Pants Flapping? – Part 2


Photo by Stephen Hunton

So last time I mentioned that I think I’m over subs. I still want them. I still need them, but I’m just sort of over them as an idolized loudspeaker. A lot of folks–probably myself included at times–have put subs up on a pedestal, and it has often resulted in what I consider to be a misappropriation of subs. I write here as one of the guilty, but today I want to start looking at how I’m rehabilitating myself with subs and using them to my advantage. If you’ve ever found yourself struggling to get that elusive, tight low-end, that’s where this is ultimately going. This is going to be a little shorter than usual because what I’m talking about today is really a fundamental in mixing.

So when I talk about the misappropriation of subs, I think my biggest issue stems from a lot of us just trying to cram too much stuff into them. Now this isn’t an aux-fed subs argument because even with aux-fed subs the problem arises; aux-fed subs might put a band-aid on it, though. I’m talking about too much stuff trying to occupy the same space in the frequency spectrum of our subs.

Whenever we have instruments occupying the same frequency space, it can be extremely difficult to get clarity between them. You can’t park things on top of each other if you want them to stand out; typically the loudest source will overpower and win. Plus, our sound sources will literally add together. When we have multiple instruments with power in the same frequencies, we often get more overall power in those bands. This is why when you stack bass, guitars, and vocals together, the mix can get muddy even though you have each individual instrument sounding good on its own. These are instruments that can all contain a generous amount of energy in that 200-250 Hz area that is often exacerbated by shoving directional mics up against those sources which increases the proximity effect of the mics. When all that energy combines, we can end up with a muddy mix, and as I mentioned in an earlier post, the clarity of our mid-range is dependent on the clarity in the lower-mids….but I digress.

This frequency addition can also work against us. If our competing sources are out of phase with each other, they might actually cancel each other out to an extent. This can result in decreased power in those overlapping frequencies giving the perception of holes in our mix.

Now, when we try and stuff too much sonic information into our sub region, not only do we end up with a potential mush of sound from competing sources, but our room acoustics can also exacerbate problems. It is very difficult to reduce the room decay times in those lower octaves from a design and construction standpoint. If our acoustics are loose down there, sounds we push up in the sub-lows can actually linger a bit in the room. So what do you think can happen down there if we have a bass player playing eighth notes on a fast song? We might have sound from previous notes hanging out and still decaying when he’s moved on to the next few. That lingering sound might not even be musically distinguishable; it might just be boom because as we start dropping into those bottom two octaves the musical content and pitches get harder to distinguish. The result can be just a lot of junk rolling around the room and obscuring the rest of our mix.

Fortunately there are some ways we can approach this to help. We need to find our low frequency instruments their own space to sit where frequency overlap is minimized. Up next I’ll get into some of the practical ways I’m doing that these days.

David Stagl

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