Hi all,
Still embarrassingly new to Renoise, and specifically to mixing & mastering. I recently learned about ISO 226:2003 and the concept of equal loudness contours; specifically, that not only do different parts of the frequency spectrum need to be played at different sound pressures (“physical” volumes) in order to be perceived as being equally loud (same “subjective” volume), but that this contour varies slightly (flattens off) as the reference volume increases. I’m also starting to develop the habit of using my eyes as well as my ears: for example, I only recently noticed that when viewing the spectrum in Renoise as a curve (rather than spectrogram), the frequency contribution of the currently highlighted track is actually overlaid on the total curve in the current track’s colour!
I get that there’s no such thing as a magical ISO 226:2003 mastering plugin, that it’s all subjective, and that it can even vary by genre - mids get a perceptual boost at higher volumes, so to a certain extent, mastering for a “target listening volume” is a thing, and explains why plugins like Fletchy-Muncher exist. Also that you shouldn’t just target full loudness across the spectrum across a whole track; again of course norms & expectations vary across genres, but dynamic variation is definitely a good thing!
That said, there does seem to be an obvious gap in Renoise’s built-in visualisation tools here. Anyone know of any tools that visually overlay one or more target equal loudness contours over the spectrum? Any monitoring VSTs that do something like this? Is it something that could be written in Lua as a Renoise script? (I haven’t played with scripting at all yet, I have no idea whether scripts have the ability to draw on the UI.) I recently laid down half a track, thought it was really well balanced, when when I went back the next day, realised the mix was all over the place: far too prominent snare, and the lead just completely drowned out the vocals. I know the concept of “tired ears” or “losing your ear” for a track is a thing, but maybe being able to see it better might help combat this.
My tracks may not be musical masterpieces, but I am trying to at least get the “best sounding” versions of my tracks out there, preferably without spending a ton of money on studio monitors 
I already had one bad experience releasing a track only to discover later that the bass completely swamps the mix in listening conditions other than my “studio” (AKA the spare bedroom at home), and I feel like being able to get a visual feel for this rather than relying purely on my ears & listening on a variety of headphones/speakers would help to reign in problem frequencies, or understand why something sounds muddy.
I am not saying I use Fletchy-Muncher on any of my tracks; in fact I don’t think it’s really intended to be used as an actual effect, more a tool to simulate how your mix would sound at higher volumes without actually having to turn the volume up super high, e.g. if your mix sounds harsh with FM turned up more than 50%, it wouldn’t sound good on a big sound system.