Audio Editing Essentials In DP5

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Digital Performer Notes & Technique

Published in SOS December 2006
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Technique : Digital Performer Notes

Quick manipulation of soundbites is useful in any audio-heavy project. Here, two soundbites are being duplicated to extend a rhythm track, while others have had fades and edge-edits applied. Quick manipulation of soundbites is useful in any audio-heavy project. Here, two soundbites are being duplicated to extend a rhythm track, while others have had fades and edge-edits applied.

MOTU's Digital Performer is a superb audio editor, especially in comparison with some other software sequencers. The keys to its power in this area are the flexibility of the soundbite-based system for manipulating regions of audio, the way in which the Sequence Editor allows viewing of soundbites right down to single-sample level, and the easy application of all sorts of non-destructive editing tasks. As is usual with DP, though, there are any number of ways to perform essentially the same task, and we users sometimes get into a habit of working in one way when an easier and more streamlined method is staring us in the face. So this month it's back to basics with audio editing, as we revisit some crucial concepts and techniques.

Essentials

Before you can do much audio editing, you need to at least know the basics, and perhaps most basic of all is the simple act of selecting soundbites so that you can do things with them. To try out some of these techniques, you might want to record or import some audio, and have a few soundbites on the screen in front of you in the Sequence Editor window.

By holding down modifier keys while dragging soundbites, you can apply a variety of simple editing actions directly. Shown here are the mouse pointers that reflect three of these: the 'move' hand, the 'duplicate' hand and the 'throw' hand. By holding down modifier keys while dragging soundbites, you can apply a variety of simple editing actions directly. Shown here are the mouse pointers that reflect three of these: the 'move' hand, the 'duplicate' hand and the 'throw' hand. By holding down modifier keys while dragging soundbites, you can apply a variety of simple editing actions directly. Shown here are the mouse pointers that reflect three of these: the 'move' hand, the 'duplicate' hand and the 'throw' hand. By holding down modifier keys while dragging soundbites, you can apply a variety of simple editing actions directly. Shown here are the mouse pointers that reflect three of these: the 'move' hand, the 'duplicate' hand and the 'throw' hand.

Selecting Soundbites: Selecting a soundbite as a whole is easy: assuming you've got DP's default arrow tool selected, you just point anywhere in the top two-thirds or so of the soundbite, and away from the left and right edges, and click. With one soundbite selected, hold down the Shift key and click other soundbites in the same way to add them to the selection.

Sometimes you'll need to deselect soundbites, and there are several ways to do this. With many selected, clicking on an empty section of any track will deselect them all in one go, as will the immensely useful Apple-D (Deselect All) shortcut. But to deselect just one or two, hold down the Shift key once more and click their top halves individually. This is a shortcut that adds soundbites to or removes them from a selection.

Moving Soundbites: So, with a soundbite selected, what can you do with it? Well, of course you can move it, either elsewhere in the same track or on to a different track of the same type (mono, stereo, or n-channel surround). Again, just click the soundbite in its upper two-thirds, away from the edges, and drag it to its new position. The mouse pointer turns into a 'one finger' hand to confirm that you're moving the soundbite.

As you drag a soundbite like this, a number of keyboard shortcuts can be brought into play, and they help enormously with all kinds of editing tasks. For example:

Hold down the Alt key to duplicate the soundbite(s). DP indicates that this is happening by replacing the one-finger-hand mouse pointer with a two-finger-hand!

Hold down the Apple key to toggle the current Edit Grid setting. What does this mean? If you've got a quarter-note Edit Grid enabled, for example, but need to adjust the position of a soundbite by a finer amount, using the Apple key as you drag turns off the edit grid temporarily. The same goes for the Beat Grid.

Fades and crossfades can be directly applied to soundbite edges by dragging fade handles. Shown here is the mouse pointer when dragging out a fade (the one with the blue arrows) and when selecting an existing fade (the simpler, curvy X). Fades and crossfades can be directly applied to soundbite edges by dragging fade handles. Shown here is the mouse pointer when dragging out a fade (the one with the blue arrows) and when selecting an existing fade (the simpler, curvy X). Fades and crossfades can be directly applied to soundbite edges by dragging fade handles. Shown here is the mouse pointer when dragging out a fade (the one with the blue arrows) and when selecting an existing fade (the simpler, curvy X).

Hold down Shift as you drag a soundbite from one track to another, to force the soundbite to exactly maintain its time location — it'll be 'vertically constrained', as a graphics program might put it.

Press the Ctrl key to enable you to 'throw' the soundbite left or right along the track, to perfectly abut soundbites earlier or later. You can also throw a soundbite back to the beginning of the track, if no other soundbites precede it in the same track. DP confirms that you're about to throw by turning the mouse pointer into a right- or left-facing 'pitching' hand (although us Brits might prefer the term 'bowling') and then you simply release the mouse button. The way you decide which direction to throw is by making the very first move of the soundbite, before you press down the Ctrl key, in that direction (see screens above).

There are two important things to note about these audio-editing key modifiers. First, they can be used together in almost any combination. So you could use the Alt and Ctrl keys to simultaneously make a duplicate of a soundbite and throw it to a new location, for example. Second, they all work most reliably if you press the modifier key only after you've begun to move your soundbite. The reason for this is that pressing some of them before then can cause other things to happen. For example, if you hold down the Alt key first and then click on a soundbite's title bar, you'll end up renaming the soundbite. And if you hold down Ctrl and then point at a soundbite that isn't already selected, you'll end up making a time-range selection in its track. The easiest way is to remember this: drag first, modifier key second.

News: Black Lion Audio Owners of MOTU audio interfaces, especially slightly older models such as the 828 MkI, 1224 and 2408 MkI and MkII II, might be interested in the work of Chicago-based Black Lion Audio. They're a small but serious outfit with a distinctly 'alternative' flavour, offering modifications and upgrades to analogue signal-path components and internal converter clocks of MOTU and other manufacturers' interfaces. These mods are claimed to improve noise, distortion and jitter specifications, with a distinct improvement in subjective audio performance too. However, they have some pretty serious implications. For example, the clock modification leaves your MOTU interface unable to sync to external equipment via AES, SPDIF or ADAT (although Word Clock should still work fine), and totally incompatible with operating systems other than recent versions of OS X. Even the analogue-stage mod, naturally, will void any remaining warranty on your interface. Having said that, there's a growing following for Black Lion's work on various Internet forums, and while you might think twice about sending off your rack of recently purchased HD192s, for example, one of their mods could be worth a shot if you're of an experimental disposition and have an older interface. I must add that I don't currently have any first hand experience of Black Lion-modded MOTU interfaces, so it's really a case of 'modder beware'! More information is available from www.blacklionaudio.com.

Fades

Positioning the mouse pointer at the left or right edge of a soundbite and then dragging allows its boundaries to be trimmed — a fundamental audio editing technique. Positioning the mouse pointer at the left or right edge of a soundbite and then dragging allows its boundaries to be trimmed — a fundamental audio editing technique.

Earlier versions of DP applied fade-ins and fade-outs to soundbites (and crossfades between abutting soundbites) using a dedicated Fades dialogue box. This is still useful — even essential, as we'll see in a minute — but now it's generally easier to use the dedicated 'handles' that every soundbite is equipped with. These are found near the top left or right corner of the soundbite, looking like a small coloured square, and when the mouse pointer is brought near them it turns into a 'fades' pointer, which looks a little like two crossed swords (see screens, right). Clicking and dragging these handles causes a fade-in or fade-out, or a crossfade, depending on the context, to be overlaid on the soundbite or soundbites. Once it's in place it can be extended or shrunk, or completely removed, in the same way.

The default fade type is the straight, linear 'Equal Gain' fade. However, the alternative, more curvy 'Equal Power' fade is normally more useful, especially for speech or audio editing. To get DP to start using these instead, just generate a fade as described above. Then move the mouse pointer into the the darker region inside the fade you just created (you might need to zoom in a little to see this, in the case of very short fades). The mouse pointer changes into a curvy 'X' shape — similar to before, but without the blue arrows. Click to select the entire fade, and then hit Ctrl-F to bring up the Fades dialogue box. Click the Equal Power option and make sure the pop-up menu is set to 'Fade selected time ranges', then click OK. Your fade will be rewritten and DP will now create Equal Power fades until told otherwise.

Edge-editing

It's not just fade handles that live at the outer edges of soundbites. By moving your mouse pointer to the very far left or right of a soundbite's waveform display (but not its solid-coloured title bar), you can access the edge-editing pointer, which looks like two blue arrows either side of a square bracket. This allows you to trim the left and right edges of the soundbite by simply clicking and dragging — one of the most useful techniques for clearing up unnecessary audio in the run-in or run-out of a take.

Edge-editing is really straightforward and intuitive, but has one crucially important complication. By default, DP applies the same edge-edit you make to a single soundbite to any other duplicate of that soundbite used elsewhere in your sequence. You might have duplicated a soundbite of backing vocals, for example, and used it several times in the same song. Editing just one of them would cause all the others to change in the same way too. Depending on whether you really do want to edit lots of occurrences of the same audio in one fell swoop or not, this is either a tremendous time-saver or a curse of project-wrecking proportions. So if you need the flexibility to be able to edit just one occurrence of a soundbite used in several places, click the Sequence Editor's mini-menu and choose 'Edge Edit Copy'. This breaks the link between the multiple occurrences, and they'll now edit independently from each other.

In the next Digital Performer feature, I'll be looking at more sophisticated audio editing techniques, and explaining how to deal with common practical scenarios. 

Using The Soundbite Volume Facility If ever there was an opportunity for confusion over terminology in DP, it's with two related features that were introduced in version 5: Soundbite Gain and Soundbite Volume. In last month's Digital Performer feature, I looked at Soundbite Gain, a non-destructive boost or cut in level that can be applied to individual soundbites. It's great for coping with soundbites of differing overall level that you want to use together on the same track, and saves you having to resort to the sledgehammer of volume automation to crack a relatively simple nut. Soundbite Volume is rather a different beast, but it's still a simple concept. It's volume automation which is contained in the soundbite rather than tied to a fixed position in the track, so that if the soundbite is moved, duplicated or exported, it carries its volume changes with it. In fact, it has very little indeed to do with DP's 'main' automation scheme. For example, Soundbite Volume doesn't result in Mixing Board volume faders moving around. Nor does it interfere with existing track-based volume automation — the two work independently of each other, and any simultaneous track-based volume and soundbite volume changes are dealt with cumulatively. You don't even have to have a track's automation playback enabled to use Soundbite Volume, which makes it very straightforward. Here's a typical example of when you might press Soundbite Volume into service. I've got a soundbite of a brass lick, which is going to be used throughout my sequence, where one note's swell gets just too loud. Rather than trying to fix this one small problem with compression, I'm going to use some Soundbite Volume automation to reduce the level momentarily during the swell. 1. After opening the Sequence Editor and locating my soundbite, I need to switch my view of the track it's on to 'Bite Volume'. If I'm sufficiently zoomed into the track vertically, I do this with the topmost 'Edit' mini-menu in the track info pane on the left hand side of the window. If my track is zoomed quite small, I do this instead by clicking the small Track Settings Menu button, choosing the Edit sub-menu, and finally selecting Bite Volume. 2. The soundbite is shown overlaid with a faint horizontal line, which matches the track's colour. You'll see, too, that the left edge of the track has acquired some simple level markings, and an even fainter grey horizontal line across the length of the track indicates the 0dB 'unity' position (see screen above). 3. In this case, I want to draw in a V-shaped curve to tame the loud swell. I make sure my tools palette is open, by hitting Shift-O. Then I select Straight Line from its Reshape Flavour pop-up menu, and finally switch to the pencil tool by pressing and holding the 'P' key. 4. Now I'm free to click and drag on the soundbite to draw in volume data. As I mouse around, DP indicates the pointer's time location and Bite Volume level in the Event Info Bar at the top of the window, allowing precise placement of data (see screen below). 5. Once my V-curve is in place, I only need to play my track to audition the results, and the Bite Volume breakpoints can be easily modified just by dragging them with DP's arrow tool. Once I'm happy, duplicating the soundbite also duplicates the volume data, so it'll be accurately reproduced anywhere I choose to use the soundbite. As you can see, getting started with Soundbite Volume is very easy, and you may find it more useful and easier to deal with than track-based volume automation for a variety of tasks. If you do get into it, there are some other things you should know and might want to experiment with: You don't have to use the pencil tool to write automation breakpoints — you can just click on the automation line with the arrow tool, then drag. However, an odd quirk means that in the case of a soundbite that otherwise has no volume data, the first breakpoint you place like this will always create a sudden 'stair step' deviation from the 0dB line, not a smooth 'ramp'. Using the pencil tool gets around this 'feature'! Some Audio menu items relate to Soundbite Volume. They're all in the Bite Volume and Gain sub-menu and are mostly self-explanatory. To use Clear Bite Volume and erase all the volume automation for a soundbite in one go, make sure you select at least one breakpoint first. The same goes for Toggle Bite Volume Bypass, which disables Bite Volume on an individual soundbite basis but leaves the data in place in case you need it again. Bite Gain (covered in last month's article) and Bite Volume work independently of each other. For example, if you have some Bite Volume automation in place, and then you boost the soundbite's gain, the breakpoints and automation curve stay put, but the overall level of the soundbite increases.