Do The Splits

If your drumming needs a little help from technology, Samplitude Pro X has the tools to fix timing.

This month, I'm going to show you some of the main features of Samplitude Pro X's Audio Quantization Wizard. The latest Pro X update has improved the accuracy of transient detection, with the inclusion of the 'percussive' algorithm, which, as the name implies, has been optimised for use with rhythmic audio material. Audio quantising (AQ) is most commonly used for fixing sloppy or fluctuating multitracked drum recordings, although it can also be used as a creative tool to modify an existing groove. The screenshots show a multitrack drum recording that would probably benefit from some AQ treatment. Imagine it's your multitrack drum recording, and I'll take you through the process.

The first step is to open the Audio Quantization Wizard from the Object menu (Object/Quantize/Audio Quantization Wizard). The AQ wizard can be free-floating or docked; my preference is to dock it to the left edge of the VIP (VIrtual Project, Samplitude's main project window).Samplitude Pro X's Audio Quantization Wizard, docked at the left of the VIP. To do this, drag the window to the centre of the VIP until a green, circular docking assistant appears. Positioning the mouse over the left arrow should turn the left side of the VIP green, and releasing the mouse will dock the wizard to the left. It can, of course, be docked to the right, top or bottom.

Before going further, you may find it useful to turn on Comparasonics waveform colours as an editing aid. Press 'Y', go to View Options and enable them under Waveform Colours/Comparasonics Colours. You may have to wait while the waveforms are redrawn, but afterwards they will be coloured according to their frequency and harmonic content. Comparasonics gives a visual representation of the difference between sounds that often look similar in a conventional waveform view: for example, the waveform of the kick will be black, while that of the snare will appear bluish-grey. This can be very useful, particularly for setting transient detection sensitivity when there is leakage from one drum into another's mic.Samplitude's unique Comparasonics waveform view reflects frequency content as well as amplitude, showing clear differences between (for example) kick drum and snare hits. Samplitude Pro X is the only DAW that offers Comparasonics, and it can make certain editing tasks much easier.

Hit Marking

First, we need to detect the transients in the kick and snare close mics, as these are the most prominent elements and will be used as the quantisation reference for the other drum tracks. Transient markers are generally placed at the initial attack portion of the sound. When you select an audio Object, adjusting the AQ Wizard's Sensitivity fader will initiate the detection process automatically, or you can click the 'Analyse again' button to do the detection first and then adjust the Sensitivity fader afterwards.

Begin by selecting the kick-drum Object and pulling the Sensitivity fader to the right. You should now see red audio quantise markers appear at the start of each hit. Adjust the sensitivity to make sure all the hits have been given AQ markers: clicking inside the AQ Wizard's Sensitivity text box allows you to use the mouse wheel to make single-digit adjustments, or, alternatively, you can click on the fader and then use the mouse wheel to adjust in increments of 10 (hold down Shift to adjust in increments of 1). You can also globally increase the height of the Object waveforms by holding down Shift and rolling the mouse wheel forward within the VIP. Next, select the snare-drum Object and adjust the Sensitivity fader until all the snare hits have been detected. If the drum session also includes tom fills, it may to necessary to analyse them as well, using the same procedure.Audio quantisation markers in Pro X. You would usually derive these from the transients in close-miked tracks, especially kick and snare, before applying them to the entire drum part.

Depending on how many markers have been generated, you might want to look at the optional Consolidate Transients button, which is intended to reduce the number of splits after slicing. For example, if the kick and snare both hit on the same beat, but are not 100 percent aligned, two transient markers will be created for the same beat, which is not usually desirable. The setting in Time Window determines whether these markers will be consolidated, and is user editable. The default setting is 20ms, meaning that if two hits fall within a 20 ms time window, the markers will be consolidated into a single marker.

It's also possible to manually adjust the position of AQ markers, although not within the VIP window. If you Shift-double-click an audio Object, you will see all the markers for that Object displayed in the wave editor. Left-click on a marker and drag to adjust, or to remove an errant marker, select it and hit the Delete key.

The Line Up

Once all the desired transients have been detected, we're ready to start the quantising process. Make sure the Objects for all drum tracks are selected and press the Split at Transients button. This will split all of the Objects at the AQ marker positions.

Next, we need to decide on the correct quantise value: click on the AQ Wizard's Grid drop-down menu to browse through the selection of Q grid presets. In my example, I have chosen a straight-16th Q grid, as I want to 'hard quantise' the drums. Included in the Q Grid list is a sub-folder of MPC groove patterns, which may be worth experimenting with and can yield some interesting results. You can also create and save your own grooves.

Any changes made from this Grid menu will be reflected in the window below, and the blue vertical lines will adapt to give you a visual representation of the loaded groove. These settings can be fine-tuned using the Q Thresh and Q Window faders, in combination with the Swing, Soft Q and Offset controls, so you are by no means limited to hard quantise settings. To return the settings to their default values, simply click the Default button.

Once you've loaded your preferred Q Grid setting, press the Quantize Slice Positions (AQ) button and the slices will snap to the Q grid. Providing you have used the correct quantise setting, your drum part should now sound a lot tighter. If you're not happy with the results, just click the Reset Quantization button at the bottom of the AQ Wizard and try another quantise setting. In some circumstances you may be better off working through the drum part in sections. For example, you may find that the verse section works better with eighth-note quantise values but the bridge or chorus with 16ths. If that is the case, split the Objects to separate the sections, then quantise each section in turn.

After quantising, there will probably be gaps between slices at certain positions, with the quantised slices having been shifted in time. There are two ways to remove these gaps: the Objects can be lengthened and crossfaded, or they can be time-stretched. Both are accessed by hitting the Remove Object Gaps button. The default mode is the former, called 'Insert Audio from the next slice's front', which will automatically add crossfades as well, but the option to remove object gaps by time-stretching is also available. Once AQ operations are completed, it's a good idea to glue the split Objects together, track by track. Select them and use the Ctrl-Alt-G shortcut, or right-click an Object and choose Glue Objects from the contextual menu. This can be undone at any time.

Transients To Triggers

Using drum samples to reinforce an original audio recording is a popular production technique, and it can be achieved very easily in Samplitude Pro X.A MIDI drum part (bottom) derived from the audio quantisation markers in my kick-drum part (top). Once you have quantised the audio, you can generate a MIDI file from the transients. Select the kick-drum track, and from the Object menu select Object/Select Objects/Select Objects in Active Track. Now choose Object/Quantize/Extended audio quantize/Create MIDI triggers from Transients. A MIDI Object will now be conveniently added to a new track below the kick drum. You can then insert your favourite drum VST Instrument and choose a sound to reinforce the original kick. Repeat the procedure to create MIDI files for the snare and toms if required. Note that when a MIDI file is generated, the MIDI notes always default to C1, so you probably will need to open the MIDI editor and transpose them to trigger the correct drum sounds.