Kick vs. Bass | Design by Ben Walker
Well, I could be satisfied. I could let it alone. But I'm not. And I don’t.
Instead, I duplicate the original track, apply judicious EQ, gating, and possibly upward expansion until all I hear are the necessary kick drum frequencies.
This may even involve making another duplicate, manipulating it, and sending the result to a buss (with no output) for sidechain purposes. Then I can use that soundless duplicate as a key to gate, duck, or compress the first duplicate.
Yes, it’s complicated. It’s messy. But I’ll do anything it takes to get a second, exaggerated kick going, provided that once it’s folded back in, it’ll naturally emphasize the element lacking in the original mix. It must improve upon the mix, or else it’s garbage.
Here we get back to the title of the article, and all the reasons this technique shouldn’t work—or at the very least, the reasons it shouldn’t be implemented on a daily basis. If done sloppily, this process can absolutely destroy a master. Even within a DAW that handles delay compensation in a smooth and timely (pun intended) manner, you are still subject to smearing; that’s the nature of physics when recombining two subtly different signals. And, as in the last tip, a linear-phase EQ used here can definitely introduce pre-ringing artifacts. These can be quite jarring, especially in the low range (they can sound like a reversed, ugly, and resonant “thwump” anticipating your transient).
As always, you must use your ears to judge if the compromise is worth it. If it is, that’s all that matters.
3. Use Region-Specific Processing with RX
Yes, the website you’re reading happens to be iZotope.com, but even if it wasn’t, I’d be recommending this tip: RX 6's spectral editor is not just a powerful post-production tool, but a scalpel that, in the hands of a skilled mastering engineer, can scrape tumors right out of the body of the mix.
Here's an example that recently came my way: A kick in a mix was flubby, with too much activity in the 300 to 400 Hz area. It didn't mask the guitar's meaningful information, or the vocal’s presence, but it somehow rubbed nastily against the bass and the keys. Unfortunately, a static EQ drained all the life out of the track. A dynamic EQ, no matter how I pushed it, gave me pumping that I didn't want, due to the timing of the rhythmic elements and the placement of the frequencies.
From my experiences in post-production, I have more than a passing familiarity with RX 6, so I fired it up, loaded in the track, and took a look. Sure enough, each kick's problematic frequency bump was laid out in explicit orange. It became clear exactly when the offending transient sounded, when it ended, and most importantly, what level it should be in relation to the surrounding color scheme.
It was a painstaking process, but I went in and manually gained the specific regions down until they no longer offended. The result was clean, natural, and low on compromise.
Why this shouldn’t work is more of a workflow issue than a quality hindrance. While the risk of doing damage to the overall sound is not especially amplified—especially if you’re skilled in the ways of RX—you are taking yourself out of the musical aspect of mastering. Using an intensely granular process, you’re zooming in on troublesome areas by sight, and with that comes perspective problems that could wreck your headspace. You can miss the forest for the trees, as they say. And the time-drain as well could sap your energy for the rest of the day’s work. Once you get a groove going in mastering an album, it often doesn’t pay to disrupt that flow. But in cases where there’s no other viable solution, it’s good to have a handy tool like this up your sleeve.
4. Use the Meter Instead of Your Ear
Here’s a tip you hear a lot: “let your ears be the guide,” or “mix by ear—not by meter.” I would never advise against these maxims. However, a situation arose where using the meter to supplement my ear—as a reality check for my ear—greatly improved the quality of my masters.
See, I have a problem with specific frequencies. It’s not surprising, as we all have our predilections. My particular ear is enervated to no end by the area between 2 to 4 kHz. This can sometimes cause problems in my mixes, as this frequency band is essential for translation: the bulk of communicable information lies between the areas of 200 Hz to 5 kHz.
Thus, my personal preferences can trick me into leaving holes in the master that shouldn't be there. I’m willing to bet the same is true for you. In this case, your frequency analyzer can act as a protective measure.
One day, as I was equalizing during a master, I thought about the general consensus of what the frequency response should look like on a textbook pop track. It’s something like this: