Reverb is usually applied to a mixture of tracks as a send effect. That's fine for creating ambiences and emulating natural spaces, but you can get a lot more creative by applying reverb to individual tracks, and then separately processing the resulting wet files. In this article, I'll discuss a number of variations on that theme and present specific examples.
I restricted myself to a 2-bar drum loop and did the processing in Apple's Logic Pro using its built-in reverb plug-ins. The same processing can be carried out in a DAW using any hardware or software reverb.
One useful reverb technique is to offset the wet signal from the dry signal. To do that you need to create a wet-only file, which you can do by soloing the bus that has the reverb and rendering (bouncing) it to disk. The reverb tail will usually make the wet file longer. But for purposes of displacement, it's a good idea to truncate the wet file to keep it the same length as the dry file (see Web Clip 1).
FIG. 1: Shown below are slices of the wet file (in blue) that are three 16th notes in length and are offset by different amounts relative to each repetition of the looping 2-bar dry file.
One of my favorite tricks is to offset the wet file by making a rhythmic subdivision. When I'm working with a loop, I may change the offset, either regularly or irregularly, at each repetition. For example, I may start with the wet file that is a 16th note before the downbeat, and then nudge it a 16th or an 8th note for each loop. The shifting relationship between the dry and wet files often generates nice cross-rhythms, and you can always delete the iterations that you don't like (see Web Clip 2).
Another useful technique that you can do is to shorten the wet file and use only a portion of it, looping it in parallel with the full looping dry file. The relative sizes of the two files will determine how long it takes for the pattern to repeat, and long cycles can yield fascinating rhythmic variations. For example, if you shorten the wet file by a quarter note, the length of the cycle will be the length of the dry file multiplied by the number of quarter notes in the dry file. (For a 2-bar file in 4/4 time, that's a 16-bar cycle.) Alternatively, you can take any group of one, two, or three beats (quarter-, 8th-, or 16th-note groupings); loop it; and offset its start time (see Fig. 1 and Web Clip 3).
Using small fades at the beginning or at the end of the wet slices gives you even more variety. It is similar to using a gated reverb effect, but you have more control. You can gate each of the wet slices by a different amount by implementing different lengths of fade. Using fades to obscure attacks, releases, or both provides a variety of pumping and breathing effects.
Reverb is typically used to create the illusion of a performance taking place in a specific space. You can shatter that illusion by leaving some holes on the wet track. Take two quarter-note slices of the wet file, apply short fades, and then judiciously place them at different points in time, leaving plenty of dry holes in between (see Web Clip 4).
Slice and Dice
Most modern DAWs have tools for chopping up audio files into equal-size regions. (In Logic Pro, use the scissors tool while holding down the option key.) Chop up the wet file, and then rearrange the slices. You can repeat, offset, loop, or omit some of the slices. You can also create patterns of varying lengths by grouping some of the slices and looping the whole group. (To do that in Logic Pro, pack the slices into a Folder and loop it.) Because the slices are actually regions in a longer audio file, you can lengthen or shorten individual slices from either end. Alternatively, convert the slices into separate audio files, load them into a sampler, and trigger them from your MIDI keyboard.
All of those variations are time based. In my next article (to appear in the September 2005 issue of EM), I'll describe additional off-the-wall techniques that involve simultaneously processing wet files on different tracks.
Eli Krantzberg is a Montreal-based drummer, bandleader, Logic user, home-studio owner, and uncle.