More drum libraries are showing up in multitrack format from companies like Discrete Drums, Wizoo, East-West, Reel Drums, etc. Although these are sold on the basis of being useable out of the box for drum parts (with the additional advantage of being mixable), I see them more as a gold mine of raw materials for creating custom drum loops. Being able to process individual tracks separately is certainly a major advantage when deriving loops from multitracked parts, and of course, proper looping allows using these parts at different tempos.
For example, I just did a “remix” of the Discrete Drums sample library for the company, who had received numerous requests for “dirtier,” lower-resolution versions aimed for more hardcore hip-hop and dance musicians. Hard disk recording programs are ideal for doing this type of remixing; this article will concentrate on using Sonar, but most techniques apply to other programs, and specific examples are given for Acid as well.
Dealing with Human Error
Drum libraries played by real drummers are great, because of the additional “human feel” compared to using machines. But due to timing inaccuracies, it sometimes takes a little tempo tweaking to line up measure markers with downbeats.
This illustration shows a loop whose stated tempo was 79 BPM, but in the upper view, note how the downbeat at the beginning of measure 9 (the loop end point in this particular case) hits a little early compared to the measure marker. In the bottom view, changing the tempo to 79.03 BPM places the measure marker at the downbeat’s exact beginning.
If you need to change the tempo compared to the original file, then time-stretching becomes necessary. Sonar has a built-in time stretch function that’s very similar to the one in Acid; Cubase SX has a nifty ReCycle type feature that works particularly well with drum loops. For programs that don’t stretch, you have three options if you want to change tempo:
* Import the file into ReCycle, change the tempo as desired, then export back to WAV or AIF.
* Import the file into Acid, Sonar, or a recent version of Sound Forge, “acidize” the file, then export.
* If the tempo change is small, change the pitch withoutcompensating for duration. Tranposing pitch upward will speed up the tempo, transposing down will slow it. For small changes, the pitch difference may not be noticeable (and in some cases, may be desirable).
After tweaking the track mix and setting the tempo, render the file to a stereo loop. Import this into your hard disk recorder or a digital audio editor and set looped playback mode. If there’s a click when the loop jumps back to the beginning, add a 4 ms fade-out to eliminate clicks, and if absolutely necessary, a 2-4 ms fade-in. In drastic cases, I use Sonic Foundry’s Click Removal DirectX plug-in to remove clicks at transition points.
Now let’s take a closer look…
Groove Clip Tricks
* All programs that use slicing to do time-stretching work most efficiently when speeding up rather than slowing down. Therefore, if you want to create a loop that works well from, for example, 100 BPM to 120 BPM, you’re better off creating it at 100 BPM and speeding it up than starting at 120 BPM and slowing it down.
* Editing markers is usually mandatory for drum loops played by human drummers instead of machines, as editing can compensate for any timing variations that interfere with the stretching process.
* Before getting too much into editing, try adjusting the Basic Slices and Transient Detection sliders first. Often choosing different values will solve flamming and other problems, without the need for editing.
* Use the lowest Slice Rhythmic Value possible (e.g., 8th note instead of 16th note), consistent with good sound. Extraneous slices can cut off drum decays. This is particularly annoying with kicks, as you lose some of the fullness and “ring.”
* Sonar will endeavor to keep any markers that you’ve moved manually in their assigned positions, so you can experiment at any time with the Slicing and Transient Detect controls without losing the positions of your carefully-placed markers.
* When you save a Sonar song or bundle, it retains all the Groove Clip parameters. To save a Groove Clip in acidized format for use other programs, simply drag the file to the desktop; it will be copied and saved with its groove parameters intact. However, you will likely want to rename it, as Sonar generates the name automatically.
To read the full detailed article see: Multitrack Drum Libraries