-BY-STEP INSTRUCTIONS ON NEXT PAGE
Step 1: Prepare your session by creating three main stereo paths with SMPTE path order: L/R, C/LFE, and Ls/Rs.
Step 2: Insert the Mix 51 Surround Mixer plug-in on any track.
Step 3: Create seven stereo aux inputs, and assign their inputs from the surround mixer. Name the aux tracks.
Step 4: Assign the outputs of the aux tracks to the main output paths you created, and assign them to main L/R and main Ls/Rs.
Step 5: Insert a Mix 51 Surround Panner plug-in on all audio, aux, and instrument tracks you want to pan in surround.
Step 6: Insert matching delay plug-ins on the two Delay auxes and matching reverb plug-ins on the two Reverb auxes.