Space Is the Place, Part 2

Jan 1, 2009 12:00 PM, By Myles Boisen

           
 

OPEN UP YOUR MIXES BY AVOIDING "SPACE INVADERS"

All Things Being Equalized

Just as blazing sunlight can make it hard to see visual details, and strong scents can overpower subtle aromas, excessive EQ can mask perception of audio nuance. When frequency buildup becomes extreme — particularly in the upper midrange, where the ear is most sensitive — subtle space-enhancing details in a mix are the first to fall victim to frequency masking and hearing fatigue.

On numerous occasions, I have encountered mixes, especially rock recordings, where it is obvious that the guitar is too bright in the upper midrange around 1 to 3 kHz. This timbre can make it hard to hear the “crack” of the snare drum, which then ends up having to get boosted as well. As a further consequence, you might then feel you need to add a brighter edge to the vocals.

As more additive EQ (boosts as opposed to cuts) gets piled on, the final result is often grating, tinny, or downright unlistenable at moderate volume. Such an excessive buildup — in addition to hastening listening fatigue — may smear or obscure subtler aspects of a production. The interaction of compression or reverb in this range further compounds the problem.

Sometimes it is possible in mastering to solve or at least soften this type of masking effect with a judicious frequency cut, or de-essing tuned to the 2 kHz area. In the cases where this approach actually works, the difference in space and openness in the mix is immediately obvious. Occasionally the transformation borders on the miraculous, causing band members to wonder what kind of sophisticated mastering black magic has been used on their tracks.

Of course, a frequency cut to the most active part of the midrange affects all instruments to some degree and could cause presence problems for some tracks. Similar issues can plague mixes where the low end or treble has been pushed out of balance. In cases where the mastering fix previously described doesn't do the trick, it's time to go back and remix the track, focusing more on subtractive rather than additive EQ.

I'll start with the low end. Once the mix level of a basic track has been established, bass boosting can be done with compression, as we have already discussed, or with EQ. A common practice that quickly eats up both space and headroom is boosting with a low-shelving EQ, which increases everything below the specified corner frequency. When applied indiscriminately, this practice typically raises the gain of a track without significantly increasing usable tone, and also boosts 60 Hz hum, ambient rumble, and other muddying artifacts.

FIG. 2: This chart shows key frequency ranges for additive and subtractive EQ that affect various elements in your mix.

To enhance your mix's spaciousness and clarity, keep any low-end EQ boosting moderate and targeted between 150 and 400 Hz (see Fig. 2). This range is most effective to add power and warmth to tonal and chordal instruments, including vocals. The tone and punch of drums can be improved in the same manner. Combining this kind of EQ boost with a careful, low-shelving cut is an excellent way to clear up mud in a mix, enhance bass tone in real-world playback environments, and achieve hotter levels in mastering. In order to make effective judgments about the low end when mixing or tracking, it is also very important to use a subwoofer.

In mastering I find that 320 to 450 Hz is a region where I often use subtractive EQ to attenuate the buildup of room tone and leakage on multiple-miked recordings, effectively reducing murkiness. Improved clarity and space usually results from decreasing the boxy-sounding effects of standing waves in small or acoustically flawed rooms (see Web Clips 3a and 3b).

Subtle attenuation throughout the midrange is another easy way to alleviate a feeling of crowding in a mix, and can make a track seem lighter or airier. Of course, when taken to extremes, subtractive EQ between 320 and 1,000 Hz risks the empty, hollow tone of the smile curve.

As a rule, whenever you add gain to a track with equalization, it is good practice to try to use subtractive EQ to cut the gain of some other frequencies. Make it your goal to keep the level of a track roughly the same, while increasing its desired tone as well as carving out more room in the mixing space. In addition, don't be single-minded about highlighting one frequency area to the detriment of overall timbral balance.

Into the Pan

In part 1, I addressed stationary panning of basic tracks. Now, here are a few advanced tricks to bring attention to the 3-D mixing space with creative panning and movement of sounds within the horizontal panning dimension.