Originally Posted by Autotune Prophet
Hello John. Thank you for your post.
However the situation I was describing is the opposite one:
I cut (not boost) certain frequencies in a sound (let's say: lowpass @ 150) and yet all of a sudden, the channel meter is not anymore at 0db as it was before eqing, but it goes into the red! Keep in mind that I cut (take away) frequencies, which should "logically" (in my own limited knowledge based logic) result in a decrease of the sound on the channel meter... or at most it should result in the channel meter staying at 0db... I don't know.
Sorry if my post was confusing. I gave the example of adding highs to get a lower level, because that's more common. If you cut high frequencies, you're allowing the lower frequency waveform to rise to it's full peak to peak waveform. The high frequencies cause the waveform to have a lower peak level, make sense? So, when you cut those highs, the low frequency waveforms can go higher, if that makes sense. The waveform isn't 'louder' exactly, but it's positive peak to negative peak distance is larger.
The frequency bump phenomenon is also a possible culprit, depending on how steep the cut is. A steep cut will often have a bigger bump just below the cutoff frequency.
Basically, you should always have a little room below 0dbfs, even with a mastered product. Bob Katz says you should have a minimum of 0.3db headroom, to account for the intersample phenomenon. (just to clarify, I'm talking about peak levels here, not RMS.)