Hey guys,
Is there a difference between lowering the song headroom parameter by, say 6 dB, and lowering the master channel by 6 dB? Is there any side effect by doing the 2nd one? I’ve read and heard it was not recommended but why?
Thanks a lot!
EDIT: I’m sorry I’m having a hard time formulating my questions 
from the manual:
Track Headroom: The amount that EACH track’s input is lowered by, which helps avoid clipping in the final mix.
They are all the same thing really. But I’d say keeping both at 0 db and adjusting levels in the individual tracks would be better in the long run. I don’t even see the point of having a headroom setting. It’s just confusing imo.
It’s usually a better idea to have your tracks gain staged properly before they hit the master buss. If you keep the master fader steady all the time and try to learn what kind of levels work for your mixdowns (using the individual track faders or better, the native gainer DSP as a trim plugin), you can get your basic balance much quicker and build yourself some reference points. For example I like my drums peak around -12db, bass usually around -14ish, the important “lead” kind of sounds around -16/-18 range, less important stuff around -24’ish etc. So when I sum all those elements together in the mixdown (with a natural master fader), I should end up with something like a -6 db on the master buss. (which is a nice amount of headroom to have if you want to try out some mastering). If I end up with a -3 or something, I’ll usually suspect having too much sub, or if I have a -8, I’ll think I’ve crushed too much dynamics etc. The numbers will be different for everyone, but you get the idea…
But instead if you just turn down the master buss to avoid clipping for every mix you do, you’ll have to figure out the same things over and over and you won’t have any reference points. Besides it’s much easier to chase your own tail and end up with 0 headroom if you work that way. For example when you think you need to turn up the bass to make it sound better and five minutes later you can’t hear the kick cause you’ve turned up the bass, so you also turn up the kick and five minutes later the snare etc etc. You end up with almost same balance but with less headroom or clipping. So you turn down the master fader down. 5 minutes later the cycle begins again. When you have a basic plan you don’t fall into that kind of traps.
It could work anyway and I’m sure alot of people are just fine turning down the master fader but proper gain staging just makes things easier imo (which is kinda hard to do in renoise btw, cause you can’t see the peak levels for individual tracks, which is a shame really) If you try it out a couple of times you’ll see the tunes will basically mix themselves 
Didn’t mean to make a wall of text but oh well…
First of all it is essential to understand the signal flow and distinguish between the IN- and OUT-Mixer. What setting headroom does, is lowering the IN-amplitude of your individual tracks by the defined headroom amount and nothing but that. Headroom is NOT applied to Send Tracks, nor to the Master Track. No matter if we’re talking about the IN- or OUT-Mixer.
Common signal flow from instrument to audio output: Track-IN (minus headroom) -> Mixer Track-IN (slider) -> DSP Chain -> Mixer Track-OUT (slider) -> Master Track-IN (slider) -> Master Chain - > Master Track-OUT (slider)
Not too hard to follow and understand once you know it . But what now happens is, the GUI / amplitude meters of the Renoise Mixer are kinda misleading, no matter what you do and in which way you setup headroom. When a signal hits the Mixer (and its Meters), the shown Mixer scale technically is simply wrong. What’s displayed as (+3db) on the Mixer is in fact +/-0db (as 0db of course is the maximum amplitude). That’s the reason why true -6db IN-Mixer amplitude always result in “only” -3db on the OUT-Mixer and similar phenomenons. That’ s at least the case, if the Meters are supposed to be related to the slider’s scale next to it, which would make sense.
0db in the Renoise Mixer Amplitude Meters = -3db in reality… BUT: at the same time all native DSP Amplitude Meters work correctly! So +/-0db in a Maximizer = +3db in the Renoise Mixer Meters. The Mixer Slider’s scale itself is correct. This indeed goes for the Mixer Meters only.
In fact I’d consider this a bug. The Mixer Meters amplitude is always indicating values 3db higher than the actual amplitude in fact is. Reported this as bug. Fixing this should take a lot of confusion out of amplitude issues, even if it atm is thought to be NOT directly be related to the slider’s scale.
Thanks for your answers.
The thing I’m wondering is when you don’t need the reference anymore (kick at -12dB, bass at -14dB etc…) because you actually finished the song, have a mix that sounds decent to your ears, have it peak at -1dB, and just want to have some 3dB headroom for mastering. What happens there if you decide to move down your master fader in order to go from, say -1dB to -4dB?
Depends on what you have used already in your master chain.
Nothing. As long as you have audio bitrate of 24 bits (renoise works internally at 32 bits, or you can render out your wav at 24 or 32 bits for mastering) you can turn it up and down all day long. Nothing wrong happens to the audio. That’s supposedly not true with 16 bits cause of the lower dynamic range (96db for 16 bits vs 144db for 24) but I haven’t tried that in 16 bits myself though so yeah…
Keeping the master fader at zero and trying to preserve your headroom before getting there is more of a workflow/reference kind of thing.
Edit: Good point from Bit_Arts about having FX on your master buss. If you have a buss compressor there and you turn down the input that would change the sound so that wouldn’t make sense. If that’s the case and you still need to turn it down you’d have to do it after any effects.
Thanks a lot, that’s what I wanted to know.
Ok, thanks for the explanation 
Just want to add something to this discussion.
If your music is going to be mastered by a mastering company they will most likely demand that the masterbus has no compression/limiting/tape simulator/reverb etc.
It’s why I never use anything on the masterbus. And I do mean anything.
I “take care” of the mix on the channels themselves and I always leave more than enough headroom for the mastering pro to do his thing.
What I’m trying to say is that if your music is mastered by others you can literally just pull down the mastervolume. Don’t be afraid to send them low volume music. They will take care of the rest.