Mid Bass Bloat

I find I mention this a lot. What is it and why am I so offended?

Let me answer the second question first.... I'm offended because I believe that tonally things should sound like themselves. If we mic'd flutes and EQ'd them in such a way that they only produced low notes, most people would notice. That is, even the untrained ear has a limited tolerance for things that don't sound like they ought to sound. Flutes don't make really low notes. We should hear high notes. That's what flutes do.

But the same thing is true of the human voice. People's voices don't have booming low registers --- well mostly --- so why should they sound like they do when they are on stage?  I find young audio engineers allow this to happen as it tends to give the voice more "authority." But, to my ears, it is just a false bravado. Kind of like Mickey Mouse trying to be Herculeshttp://www.parts-express.com/pe/showdetl.cfm?Partnumber=248-730. Most folks are pretty tolerant of it after a few minutes, but it drives me buggers.

So what are we talking about here? Most of the time we are talking about fairly low tones - say 150hz or below - that are louder than the device would noramlly produce. You'll find this in a lot of venues on bass and kick drum feeds. The instrument in question does produce some of these notes, but not at the volume coming out of the PA.

In short (do I ever say anything in a short way? hunh.), engineers are trying to compensate for the lack of low tones in their mix by adding what they think should be there. As I've said elsewhere, you can't produce via EQ what isn't there to begin with. When you do this you just end up with flabby sounding tones. Sure they are low, but they don't really sound like real instruments. In fact, it often sounds pretty "rude" to me.

So what is wrong is that the engineer doesn't know how to find the real low notes and accentuate them. In addition, the engineer needs to make sure that the low tones that are there don't overlap. This is most often the case with bass and kick drum. These sounds can be moved around in the frequency spectrum (move the mic, change the mic, change the pickup on the bass) and then you can concentrate on one of them for each instrument.

If you remove the stuff that shouldn't be there (e.g. the midbass bloat), there will be less noise in this frequency spectrum. But the sounds that are there will be distinct and isolated in space. They will have a much more dynamic impact on the audience. When I do this at someone else's venue I often have young engineers think that I've taken the life out of the mix. But then they --- if they care to learn -- see the reaction of the audience when that kick drum thud hits them in the chest out of silence. Music, particularly live music, is about dynamics. Adding crud that shouldn't be there kills the dynamics. Sure it also reduces the continuous low drone that some think is bass, but it just sounds better. And, it will seem lounder on each note than it did before. This is true even when the total SPL of the space is a bit lower. A distant thounder crack will always get your attention. A distant freeway is just annoying.

One final note.... I'm unfortunately sometimes faced with the would-be engineer who does not get this concept. Frankly, I have no solution for them other than seeking other interests. Bad low-end is worse than none at all. Really. Try this for yourself - it works every time.

Random associated notes:
1) Use the HPF on instruments that have no low tones. I have the HPF on virtually every channel except bass, kick, floor tom and keys (sometimes). Get rid of low overtones. Create a "black background." You'll like it when you hear it.
2) Learn to use gates/compressor to isolate the leading transients of low instruments. I've written an article elsewhere on mic'ing drums that goes into greater length.
Comments