New jargon - redefining the language of mic placement

[Scodiddly]

It occurred to me the other day that we tend to use techniques that really aren't very well defined. Mostly I think this is because these are new techniques, rooted in some interesting new possibilities that come with digital recording or even just digital consoles.

Let's say you put a DI and an amp mic on a bass... you might buy that little box that adjusts relative phase, or just slide tracks in your DAW to line them up for phase. In a live setting you might use a delay on the DI channel to keep the phase the same between the two inputs. Or take the classic Glyn Johns drum mic technique - as I understood it, an important component is making sure both overheads are the same distance from the snare. That's because in the old days they didn't generally have the ability to make subtle changes to the relative time between tracks.

Imagine that you have an overhead mic and a close snare mic, and that you delay the snare mic to be in time with the overhead. Now how do you define the relative placements? One mic has a specific X, Y, and Z placement, the other also has a specific X, Y, and Z placement. But there's another parameter here, T for time. Each mic can now have X, Y, Z, and T placement.

So, we now have 4-dimensional mic placement, because T is now something we can independently control.

More classic techniques - say there's a "room mic" 20 feet away from the kit. It does get a bit of a different mix and some room reverberation, but it will also get the drums delayed by 20 feet (roughly 20 milliseconds) into the mix. Imagine instead that you put the same mic right in the middle of the kit and then delayed it by 20 feet. Sure, people in the past could rig up some way of doing that with an external delay unit, but since adjusting relative time is now as easy as adjusting treble or bass, I think it's important to recognize that fact. And for the sake of stimulating better communication, to come up with language to properly define this way of thinking.

So there you have it - 4D mic placement.

[RoyMatthews]

Don't we already indirectly refer to time when we mention the distance? Is there a need to say the drum room mic is 20' away and 20ms later?

[Scodiddly]

I think the point I'm trying to make is that we should be thinking of distance not only in physical space but also as artificially delayed. So delaying inputs/tracks isn't just a mixdown technique, but should be thought of as part of the initial microphone setup.

So going to the example of a "room mic" being right in the middle of the kit - that could be a standard setup approach, such as putting an omni right in between the kick and snare, delaying it X milliseconds, and washing it in reverb. A "4D" mic setup to get around not having a 20 foot long drum room.

(I haven't actually tried that, mind you. It's something I thought up while out for a walk today, but it's a good example of what I'm trying to describe)

To put all this another way, I've started looking at mic setups as having a possible "wormhole in space" component. A mic can be physically very close to a particular source, which determines what mix of sources it "hears", but if delayed some amount it's as if there was a 4th-dimension wormhole that allowed a perspective very close to the source while having the time alignment be very different.

As you say, we can already describe doing this. I'm interested in describing it in a way that maybe stimulates creativity in mic placement and processing.

[RoyMatthews]

Ah, got it. Interesting.

Edit: Maybe in relation to a 'zero' point? That is all mics on a given instrument are (x) distant (and (x) ms time wise from a set point instead relatively to the point they're aiming at.

[Scodiddly]

So going to the example of a "room mic" being right in the middle of the kit - that could be a standard setup approach, such as putting an omni right in between the kick and snare, delaying it X milliseconds, and washing it in reverb. A "4D" mic setup to get around not having a 20 foot long drum room.

Oh, and because this is TapeOp, add the following to the above quote:

"...and then squash the crap out of it with a cheap compressor."

[thunderboy]

So going to the example of a "room mic" being right in the middle of the kit - that could be a standard setup approach, such as putting an omni right in between the kick and snare, delaying it X milliseconds, and washing it in reverb. A "4D" mic setup to get around not having a 20 foot long drum room.

Oh, and because this is TapeOp, add the following to the above quote:

"...and then squash the crap out of it with a cheap compressor."

Ah. NOW I understand!

jt

[firesine]

So going to the example of a "room mic" being right in the middle of the kit - that could be a standard setup approach, such as putting an omni right in between the kick and snare, delaying it X milliseconds, and washing it in reverb. A "4D" mic setup to get around not having a 20 foot long drum room.

That's a cool idea, I'm definitly gonna try it!

[ashcat_lt]

I'm here for you man.

I just need to know: did you eat the red stuff or the blue stuff?

The truth is that your T = d / v .(yes, that's a bold, underlined, period)

The difference between your mic in the middle of the kit and the one 20' out, not counting positional differnce in intra-drum balance, will be the relationship between the direct and reflected sound. That, and a bit of high-frequency attenuation. Some overall volume loss, since there's so many more molecules to move. Maybe a (sometimes signicant) difference in the low-frequency response thanks to standing waves.

Put a speaker in a room. Play back anything and record with a mic right in front of it and one 20' out. Now nudge them together, and flip the polarity on one of them. Theoretically, you'll hear almost nothing but reverb.

Try the opposite. Duplicate a track. Nudge one of them out 20 ms without changing anything else. Likely you'll get that "sterile, digital" delay effect. It might work for some circumstances, but it won't be anywhere near the same as a distant mic in a great sounding room.

And then smash it with a cheap compressor and everybody will think you're a genius.

[Scodiddly]

The difference between your mic in the middle of the kit and the one 20' out, not counting positional differnce in intra-drum balance, will be the relationship between the direct and reflected sound. That, and a bit of high-frequency attenuation. Some overall volume loss, since there's so many more molecules to move. Maybe a (sometimes signicant) difference in the low-frequency response thanks to standing waves.

All of which can be somewhat recreated in various ways. Using a separate mic from the other drum mics, and adding artificial reverb as I mentioned above. Atmospheric effects can be simulated with EQ, if even needed since a separate room mic would be subject to creative EQ during the mix anyway.

But hey, this is more of a thought experiment and an example of trying to define some language to describe such techniques. The bass DI/mic example would be pretty hard to debunk.

And then smash it with a cheap compressor and everybody will think you're a genius.

"The important thing is that I had an onion tied to my belt, which was the style at the time."

[Randy]

So Scodiddly, what you are saying is that in terms of quantifiable and adjustable parameters in the realm of recording, "Time has come today."

(sorry, it seems like every thread needs at least one quote from a song lyric and that was too juicy to not bite.)

[JGriffin]

(sorry, it seems like every thread needs at least one quote from a song lyric...

I think this is our first foray into the Chambers Brothers though.

[Wagz]

Sounds interesting to say the least, could be fun to experiment.

I think it all depends on what your after. The reason you place a mic 20' away from a kit is because you want the room noise and to capture the kit as a whole. Trying to recreate that by sticking an omni close to the kit sounds to be more trouble than its worth. Why would I want to do that, then play around with reverb and filters when I can so much easier stick the mic where i want to in the room.

Now if your looking for something different and trying to get a different sound, play with some effects, then it may be worth experimenting. It might be fun to try doing both on the kit. On a breakdown put some crazy delay effects on the close omni, then fade it into the room mic.
But if trying to recreate something, why?
knowing how to recreate it when you don't have access to a room that size is the only reason I would do that. then it would be good to know how.

But I would much rather try to capture a real, natural sound from an instrument than trying to find a way to recreate it later.

[Scodiddly]

Let me reiterate that I am not selling a particular microphone technique. I'm selling a way of talking about microphone techniques.

Here's another example:

A few years ago I did sound for a bluegrass group, a group who used a variation of the "one mic" technique. They had a LDC up on a stand in the middle "for vocals", and a much smaller mic a bit lower on the same stand "for instruments". All this got set up in a hurry because they were the opening act, so we didn't realize until their show was underway that there was some rather nasty comb filtering going on. Gross violation of the 3-1 rule. So, what to do? The LDC was aimed too high to get a decent balance of instruments. But because this opening act played rather too long I had time to think about it, and eventually figured out that I could use an effects processor to delay the lower mic by a few milliseconds. This had the effect of shifting the mics "apart", at least as far as phase was concerned, and significantly reduced the comb filtering. Artificial distance, basically.

[ashcat_lt]

...delaying it X milliseconds, and washing it in reverb. A "4D" mic setup to get around not having a 20 foot long drum room.
...

For some reason (probably alcohol related) I read this as "4AD" last night. I was all like "Don't you be dissing on Ivo!"

I have to admit that I'm still not exactly sure what you're getting at. I feel like such a downer coming in here and raining all over your stuff, but I do have to mention that the 3:1 rule has more to do with relative volume than time.

What you likely accomplished by delaying the lower mic was to actually bring them into closer phase coherency, bringing them closer together in terms of the instrument bleed. That, or you pushed them so far apart that they no longer correlated enough to cause comb-filtering. At that point, though, it should have been noticeable as a slapback echo type sound. It is great, however, that you had the insight and the guts to at least try it. Even better that it worked!

[Scodiddly]

What you likely accomplished by delaying the lower mic was to actually bring them into closer phase coherency, bringing them closer together in terms of the instrument bleed. That, or you pushed them so far apart that they no longer correlated enough to cause comb-filtering. At that point, though, it should have been noticeable as a slapback echo type sound. It is great, however, that you had the insight and the guts to at least try it. Even better that it worked!

Ah, but that's entirely my point here. At the time I hadn't yet thought up this crazy "4D mic placement" thing. But once you start thinking that way, all sorts of interesting ideas start flowing. Take the drum room mic... setting aside whether or not it's possible to simulate one with a close mic and delay, how about applying negative delay to a real room mic? Slide that track back in the DAW 20 milliseconds to bring it up close to the kit. The reverberation won't change, but you'll get rid of any 20 millisecond delays in whatever direct kit sound is reaching that mic.

Think about the history of recording, and how various techniques sneak into the production of music and change what we expect of music. Listen to Van Morrison's "Moondance" album - there's acoustic guitar in front of horns, which was possible in the Victrola days but so implausible that nobody would have arranged music that way.