Mud is a badge of honor if you’re obsessed with off-road hijinks in a Ford F-150 Raptor. But a muddy mix slathered with low-end sludge can annihilate an otherwise great piece of music. Rampant bass rumbles, indistinct and slurry low-midrange frequencies, and an overall corpulent soundscape can present a less-than-alluring listening experience—especially for those potential fans who consume music on earbuds or headphones that put the boom so close to their eardrums.
Modern music has absolutely pushed the envelope on bass content. Back in the vinyl era of the 1960s and ’70s, too much low end could jettison the phonograph needle right out of an album’s grooves—a mechanical safeguard for anyone attempting to pump up the bass beyond the limits of the technology of the time. But there are few constraints with digital audio, and, to an extent, the stylistic requirements of rap and hip-hop artists have served to significantly expand the amount of bass that can be captured and replayed on vinyl records. However, while having the capability to “get low” (shout out to Lil Jon & The East Side Boyz) is an excellent option for your creative trick bag, you still have to monitor how much low end is appropriate, what you’re trying to achieve artistically with increased bass frequencies, and, ultimately, what sounds good in the overall soundscape.
How Much Bass Is Too Much Bass?
Now, there’s a question. Today’s production principles can be subjective in the extreme, and on the surface, it’s almost a “whatever works” state of affairs. There’s not a production police force monitoring a track’s frequency spectrum—one that sends out an “Abusive EQ Squad” if you make an unlawful tonal decision.
For example, the sonic makeup of hit songs can be bright and thin, fat and warm, and everything in between. But if it’s truly the audience that decides whether a track is pleasing or not, then you should at least craft a spectrum that is seductive to the ears of potential fans. While the ball is still in your court, consider staying within “reasonable” sonic boundaries—meaning, don’t pump up the bass until it causes the drivers in a good set of headphones to explode, or overwhelm everything else in the mix. It helps to seek outside counsel from trusted friends to get their perception of the bass content.
Pro tip 1: To get a read on whether you may have put too much—or too little—low end into your mix, reference your track to a few of your favorite songs. Listen critically as you A/B the two mixes back and forth. For example, if you dig the percolating bass line of Harry Styles’ “Adore You,” reference your track against it and determine how your low end stands up. It’s a good idea to also reference the mid-range and high-end content, as well as the overall sonic spectrum. Sure, true artistry should follow its own path, but it never hurts to compare your work with bona fide hits, deep cuts, classic tracks and songs you love.
Pro tip 2: People listen to music on all kinds of playback systems—massive home stereos, laptops, mobile devices, earbuds, automobile audio, outdoor sound, etc.—so referencing a mix on one type of speaker could mean your aural awesomeness won’t translate very well to something different. Professional studios typically have multiple playback systems for just this reason. An engineer usually references the frequency spectrum on small and large monitors, as well as huge “party” speakers (to thrill the artist with a loud, raucous and celebratory playback). Evaluating a mix on diverse systems can answer essential questions, such as does the bass disappear when played on small speakers at low volume, is the bass too prominent when blasted out on big speakers at a relatively high volume, or will the midrange become too bright and searing when playback is on tiny laptop speakers?
Once you have some indication of how your mix might sound out in the real world, you can make adjustments to ensure relative compliance on myriad playback systems. You won’t be able to craft the perfect mix for all speakers and all environments—well, unless you are some kind of magician—but you’ll get far closer than if you had listened to a single system.
In addition, it always helps to do a listen or two on a good set of headphones. You’ll want to know how the mix might sound on earbuds and headphones, of course, but perhaps more important, listening on closed-back models takes your studio environment—and its good, bad, live, dead or imprecise acoustic properties—out of the equation. Ultimately, what you want are several “sources of audio truth” in play, so you can make calculated decisions about translating the mix you hear in your studio out to a vast audience of listeners.
Should You Boost or Cut EQ?
Point someone to an EQ knob, and they’ll likely boost the frequency without even thinking about it. Habit? An obsession with “more?” Fear of “less?” Whatever the reason, making any tonal adjustment without first establishing why you are doing what you’re doing is, well, the definition of “oblivious.” Don’t be that person.
Boosting lows somewhat indiscriminately is hardly a guarantee a mix will sound powerful and delightfully in your face. Instead, you might be increasing the mud factor by causing already prominent bass frequencies to rage unchecked. So, if you’re sensing some low-end corpulence, try cutting (diminishing) the bass within the sonic spectrum.
Many professional mixers advocate initially prioritizing subtractive EQ before you start boosting frequencies, and this is a very good practice for attacking low-end muck. Even those obsessed with boosts need not tremble and moan about subtractive EQ, as it typically doesn’t take much of a cut to drop a little “weight.” All you should be looking to do is rein in any teeming lows without significantly altering the track’s heft, depth and warmth. Start with a rather subtle 2dB or 3dB cut. If that cleans up the mud—bravo—you’re done.
However, if you still perceive unwanted sludge, try cutting 6dB or more. That may be too drastic of an EQ move, but you can always reduce the cut to taste. In fact, you should never fear going too far with tone tweaks. Radical adjustments are a great way to learn how dumping (or boosting) certain frequencies affects the overall soundscape, and once you’ve evaluated the result, you can always scamper back to more subtle alterations.
Let’s look at some frequency-spectrum hacks for specific bass cuts:
Pre-emptive strike. Super low frequencies may not be audible through earbuds, laptop speakers and consumer-quality headphones, but those lows may still be messing with other sounds in your mix. Why risk it? Cut frequencies at 60Hz and below to ensure sub-low rumbles aren’t muddying up the joint.
Keep in mind that just because an instrument isn’t primarily in the bass range, it can still produce frequencies that obscure the overall mix. For example, a midrange-heavy guitar track could still have blossoming harmonics, low-end string rumble, room sounds and signal bleed from other instruments (if, say, the guitar and bass were tracked simultaneously and some low end from the bass snuck into the guitar amp mics). Why worry about these sneaky beasts? Find the lowest frequency that you want your guitar sound to retain and cut everything below that frequency.
Terminate the boom. Bass bloat can usually be found in the 100Hz to 125Hz range, so zero in on that area and try a 3dB cut to clean up any boominess. Admittedly, things can get a bit tricky when dialing in elements such as a kick drum. You may want that huge, chunky John Bonham-approved wallop, so cutting too much low end will likely end in disappointment. But if you listen closely to Led Zeppelin tracks such as “When the Levee Breaks,” you can hear the warm boom, but also a powerful low-midrange thud/snap to the attack of his kick. Again, referencing professional recordings can help you immeasurably when you’re in EQ mode. In this instance, you should discover you can delete a fair amount of low-end harmonics and other resonances without tanking the Bonham vibe. There’s no audible mud in “When the Levee Breaks” and it still drives like a runaway freight train. Let your ears take a lesson from the legends and hitmakers of the recording arts before you indiscriminately adjust EQ.
Seek out the muck. A balanced frequency spectrum in the 100Hz to 400Hz range can produce warmth, fullness and punch. But if those same frequencies are too prominent, the result can be the appearance of the dreaded mud gremlins. Critically listen for any sounds that are overly muddy (80Hz–400Hz), boxy (300Hz–600Hz) or boomy (40Hz–125Hz), and cut the appropriate frequencies as needed or desired.
Q Settings and Why They’re Important
One of the perils of cutting offending bass frequencies is that you don’t want to diminish lows so much that your mix sounds thin, weak or hollow. So, watch out, as the parameters of some DAWs and EQ-specific software tools may default to wide cuts. What this means is that when you make a cut at, say, 400Hz, you may also be cutting a broad expanse of frequencies above and below 400Hz. For example, perhaps you were trying to diminish a bit of bloat in a bass guitar with that 400Hz cut, but if a wide filter is also affecting other frequencies, you might say, “Oh, no. Now, my kick drum sounds feeble.”
However, you can avoid such grief by narrowing the frequency band—or “Q”—on your EQ program to incisively target the precise frequency you want to cut. Most professional and semi-professional EQ tools allow you to control the width of the filter. Dig into the parameters, and narrow that Q setting as much as you need to pinpoint the problematic frequency and avoid tweaking non-problematic frequencies. Adjusting EQ to achieve the optimum sonic impact for a mixdown can be like a “skydiving into a chase-your-own-tail” wormhole at best. Don’t make things even more difficult with widescreen-style tonal changes that you don’t need and don’t want.
Why High-Pass Filters Can Be Quick Fixes
Sometimes, you can de-mud a mix—or, at least, start the cleansing—by deploying a high-pass filter (HPF). A high-pass filter can be set at a specific frequency, say 3kHz, to completely eradicate all frequencies below the selected range. The high frequencies above that range are allowed to pass through and be heard, hence the name. (At the opposite end, a low-pass filter cuts out high frequencies and lets low end pass through unhindered.)
If you suspect something ugly is going on in the 80Hz area, you can set the HPF at that point, and—voila—everything below 80Hz will be inaudible. It’s like those “Got Junk” commercials on television—snap your fingers and the sonic debris is gone. Deploying a HPF can clarify the tones of guitars, keyboards, horns, vocals, stick and kick pedal impacts on drums, pick and finger attacks on bass guitars and more. Again, if you don’t need a specific patch of frequency information, remove it.
However, a high-pass filter can be considered radical surgery, and your mix may not be well served by terminating a massive heap of low-end content. But you can still diminish a muddled frequency range with a more controllable and less-drastic action called shelving EQ. The difference between an HPF and shelving is that an HPF completely removes all content below the chosen frequency, while shelving lets you cut (or boost) everything by a specific amount—such as 3dB. For example, if you want to diminish some woofiness on a keyboard bass line, you could set the shelf to cut 3dB below 100Hz. You’ll still hear bass content below 100Hz, but the 3dB shelving cut might be enough to let the bass line speak clearly without annihilating all frequency content below the set range—which is what a HPF would do.
Whichever method you choose, be sure to let your ears evaluate the result. If it sounds good to you, you’ve probably done the right thing. But if tonal anomalies or any kind of sonic ickiness persists, jump back into the EQ parameters, find the trouble spot and terminate it with extreme prejudice. You don’t have to fear making mistakes, because you can always undo any tweak that doesn’t do the job, or that gets you into more trouble. Here’s your mantra: Be confident. Banish the mud. Deliver an awesome mix.
Pro tip 3: If your HPF or LPF offers different EQ slopes, here are some basic guidelines. A 6dB per octave slope is typically used for moderate and mellow tweaks—a tad less brightness, or a bit less heaviness (depending on the filter you’re using). If you need some more shaping but also want to keep things fairly balanced and musical, a 12dB per octave slope may be your go-to. Selecting an 18dB per octave slope is like using a Magic Eraser for a chunk of frequencies you don’t want to hear. Still not happy? The terminator of slopes is 24dB per octave. It may be too much of a purge for many situations, but it’s there if you really need an “end of days” cut.
Other EQ Techniques to Consider
Tremendously talented remix engineers, DJs and producers with oodles of platinum records adorning their studio walls have proven they can deliver the goods when it comes to addressing a frequency spectrum. But just because you may be a home-studio musician with minimal recording experience and zero Grammy Awards doesn’t mean you’re a sonic lost soul. Granted, it can take some time before you’re comfortable and consistently delivering incisive and beneficial EQ adjustments, but even the pros have a few tricks up their sleeves to help them make good mix decisions. Here are some procedures you can try right now to help make your mixes glow with awesome sound quality and impact.
Rules? What rules? There are a fair number of books, YouTube videos and recording seminars that pontificate on “things you should do” to create a remarkable mix. Many of those educational resources actually offer excellent tips and techniques, and you should absorb all the knowledge you can from them. But you can also toss that stuff aside and follow your own creative muse, because there are no “rules” in art.
In fact, some of the sounds and effects that have forever changed music culture and recording strategies started off as actual mistakes (“Oops, I didn’t mean to do that”), or revealed themselves after truly unhinged flashes of wild experimentation. Remember that. Learn what you can about EQ—knowledge is power—but never let a “conventional recording technique” stop you from doing what sounds good to you. After all, it’s your mix. Own it.
Listen. Stop. Does your mix even need EQ adjustments? You may have recorded all of the mix elements in such a way that they stand strong untouched. Or a raw, unpolished soundscape is 100-percent appropriate for the mood and overall presentation of the song. Don’t touch the EQ controls just because you think you should. Close your eyes. Play the track. Evaluate the complete frequency spectrum. If something is missing or odd, then adjust EQ as needed. But if the track sounds great as it is, then freeze. You just hit a home run without swinging the bat. Bravo.
Go easy on the Solo button. Some people love to solo tracks and mess around with EQ tweaks for days. Well, have some fun if you want to, but soloing a track outside of the overall mix can be dangerous. You are not mixing one track—say, a snare drum—because your audience is not going to listen to a solo snare drum track. They are going to hear an entire song, and all of the frequency relationships within that soundscape have to nurture each other and collaborate to deliver a pleasing and/or powerful listening experience. So, instead of focusing on a single track, listen to the entire soundscape as you make EQ tweaks. All frequencies matter. Which brings us to our next tip …
Minor adjustments can have major ramifications. You may ask yourself, “What’s the big deal about boosting 3kHz by 3dB to add presence to a vocal track?” If only that 3dB boost was a surgical, precision strike on the vocal track alone. But it’s not, is it? The boost will also change the tone of other elements in the 3kHz range, such as the snap and pop of a bass guitar, the click of a kick drum, the bark and sizzle of a snare, the clang of a ride or crash cymbal, the presence of electric and acoustic guitars, the articulation of a piano and/or organ, and so on. Lots of instruments will attend your 3kHz party, so, [A] take care to listen to the entire mix when making tonal adjustments, and [B] confirm that the adjustments do not adversely affect other elements of the mix.
Go mono. Listening to a mix in mono ensures you won’t be fooled by the spatial relationships produced by stereo panning. During a mono playback, you will be forced to create instrument separation and space within the soundstage using EQ alone. If you can separate mix elements with savvy frequency tweaks, when you return to stereo listening, your track should sound as expansive and cinematic as an IMAX movie.
Experiment. Musicians who have always had home studios are likely unaware of how expensive commercial recording facilities were back in the day. As the only viable option to document music, big studios enjoyed a monopoly of sorts. If you wanted someone to hear your song, it was off to the studio. And with hourly rates from $50 to $400 and up being the norm in the 1980s, experimenting while on the clock was something few bands should afford. As your home-studio costs are near zero once you’ve acquired the recording gear you want, it would be a shame to ignore the opportunity to try anything—no matter how wacky or time consuming. Great things can come from diving into the creative abyss. Make the jump.
EQ With Your Ears, Not Your Ego
EQ is a powerful tool, and, as with people in positions of authority, power can corrupt. If you don’t maintain an open, subjective, collaborative and curious approach to mixing and EQ, you may sully more soundscapes than you actually improve. Arrogance is not your best buddy here. Surrender to your ears—not your need to be right, or willfully oblivious, or a prisoner of habit and assumption, or a steadfast disciple of so-called rules. Jettison all biases and prejudices and habits, and simply trust what you hear. Maybe people will adore your productions, or maybe they will hate them, but at least you’ll have put yourself out there in all your artistic glory.