Mix bus processing vs Master bus processing

[EliasMooseblaster]

I recently learned about the potential benefits of some subtle mix bus processing, and it has been quite eye-opening (ear-opening?)

 

However, a big source of disagreement seems to be around where you do this processing: apply effects to the master bus, or create a separate aux channel which then goes out to the master bus? Being the internet, opinion I've seen sits on a scale between the extremes of "it doesn't really matter" to "only someone on a par with Harold Shipman would apply effects directly to the master bus."

 

So, looking to a more level-headed community for advice: is there a good reason to keep effects off the master bus (at least at the mixing stage)? Is there a big benefit to routing everything through a separate bus before sending that onto the master? Or does it mostly come down to personal preference?

 

 

(Not that I expect it to make much difference, but I'm working in Ardour, in case that informs anyone's response!)

Edited October 25, 2022 by EliasMooseblaster

[Dad3353]

14 minutes ago, EliasMooseblaster said:

... is there a good reason to keep effects off the master bus (at least at the mixing stage)? Is there a big benefit to routing everything through a separate bus before sending that onto the master?...

 

If I'm reading this correctly (that's not certain...), I can think of only one 'good' reason for having a separate, common, channel for Fx destined for the Master. During the mixing, it may end up desirable to have a channel not going thought these common Fx, or at least switch between in/out to compare. If sending to a common Fx, it would be possible to 'dose' the amount of Fx for each 'send', which would no longer be possible, individually, if the Fx is only on the Master. If this individual control is not required (overall compression, for example...), having this on the Master alone could make sense. There's nothing wrong with using both notions, though: route all channels through a common Fx channel, to 'dose' them if they require tweaking, and have global Fx on the Master as well, knowing that these will affect everything, together. I'd use both; for instance I have my drums in a group channel, and apply individual Fx to each drum element, but also a NY Drum Bus Glue compressor on the drum group channel. I have another NY Glue compressor on the Master, too. My answer, then, is... Both..!

[EliasMooseblaster]

No, I think you've understood me quite correctly - and I take your point re group channels as well. I've found those make life much easier when I've pointed multiple mics at a piano or drumkit, for example!

 

As far as "global" effects go, so far I've put them on the Master - I figured that whatever goes through a separate "Mix bus" would end up going out to the Master anyway. (And if there are other things which bypasses that Mix bus, is it really a Mix bus / global effect any more?)

[BigRedX]

I think this mostly comes from the way that the effects would have added in a traditional hardware recording/mixing setup.

 

In this case the master output would have been split two, ways between the monitors and the stereo mastering recorder and often there would be no insert points on the stereo master bus, so no opportunity to add effects at this point in a way that could be applied both to the mastering recorder and the monitors.

 

Mixing in the box doesn't place any restrictions on how you route the audio and where you apply the effects. However you'll get more control over the final level, the various effects levels in relation to the dry signals, and be able to avoid digital clipping more easily if you apply your effects individual buses before the master bus in the traditional way.

[WinterMute]

This kind of parallel master processing is more often seen in Mastering than in multi-track mixing, it allows a more aggressive compression/limiting to be used that can then be blended with the uncompressed master signal to retain clarity but add required loudness.

 

It's a perfectly legit technique for mixing too however, I tend to run 2 sub-masters, one a return from my summing mixer and one ITB master, the summed return will have a limiter attached and then blended underneath the main mix till I get the loudness I'm looking for, both are then run into the Master I'll add a general EQ to the Master, in case I need it, but it's not used often.

 

Personally I'd never add time-domain effects to a master, they will be handled in aux sends and returns, and I can EQ or dynamically control the stem signals going out to the summing mixer if needed, this can be very useful to add a bit of control to the drum overheads or the kick generally before it hits the summing mixer.

 

In the end all you gain is a measure of control of the amount of limited or compressed signal you add to your main mix buss, but that can be invaluable.