Nudging Tracks To Compensate For Mic Distance?

[A-Barr]

Howdy all, here is a pretty cool link:

http://www.sengpielaudio.com/calculator-speedsound.htm

It allows you to calculate the speed of sound for a given air temperature and other factors.

You could roughly say that sound will travel at about 1 millisecond per foot.

So placing a mic 3 feet from the source will cause a 3 millisecond delay, more or less. Sure doesn't sound like much but if I had that kind of delay as a result of hardware latency, I would definitely nudge that track back the 3ms.

Is anybody doing this to comp. for mic placement? I guess it couldn't hurt, unless the extra brainy nerdlyness required to pull it off interfered with creativity or work flow. It occurs to me that nobody did this in the analog era and I don't hear any complaints, but if there's room for improvement in technique, why not?

[A.David.MacKinnon]

Some times I align room mic. Sometimes not. Depends on the sound I'm going for.

[chris harris]

it's good for effect. but, why put a mic 3 feet away if you don't want it to sound like it's 3 feet away?

Again, this can make for a cool effect. But, if you're doing this all the time with drums, I'd suggest that it may just be a hack shortcut to actually learning to place mics correctly to begin with.

[RodC]

I nudge if it sounds good, but mostly for DI vs mic.

Cracks me up the ppl who wont nudge a track, but they will flip the phase all day long....

[8th_note]

I'd suggest that it may just be a hack shortcut to actually learning to place mics correctly to begin with.

OK, I guess I'm a hack but I do this with my drum tracks religiously. It makes a huge difference and I'm very happy with the drum sound I'm getting.

My theory is that if you've got a great room you can get away with something like a Glyn Johns technique but if you're dealing with an average house room sound then it's best to eliminate the room sound as much as possible. I mic all the drums, I align everything to the snare (especially the overheads), I manually gate the toms with volume envelopes, and I often use three or four different reverbs and four or five compression settings within just the drum tracks (typically 7 or 8 ). It's a lot of work but I'm trying very hard to achieve a commercial sound instead of something that sounds like it was recorded in my basement.

[chris harris]

Cracks me up the ppl who wont nudge a track, but they will flip the phase all day long....

assuming you meant flip "polarity", these are two TOTALLY different things.

[chris harris]

I'd suggest that it may just be a hack shortcut to actually learning to place mics correctly to begin with.

OK, I guess I'm a hack but I do this with my drum tracks religiously. It makes a huge difference and I'm very happy with the drum sound I'm getting.

My theory is that if you've got a great room you can get away with something like a Glyn Johns technique but if you're dealing with an average house room sound then it's best to eliminate the room sound as much as possible. I mic all the drums, I align everything to the snare (especially the overheads), I manually gate the toms with volume envelopes, and I often use three or four different reverbs and four or five compression settings within just the drum tracks (typically 7 or 8 ). It's a lot of work but I'm trying very hard to achieve a commercial sound instead of something that sounds like it was recorded in my basement.

whatever works for you. but, it sounds like you're going around the block to get to your next-door neighbor's house. Have you really experimented A LOT with mic placement? Experimented with acoustic treatment of some sort? Even packing blankets? Seems to me like it's just easier for some people to "experiment" with the tracks in a DAW after they've been recorded, than to experiment with the actual sounds before they're recorded.

from your myspace page:

"I'm fortunate to have a large room with high ceilings and good acoustics."

If that's true, and you still have to do all that stuff to your drum tracks to make them sound good, then you're probably doing something wrong in tracking.

[MoreSpaceEcho]

moving tracks around in time is entirely different from flipping a polarity switch IMO.

i don't like it on drums at all, but i do usually line up the bass amp with the di. and sometimes if i have two mics on a guitar amp in essentially the same spot, if i zoom all the way in they'll be a few samples off from each other...lining those up i find usually makes the high end sound way better...

[chris harris]

if you line up all of the transients on your drum parts, you can still have phase issues.

[RodC]

Cracks me up the ppl who wont nudge a track, but they will flip the phase all day long....

assuming you meant flip "polarity", these are two TOTALLY different things.

They are TOTALLY different things but when you flip the "polarity" it can exibit the same problems canceling out certian freqs and such. You may be trying to get more out of one mic, but makeing the other one suffer.

Put a 3K sine wave in, flip the polarity, now pretty much the same as nudging the wave over half a wave lenght. It may sound good at 60Hz but when you flipped that mic did it cancel out, create a phase issue at 3K???

[A-Barr]

Very interesting replies and good advice, thanks!

I was thinking more for electric guitars actually, though of course this applies to anything...

I like to use a ribbon mic 3 or 4 feet back from the guitar cab, not taking any shortcuts with mic placement or anything, just sometimes the sweet spot for a particular mic in a particular track happens to be a particular distance. Phase issues are one thing, but I was wondering more about timing/performance issues when layering tracks.

Say you are a home recordist, doing your own project. You lay down an acoustic rhythm track, mic'ed 2 feet off the guitar, then play an electric track on top, mic'ed 4 feet from the cab, another 4 foot electric track and then follow that with a vocal 1 foot off and bass 2 feet off. By the time you get around to adding bass, you have accumulated a lot of delay between the initial track and where you are now. Especially if you aren't playing to a click, things could be getting pretty wishy-washy.

Again, I don't have any complaints with the way things are going now, I'm just doing a "thought experiment," wondering if others have implemented this to any noticeable improvements in their music.

Thanks again for all the responses!

[RodC]

Very interesting replies and good advice, thanks!

I was thinking more for electric guitars actually, though of course this applies to anything...

I like to use a ribbon mic 3 or 4 feet back from the guitar cab, not taking any shortcuts with mic placement or anything, just sometimes the sweet spot for a particular mic in a particular track happens to be a particular distance. Phase issues are one thing, but I was wondering more about timing/performance issues when layering tracks.

Say you are a home recordist, doing your own project. You lay down an acoustic rhythm track, mic'ed 2 feet off the guitar, then play an electric track on top, mic'ed 4 feet from the cab, another 4 foot electric track and then follow that with a vocal 1 foot off and bass 2 feet off. By the time you get around to adding bass, you have accumulated a lot of delay between the initial track and where you are now. Especially if you aren't playing to a click, things could be getting pretty wishy-washy.

Again, I don't have any complaints with the way things are going now, I'm just doing a "thought experiment," wondering if others have implemented this to any noticeable improvements in their music.

Thanks again for all the responses!

This is the type of things I nudge for the most.

Where I dont like it is for 2 guitar mics recording the same signal at the same time. If you didnt get the distance right the first time, nudging it dont seem to make it sound right.

I also nudge for overdubs to correct if the DAW does not have latency compensation, Sonar 6 does this pretty well but did not exist in 5. It can tighten things up if you know what that factor is. This has been discussed to death here and on other boards.

[MoreSpaceEcho]

but I was wondering more about timing/performance issues when layering tracks.

i think if you're talking about moving, say, a guitar track 2-3ms it's really not gonna make much difference, timing-wise. and i say that as a total Timing Nazi. 10ms you can hear, but i don't think 2 or 3 is really gonna mess up the feel. but an easy way to check is just copy a guitar track, move the copy ahead 3ms, and switch back and forth between that and the original, close your eyes and see if you can tell the difference.

besides, every guitar player in the history of the instrument plays too on top, so a little delay courtesy of the computer is a GOOD thing.

i'm kidding. put the flamethrowers down.

[chris harris]

Cracks me up the ppl who wont nudge a track, but they will flip the phase all day long....

assuming you meant flip "polarity", these are two TOTALLY different things.

They are TOTALLY different things but when you flip the "polarity" it can exibit the same problems canceling out certian freqs and such. You may be trying to get more out of one mic, but makeing the other one suffer.

Put a 3K sine wave in, flip the polarity, now pretty much the same as nudging the wave over half a wave lenght.

"pretty much the same" but, not exactly the same. but, lining up transients on drum tracks involves nudging more than a half or a quarter of a sample.

It may sound good at 60Hz but when you flipped that mic did it cancel out, create a phase issue at 3K???

this sort of makes my point. With several mics on a source, you're ALWAYS going to have phase issues somewhere in the frequency spectrum. Proper mic placement is intended to MINIMIZE these problems.

But, time aligning something is different from phase aligning something. It may make the drum hits sound "bigger". But, it skews the SIZE of the room. It's good for an effect. And, if this "big" drum sound, with little to no "room" sound is your signature sound, then go for it. But, this technique shouldn't be seen as a shortcut to correct phase issues or to get a realistic drum sound.

[Vogon]

It allows you to calculate the speed of sound for a given air temperature and other factors.

I made a spreadsheet to do this when I was bored once... but it calculated sample/distance too, a few permutations on the theme.
What I initially found so weird, is how much difference a *single* sample offset can change some sounds - esp. 2 mics on one cab. Well, I track at 44.1, so I s'pose that's part of the story.