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Thursday 9 december 2004
Instructors: Eddie Ciletti and Paul Peterson

5.1 Drum Mic Set-up and comments. 

See layout and kick response of various mics at this link.

  • Drums backed up to the booth— that's drummer's ass by the booth door. 
  • CARPET under kit OK, but "trashed" hi-hat cymbal under snare to reflect snares into room.
  • AKG C-24 in booth
  • B&K omni for the overhead
  • Coles 4038 ribbon for the room (left and right of kit, positioned for max direct drum cancellation, rear of mic trapped with acoustic absorption panels).
  • Drum (piano) side of the studio deadened with packing blankets (and blankets removed from the opposite side of the room). See image at this link for location of acoustic panels.
  • Sennheiser MD-421 on kick 
  • AKG-414EB in omni (or any large diaphragm multi-pattern condenser mic) located in between the toms on the beater side of the kick.
  • I prefer the kick drum to have only one head (as was the case).
  • Shure SM57 for the snare and toms
  • Neumann KM-84 for hi-hat and opposite side of the kit. If these are not available, then the Shure sm-81. 
  • OPTIONAL ACCESSORIES: A dead ringer for the snare and alternate kick beaters (not needed for this session).
  • CONTACT edaudio@tangible-technology.com for more info
NOTE: Monitoring via Genelec 5.1 system only.

Hello!

My plan is to update this page and add links as things progress.  Considering the interest in 5.1, every issue is a potential topic.  Feel free to e-mail and contribute.

As for follow-up to thursday's 5.1 drum class (9 nov'04), I think the students should sit down with the tracks and attempt to mix and burn them to DVD-A. The software link is below. We should at least get a few copies of Minnetonka's Bronze for student use as the MAC version is now available. Unlike dolby AC-3, DVD-A does not compromise the signal AND, when data compression is required, MLP (Meridien Lossless Packing) is used.

http://www.minnetonkaaudio.com/

Paul is so right to suggest that students find their voice, their sound, and I believe that while my approach is not intended to be an "absolute method," the geek slant will certainly assist in accomplishing that goal. 

So much of what we did on Thursday leaves so many questions unanswered - questions that would be defined by the material, the arrangement and preference. For example, while all the students seemed impressed with the sound, one question concerned how other stuff might be made to fit on top of the drums. I can't emphasize the importance of arrangement over technology, my example being how to make a big fat acoustic guitar not get in the way of the bass track by having the guitarist play a chord inversion that made sonic real estate for the bass region. That's so much better than rolling bottom of the acoustic.

Of course, one of the answers is to make the drums smaller, but we should try to take advantage of 5.1's potential so that we, as "creators" set the standards rather than be forced to fit a poorly designed mold. I'd love to hear the student's sonic interpretation of the tracks -- or anyone else interested in playing with them -- as well as commercial 5.1 releases that would be a of interest.

The bass management issue is huge - we could spend a whole class in perception alone, hence my emphasis on the Loudness curve and the use of tools (such as the spectrum analyzer) so that we can all have a better idea of how things work (or why they're not working). That said, we shouldn't be afraid of bass, but we could all be better educated as to what is generating low frequency information and how to reproduce it.

Clearly, the spectrum analyzer proved that the kick had plenty of low frequency information - we didn't get to compare its sound on different speakers or systems - but if left as-is - rather than boost because it "seemed" thin by itself on the genelecs (without sub).  This is both a LOUDNESS issue as well as the fact that the kick mic generated low frequency information that is not easily reproduced by a single 8-inch woofer located behind the console, rather than on the meter bridge. 

NOTE: Generally, you can expect a low frequency boost of at about 3dB for each "boundary," a wall or a shelf, for example.  Placing an audio monitor on the floor and in a corner will produce the most bottom.  A free standing monitor will product the least bottom. Here's Genelec's explanation and guide to monitor placement.

I think believe the kick mic would certainly have worked in both 5.1 and stereo because all of the other mics did such a good job of capturing a completely different "kick textures," some enhanced by room ambience (more about that in a moment) but you can see the pix now if your like.   Thanks to Colt Leeb for providing the spectrum analyzer screen shots of the kick drum, as captured not only by the kick mic but the other mics as well.

The images very clearly proved every point I've made about the perception of bottom (or more precisely, the lack of same) and the loudspeaker's inability to reproduce really low frequencies. In this case, the kick's low frequency "bump" started at around 20Hz and extended up about to 200Hz - a range that extends from subwoofer to the main monitors. Below 63 Hz is not such a good range for a 30IPS, 24-track analog multitrack recorder.

In addition, the kick was helped by the room mics - the decay of the room elongates the attack and the resonance - I suspect spectrum analysis would also show a harmonic shift toward a more reproducible frequency range, and THAT would explain why the C24 (in the booth) made the kick feel so natural. The kick mic just provided a little extra support or reinforcement to what the other mics brought to the mix.

Below is a link to a basement recording I made with a neighborhood teenage trio. The drums were recorded with two mics - an omni overhead and another omni about 20 feet away, the distant mic is the source of all the low bottom.

http://www.tangible-technology.com/music/wsp/10_inst%20.mp3

Another way to look at recording and mixing kick (or any low frequency instrument) is to mix a bit of "house philosophy" with "scientific data." I understand that adding a little 80-Hz to kick is very common. The spectral analysis shows far less 80-Hz than 40-Hz, so this indeed would be ONE way to get it up. HOWEVER, what if we took the data and tuned the kick up instead? That would be worth trying in any class

The kick, as is, leaves a nice big whole for the bass - this is a good thing. Even though open E on the bass is 41.2-Hz, it is generally the second harmonic that is more easily reproduced on small monitors - what a ampeg B-15 does for bass and what we normally perceive as the beginning of the bass region.

A little education about "low frequency awareness" will make it possible to more predictably get the bottom you want.

that's all for now,

ec