Re-amping - phase issues with two microphones.

[Thumbpicker]

I'm having a problem re-amping a raw guitar signal and mic'ing up my amp. So at first, I recorded my track with a condenser microphone and then re-recorded it on another track with a dynamic microphone using the same raw signal track. When I looked at the two recorded tracks in Logic Pro, I couldn't quite line up the phases over the entirety of the track because the peaks wandered slowly over the length of the whole song causing weird phasing issues when I panned my tracks - I could hear the audio shifting between the speakers. So then to try and solve it, I set the two microphones up at the same time and recorded both tracks in one go. But still the recorded tracks have the same problem - the peaks and valleys of the two tracks don't line up over the course of the whole track. It slightly goes out of sync. So for example if I line them up at the beginning, middle or end of the track they won't line up somewhere else in later or earlier in the track. Why would this be? Tearing my hair out.

 

[Ben Waylin]

Several ways to solve this, but an inexpensive one is to use a plug-in from Waves called InPhase.

 

[Thumbpicker]

Several ways to solve this, but an inexpensive one is to use a plug-in from Waves called InPhase.

So does in-phase change the duration of one track because I imagine for this to be happening the lengths of the tracks must be slightly different.... even though I can't fathom why they'd be different. Or it's like even though this is digital recording there is inconsistent tape stretch over the course of the track.

 

[Ben Waylin]

So does in-phase change the duration of one track because I imagine for this to be happening the lengths of the tracks must be slightly different.... even though I can't fathom why they'd be different. Or it's like even though this is digital recording there is inconsistent tape stretch over the course of the track.

The image I posted was captured from a recording I did, where one signal was a line-out from a reactive load (blue waveform) and the other was a Shure SM-57 on a speaker (yellow waveform).

The plug-in will allow you to align the two signals and eliminate any phase offset.

 

[Thumbpicker]

The image I posted was captured from a recording I did, where one signal was a line-out from a reactive load (blue waveform) and the other was a Shure SM-57 on a speaker (yellow waveform).

The plug-in will allow you to align the two signals and eliminate any phase offset.

I had another look at my waveforms and the dynamic mic recording is actually shorter than the length of the condenser recording. It's crazy. I can make the condenser wave start earlier and it ends later. So if I nudge the wave to correct the offset it goes out later on. I watched a vid on the plugin and I can see you can flip the waveforms and nudge but effectively I'm doing the nudging already. I would have to actually effectively shrink one track.

 

[Thumbpicker]

@PLX I worked out why this whole problem happened. I had flex and follow ticked on one of the two tracks which is weird because I didn't want it on. That's why the waveforms wandered between the two tracks and as soon as I saw that and unticked it the whole problem went away. I started cutting one of the tracks and manually aligning it all over the place. I was pulling my hair out.