Audio in Rich Media
Tricks of the Mix
The most common type of mixing automation is what engineers call a “volume ride” — raising or lowering the volume of a track. Let’s create one in Soundtrack Pro to fix those problematic schoolyard sounds.
Click the twirl-down triangle next to the name Schoolyard Ambience. Increase the vertical zoom so you have lots of room to work, like so:
First, we’ll lower the overall volume of the sound by click-dragging the triangle next to the word “Volume.” If we pull it down to -8 dB, it sounds about right following the voiceover segment, but it’s still too loud when the interview resumes. A good volume ride would allow the sound to enter with impact, but duck it down behind the interview.
You write automation by double-clicking directly on the volume line, creating an “envelope point.” (Other audio applications call these “breakpoints” or “nodes.”) In this case, we create an envelope point at the beginning of the clip, and then another when the interviewee starts speaking. We click-drag the second one down to -20 dB.
Now the effect sits comfortably behind the interview. Hear the clip for yourself.
There’s still the problem of that abrupt ending, however. We could create another envelope point at the end of the schoolyard clip and drag it down to zero so the effect gradually fades. Instead, let’s extend the ambient effect so it continues for the duration of the interview clip.
We select the schoolyard clip and choose Duplicate from the Edit menu.
Now the effect continues long enough, but you can hear a jarring volume dropout at the point where the two schoolyard clips intersect. Listen to the clip.
Fortunately, Soundtrack Pro offers a quick fix: If we click-drag the second schoolyard clip back a few seconds so that it overlaps the first clip, the program automatically writes a “crossfade” — a smooth audio transition between clips. Finally, we’ll add two more envelope points so the sound fades smoothly as the interview clip ends.
Hear how the revised section sounds.
Another likely place for a volume ride is on the voiceover track, which is a bit loud relative to the interview track. Since the third voiceover clip is a bit quieter than the first two, we lower the first two clips by -2 dB, but leave the third one as is, like so:
Note that you can nudge envelope points just like clips. Simply select a breakpoint and hold down the option key while clicking the arrow keys. The left and right arrows nudge the envelope points in time, while the up and down arrow keys raise and lower their volume.
Let There Be Music (Or Not)
Soundtrack Pro comes with a 7.26GB library of sound effects, music phrases, and loops. They offer a super-fast way to enliven your productions with dramatic music — or smother them in cheese. We’ll pursue the latter option.
Return to the Browser window’s Browser tab and navigate to the Apple Loops for Soundtrack Pro folder. Here you can audition library sends simply by clicking on their names. When you find something promising, control-click on its title and select Add to Bin from the menu that appears. After you finish searching, click on the Bin tab to reveal all your contender clips.
We choose two eerie sounds, “Drone Machine” and “Vibra Tone 01,” to use as intro, outro, and transition music. We add them to separate tracks, duplicating each sound several times. We nudge all the interview segments back in time in order to feature the music at the beginning, add volume automation throughout, and massage some of the earlier volume rides to work with the music. Next, we delete the unused tracks by highlighting them and selecting Remove Track from the Multitrack menu. Our near-final mix looks like this:
Listening through, the bell-like “Vibra Tone 01” feels too “in your face”.
Let’s add a reverb effect to this clip for a more distant, diffuse sound. When you add a plug-in effect to a track, it processes everything on that track in real time. To add an effect, click on the Browser window’s Effects tab and select Soundtrack Pro in the Category list. From the Show pull-down, select the track you want to process. In the Effect list, double-click the effect type you want, which adds it to the Name list. You can load multiple effects per track. To compare the new effected sound with the old sound, click the check mark next to the effect name. To edit an effect setting, click the Advanced tab in the Parameter list. Here we’ll opt for the default Soundtrack Pro Reverb sound.
The Output Track
Once the mix starts to solidify, you can finalize things by working with the Output channel. Like regular tracks, the Output track lets you write automation or add plug-in effects. However, anything you do on the Output track affects all the tracks in the project. If, for example, you want to fade out all your tracks simultaneously, you can write a fade with envelope points on the Output track rather than writing individual fades on each regular track. And that’s exactly what we’ll do here, fading out the project right after the final “Vibra Tone 01” clip.
Last of all, let’s finalize the mix with an output limiter. Limiters let you boost the overall volume of a track while ensuring that you don’t spill over into digital distortion. With the Effects tab selected, choose Out 1 from the Show menu. Find the Limiter plug-in on the Effects list and double-click on it. Click the advanced tab to reveal the plug-in interface. Set the Output knob to -0.100 dB, the smallest possible increment below zero. Raise the gain slider to +2.0 dB. Now the mix is loud but distortion-free. Have a listen.
The Final Product
Once we’re satisfied with the mix, it’s time to save it to disc. From the File menu, select Export/Export Mix. The Save As dialog that appears lets you select your target sample and bit rate. For audio CDs, choose 16-bit and 44100 Hz. For QuickTime movies, select 48000 Hz. For web use, you’ll need to bounce your mix down to MP3 format. You can’t do that within Soundtrack Pro, but you can simply load your mixes into iTunes and choose the Advanced menu’s Convert Selection to MP3 command.
This tutorial covers some of the most common Soundtrack Pro techniques, but it barely scratches the surface of what’s possible. The program teems with powerful plug-ins and clever editing features. You can create with its prefab content, or twist your own material into startling new shapes. Soundtrack Pro also supports the huge library of third-party Audio Unit plug-ins.
With tools like Soundtrack Pro, plus some basic audio recording equipment and a bit of practice, it’s easy to create rich media projects with audio. In this series we’ve given you much of the know-how you need to get started. The next step is simple: Experiment! Learn which tools and techniques work best for you. Before long you’ll be able to add “audio expert” to your curriculum vitae.
