Topic: 4-Mic Configs

[BayTaynt3d]

Well, now that I'm running the R4 in full swing, I thought four-mic configs might be a worthy topic for discussion. Let me start by saying I've learned tons from the TS Matrix PDF, which hammers through loads of matrix configs involving an AUD pair and a SBD pair of channels with all sorts of AUD combos from PA sweet spot to on-stage card configs (coincident and near-co) to on-stage omnis. I've been using and experimenting with those techniques a ton in the past few weeks, and have gotten some incredible recordings from them. However, for this specific thread, I'm (personally) more interested in discussing 4-mic configs, not 2-mics and the board.

So far I've played with four main combinations:
(1) Standard stereo pair on a stand plus one omni in the middle (two cards on my AKG bar, plus an omni on the center 5/8 thread). This is only 3-mics, but whatever...
(2) Standard card pair on a stand (XY, DIN, whatever) in PA sweet spot, plus two wide split omnis on stage on different stands
(3) Standard card pair on a stand (XY, DIN, whatever) in center on-stage, plus two wide split omnis on stage on different stands
(4) Standard card pair on a stand (XY, DIN, whatever), plus two other mics in various locations for reinforcement of weak-balanced instruments

I tape a lot of small jazz ensembles with four instruments or less, and for that, option #4 has been working out really well. I setup XY like usual, then strategically place the other mics to reinforce things I'm worried will have bad balance in the mix. For example, one venue I tape at has the piano way in the back of the band's setup with the lid facing away from the stereo pair -- it's always hard to hear and sounds kind of crappy on the tape. By putting a mic back there behind the lid (omni or card), I can totally bring in the piano like I could never do before. Also, I'm finding the XY on stage with split omnis on seperate stands several feet or more to the left and right of the XY stand gives me some great options in post (option #3). Sometimes the XY pair is plenty by itself, but it seems when I bring in even a little of the omnis, it just sweetens up the whole mix real nice. One thing I haven't done yet is just mic each player/instrument seperately with cards (let's call that option #5) -- just stick a card in front of each performer and mix/pan in post to get the stereo image -- I'll probably try that soon...

Anyway, I was curious if anyone else has played around with these or other 4-mic configs, and what your experiences have been and if you have any suggestions for me to goof around with. I was also thinking about running a variant of option #3 where I would use split cards (instead of omnis) at the sides of the stage, but I wasn't sure if that was just a stupid idea or not. Seems like that could help me with my image in post, but maybe it'd suck?

What do you think?

[KLowe]

I'd love to hear some of your samples.  THis sounds awesome.
Specifically the cards plus omni...three mic mix.
been thinking about this alot.  (cause that is all I can do right now)

Are there XLR to RCA adapters.  I'm only running a UA-5 and I think I could mix on the fly.

I think I can do this now.  (not sure...first one but T+ for you).

KLowe

[BayTaynt3d]

I'd love to hear some of your samples.  THis sounds awesome.
Specifically the cards plus omni...three mic mix.
been thinking about this alot.  (cause that is all I can do right now)

Are there XLR to RCA adapters.  I'm only running a UA-5 and I think I could mix on the fly.

I think I can do this now.  (not sure...first one but T+ for you).

KLowe

You'd need another preamp for your third mic.

[RebelRebel]

the main ones I use are either
1.) 3 omnis across the front of the ensemble. This technique is used by telarc(the big classical label) a lot. Helps to sidestep the "hole in the middle" that can come with spaced omnis.

2.)meter bar, with a mounting post in the center. the outside mics are Omnis(spaced 1 meter), the middle mic pair is blumlein , ortf, or M/S. So far I like this one the best , with blumlein in the center. the two omni outriggers help to solidify the center image.

3.) Jecklin Disc in the center of the meter bar, with Cardiod Outriggers.

4) Decca tree---probably not practical..but worth mentioning.

for an excellent meter bar, look no further than Mr. Brissette. Master craftsman, great guy. I think he is building them for folks by request?? 
http://taperssection.com/index.php?action=profile;u=569

[BobW]

interesting material, interesting methods

I like Blumlein in a very quiet room.
Much bigger soundstage than coincident cards

[BWolf]

Check this I just stumbled upon while looking for some info on M/S.....

http://www.posthorn.com/S_doublems.html

[BayTaynt3d]

Check this I just stumbled upon while looking for some info on M/S.....

http://www.posthorn.com/S_doublems.html

Pretty sweet! Only need three mics too, two of which most of us already (pair of cards). Add one F8, and you've got surround sound!!! 

[grider]

I did for STS9 on 12-30-04 and 12-31-04; fellow taper and I ran four 483's, two in the center in a DIN right angle, and the other two spilit about twenty five feet apart and pointing at the stacks; worked out well, they are on the archive, the second night has been downloaded more than 15,000 times, I'd call that a stamp of approval of some sort

[guysonic]

There's another type of 4 mic setup being currently being used for two field recording projects.  Their mic system is made by my Sonic Studios company and is being used in two configurations; either HRTF person headworn, or 'LiteGUY' baffled using 4 carefully aligned matched onmi capsules of 5-45,000 cycle wide frequency response. 

One project is being done by Sound Ideas 'Immersion' division in Canada to produce surround sound ambient library. 
Samples of their offerings athttp://www.sound-ideas.com/immersion-surround-demo.html


The other is being done by Steven Feld with the Edirol R-4 for documentary-style sound compositon of bells, ethnic music, and associated ambients in various worldwide locations.  His use of the HRTF 4 channel mic system is recent and ongoing at this time so no samples available until sometime maybe this fall.   

An article about his project is at: http://preview.emusician.com/em_spotlight/time_bells_steven_feld/index.html 

The HRTF 4 channel mic array is shown below, and can be personally headworn, or placed on a specially designed HRTF baffle called the LiteGUY.  The special 4 channel preamplifier that works best with the R-4 and this mic array is also shown below.

The advantage of HRTF seems consistent imaging regardless of subject type or distances.  True HRTF baffling, with specific mic alignments, records exactly what can be heard by a person standing at the mic postition.  This is not true of any other type of mic array configuration that produce effects or interpretations of the sound field, recording sounds in an inconsistent (although at times interesting), incoherent fashion that does NOT match our own perceptions of multi-dimensional sounds.

[balou2]

I LOVE doing multiple (4+) mic stuff.

I do this regularly when the Sons play and use something similar to your #3:

- 184's on stage, center, 3 ft stand
- split omnis, one stage left, the other stage right.

I too found that most of what I wanted I could get form the 184s, but when I started including the split omnis the sound opened up...like maxing out an externalizer.  Really great openness and spread.  Generally, I put the 184s XY, but angle the pair about 20 degrees up.  This seems to contribute to some of the openness as well, and helps on a the larger stages.

A couple variations I tried:

#1)
- same 184-pair set
- split omnis, still on left and right, but at the back portion of the left and right point at each other (i.e. across the stage).  This picks up a bit more room, which I like, but still maintains the stage clarity.  It's a real personal opinion, but I've enjoyed it.

#2)
- switched places, and ran omnis on center stage, XY etc...
- spread 184's to left and right (tried both facing each other and interior pos.)
I did NOT like this...for obvious reasons.  I think I just wanted to hear how bad it would be.  Too much loss in consistency.  I like the paired omnis, but the cards spread didn't do it for me.  I've not yet tried running a small card spread at center stage.  That might be o.k..

#3)
I only tried this once, and damn it if I didn't lose the source DATs during my last move.
- hung the 184s above the band, triple-axis centered, XY, 10 degree incline (large stage, with HIGH ceiling
- split omnis, 2 foot stand each, stage left and stage right, perpendicular axis cross at center stage, 30 degree incline.
The results on this tape were friggin' amazing.  I compared the sound to a Heally UM circa '87...really nice, with awesome presence, and very desireable amount of house sound.