It’s the heart and soul of the rhythm section–track it right!
By Eleanor Goldfield
The bass is the mysterious glue that holds a song together, the riddle that can’t always be heard but is always felt, the headache and triumph of many an engineer. Indeed, in the studio, recording and mixing bass can be one of the most challenging aspects of recording and mixing. Too much bass makes the mix bottom-heavy and wobbly; too little and you lose a key element in both rhythm and tone. And how are you supposed to get the bass to even come through at all if you’re listening through tiny earbuds?
Few things betray an amateur recording as much as an ill-placed bass track. Why? Well, because it is that mysterious glue. It’s the backbone of most recordings but you may not even notice it until it’s not there. Because it’s both rhythmic and tonal, it doesn’t always settle its schizophrenic self into a nice comfortable niche… so you’ll find yourself wrestling with a bass that sounds woofy or too nasal, or it’s fighting with the kick drum, the guitar, or both… or you just can’t hear it at all. And that’s a problem, because if the bass doesn’t sit right in a mix, nothing else will.
First things first
Before you start thinking about how to record and what gear you’ll use, ask yourself these two questions:
First: What is the bass’s job in this song/album?
Second: Where will the bass sit in the audio spectrum?
Are you dealing with a slap player like Les Claypool from Primus, where the bass is not only holding down the bottom end but is also the main rhythm and chordal pillar for the song—basically everywhere at once? Or are you dealing with AC/DC-style bass, where the guitars are the main players and the bass is there to give a nice foundation that is tucked nicely in the background, hardly noticeable until you take it away?
How do the drums and other instruments sound in context? I can’t stress this one enough. Before you become best friends with the Solo button, consider how the whole mix sounds. I’ve heard a lot of things that sound great on their own and awful in the mix… and vice versa.
For example, in a situation where there’s a slow and steady beat and a 26-inch kick drum that’s supposed to fill out the majority of the low end, the bass should be centered at a higher frequency. But if you’re dealing with a small jazz kick and a more uptempo beat, you can let the bass swell a bit more in the low end. If you’re working with extreme hard rock or metal, the kick will typically be clickier, once again leaving more low-end space for the bass.
In most genres and styles, the bass lays down the chordal and tonal foundation of the song. If the bass is playing C, then that chord will feel like a C, even if the piano is playing G. So if you record and mix the bass so that you can’t hear or make out that tonal foundation, regardless of listening space or situation, you are actually damaging the entire song’s effectiveness. No pressure, right?
Basically, it’s important to listen to the song before hitting that red button. When you have the answer to those two questions I asked at the start, you’ll also have a blueprint and a better idea of how to tackle the recording and mixing.
Here are some methods that have worked for me. Use as many or as few as you like; remember that ultimately it’s what sounds right to you and your clients.
Pretty much every time I record bass, I use both a DI and a mic on the amp cabinet. If it’s an acoustic bass with a built-in mic or pickup, I’ll record that but place a mic in front of the bass as well. I feel that this simply gives you more options for a better blend. Even if you don’t end up using both, it’s great to be able to capture several varied nuances from the bass.
The DI provides a very clean signal that can give you presence, punch, clarity and bite, but left on its own could also come across as cold, thin and two-dimensional. Traditionally, you’ll want a passive DI box for basses with active electronics and/or active mics, vs. an active DI for passive basses.
Most feel a passive DI is simply more transparent; it’s only a transformer in a box and doesn’t have much “sound.” An active DI box often has an added gain stage and gives you higher output but may color the bass tone. I personally use a Jensen passive DI box that works great even with passive basses. You should find what works best for you and your situations by testing as many DIs as possible with a variety of basses.
Now let’s consider the mic. This is where you get your warmth and the natural characteristics of the bass, along with the room and the amp. As with guitar recording, you’ll get more treble and presence the closer you are to the center of the speaker cone. The further away you are from the cabinet itself, the more of the room you’ll get and you’ll notice a slight drop in both bass and treble response. Try a few different setups and listen to what sounds best. Please don’t just throw up a mic anywhere and hit Record. Get it right before it goes into your DAW… it’s worth the time.
When it comes to the bass cabinet speaker, size does matter. 10″ speakers can get a little nasal on their own, but if you combine them with a 15″ you can get some really nice blending. You get punch and attack from the 10 and a deep silky bass from the 15. Make sure your amp head and cabinet(s) are properly impedance-matched, and make sure that the bass itself is properly set up, in tune, with good-sounding strings. Have a tech help you if you must.
My favorite bass mics are mostly, but not all, dynamics. The Shure SM7 has a nice, warm and even frequency response. The Sennheiser MD 421 is another staple, capturing a clean tone with a bit more bite in the mids. The Electro-Voice RE20 is clean and honest, even at heinously loud SPL; it also has a pretty flat frequency response curve. The Shure Beta 52 is a bit dirtier than the others and a bit scooped in the low mids; I think it’s killer for punk. On the condenser side, the Neumann U 47 fet is warm and clear with-out being nasal. It’s a pretty expensive mic, but you can rent one if you have your heart set on trying it, which I really think everyone should do before they die.
Kick mics are common in this application. I’ve heard of sessions that got stellar results from the AKG D112, the Audix D6, and the Audio-Technica ATM25. The Lewitt DTP 640 REX and Audio-Technica AE2500 are kick mics that have phase-matched dynamic and condenser capsules in one body, which can be cool.
If you’re thinking of putting signal processing between mic and DAW, choose sparingly and wisely. I prefer to record without EQ tugging and pulling at my sound source. Besides, you can always add processing to a recorded track, but you can’t remove it. If you can get a good sound up front, get it. Use effects in the mix to enhance, not to fix.
That being said, I will almost always record bass with a little bit of compression. It makes everything smoother—literally, from workflow to the bass itself. Not a lot! Just a ratio about 3:1 with the threshold set to only clamp down by a few dB, giving steadiness to the recording without making it sound compressed.
If you’re combining a DI with a mic, and/or several mics on the amp or bass, make sure that you check for phase issues. Simply take note as to whether the sound becomes thinner when adding in the second, third, and fourth signal. If so, you’ve got phase issues. You can combat this by moving the mics until the phase aligns, or fix the misalignment with a plug-in or out-board gear. The Little Labs IBP (In Between Phase) is probably the best known in terms of allowing you to change the phase of a signal through a potentiometer, giving you a wide array of options besides just 90 and 180 degrees. Radial Engineering’s Phazer does the same sort of thing.
If you choose to fix it later—maybe you didn’t want to compromise some awesome mic placement that you had?—you have a few options. One thing to keep in mind is that the DI signal will naturally come before the mic signal. Depending on the feel you’re going for (dragging behind the beat vs. pushing it for a more energetic feel), you can move the DI waveform to fit the mic signal or vice versa. Take note that these are very small nudges; also that perfectly in-phase does not always sound the best.
One creative trick is to use EQ to dodge phase issues by allowing the signals to occupy different frequency areas. For example, put a lowpass filter on the DI at about 100 Hz so it only sits in the lower bass frequencies, and a highpass filter at the same point on the mic signal.
Consider, however, the drawbacks of putting up “walls” around your mix. Let’s say that you put a highpass filter on everything but the bass and the kick drum. In certain cases, this can be the right move in order to get the mud and woof out of your mix. However, this could also make your mix sound pieced, parted and sterile, and effectively neuter the strength and punch of your guitars.
As with everything else, try it out and see what you come up with. Play around with your center frequency and Q. Do you want the sound to slowly duck in or out at that frequency, or more sharply? Again, hopefully in this phase of the production, you have some time to get creative and experiment with not only phase, but all the facets of your recording.
In this mix phase (pun intended), you will once again find yourself staring at those two questions we started with. If you’ve kept them in mind so far, most of the work should already be done for you, at least in terms of an outline and goal. Your job now is to fine-tune the bass and place it exactly where it needs to sit in the mix, in balance with all the other instruments and sounds to ensure that it elevates the song. Some engineers check tracks in Solo as they go, some avoid it because it misses the point… see what works for you.
When I mix, I typically bring up the bass after the kick and snare. I use EQ to carve each instrument out so that in terms of frequency, each instrument has its own center and isn’t overflowing into other parts of the mix, making a muddy mess. This is particularly important when dealing with the bass and kick, so make sure you listen to one as you mix the other. Remember our earlier discussion of bass tone vs. what the kick is doing?
For example, if the kick is big and bassy, under the bass frequencywise, 50 Hz is a good place to start boosting the kick. Then I’ll draw back on 100 Hz and put some of the bass in that opening. I’ll then pull back on the bass at 50 Hz to make room for the kick.
In the low mids, around 200–250 Hz, the bass tends to get bloated and woofy, but these frequencies are also where a lot of the bass’s foundation will lie, particularly on small speakers. Chisel the bass so it doesn’t sound like an old puffy blanket, but be careful not to slice away the tonal foundation.
The 800–1500 Hz area is where you’ll find some of the finer grain and clarity of the bass, which you might need to push up if you’ve compressed a lot. Around 2 kHz is where you’ll find string noise; raise or lower depending on what you’re trying to achieve. Slap and hard-picked bass will benefit from a boost at 2 kHz, others not so much.
Because the bass doesn’t just live in the low frequencies, you have to be careful when adding in the other instruments. If you want more shine from the bass, for example, make sure you don’t go traipsing into the guitar frequencies—then all you’ll get is mud, and more than likely an angry guitarist. If the bass is playing with the guitar, you can more easily play with the relationship between the two, as opposed to if the bass follows the kick drum the whole time, playing mostly whole notes. The ultimate goal is for the listener to hear everything without straining, regardless of what kind of audio setup they have.
Now we’ve tackled some EQ elements, but there’s a whole other world waiting when you consider the balance between mic and DI tracks. Most engineers I know use the DI as a spice instead of the main course. Again, it really depends on what you’re going for. As I mentioned above, you can give each signal its own frequency space using low- and highpass filters. You can then process each one using complementary EQ and compressor settings, balancing low bass with the higher frequencies simply by moving faders.
One advantage of this setup is that it can often sound really good to compress the low bass harder, while allowing it to open up in the higher bass frequencies. Having two channels with their own discrete frequency areas makes this easy.
Now, it’s not all EQ and compression—it can be a lot of fun to open up the toolbox further and get into effects. For example, distortion can make the bass stick out more, particularly if you duplicate the main bass track, adding distortion to the duplicate and adding it in a little at a time. Chorus or harmonizer effects can make the bass sound fuller and broader, likewise with a little bit of reverb.
Finally, the most important tools you have are your ears, and what’s hitting your ears: the monitors. Make sure you have speakers that have a good bass response; otherwise, how could you possibly mix what you can’t hear? If you don’t have access to broad-spectrum speakers, then make sure you listen to your mix in as many varied places as you can, trying to find the common ground where the bass sounds solid and seamless throughout.
The end goal is obviously to give the listener the best mix possible, regardless of whether they’re at a club with an arrhythmia-inducing sub system, on a bus with earbuds, in a car, or through regular consumer grade home speakers. Even if you have the ability to mix on the “best” speakers, make sure to check your mixes on low quality speakers. There’s a reason Auratones are popular in some of the biggest and most famous studios in the world. If you can make the bass sound good on those, you have won.
There’s a lot to keep track of, but try to remember this: use your ears and work from the bottom line of what’s best for the song, the bass-ics, as it were. Now let the band play, and happy bass recording!