Before mixing, many rap vocals need a little cleaning. Common issues are - the vocals were recorded in an unideal location, such as a closet (I get that one all the time) or a bathroom. I know it sounds weird but the myth has gone around that recording in a closet or a bathroom is a good idea. Generally speaking, it’s not.
The other common issue - the vocals were recorded too hot. Again, a myth has seemed to perpetuate that it’s a good idea to record the signal as loudly as possibly. This is totally untrue, particularly in the age of 24-bit audio.
Cleaning up is a little rough at times - because the scope of what you can do is limited. For audio that came in too hot - ie, is clipping, distortion removal software such as iZotope’s Rx De-Clipper is ideal. Also, that distortion will create frequency center resonances, which can be eased off with an EQ.
For vocals tracked in a reverberant space, subtle gating, and careful EQ can suppress the room sound - or you can use software like SPL De-Verb. The other option is to mix the track in a way that makes the reverb appear deliberate.
For vocals tracked in closets or corners, the issue will be comb filtering. One trick for easing off comb filtering - if there are doubles of the vocal, pitch shift them up or down a slight amount. This will change the frequency bands that are being filtered, so that when layered with the main vocal, the same bands will not be missing all across the board. The backups will “fill in” the missing bands. The comb filtering will still be there, but it won’t be as readily apparent.
Now you have the vocals clean (or maybe they came in clean to begin with). It’s time to decide what to do with them. Now, I can’t write how you should or should not process your vocals, but I can give some insight into things to consider and think about.
Figuring out the relationship between the vocals and other instruments in the same frequency area is extremely important. Quintessentially, Hip Hop is all about the relationship between the vocals and the drums - and the number one contestant with the voice is the snare. Finding a way to make both the vocals and the snare prominent without stepping on each other will make the rest of the mix fall nicely into place.
In “1nce Again,” you’ll notice that the snare is a little louder than the vocals, and seems to be concentrated into the brighter area of the frequency spectrum, while the vocals are just an inch down, and living more in the mid range. This was a conscious decision made in the mix. But mixes like Loungin’ have the vocals on par with the snare. And Massive Attack has the vocals up - but it’s not really a snare, it’s a percussive instrument holding down the 2 and 4 that lives primarily in the lower mid region.
Hip Hop vocals generally do not have much in the way of reverb. There are three reason for this primarily. 1) Rap vocals tend to move faster and hold more of a rhythmic function than sung vocals - and long reverb tails can blur the rhythm and articulation. (2) The idea of Hip Hop is to be “up front and in your face”, where reverb tends to sink things back in the stereo field. (3) Everyone else is mixing their vocals that way. Not a good reason, but kind of true.
However, vocals usually do benefit from sense of 3-D sculpting, or “air.” A sense of space around the vocals that make them more lively and vivid. Very short, wide, quiet reverb can really do the trick here. Another good thing to try is using delay (echo) - and pushing the delay way in the background, with a lot of high end rolled off of it. This creates the sense of a very deep three dimensional space, which by contrast makes the vocal seem even more forward.
Lastly, if you are in a good tracking situation, carefully bringing out the natural space of the tracking room can be a good way to get super dry vocals with a sense of air around them. Compression with a very slow attack, and relatively quick release, and a boost to the super-treble range can often bring out the natural air.
Shape & Consistency
A little compression is often nice on vocals, just to sit them into a mix and add a little tone. On a sparse mix, a little dab’ll do ya. The most common mistake people make when processing vocals for Hip Hop is to over-compress. High levels of compression is really only beneficial to a mix when there is a lot of stuff fighting for sonic space. When you read about rapper’s vocals going through four compressors and really getting squeezed it’s probably because there are tons of things already going on in the mix, and the compression is necessary for the vocals to cut through. Or because it’s a stylistic choice to really crunch the vocals.
What’s going on around the voice is just as important to the vocals as the vocals themselves. Carefully picking what to get rid of to help the vocals along is very important. For example, most engineers hi-pass filter almost everything except the kick and bass. That clears up room for the low information.
But often the importance of low-pass filtering is overlooked. Synths, even bass synths, can have a lot of high end information that is just not necessary to the mix and leave the “air” range around the vocals feeling choked. A couple of well placed low-passes could very well bring your vocals to life.
Also, back to the subject of hi-passing, unless you are doing the heavy handed Bob Power thing, you really don’t need to be hard hi-passing your vocals at 120 Hz. The human voice, male and female, has chest resonance that goes down to 80 Hz (and even under sometimes). Try a gentle hi-pass at around 70 or 80 Hz to start with if you’re clearing up the vocals. Or maybe no hi-pass at all…
Deciding where the vocal lives frequency wise is important. Mid sounding, “telephonic” vocals can be cool at times, low mid “warm” sounding vocals certainly have their place. Commonly, the practice is to hype the natural presence of the vocals by getting rid of the “throat” tones and proximity build up which generally live around the 250-600 Hz range (but don’t mix by numbers, listen listen listen). This in turn exaggerates the chest sound, and the head sound - particularly the sounds that form at the front of the mouth, tongue, and teeth - these are the tones that we use to pronounce our words and generally live in the upper midrange (2-5 kHz, no numbers, listen listen listen).
Matthew Weiss records, mixes, and masters music in the Philadelphia, New York, and Boston areas. Find out more about him here.
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