Consisting of frequencies from 1.2 to 3.5 KHz, we once again have a nice range of frequencies to play with. The high-mids contain lots of harmonics, especially the lower to mid order harmonics for the mid-range instruments. The range of 2300 Hz gives you plenty of room to work with in carving out specific places for various instruments to sit. Only the highest instruments can really play in this range: the piccolo can sound in this band and it also accounts for the top octave or so of the piano, which most people know not a whole lot happens there. So there are no new instruments sounding fundamentals to get in the way and cover up the harmonic content that you are treating in this band.
Additionally, this range is very important because it contains much of the sudden transient content. Attack transients, sibilance, consonants and more all live in this register, so it is very important for understandability as well as punchiness, presence, and dynamics.
The human voice is the most dynamic instrument on the planet. When I work on TV and movies, I’m always amazed at how suddenly the voice changes dynamics. Looking at the waveforms, the T, C, D, B and other consonant sounds are so short and quiet while the vowel sounds are exponentially louder and longer. This can be a problem when mixing music because you might miss out on an initial or ultimate consonant sound that totally changes the meaning of a song without that consonant. I remember working on a Christian rock album and the line was “We know that we can’t live with out you.” When the mixing was done, they loved the track, but the “t” in “can’t” had disappeared. Of course in a religious context you don’t want to be saying that you know you can live without God, so we had to spend a little extra time making sure that came across without being overbearing.
Just a crazy little factoid, almost all consonant sounds sound the same no matter who says them. The majority of the time, you can fly in a t from one person, paste it in, and no one would know the difference. You really only know from the vowel sounds what somebody sounds like. Consonants are just air pushing against your lips, teeth, tongue, and mouth and we are all roughly equal to each other in body composition—at least enough that it isn’t imminently audible in most instances.
This is also the range where attack sounds live: picks strumming strings, sticks striking cymbals, this is the range where you can hear all that. Giving a boost to those sounds in this range can lead to a more present sound. After all, your mind thinks your closer to something the more detail you can hear of it. So if you can hear a stick tapping a drumhead, by god you must be close to it. We’ll talk more about psychoacoustics and proximity in the next article.
Also, many big time producers believe that in this band lies the frequency that makes digital sound abrasive and therefore worse than tape, which centers around 2 KHz. While this may or may not be the case, it certainly cannot be argued that harshness, edginess, and abrasiveness live in this frequency band. Raucous and in your face sounds like screeching guitars and sailing synths need this range so that they can cut and make your ear drums bleed.
Next week, I’ll look at some common terms for upper-mid range problems and some common solutions