djdarwin said:
Using the RTA on the mix to locate "blank" or "missing" spots in your "Wall of sound." Just like chess said, you can identify where there is room for more high end or whatever.
Regardless of the genre of music, a "hole" in the response curve doesn't necessarily mean something is missing; that could simply mean that because of the instruments and arrangements used that there are *natural* spots in the curve that are not filled. That is neither a bad thing nor an indication of there being actual holes in the wall. It's *normal* for there to be an unevenness in the response curve.
And, OTOH, a perfectly "even" response across the spectrum has another name: it's called "white noise". Perfect spectral response, but not exactly what I'd want to listen to

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It's perfectly possible - hell, it's been done a million times - to have a great hip hop composition that's in your face, that gets the blood flowing, that makes the old fart in the car three lanes over from you get a queesy stomache, with nothing more than a beat track, a synth sequence, lead vocals and choral backup vocals. There's going to be more ups and downs in that response curve than there are in a San Francisco car chase, and
that's how it's supposed to be. Filling in those holes via signal processing will do nothing but muddy the mix.
As far as the idea of using the RTA to determine the composition or arrangement of the song, I'm not even sure where to begin on that, that just seems so wrong to me 9 ways to Sunday. Let me just grab a few at random:
First of all, if you need a meter to tell you that you have a "hole" in the upper mids - or any other general section of the spectrum - then your ears just are not ready to mix. And if you can't train them any better than that, you need to find another hobby or line of work. Honestly and seriously. I'm not saying that to be mean any more than I was being mean if I said if you can't run 100 yards in under 10 seconds, you have no business being a cornerback in American football or if you're 5'2" and can only vertical jump 5" you probably should not take the position of power center on a basketball team.
Second, you should compose a song to convey feeling and emotion, not to please an oscilliscope. I don't care what the genre of music is, there are millions of examples where the producer or arranger purposely emphasizes a particular frequency range or leaves another one out in order to convery specific feeling. The same can be said for selection of instruments and their arrangement within a song. In such cases the response curve will certainly not be "even" in the least. 100% frequency spread 100% of the time will get boring and monotinous real fast.
As to those who ask "what's wrong with using ears and an RTA both?", I would reply, well, if it works for you, that's fine, and I won't tell you to change. But to those not yet set in their ways, I reply, "what's the point?" It's unnecessary, it takes longer, and it is more dependant on outside sources than simply training you ears like 99% of pro engineers have.
There is no reason to have to depend upon an RTA to do your mixes right, and there is no advantage to doing it that way either. As good, and often better, results can be had with a good set of ears alone as can be had with an average set of ears and an RTA. So why bother with the excess baggage? It's just an unnecessary complication, not a way to make it easier - which after all is what the ulterior motive to this thread is, isn't it? Aren't we really looking upon using an RTA to make the job easier? Well, if so, we are seriously barking up the wrong tree.
And, as I said earlier, not only do those with well-trained ears and the disclipine of concetrated and critical listening simply have no need for an RTA, use of an RTA before the ears are ready can hamper or at least slow down the ear training process. When one is not dependant upon their ears, one tends to not use them as much or as critically. An RTA may make it easier on the ear, but that also means that the ear is not exercised as hard and, just like a muscle, tends to atrophy when not regularly exercised.
Finally @ Tom: Hey you, if my being on the case means you are around here less, than take me off the case, I'm doing this board more harm than good. Don't make me come out there and force you to eat a cheesesteak made with mozzerella cheese instead of cheese whiz just because you disappeared on me

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G.