Something I realised recently with this tool is:
[s]If you are trying to match absolute loudness levels with the reference, you will need to add a gainer that compensates for the renoise Track Headroom setting.
So if your song Track Headroom setting is at -6dB then you need to add a gainer at +6dB on the reference track. This will make the reference song play at it`s normal level if the master track fader is set to 0dB.[/s]
edit: please see following posts
I thought the Headroom counts for the mastertrack only, so everything you play and compare is with the same -6db head room.
Hmm, I may have to get my head around this better:
-The tool routes the track to the same output as the master bypassing the master fx, except for the master fader.
-Due to the auto-adjustment function on the master, if you drive the mix past 0dB, the master gainer will bring down the reference track aswell as all others. You can be pushing your mix to 0dB in this situation while your reference has been attenuated by whatever the master has gone down by.
So if you are mixing with the auto-gain reduction disabled then yes it looks like the compensating gainer would not be necessary, If you want to mix with the autogain reduction enabled and end up pushing your mix to 0dB absolute peak output, then you need to compensate the reference track to get an accurate volume comparison, though I guess by the level the master is below 0dB and not the headroom level…
If I`ve got this right 
You don’t need a compensating gainer on the master, because you can simply set the track headroom to 0 db.
Simply sliding down the fader on your reference track:that only gives you a slight idea of the peak dB that your own track hardly reaches.
I’m not sure why you would desire to use gainers to compensate loudness:it is about the depth of your mix and allowing more dynamic space in the power range so that your instruments give their distinctive output that are part of the composition. Not overwhelming the user with the wall of sound…
You don’t need a compensating gainer on the master, because you can simply set the track headroom to 0 db.
The gainer would not be on the master but on the reference track to normalise it. It is also worth being aware of this if you want to use the headroom feature but are aiming to mix at peak 0dB (a normalised wav). Like I was trying to figure out/ flesh out in my last post the auto-reduction feature on the master seems to be the main factor as it is the thing that modulates all signals, reference and whole mix to 0dB max output (or whatever exact value it is set to aim for.) If the mix becomes to hot, and the AD kicks in, your reference is reduced also.
Simply sliding down the fader on your reference track:that only gives you a slight idea of the peak dB that your own track hardly reaches.
I’m not sure why you would desire to use gainers to compensate loudness:it is about the depth of your mix and allowing more dynamic space in the power range so that your instruments give their distinctive output that are part of the composition. Not overwhelming the user with the wall of sound…
The aim of all this is to get an accurate reference, nothing to do with how you use it or what perceived loudness you are aiming for. You can use a reference track to match loudness to a commercial track of the same genre, (jazz, classical, hiphop…), another track in your own album you want to check against, or reference against a mix you think sounds bad in any way to avoid getting close to that. If your reference level is jumping about the place (becoming non normalised) then this becomes harder and can defeat the point of using it in the first place.
Edit: a good little vid on the Fletcher Munson curve, a good reason to keep your ABing at similar dB:
Awesome Tool Ledger, now in my default template I have 3 small ref loops. I have a problem though Its not playing nice with this tool:
After loading a new song or restarting RNS the graphics seem to be stuttering. KMaki’s tool creates a track called MNTR in the sends which is part of my default template, if I delete this track all is ok and all is ok if I use KMaki’s tool after the delete of the MNTR track (it creates the track again).
This sounds like it could be a notifier being retriggered constantly. The only notifier I have in this tool attaches the menu entry to the instrument box. This is triggered on renoise start-up or a new song being loaded but should/ will only trigger once. It seems with kmaki’s tool there is an idle notifier running . These will trigger regularly and I suspect something could be happening there, though I`m not sure. I have only had a short chance to look at kMakis code, have you contacted him aswell?
Hello! Chiming in here - I do indeed have idle notifiers there. My memory fails me but at least I’m following the selected track constantly, when monitor tool is active.
Though I’m not really sure how that could choke the startup routine. Maybe I’ve defined the new_document_observable notifier in some weird way… I think I’ll have to test this myself before I can get a hold of this issue. I’ll try to do this soon and get back.
Cool,
was just thinking it might be useful if Dunks can provide the template xrns that causes the problems? to help narrow it down on both sides here.
Here it is:
Thanks, I can`t seem to replicate the GUI stuttering here, I can however crash renoise completely just by using the Monitor - Exit shortcut from kMakis tool.
I guess this may be to do with the fact I don’t have the plugs installed from the template, I’ll at least pass this crash report on the devs as they will be sure to want to know about this. This may be unrelated to the issue you are experiencing though.
Maybe kMaki might be able to reproduce it?
I’ll check this asap…
–
No Gui Stutter here either. But crashing… - yes. Maybe we’ll let the German headquarters sort this one out… Added my log to your crash report, Ledger.
Good stuff, I`m sure HQ will be onto it shortly!
Ok after I unistalled afta8’s multi-volumes Everything works fine so it seems as if all 3 are conflicting. (I will tell afta8.) 
Thanks for letting me know, I’ll look into it. Can’t promise this is going to be an easy one to figure out, multivolumes is quite complex under the hood, it has an app idle notifier creating track notifiers that in turn create and remove other track notifiers…
Is there only an issue when all three tools are run together or does it happen when its only multivolumes and one other tool?
Ok this is weird, I disabled both Ledgers tool and kMaki’s and the problem is still there after startup unless I delete the MNTR track after startup. Im getting this when deleting:
'C:\Documents and Settings\Ian\Application Data\Renoise\V2.8.1\Scripts\Tools\com.afta8.MultiVolumes.xrnx\main.lua' failed in one of its notifiers.
The notifier will be disabled to prevent further errors.
Please contact the author (afta8 | fathand@gmail.com ) for assistance...
main.lua:160: attempt to index field '?' (a nil value)
stack traceback:
main.lua:160: in function 'remove_postfx_vol_notifiers'
main.lua:262: in function 'deactivate'
main.lua:269: in function <267><br>```
</267>Could really do with this 1 working in R3.
Edit: works with API v4
Added 3.0 beta version to first post as the file got trashed in the tools website upgrade aswell.
Another video explaining volume effecting perception and ABing:
If anyone wants a free (light nagware) R128 VST, Melda has one here included in a bundle.
Version 1.2
Shortcut added for quick mono-ing of a whole mix by use of a custom Stereo Expander. “Mono Mix” is added the Master track and the Reference track (if present).
Can be used without a reference track to just to check your mono compatibility while mixing