Phase cancellations

[grandmsterflash]

Ive been recording an guitar amp cabnet, with an sm57 put in the back of the cab and a pencil condenser about a foot away from the speaker cone centre at the front. I know one of these mics should have the phase reversed, but i re-wired the sm57 myself and i dont know if the wires are the same polarity they used to be, so i dont know the phase. I cant really tell either when i pan them together, i move one waveform by 1ms and it sounds different, but not necessarily worse. Does moving by 1ms reverse the phase after recording? Is it suddenly noticeable when they are just right in phase?

 

[giraffe]

it's not necessarily noticeable when phase is just right, but you can sure tell when it's just wrong.

try to get it to sound as thin, canned, and all around crappy as possible.
then flip the phase of one of them.

do this on the amp (with mic placement), and not in your daw (in mono, and it helps sometimes to record, play back, and then move the mic, so you're hearing all recorded sound, and not the amp sound.)

 

[MessianicDreams]

Ive been recording an guitar amp cabnet, with an sm57 put in the back of the cab and a pencil condenser about a foot away from the speaker cone centre at the front. I know one of these mics should have the phase reversed, but i re-wired the sm57 myself and i dont know if the wires are the same polarity they used to be, so i dont know the phase. I cant really tell either when i pan them together, i move one waveform by 1ms and it sounds different, but not necessarily worse. Does moving by 1ms reverse the phase after recording? Is it suddenly noticeable when they are just right in phase?

Line up the waveforms by zooming in like a mofo. Make sure that the initial transient is firing in the same direction, ie they're both showing a positive cycle.


To test whether you've got the sm57 refeversed, the easiest way if you don't know the wiring is to set 2 mics up so that they're capsules are next to each other (pointing at the source), and make a sharp noise (like a snare hit or clap your hands, something with a big transient) and have a look at the waveform..