Many home engineers might cringe in fear at the thought of a double-bass player walking in to record a jazz session. The instrument itself is large, has strings made from sheep’s intestines, and isn’t likely to show up in your usual rock and roll scene. Not to mention that jazz players ain’t impressed with hammer-ons, sweep picking, or bitchin’ tats, and they play in keys most rock musicians have never even considered. Jazz is its own world with its own priorities, Daddy-o, and while this bit won’t have you digging Kerouac or Coltrane, it may keep you from looking like a square when the cats come to your studio to really blow.
Find the Sweet Spot
Acoustic instruments rely on the environment they are recorded in for a good deal of their sound, so take the time to find the sweet spot in the room—that is, the location where the bass sounds best. It’s also no sin to trust the bassist’s choice of the spot where the instrument produces its finest tones. Jazz bassists have sacrificed most of life’s wonders to learn their instrument from the headstock scroll to the pointy thing that sticks out of the bottom, so don’t second guess them just to massage your ego.
Use Two Mics
For all its size and intimidation factor, the double bass would have to work pretty hard to overcome a ukulele when it comes to volume. So unless you have access to some very sensitive dynamic mics, condensers are usually the way to go. A good start is to use a large-diaphragm condenser to capture the low-end thump, and a small-diaphragm condenser to pick up the woody midrange of the body.
While you might think the best position to start miking a double bass would be around the f-holes, the rush of air shooting from each hole space can produce boomy, indistinct sounds. Instead, place the largediaphragm condenser roughly six inches from the body of the bass, and pointed at a spot between the bridge and the f-hole. Now, position the small-diaphragm condenser about a foot from the bottom of the fingerboard, tilted up at a 90-degree angle. If the large-diaphragm mic is picking up too much low end (or wind from the f-hole), point it closer to the bridge, keeping the same distance from the bass itself. If a more articulate sound is the action you crave, try raising the small-diaphragm mic until it’s closer to where the bassist is plucking the strings.
Frank Zappa once referred to jazz as “the music of unemployment.” While I’m in no position to argue with one of the greats, I can tell you that when it comes to recording, jazz is the music of no compression. Dynamics are important to jazz music, so why would you want to stomp all over them? If you are having problems with too much dynamic range—say, if the bassist uses a combination of soft plucks and violent slaps to play a passage— then man up and ride the fader like a real engineer. (Which means you actually learn the song, dipping the fader during the slap phrases, and boosting it when the bassist’s touch gets light.) However, if you are compelled to use compression, use it lightly—no more than a 2:1 ratio, with a fast attack and a medium release
Dial Out Bad Things With EQ
Equalization however, is a different matter. Most double basses produce copious amounts of sonic blubber between 80Hz and 120Hz. You can help alleviate any muddy or woofy low end with a notch filter. Start by notching out 5dB to 10dB at 100Hz, realizing that every bass has its own sonic character, and you will most likely have to play with different frequencies and cut/boost levels to bring out the instrument’s hippest tone. For punch and clarity, experiment with boosting somewhere around 800Hz to 2.5KHz by 2dB–3dB. It is important to do EQ adjustments with the bass in the mix, rather than soloed, to ensure your tweaks don’t adversely affect the other elements of the track. A big low end on the double bass, for example, might overwhelm the sound of the kick drum. Critical listening should point you to any tonal problems or challenges, and appropriate EQ adjustments can save you from having to re-mic and re-record. Dig?