Recording - July 2010 - 22

other sound source that supplies the new drum samples must be set up and tweaked to provide the proper musical response, and this step may require a fair bit of specific effort for optimal results. • Compensate for any timing issues that arise—drum replacement processing typically will result in some latency (slight time delay) or timing inconsistencies in the replacement sounds. This must be compensated for, if the drum performance is to remain in proper musical sync with other tracks in the song (and with other drum tracks, like overheads or room mics). So close but yet so far Obviously, replacing individual drums is best done via the separate close-miked tracks rather than tracks that contain all the elements of the kit, like overhead mics (that’s not to say it can’t be done—I’ve had to do drum substitution off a single stereo

drum track, but it’s wa-a-y more labor intensive). One of the choices that presents itself is whether to completely replace an individual drum track with a sampled drum, or to blend it in with the original close-miked drum track. Remember, there will also be a stereo overhead mic track containing not only cymbals, but all the drums in the kit as well, and that track is typically blended in with the replacement drum sounds. Sometimes the amount of drums in the overhead track can be reduced by eq or filtering, leaving mostly just the (higher frequency) cymbals. However, even in a drum mix that uses all the original tracks, the sound of kicks, snares, and toms is usually a blend of the close mics (which often sound overly dry or dull), and the same drums in the overheads, which add air and a more 3-dimensional ambience to the overall sound of the kit. If the samples chosen for substitution are similar enough to the general tone of the original, then some degree of blending is often a good idea. For this project, after a little experimentation, we chose to completely eliminate the close-miked kick and snare tracks (due to excessive ring) in favor of the samples, but blend in full-range overhead mics to better integrate the samples with the other elements of the kit (toms and cymbals) from the original tracks. Choosing to go with a blend meant that we would have to

be even more careful to insure that the timing of the sampled drum sounds would match the originals. However, since mismatches would be more noticeable, it would be less likely that we would miss something that would become more obvious later on as the mix progressed. Pick a drum—any drum The first step was to set up the drum replacement feature to correctly detect the individual notes (drum hits). The main setting for this is Threshold (“Velocity” Threshold in Audio-to-Score; “Sensitivity” in Drumagog), which determines a volume level above which drum notes detected from audio transients will be used as replacement triggers, and below which any notes detected will be ignored. This is exactly the same as in Noise Gates or Strip Silence features—in fact, it might sometimes be useful to run the audio track through one of those options first, if it offers better tools for separating unwanted notes (leakage) from notes to keep and replace. This setting is made both by ear, and by referring to a visual display which shows which notes are being rejected (see Figures 1–3). Right away we ran into issues; with more isolated close-miked recordings, a good Threshold is often found quickly, but because there was such significant leakage in the individual kick and (especially)
http://www.bfd-eco.com http://www.bfd-eco.com http://www.fxpansion.us http://www.fxpansion.us
Recording - July 2010

Table of Contents for the Digital Edition of Recording - July 2010
