When revisiting mixes, working with premixed audio has fewer limitations than was once the case. We look at one technique that works better than you might think…
Baking In
Not so long ago, those working with bounced audio were, on the whole, carrying out editing tasks or mastering. One long-standing edit job for premixed audio has been creating stings or radio mixes. When it comes to mix edits, shortened versions for radio or advertising have been possible for as long as tape has been around, with engineers able to ‘rock’ the tape to the all-important edit point long before anyone had the ability to see the waveform. When it comes to mastering, traditionally any non-intervention could be considered a good day at the office! Certainly the name of the game, if anything at all, was correction and subtle enhancement. Increasingly, mastering engineers, artists, and labels will all be aware of a wider shift towards processing happening further upstream than was once the case.
Why Un-Pick A Mix?
One thing that has certainly been off the menu up until now is actually replacing sounds in premixed audio. With a wider blurring of the lines between mixing and mastering in full swing, there is nothing to assume that this wouldn’t include the question of the arrangement itself. Up until now, the only consideration here has been whether or not the editor or mastering engineer has access to stems or even the DAW session itself. Those carrying out mastering duties will certainly have experienced the challenges arising from structural musical problems within the audio. Despite the multitude of techniques available in mastering, sometimes a fundamental change to the instrumentation may be the ideal fix. For the editor, removing a vocal, or replacing it with a top-line instrument would be a great luxury to have.
Stems Vs Magic
Traditionally, there has been only one way to remove or replace sounds within a mix, and this means access to the DAW session or to stems. This latter option is arguably the best one owing to the fact that the editor or mastering engineer isn’t trying to start from scratch! In a best case scenario, the mix engineer will have had one eye on this scenario having bounced out stems beforehand.
In the absence of stems, engineers can use a rebalancing or ‘un-mixing’ tool to get to the constituent parts. Up until recently, this has afforded broad-brush control of general balance, usually with a stem mixer GUI or similar. Going further, using a tool to completely remove a sound, and to subsequently re-export an entire mix without it affords the ability to replace audio back in the DAW. More recent tools, such as RipX Deep Audio allow the engineer to extract MIDI data to drive replacement virtual instruments back in the DAW where using the musician is not viable. Watch below how we use RipX Deep Audio to replace a double bass with an electric bass VI within premixed audio:
Is Software Perfect?
There is no doubt that for the time being, solo’d stems can suffer from audible artefacts. However when it comes to generating MIDI data from individual stems, the user only need do a bit of cleanup here and there to avoid any errant notes. For me, this has only involved the lightest of touches here and there. While the remaining audio can be affected by missing information ‘taken’ by the extracted audio, for simple rebalancing tasks, artefacts will be negated. Although it’s tempting to solo through all of the extracted stems just out of interest, the engineer shouldn’t be alarmed by any artefacts they hear. After all, we’re essentially reconstructing the original waveform on the way back out. With impressive audio quality that will only improve, musical replacements for a change of feel, or for problem solving are now entirely doable.