From The SOS Guide To Live Sound
LIVE SOUND
Paul White is Editor-In-Chief of Sound On Sound . Trained in electronics , he has been recording music since the 1970s . He also performs and mixes live gigs , and is the author of a number of music recording textbooks .
By Paul White
Capturing The Bass
From The SOS Guide To Live Sound
Electric Bass
Bass guitars are frequently DI ’ d in preference to miking , and there are some excellent dedicated bass preamps available for those who want the convenience of a DI but the sound of a real amp . Most high-quality bass combos and heads now come with a balanced , post-preamp DI output . Sometimes , a direct feed from the instrument is still useful , though , to avoid having the PA feed compromised by the player ’ s preferred on-stage EQ setting . Bass guitars fitted with standard passive pickups should be mated with a high-impedance DI box ( usually an active model ) to avoid loss of both high-end and level . Active basses ( and guitars ) have buffered outputs that can be plugged into passive or active DI boxes .
QUICK TIP : Bass speaker cabs seem to benefit from being miked a few inches further back than you might choose for a guitar speaker , but make sure you know how much of the bottom end is being rolled off by the absence of proximity effect – some models exhibit dramatically more than others .
Miking a bass amplification system is similar to miking guitar speakers , the main difference being that the sound often benefits from the mic being set up a few inches back from the speaker grill , rather than being pressed right up against it . It is also self-evidently important to choose a mic that has a good bass response rather than a vocal mic , where the bottom-end will be rolled off to counteract proximity effect . In most cases , low-cut filtering will not be required , but let your ears decide . If you are working with a PA system that doesn ’ t have a sub , you may need to engage a bit of low-cut to moderate the level of deep bass fed through the full-range speakers to avoid overtaxing them .
A little broad-band EQ may be needed to achieve a more even response across the range of the instrument , and to deal with room resonances . ‘ Modern ’ bass-playing styles will also often benefit from compression , particularly because the different techniques — plucking , slapping , and pulling — used today tend to produce notes with widely differing volume levels .
Acoustic Bass Acoustic double basses can be more problematic . The combination of the instrument ’ s relatively quiet acoustic output and the proclivity of most upright bass players to move around means that , other than for classical ensembles , miking it up live is a recipe for disaster . If the bass is fitted with a dedicated pickup system , you will at least be able to get some decent level into the PA , albeit not always sounding much like an acoustic bass . Players will often turn up with a mic wrapped in foam and wedged under the tailpiece . If you ’ re lucky you might be able to EQ this to sound OK , but they are always prone to rattling and picking up high levels of spill .
QUICK TIP Conventionally miking an upright bass is fraught with problems , so some kind of contact pickup or instrument-mounted mic is often the only practical approach .
Whatever you do , the end result is usually a compromise . Rockabilly-style slap bass players will usually want to emphasize the string slap of an upright bass , so even if their instrument is fitted with its own mic or pickup , you ’ ll need to put a separate mic as close to the strings as possible without it getting in the way of the player , usually around halfway up the neck . Then , you ’ ll need to EQ out all low-frequency content until you just hear a percussive slap . This can be mixed in with the basic sound of the instrument to achieve the desired effect . Ensure that the mic on the strings points away from the drum kit and any nearby back-line amps or monitors to keep spill to a minimum , as the sound coming off the bass strings isn ’ t particularly loud .
I prefer to use dedicated acoustic bass pickups whenever possible in live situations .
This is an excerpt from The SOS Guide to Live Sound : Optimising Your Band ’ s Live-Performance Audio , a new book / ebook from Focal Press by Paul White . Reprinted by Permission of Focal Press . The title is available through MusicBooksPlus . com .
60 • CANADIAN MUSICIAN