Producing a slammin' bass track starts with getting a great recording. A well-recorded bass guitar track can grace a mix with warmth and power, but a poorly recorded one can obscure it like a murky cloud. Which microphones are best for recording electric bass? How does mic placement affect the sound? Should you use a DI box? What about compression and EQ?
We'll get to all of that sexy stuff, but first let's address how to set up the instrument itself. Unless your source sounds great to begin with, you'll just be dealing with a "garbage in, garbage out" situation. Put another way, a skillful recording of a lousy instrument is just that.
Beyond proper tuning and intonation, the three most common problems with electric bass guitars are grounding noises, fret-related artifacts, and poor height adjustment of the pickup.
The time to hunt down the cause of ground-related hum and buzz is not just before you press the Record button. Most DI boxes have a ground-lift switch that may kill the noise, but what if you are not going direct? Fortunately, if the hum goes away whenever the player is touching the strings, there's an easy solution. Attach one end of a piece of wire to the guitar's tailpiece section, at a point where it will be out of the way and won't make any noise as it moves about (for example, wrapped tightly around a string behind the bridge). Stick the other end of the wire into the rear pocket of the player's pants. This usually eliminates the problem.
Fret noise can result when an instrument's string height, or action, is too low. The best solution is to raise the action, but that will adversely affect the intonation, so you'll need to adjust it, too. What can be done if you must record immediately? Borderline fret-noise problems are often avoidable if you simply play with a lighter touch (which is usually a good idea anyway). In my experience, most extraneous bass-track noises are caused by heavy-handed or otherwise poor technique. A moderate and consistent attack yields the most even tone, decreases the amount of corrective compression you'll need, and avoids the insidious clackety- clack of fret slap that plagues many amateur bass tracks. There's simply no way to roll off enough highs to rid a track of these artifacts-that is, not without making the bass sound as if it's being played through a bale of wet cotton. In this case, an ounce of prevention is definitely worth a pound of cure.
Before the session, have the bassist play a chromatic scale from top to bottom and back on each string, with all EQ and tone controls on the instrument and amplifier set flat or bypassed. Do all the notes on a particular string tend to sound either boomy or thin? If so, you may need to adjust the pickup height for a more consistent response across the full range of the instrument. If the notes sound boomy, move the pickup farther away (down) from the strings; if the notes sound thin, move it closer. Failure to nip this problem in the bud will force you into riding the fader on certain notes or applying massive amounts of frequency-conscious or split-band dynamics processing at mixdown. Again, an ounce of prevention...
Now that the instrument is ready to rumble, it's time to set up the amp, microphone, and DI box for recording.
You probably noticed I mentioned using both an amp and a DI box. If you have enough open tracks to record the miked amp and the DI signal on separate tracks, by all means do so. You'll get two different timbres for the same performance and far greater flexibility in sculpting the final sound at mixdown. The miked amp will have more ambience, and the DI will usually sound clearer and more focused. When you mix, you'll be able to choose which timbre is more appropriate or, more likely, combine the two tracks for a fat hybrid sound (more on this later). In fact, if you're pressed for tracks but have two available mixer channels, you can combine the two signals via the multitrack bus-adjusting each fader to favor one sound over another if desired-and record the summed channels to one track.
No matter how many tracks you decide to use, you'll need to split the signal at the DI box so that one path goes to the mixer and the other goes to your bass amplifier and speaker cabinet (see Fig. 1). For this purpose, most DI boxes feature an unbalanced input and an unbalanced output-typically on 11/44-inch phone jacks-along with a balanced output, usually on an XLR connector. Simply plug the bass guitar into the DI's unbalanced input, connect the unbalanced output to an instrument input on your bass amp, and route a mic cable from the DI's balanced output to a mic input on your mixer. The DI box converts the bass's high-impedance, unbalanced instrument-level signal to a low-impedance, balanced microphone-level signal that gets routed to its balanced output. But before the conversion, the DI splits the signal and sends the unbalanced input signal-unchanged-from its unbalanced output to your amp.
You can choose from a number of DI boxes, ranging from inexpensive solid-state models to pricier tube offerings. The Stewart Audio ADB-1 ($109) and the GRM BPH Missing Link are two cost-effective solid- state workhorses. The BPH box sounds a little brighter and more open, but the ADB-1 nevertheless offers plenty of presence. (Unfortunately, GRM recently closed shop, so the BPH is no longer available; but you might be able to find one secondhand.)
If you can afford them, the Demeter HdI-1 Stereo Tube Direct/Line Driver ($899) and the Ridge Farm Gas Cooker ($1,279) will take your sound to another level. Both are tube DIs that add a warm, lush dimension to bass guitar. I'm slightly partial to the Demeter unit; it offers a bit more presence and definition than the Gas Cooker, which has a softer sound.
Because loud sources with long wavelengths (in other words, bass frequencies) record best in big rooms, you should put the bass cabinet in the largest room you have-unless you're recording a drum set simultaneously, in which case you should use your second-largest room for the bass. By recording bass and drums in separate rooms, you'll achieve the isolation needed to perform punch-ins on the bass track without having to deal with clunker notes that leak into the drum mics.
If possible, place the bass cabinet in an acoustically dead room. Adding digital reverb to a bass track rarely improves it, so why would you want natural reverb on that track? A dead room gives you a tighter sound. A carpeted space will do in a pinch, but a room that's correctly treated with acoustic foam or fiberglass wall panels will sound much better. This is an excerpt from the following article: The Bottom Line.
To stay informed about new articles, be sure to click here to sign up for the DigiFreq Music Technology Newsletter. It's free!