Spectrum Slope Question

I love the new spectrum tools. One very handy feature that I like is being able to adjust the slope, which pivots on the 1k centre point as it should. I am interested to know why the team chose the specific slope values they did, if that is based upon some sort of body of research. In the past I’ve tried finding such research but couldn’t come up with anything. For some time now I’ve used Voxengo SPAN for spectrum analysis, and it defaults the slope to +4.5dB/oct. As far as my ears go (subjective measure) +4.5 seems to be just right - a busy mix presenting a flattish line from 20hz-20khz feels ‘balanced’. I’ve seen posts on other forums to say that people like sticking with the +4.5dB setting. However, Renoise only lets you choose from +4.0dB/oct and +4.8dB/oct in that range. So far I find +4.0dB/oct workable, but I’m wondering if those value were anything other than arbitrarily selected?

On a side note, white noise produces a roughly flat response at a slope of 0dB/oct, and pink noise produces a roughly flat response at a slope of +3.0dB/oct. Pink is pretty endurable.

Yours,
Mixing Nerd. :)

Am I making any sense here? Or is this yet another case of first class rambling? ;)

Pink Noise is equal energy per octave, White Noise is equal energy per frequency, so that is expected with the curves.

The rest of it makes sense to me reading but I wouldn’t have a clue about any answers. Quick research shows SPAN used to use a default of 3dB/Oct and more recently changed it to the 4.5dB/Oct you mention, neither of which are available. My very, very brief tinkering found 3.2dB/Oct to feel about right personally. Due to sensitivity of the ears not being linear at all frequencies I can’t imagine a simple flat slope curve is ever going to be perfect, plus sensitivity changes with loudness…

Here appears to be a paper related on the subject though. http://www.speech.kth.se/prod/publications/files/1669.pdf

Interesting paper Kazakore! Thanks for digging that up. I guess it simply is a matter of personal choice. I’d still like to know why the team picked the values they did though.

well, i picked some spaced values that may be common (i personally use 4.0db/oct) but this may be subjective and probably a menu here doesn’t fit for this kind of parameter. It’s just i don’t want to make a panel to configure this at this point of the beta…

Agreed, and thank you for your response! I can certainly live with +4.0 for now. :)