Stereo Phasing Automatic Alignment


I use Audacity 2.1.2 into Ubuntu Studio 16.04 LTS.

I wonder if there is some Stereo Phasing Automatic Alignment Plug-In, somewhere… ???

It is intended to align the typical old stereo recordings (from cassette tapes, more often).

I know we can do it with Audicity, splitting both channels and move forward or backward one of them vs the other. Yes, it is possible. But… when we have to perform this into more than 1000 songs… Then, you can see we have a serious… headache!!!

I’m not a programmer, but… In the analog audio world, it is achieved comparing the L+R vs L-R levels, while we change the input stereo channels phase (it was a mechanical action on the cassette recording/play-back head). So, into a full mono recording, the L+R sum channel level should be full scale output and the L-R subtraction channel level should be absolutely 0 (zero). In a full stereo recording, the L+R channel always should be more than L-R channel. Of course, it was intended to do without hearing the final sound (if we heard the final sound, it was so simple because the out-of-phase signal isn’t a “comfortable” sound).

I think this automatic action could be done into the digital audio world, because machines work so quickly than humans.

Well, if somebody knows something about this, please, let me know!

Blessings & Greetings from Chile!!!


In the digital world it shouldn’t be a problem. There are no heads to align, so why is it a problem that needs to be fixed?

If it’s an audible problem in already recorded files, and Ubuntu Studio does not have such a plugin, have you looked online? There are VST plugins that should be able to do this, and 2.1.2 supports VST plugins now, including in Chains which means you can apply the effect as a batch process to multiple files.

Perhaps do it 200 files at a time though, due to limitations in Chains.


but there’s not many VST plug-ins for Linux.

If you’re digitizing the L & R tape-recordings separately, (i.e. in 2 passes), they will inevitably be incurably out-of-sync when you combine them, due to the nature of tape. You have to digitize them at the same time to maintain synchronization.

True, but there are ways to run Windows VST plugins on Linux if the only option is a Windows VST (such as running the Windows version of Audacity under WINE). I have not researched whether there is something suitable in LADSPA or LV2.

Is this a task that Nyquist could do?


“Head misalignment” isn’t a problem with digital recording, so I’m not clear what problem we are trying to fix.

Neither am I, but in the absence of any response from the OP I can only assume (based on their comment about manually fixing the files) that they have files already recorded that display phase misalignment when zoomed in.


So you’re thinking of something like this?
phasecorrect.ny (2.08 KB)