Room micing tips for drums

[slowcentury]

Hey I was wondering if you all can share some room micing tips for drums. I have been messing around with some stereo mic setups and getting decent results but any tips would be great. I'm really quite into the room sound for drums (Weston/Albini etc). The room I have been working in is huge 30'x50' with 20' ceilings. Any phase tips with placement? Height for the mics? Stereo vs Mono room mic etc? Thanks!

[Theo_Karon]

A starting point that's always worked well for me (especially in bigger rooms) is to have someone else (preferably someone good) play the drums and walk around the room until you find a spot that you like the sound of... mark it off and place your mic(s) there, tweak to taste.

[drumsound]

Use a mic cable and measure so that the two mics are equidistant from the BD. They should then be phase coherent to each other. Then check the coherency of the room mics to the other mics.

[palinilap]

On wood flooring I like the sound of sdc omnis placed directly on the floor. Seems like you get more of the good reflective information that way, and reduce harshness in the cymbals. I usually play with a highpass on that mic until it sits well with the kick, and experiment with nudging slightly to the right. But always note where it sat originally. What sounds awesome tonight can sound over-the-top tomorrow.

[mwerden]

Use a mic cable and measure so that the two mics are equidistant from the BD. They should then be phase coherent to each other. Then check the coherency of the room mics to the other mics.

You can run into trouble if you do this and end up with your mics in an equilateral triangle with the bass drum. Then the bass drum will be in the center of the image but it will likely be a phase nightmare.

A spaced pair sounds great, spaced omni can sound enormous in a big room like that. If you put them on/near the floor you might be able to get some low end buildup. You can also pick a spot that sounds great and put up Blumlein or similar - to me this sounds more real than a spaced pair but not quite as wide. Still, in a room as big as yours you could get pretty far away with a coincident pair and it would still sound pretty massive.

In a busy mix you can usually get a mono room mic to poke out more, effectively ending up with roomier drums than if you used a stereo pair. You can also put the mic into a corner and end up with some bloomy type low end for kick and toms. You can also put the mic behind a baffle - sometimes cures harsh cymbals, sometimes makes a muddy mess of things.

Another thing that can sound deceptively huge is if you put a mic close to the kit somewhere on the floor and spank the crap out of it (like 20db). Without compression it might sound close and dinky, but you can usually get some room tone and character out of it by totally abusing it.

[losthighway]

Yeah, I was going to say, sometimes mono room mic ironically has more depth, probably because it's easier to pull off, phase-wise. Compression is usually nice, sometimes to obscene degrees.

The thing I've learned about room mics is just how many anomalies there are, tens of spaces to put them where they sound amazing, and others where they just don't work well. Sometimes a room mic will sound impressive to me right up until the mix process and I realize something about it doesn't work.

Often times I really like it a little less than a third of the way across the room from the drums, somewhere relatively centered. Sometimes I use cardioids placed in such a way to under-emphasize the hi hat if possible. Sometimes I put a small baffle of rigid fiberglass as close to directly in front of the hi hat as the set up allows and then line the mic up with the baffle, pointing a cardioid so it's just peeking left of the baffle, more towards the rack tom than the covered hi hat.

There was a cool tapeop article on metal/hardcore producer Kurt Ballou. He built a hi hat vacuum out of a giant metal flower pot with absorptive material inside, there is a picture that shows the flower pot around almost half of the hi hats, removing much of them from the room mix.

My favorite room mic sound, in the end, have had less to do with placement and more to do with drummers that know how to make their drums attack, and resonate strong, and know how to be light handed on their hi hats, while being firm on the skins. That's a huge drum sound to me. Compress to hell and watch the drummer smile at playback.

[MoreSpaceEcho]

^^^^^^^^^^ that last paragraph there is the key.

[drumsound]

Use a mic cable and measure so that the two mics are equidistant from the BD. They should then be phase coherent to each other. Then check the coherency of the room mics to the other mics.

You can run into trouble if you do this and end up with your mics in an equilateral triangle with the bass drum. Then the bass drum will be in the center of the image but it will likely be a phase nightmare.

I find the equal spacing keeps the two mics phase coherent to each other. Then I check the pair's coherency to the rest of the drum mics. I spend a lot of time at the beginning listing to different mics against each other and the the whole of the drum-set. There are times when the rooms have the polarity reversed, and times when other things are. I'm very conscientious of the whole of the drum-set as I'm getting sounds. How each mic interacts, both close and far. Low cuts can also be useful, but not as a way of making up for improper phase relationships.

[losthighway]

I'm very conscientious of the whole of the drum-set as I'm getting sounds.

And so they called him drumsound.....

[mwerden]

I find the equal spacing keeps the two mics phase coherent to each other.

I'm all for keeping the mics equidistant, I almost always start that way too. But I try to keep more space between the 2 mics than between either mic and the kick. 3:1 rule and all that jazz. Whenever I've ended up in an equilateral triangle it's always been a problem, although I suppose it depends on the room you're working in.

[MoreSpaceEcho]

huh, that's interesting. i put the omnis on the floor about 6 feet in front of the kit, pointing at the kick drum spurs. so the mics are pretty close to each other. i don't like them wider than that because i find the kick/snare lean too much left/right respectively. been doing that for years and never had a problem with kick phase. i do remember once having them spaced out really wide and the snare was out of phase between them....

[mwerden]

Having either the kick or snare out of phase is usually the problem I get with the ol' equilateral triangle.

I've never tried your setup, but theoretically it works 6' out as long as the mics are about 2' away from each other. I've been doing the wide thing, but I'll try that out next time I'm recording drums. You ever stick a baffle between them?

[Nick Franklin]

I'm another advocated for the room mics close to the floor. Often Blumlein type arrangement with 2 ribbons.

I like what being down low does for the balance of frequencies in the drum kit. It really shaves off the harsh high end of cymbals and brings out the body of the kick and toms.

I'm usually 2-4 meters back from the front of the kit, depending on the room.

This said, I had success with a spaced pair of small diaphragm condensers the other day, way up high in the air, like 3.5 meters and about 4 meters from the back of the drum kit, pointing over the drummers shoulders.

[cgarges]

If you're going for the Steve Albini thing, here are a few keys to what he almost ALWAYS does:

There's almost nothing that I do all the time. But normally I'll have close mics on all the drums, a stereo mic to pick up the drum kit sound as a whole, and then distant ambient mics. The ambient mics are generally on the floor and triangulated from the seated position of the drummer, equidistant from the drum seat.

As normal practice, I combine multiple microphones for certain sounds. For example, I normally mic the top and bottom of tom-toms. I reverse the polarity of one of them because the two mics are pointed in opposite directions. But I'll sum those to one channel each, so there will be one track for the rack tom, and one track for the floor tom, for example. You just make sure the balance sounds good and then print that balance.

I'll often do that for the bass drum as well. I'll have a batter-side mic and a front-side mic, and I'll get a balance between those that sounds good and record that. I don't often use a snare drum bottom mic, but when I do, I'll do the same thing there.

I tend to use microphones as they were made and choose them accordingly. I'll put a microphone up, and if I like it I'll leave it, and if not I'll put something else up. Occasionally I'll think, ?I like that, but there's a little low-frequency rumble in there that's not going to be helpful,? so I'll roll that off. Most of the time, though, I'm using things flat, no EQ. In a typical tracking session, I'll probably end up brightening the top mics on toms to get a little more attack out of the toms, probably brighten up the top mic on the snare drum.

Almost any microphone you put on the snare drum is going to sound thick and meaty when it's right up next to the snare drum, but it may not give you enough of the impression of crispness. So I would expect to have to use an equalizer to brighten the snare drum, to brighten the top mics on the toms. But that would be about it.

Also, most of the time, the drummer's in the room by himself ? I'd say 80, 90 percent of the time. But it's not as if the drums are recorded and mixed on their own and then the band is added later. My normal working method is to have the whole band play, and then from the first playback, you have about 80 to 90 percent of the record. That way, you can tell very quickly if there's a problem, and if there is a problem, you can stop and fix it before you continue.

What do you use for the stereo-mic setup on the drums?

For the stereo mics, I use Blumlein or M-S setups for a lot of stuff, especially in front of the drum kit.

And the choice between the two is dictated by what factor?

Whenever I'm bored with one, I'll throw the other one up. I don't make a real distinction between them. Blumlein stereo is slightly hollow in the middle, so if I feel like the majority of the drum sound is going to be coming from the stereo microphones, I'll probably use M-S rather than Blumlein. Whereas if I feel like the stereo mic is going to be mainly an addition to the close-mic sound, then I'm more likely to use Blumlein. But that's a real subtlety.

Do you run into phase issues from using so many mics on a drum kit?

It's not really that much of a problem. If it starts to sound weird, I'll just move a mic. I'm not afraid of getting out of the chair and moving a mic. It can be more of a pain with more mics, but that would never prevent me from doing something that I thought was the right thing to do.

Here's Bob Weston on boundary mics:

By definition, a PZM (Pressure Zone Microphone), or Boundary mic, is an omnidirectional capsule against a boundary (floor, wall, metal plate that is built into a Realistic or Crown PZM).

A cardioid against a boundary would not be a PZM. I'm not sure what the pattern would look like. Try it out and let us know what it sounds like.

Typically, people at Electrical tend to only use 2 on the floor in a triangle with the bass drum.

Here's Steve on the subject:

An omni microphone on a boundary (the floor) has a hemispherical pickup pattern, with minimal change in sound quality across this hemisphere. A cardioid mic typically has lumps in its frequency response as the signal moves off-axis. In some cases, there is also a pronounced lobing of the sensitivity that varies with frequency. Also, given that the idea of the room mic is to pick-up the diffused room ambience, the less directional, the better.

Unless you figure out a magic sound-stopping raygun, it is unlikely that you will be able to isolate different elements of the room tone (different instruments, for example) once the room has been excited by more than one sound source, other than by using proximity to accentuate one thing or the other.

The boundary effect is exploited by the PZM microphone in a special way: The microphone element is very tiny, and placed in a small air gap above a plate. Since this air passage is so small, it is operating in a pure pressure mode, with flat phase response up to a very high frequency. This concept was presented at Syn-Aud Con in the 1970s, first manufactured by Ken Wahrenbrock and explained here: http://www.pe.net/~tmaki/pzms.htm among other places.

While all PZM microphones are by definition boundary mics, not all boundary mics are PZM mics. In the examples you give, there is no second boundary to create a gap. Well, there is, but it's the roof of the building, and that isn't really the same thing.

Crown (Amcron in Europe), makers of the PZM, made a directional boundary mic using a cardioid capsule on a mounting plate. It was called the PCC (an acronym for Phase Coherent Cardioid) mic. We own one here at Electrical, but it hasn't made its way to the mic page of the website yet, and from my experience, it's nothing to fight your grandmother over.

In the 1980s, there was a minor engineering fad to use cardioid mics as ambient mics, facing the reflective surface opposite the sound of interest (rear of pattern facing the sound source). Not being a big Robert Palmer fan, I never pursued this approach.

The ambient mics in the photos you see [photos from a Don Cabellero session, I think.-cg] are in A/B stereo, which has a poor stereo image from a localization standpoint (too wide to have good phantom center image), but bearing in mind that these mics are usually used to supplement the close mics, it's an appropriate choice. I often use an M-S pair as ambient mics, and even in this case, I will often have the stereo image wide enough to create a "hole" in the center for the same purpose.

Steve also frequently delays the room mics to tape, usually through an Eventide H3000. Here's some information on that:

The ambient microphones receive both a direct signal from the sound source (this is the first arrival of sound at the mic) and a diffused omnidirectional reverberation from the room reflections. The direct signal is acoustically slightly delayed from the close mic signal (as determined by difference in distance from the sound). Notice also that the delay is different for each part of the drum kit, as there is a non-trivial (at audio wavelengths) distance between the hi-hat and the floor tom, for example. These differences create a complex comb-filtering effect which can muddy or hollow-out the sound quality when the two signals (close and far) are added together.

Since sound travels (very roughly) at 1000 feet per second, one foot of distance roughly equals 1 millisecond of delay.

Now imagine a stereo pair of ambient mics on a drum kit at an equilateral distance of 10 feet from the center of the bass drum. The mic on the left side would be only 6 feet from the snare drum, while the ambient mic on the opposite side of the kit would be 12 feet away, but only 8 feet from the rack tom. This creates a mess of overlapping short delays specific to each instrument, and different for the left and right ambient mics.

You proposed delaying the close mics to match the acoustic delay, which might work for a physically small point source and a single ambient microphone, but would entail running the principal signal through a delay unit (which could degrade its sound quality), and would require monitoring and recalibration of the delay whenever climatic conditions changed. This is also ruled-out when using stereo ambient mics, as time differences are inherent in stereo recording, and it is also impractical when using several (many) close mics, as it would be a total pain in the cock.

Much easier is to delay the two ambient mics by a few milliseconds, which moves them out of the haas effect (the delay range where delays affect sound quality and localization rather than being perceived as ambience) and into the range of perceived ambience.

There is a logic to this from acoustic perspective as well. If there is a boundary 20 feet from you, its reflected delay time (from your position) is double the physical distance to the sound source (approximately 40 milliseconds), because the sound has to make a round trip out-and-back. Adding a few milliseconds to the acoustic delay inherent in a room mic seems to mimic this effect, making the ambient sound seem less muddy.

Here's Bob on the delayed room mics on Nirvana's In Utero:

It was a long time ago, so I may be completely wrong. But I'd guess 10-20ms on the delays. The room mics wouldn't have been turned up or down for the intro /stick-clicks. That would have been the room mic level for the entire song - no compression.

And more from Bob:

I don't want to speak for Steve. But I'm pretty sure that on the Nirvana and PJ Harvey stuff, there would have been no eq or compression on the room mics. Probably some ddl to tape.

Then when mixing there may be eq on the room mics. But still no compression.

I have a feeling that Steve probably never compresses an electric guitar track. Maybe occassionally bass drum or snare drum or overheads for a special effect.

The bass and vocals probably always get some compression to tape and then maybe even at the mix.

Stereo bus - no compression.

I've never seen him do drum bus compression.

But, I haven't been around during any of his sessions in a long time. Please correct any of my assumptions, here, Steve....just trying to help.

Hope this helps!

Chris Garges
Charlotte, NC

[Mane1234]

Use a mic cable and measure so that the two mics are equidistant from the BD. They should then be phase coherent to each other. Then check the coherency of the room mics to the other mics

I have a question about where exactly on the BD are we measuring from? Where the beater hits? Wouldn't you want the distance to be from the BD mic?