Auto Align Post is one of the most innovative new post production plugins on the market from the last few years.
It's basic function is to phase align two or more sources containing common audio material. This simple function can improve the clarity of audio recorded from multiple mic sources across a wide variety of applications. The most common use would probably be to blend a number of radio mics and booms on a film set. It can also be applied to acoustically recorded music say an acoustic guitar and a vocalist in close proximity (of course you'd aim to get the best result with mic placement, but sometimes in post you can improve).
Here are a couple of use cases that I've gone through recently.
Blending a hidden radio mic with a boom to get the best elements from both sources and create a full voice reproduction, but with a natural acoustic. Both were clean, usable recordings, but I found the hidden radio mic a little too chesty, as it was placed on the chest under quite a thick sweatshirt; and the boom was a little too roomy on its own. The resulting audio was clean, clear with plenty of presence from both the low end, generated by the lav mic, and air and space from the boom mic.
Blending acoustic guitar (DI & mic) and a vocalist
In a personal music project I also made excellent use of Auto Align Post to improve clarity in a vocal and reduce some phasey spill from a live acoustic performance. Having mixed the project to a decent level, I still wasn't overly happy with the way the acoustic guitar sounded from a blended DI and mic pair, in conjunction with a loud vocalist in close proximity. I aligned all of the sources to one of the acoustic mics and the cohesion of the mix improved instantly. A little more mixing through my Console 1 and I was super happy with the new result; a vast improvement over the original live mix and all of my previous mix revisions.
Fix: Take a distorted radio mic and distant camera mic and produce a usable final output.
In conjunction with iZotope RX tools for reducing clipping, I was able to bring back the distortion to a level where it was improved, but not really good enough to use on its own. The camera top mic was very roomy, in a not very good room. I used Zynaptiq UNVEIL to remove as much room as possible before it started falling apart.
Finally, applying Auto Align Post and perfectly aligning the two sources I was able to create a balance of the two that was actually surprisingly usable. It was a fascinating experiment, and I was hailed as a "magician" by my client. Of course in reality I'm simply a problem solver with a significant investment in some very clever software.
What these results show, more than anything, is the importance and power of phase alignment. Two aligned sources can create a significant improvement and boost in clarity. While the destruction that two out of phase sources can cause to so much of the useful audio material, let alone the unpleasant sound caused by two mics moving in phase alignment throughout a sequence can be very significant.
Auto Align Post is available directly from SoundRadix, or a number of other third party retailers.
Finally, please note that Auto Align Post is currently only marketed as a Pro Tools plugin but there is also a very functional VST version that works with Reaper, Cubase, Nuendo and other DAWs. It is in the Beta public testing stage, but I’ve found it to be very reliable while working in Reaper.
Version 2 is coming soon with full VST and ARA2 support, which will cost a small upgrade fee...