Time alignment / Phase alignment. Picks and Audio examples.

[tarnationsauce2]

Time, distance, and sound pressure… all very well defined variables, but also very hard to control variables. Luckily we have a DAW to correct some things that would take hours upon hours of mic placement in the old days. And well make the impossible possible, like making the snare mic coincident with an OH mic 6feet away.

In this example I used:
Kick - AKG D112
Snare – SM57
Under snare – CAD M179 set to cardioid pad engaged
Over Heads - Spaced pair 2x Stellar CM-1 set to cardioid (Apex 460 variant)
Toms - CAD M177 pad engaged

The audio is completely dry, no compression, no mixing, no panning, no EQ. Completely stock.

The ONLY differences between the audio files are time alignment, and phase alignment. This should help demonstrate how these variables affect frequency response, power, and imaging.

Here are some pictures of what an un-aligned vs. aligned waves look like. Phase, well that’s just a button on my DAW so it doesn’t show it graphically. But I’m sure you already know what it looks like when you invert phase.

Go ahead and load the files in your audio editing software to “see” the level difference if you can’t hear it. But I bet you’ll hear it.

The stock, untouched mix:
stock.mp3
The mix with only time alignment on all tracks, even toms:
time_align_phase_normal.MP3
The mix with time alignment, as well as phase inverted on under snare and kick:
time_align_phase_corrected.MP3

The picture below is split into 4 sections. I didn’t post pics of the toms, but it’s the same deal.
Section 1 Shows the stock time alignment.
Section 2 Shows the snare / bottom snare aligned to the overheads the overheads always should not be moved. Notice the under snare is inverted?
Section 3 Shows stock kick alignment. There is a lot less kick power in the overheads, that’s why it is so small. But alignment still helps. You can also see that the phase is pretty close to inverted here too.
Section 4 Shows the kick aligned to the overheads. Again, do not move the overheads, only move the kick track.

You'll also notice the overheads themselves have the snare a bit sooner on one side than the other, that can even be corrected. In this case it's a bout an 7 sample shift. Probably not even worth moving. This is best to align by better mic placement in relation to the snare.

[MadAudio]

I'll bet Dragon could free up some server space with all the lost threads that are hiding there somewhere......

[tarnationsauce2]

Anybody have a chance to check the sound clips out?

[guitarboi89]

erm....
WOW i dont get to record drums often.. but there gonna be sooo in time with each other next time i do

[Chris.]

I was actually just thinking about making a thread about this. I was wondering how exactly you should move things. All the close miked stuff to the overheads, or the overheads to the close miked things?


Actually here's another thing I'm curious about. If you have a room mic, what do you do with that?

[flatfinger]

And a gold star (or g square) for you. Nice!

[MessianicDreams]

Time alignment (and thus phase coherencey) can make a MASSIVE difference to your sound. it can be a bit of a painful process, but well worth it. Consider making a really transient noise just before the section of interest is recorded (for example, a stick click or something similar. This will allow you to roughly time align the kit.


For a closer, more exact time alignment go through each piece of the kit hitting it once or twice. Then you need to time align each close mic to the OHs (because they'll be different distances from the mic to the OHs, they're phase shift will be different).

However, if you're going to start getting really anal about things, you'll soon find that this doesn't work: the hihats will hit one OH sooner than the other, as will any piece of kit which isn't exactly in the center of the OHs..

[EdWonbass]

I just took a song I recorded and went back and lined up the tracks. I used the OH's as the starting point and brought the snare up to that and then the kick to match the OH's. You really have to zoom the crap out of you tracks before you can see how off they are. I think doing this really tightens things up. The snare now seems more focused and the kick has more punch.

While I think this is a quick and easy thing to do and to my ears it sounds better, I have been reading up on this for a week now and some guys swear by it and some guys say it's the devil.

For room mics I think it's better to leave them alone. Lining them up would defeat the purpose. At least that is what I have read. I have never tried to use a room mic. Never had a good enough sounding room and never had enough channels.

[RAMI]

Is time-alignment and all these adjustments something that only became neccassarry with digital recording? Or is this something people in the know have been doing since analog???

[MessianicDreams]

Is time-alignment and all these adjustments something that only became neccassarry with digital recording? Or is this something people in the know have been doing since analog???

These delays have always been present (they quite simply reflect the physical distance seperating mics). It's just become much easier to do it.