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micing a djembe

Discussion in 'Recording' started by ThirdBird, Jul 15, 2009.

  1. ThirdBird

    ThirdBird Active Member

    i am putting a large dynamic underneath, an sm58 close to the head, and an AT2035 to capture room. how far away should i put the 2035 to prevent phase problems?

    thanks!
     
  2. Guitarfreak

    Guitarfreak Well-Known Member

    I'd go for either 6 or 9 feet, any further and it would sound too distant. This is assuming you follow the 3:1 phase cancellation law. I've also heard of people using the 2:1 phase cancellation law in which case putting it 4,6 or 8 feet would be good. I am still fuzzy on this myself so if someone could set me straight it would help the both of us :D
     
  3. FifthCircle

    FifthCircle Well-Known Member

    Most of those "phase cancellation" laws are BS in my opinion. Use your ears and place the mics where they sound good. Those "rules" are most applicable with close mic situations.

    I rarely deal with Djembes in studio situations, but I get them live regularly. The most success I get is usually an overhead mic- probably about 2 feet up over the top head. I prefer a small diaphragm condenser there. Under it, a dynamic that has a good low end is great. A 421, RE20 or other can work well to get the low end that is produced by the body and throat of the instrument. In the end, the best sound is in the room. A small dead room will not do the instrument justice. Larger rooms with good early reflections will allow the sound to develop. I'd probably go with 1-2 omni mics in the room 6-10 feet out adjusted to the sweet spot in the space. Whether you mix the spot mics into the room or the room into the close mics will depend on the style of music and the sound of the room (and what those room mics give you).

    --Ben
     
  4. Cucco

    Cucco Distinguished Member

    I wouldn't say that the phasing laws are BS. They're based on sound (pun...) physics. However, they're often over-simplified to the point of uselessness.

    I did just do a recording of djembe with guitar, bass and voice over top. The djembe was difficult for sure. Ultimately, I went with a ribbon (one leg of an AEA R88) over and pointing down (off axis from the head) at roughly 3-4 feet distance. Also, I came about directly off the side and aimed a brighter condenser in at roughly the same distance. The ribbon gave me to clean but not over accented attack while the condenser filled out the bottom and added a bit more "thwak" to the sound.

    Try many things and see (hear) what works.

    Cheers-
    J.
     
  5. BobRogers

    BobRogers Well-Known Member

    The 3:1 rule doesn't do you any good when you are micing a localized source like a djembe. It's meant for a large source like a choir. The basic idea is this: by keeping the mics relatively far apart compared to the distance from the source you ensure that the sounds that are loudest in mic A are relatively soft in mic B and vice versa. It doesn't eliminate phase problems, it just minimizes their effect. It's nothing really more than that. The number three isn't some scientific constant. It's just an empirical rule that balances minimizing phase problems with getting a unified sound.

    For two mics on a single source you simply align the two tracks. You could do this with a delay if you measured the two distances to the drum, divided each by the speed of sound, and delayed the closer mic by time difference...or you can just nudge the two tracks into alignment after you record.
     
  6. kmetal

    kmetal Kyle P. Gushue Well-Known Member

    Get your self a chart that relates frequency to distance and a measuring tape. so if your 58 is 6 inches away, your at note A#6 (on the keyboard) or 1864.66 HZ frequency. the put the condesnser 4.85 ft. away @ A#3 no phase cancellation....Then use your ears to fine tune the placement.
     
  7. TheJackAttack

    TheJackAttack Distinguished Member

    Are you stoned?
     
  8. kmetal

    kmetal Kyle P. Gushue Well-Known Member

    not yet... Can you please explain my mistake or why these mics would be out of phase?
     
  9. TheJackAttack

    TheJackAttack Distinguished Member

    So are you telling me the engineers at ORD last January 1st got out their tape measures and piano frequency chart when they made that beautiful CD/DVD at the Musikverein? What about the other 87 notes of the piano? Will they all be out of phase? What's special about A# other than many oboes start on A# before they lip the note down to match their idiot box-kind of like badly played bagpipes.

    Thirdbird didn't state he had phase problems. He has obviously read a bit about phasing issues and has also read the plethora of folk remedies for phasing issues. He was trying to be preventative unecessarily. Until such time as a problem actually exhibits itself. The best advice is to use one's ears for positioning microphones. They'll never be in the same spot twice-either your ears or the mics.
     
  10. jg49

    jg49 Well-Known Member

    My ears have been in the same spot for the last 54 years or so directly opposite each other on the side of my head, at least I thought so.
     
  11. TheJackAttack

    TheJackAttack Distinguished Member

    :cool: Nice.

    Of course those ears change position in any given room. And of course diet immensely affects the way we hear. Too much salt and protein causes the cilia in the ears to lay down. Or maybe that was me laying down after eating a bucket of the Colonel's finest.........maybe it was the Abbey beer I had with it.
     
  12. Link555

    Link555 Well-Known Member

    You may want to invert the phase (180 degrees) of the bottom mic, if the mics are facing each other.
     
  13. kmetal

    kmetal Kyle P. Gushue Well-Known Member

    No, i doubt they used frequencey charts, but i was there, so thats my best guess. As far as the A# that was just the note that coincided for the distance of.62 feet. Coulda been any distance your ears desire.
     
  14. TheJackAttack

    TheJackAttack Distinguished Member

    kmetal, I should have done this earlier today. Before I rode you all day long. Welcome to RO.

    /hijack
     
  15. kmetal

    kmetal Kyle P. Gushue Well-Known Member

    No sweat glad to be here, looking forward to learning alot in this forum. I appreciate you and everyone elses's input. Keep up the good work! Cheers!
     
  16. BobRogers

    BobRogers Well-Known Member

    kmetal-

    There are a couple of things wrong with using measurements to place microphones a integer multiple of wavelengths apart.
    1. A djembe is played to excite three different modes of vibration (bass, tone, slap). These each have their own fundamental frequency. Since a drum head has resonant frequencies that are not harmonic multiples, the wavelengths of these three won't be exact multiples of each other.
    2. Even if you have one fundamental in phase, the overtones will not be.
    3. I doubt that you can be precise enough in your measurements of distance from the djembe to the microphones (what point on the djembe should you measure from) to get the overtone waves to align.

    Far easier to record and then time shift one of the tracks so that they are simultaneous. Then all frequencies are in phase.
     
  17. FifthCircle

    FifthCircle Well-Known Member

    Since we are talking phase, I'll also put in a plug for the radial variable phase box. It is pretty amazing what it can do for a mix. Little Labs also has a similar box that is available as a plugin for the UAD platform.

    You can insert it on one or more of the mics in a collection of mics and continuously adjust phase to make things work together. I use the Radial most often when I'm mixing live sound and I have (for example) a mic on a bass amp and a DI. By adjusting the phase, you can get things to either line up perfectly and "pop" or not line up and "fuzz" out as I see fit.

    If you have 2 mics on an instrument that are facing each other, it is true that you'll usually phase reverse the underside mic. You see this most often on the top and bottom of a snare or front and back of a guitar cabinet.

    --Ben
     
  18. kmetal

    kmetal Kyle P. Gushue Well-Known Member

    Bob-
    Your points are interesting, especially the your first two points. I wasn't thinking correctly when i made the original post. i'm glad that i learned something new today. Coincidently i'm going to record a djembe tonight for a jazz tune i'm working on. This thread came in quite handy. i'm going to try using 2 mics (AKG 414, AT 3035) on it just for fun. And no i wont be using my frequency chart. lol. Bottoms up!
     

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