The Beat Detective window in Pro Tools is a really useful collection of tools and processes, which comes onto its own when you need to ‘fix’ the timing of recorded audio, especially drums. It is a modern obsession that all drummers should sound "perfect", and it is not the aim of this tutorial to discuss these merits, or otherwise making drummers sound better than they are. But being able to modify the timing of recorded drums is a must-have skill for anyone recording and mixing popular music.
This task becomes much more manageable when the session is divided up into meaningful and manageable sections. In this example I have divided the session into 8-bar sections. Note however that the division in the screenshot below is not on the 9th bar line. This is because at this stage the tempo is ‘wrong’.
Dividing the session into sections will really help the editing process.
You are probably going to be dealing with one of two scenarios: either the drums were played to a click track so you have a tempo and it is the same throughout, or they were not, in which case you need to find the tempo for each section. If you have scenario one you can skip to Step 3. Otherwise:
Open Beat Detective. Choose Event > Beat Detective (shortcut: Command-8)
With the separated regions selected for the section you are working on, choose Bar | Beat Marker Generation in the Operation section.
Note: Beat Detective can work on a single track or across multiple tracks.
Ensure that the Selection section states the intended number of bars and beats and the correct start and end points; this can usually be entered by clicking ‘Capture Selection’.
In the Detection section, under Resolution, click the ‘Bars’ radio button and move the Sensitivity slider to the left until you get as few beat triggers as possible showing on the regions (the purple lines); you are aiming to have only one at the very beginning of the regions but may not be able to reduce sensitivity low enough to leave only this one.
With the Grabber tool, Option-click on unwanted beat triggers to leave only the first one at the start of the regions
In Beat Detective click ‘Generate’ and a tempo event will be created—in the Tempo ruler—that matches the session tempo to the audio.
'Bar | Beat Marker Generation' is selected in the Operation section.
By default, the timebase for audio tracks is samples, in which case the above process has no effect on the relative timing of audio events. If for some reason you have audio tracks with ticks as their timebase, you will get the following warning dialog when you click ‘Generate’ in Beat Detective:
The 'Realign Session' dialog box opens when audio tracks have a tick timebase.
Choosing ‘Preserve Sample Position (Don't Move)' means that any changes of tempo will not affect the absolute position of regions following the tempo change. If 'Preserve Tick Position (Move)' is clicked, audio regions will change their absolute position (in time) following any tempo change. The former is therefore the obvious choice in this situation. So generally speaking, keep the track timebase of audio tracks set to samples unless you want to work with Elastic Audio (stay tuned for a future Feature Tutorial on Elastic Audio here on The Hub).
A new tempo event has been created for this section.
For subsequent regions, repeat steps 1 and 2, each time checking that the Selection section of Beat Detective has the correct intended Start and End points.
Note: the Trigger Pad can be a value (0–50 ms) in this field to pad region start points and defines where the separation point is located in relation to the beat trigger. This will create a space between the region start point and the region sync point, which ensures that the attack portion of the audio event remains intact.
An individual region will be created at each Beat Trigger.
Beat triggers created at each transient, before division.
In Beat Detective, what we normally refer to as Quantize is called Conform. Click 'Region Conform' in the Operation section, followed by the 'Conform' button.
Depending on the value chosen in the Subdivision Setting drop-down menu in the Selection section, selected regions will be moved to the nearest grid value.
The other way to do this (with a lot more control over values and behavior) is to choose Event > Event Operations > Quantize...
The gaps created by conforming the separated regions.
When you have conformed (or quantized) the regions you will see—and worse, still hear—gaps which can sometimes cause audible clicking. To rectify this:
Choose 'Edit Smoothing' in the Operation section of Beat Detective.
In the smoothing section which now appears you can choose to just ‘Fill Gaps’ which fills all gaps with underlying audio, or “Fill and Crossfade’ which adds a crossfade at each region boundary.
Sometimes, when Region conforming creates large enough gaps, the underlying audio that fills the gap when smoothing can have audible audio in it that is undesirable, so do check your results when using this method!
Before and after filling the gaps and adding crossfades.
There are quite a few steps, I’m sure you will agree, but after you have run through the routine a few times you will find the sequence of actions straightforward and logical, so that they can be remembered quite easily! Once you have tried this out on drum tracks you might also like to try it with other audio files or regions, but remember it will always be most successful where the material includes clear transients, and where those transients are intended to be on beats or subdivisions of beats, otherwise you will be spoiling the natural human timing that gives the music its particular feel.