Master Class: Bits and Pieces: Composite Vocal Tracks

May 1, 2009 12:00 PM, By Michael Cooper

           
 

CREATING COMPOSITE VOCAL TRACKS USING BUTT SPLICES, FADES, AND CROSSFADES

FIG. 4a: A zero crossover point cannot be found anywhere near the desired splice point for these two Soundbites.

There will be times when you simply can't find an edit point that fits the criteria just mentioned and a crossfade at the splice point won't get rid of the resulting click. In those instances, choose a splice point where one of the Soundbites has zero amplitude. Then edge edit the other Soundbite to its closest zero crossover point where its phase trend will be the same as that for the first Soundbite at its splice point (see Figs. 4a through 4c). Trimming will initially cause a slight gap between the two Soundbites. Select one Soundbite and, in DP6, Ctrl-drag it toward the other to make it snap to it, eliminating the gap. Usually, trimming and snapping a Soundbite thus will offset it from its original articulation by only about a millisecond along the timeline — not enough to affect the vocal's groove on a short phrase.

FIG. 4b: Around half a millisecond is trimmed from the start of the following Soundbite so that it begins at a zero crossover point.

Don't be afraid to break the rules if it sounds good. Suppose the singer sang a consonant such as t or k so softly that it becomes masked by accompanying instrumental tracks. A Soundbite pasted immediately before the consonant might cause a click if you're not careful. But if the click is soft enough, it might actually accentuate the soft consonant it abuts in a way that sounds totally natural. Likewise, an extremely mild pop might make an immediately following b or p sound more intelligible. Just be sure to check the result both on headphones and on full-range monitors (or a subwoofer) to get a feel for whether it might sound excessive or artificial on other monitors.

If a consonant still sounds too soft, you can always copy the same consonant from somewhere else in the song where it was sung louder. Then simply paste it over your soft consonant to replace it. Can't find a loud-enough consonant anywhere? Make a time-range selection across the one that's too quiet, press Command + Y to make the selection a separate Soundbite, and then increase the Soundbite's nondestructive Bite Gain setting to make it louder. (The Bite Gain setting is located in DP6's Sound File Information dialog box; open the dialog box from the Studio menu or by pressing Ctrl + Option + Command + A.)

Double Cross

FIG. 4c: The following Soundbite is then snapped to the end of the leading Soundbite. Now both Soundbites exhibit zero amplitude and the same phase trend at the splice point.

In most cases, careful placement of a splice point will preclude the need for placing a crossfade across it. The fewer crossfades you have in your Project document, the less CPU drain there will be on your computer and the quicker your document will open.

That said, crossfades are sometimes necessary to eliminate clicks, pops, and other artifacts. Your DAW will likely give you a choice between making an equal-gain or equal-power crossfade at the splice point. I find that equal-gain crossfades typically yield better results when the adjoined Soundbites contain similar material (as is the case when comping vocals). In any event, you'll want to be able to adjust the length of your crossfades to achieve the best results. Open DP's Create Fades dialog box (in the Audio menu) and choose Fade Selected Time Ranges.

Most of the time, a crossfade spanning only 5 or 10 ms of material is all that's needed to clean up a splice point. Particularly stubborn artifacts, however, may require a 30 ms crossfade or longer. Just be aware that a long crossfade will likely create an audible doubling effect across its span because both Soundbites will voice during the crossfade. That can be either distracting or a nice creative touch, so judge the results carefully.

FIG. 5: The center handle of a crossfade is dragged to the right here in DP6’s Create Fades dialog box to create an asymmetrical crossfade. This emphasizes the leading Soundbite’s material at the splice point.

If even a long crossfade doesn't clean up the splice point, try skewing its crossover point (that is, the point where both Soundbites are equally faded) so that it's slightly earlier or later in the timeline. In DP's Create Fades dialog box, grab the crossfade's center handle (the crossover point) and drag it to the left or right of center. This creates an asymmetrical crossfade across your time-range selection (see Fig. 5).

To appreciate what this accomplishes, remember that a crossfade includes material in both joined Soundbites beyond the splice point: material after the end of the leading Soundbite and material before the start of the following one are both voiced. (This is true only if each Soundbite's edge was trimmed and there is more material in each parent file beyond the current edge.) Creating an asymmetrical crossfade results in an exponential curve that accentuates one Soundbite with respect to the other for a longer period during the transition (including beyond the splice point) between them.