Topic: Three omnis > stereo

[Gutbucket]

I dig omnis. Spaced, baffled with a traditional Jecklin disk or with not so traditional barriers, boundary mounted or otherwise, I like the big, open natrual timbre. I'm fortunate that for much of the music I record I can get them close to where I want them so they can work well. 

Recently I've been doing more open recording with three main omnis- two wider spaced and one in the middle, either all in a row, or with the center one a bit ahead of the other two.  I started doing this so I could play these back as three channel stereo (L/C/R) and that works really great, but I know not many here are not interested in doing that.  The motivation for this post is that I really find the center mic helpful in mixing to stereo. The ability to adjust the level of the center mic until it perfectly fills the center of the stereo soundstage is really cool and I've yet  to have a situation where I prefered no center at all.  For two channel stereo, the additional center mic makes the Left/Right mic spacing less critical and allows for wider spacings than I'd use otherwise without hesitation.

Aknowledging that using words to describe sound is like dancing about architecture, I'll try to describe a few things the center mic seems to help me with.  When playing back a recording and bringing up the Left/Right pair first then slowly adding more Center, I find that I gain the ability to control and balance:

• Solidity and even-ness across the entire soundtage.
• Clarity of timbre, especially for the important stuff in the middle.
• Depth.. sometimes adding center is almost like a zoom in-out control.  The right amount gives a nice 3-dimentional feel of depth and space to the stage, too little or too much is flat and more 2-dimentional.  I can push the middle back or bring it more upfront and in your face.

If you have three omnis and a way to mount them with enough spacing, give it a try.  You could also use two omnis with a center cardioid, which might be even better for a number of situations.  Just space them a more than you otherwise would.

I don't think many do this simply because recorders channels come in pairs.  If you have 4 channels you want to use them!  But three may mix to stereo better with less problems, especially if the mics are closer together than optimal.  Maybe use the 4th channel for a mono SBD patch if it makes you feel better. 

Any one here using the original three channel Nak box?  They came as sets of three.. they knew!

[WiFiJeff]

What spacings are you using?

I may be going to three channels to use the Josephson C700S, so this would be nice to try too.

Jeff

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Recently I've been doing more open recording with three main omnis- two wider spaced and one in the middle, either all in a row, or with the center one a bit ahead of the other two.  I started doing this so I could play these back as three channel stereo (L/C/R) and that works really great, but I know not many here are not interested in doing that.  The motivation for this post is that I really find the center mic helpful in mixing to stereo. The ability to adjust the level of the center mic until it perfectly fills the center of the stereo soundstage is really cool and I've yet  to have a situation where I prefered no center at all.  For two channel stereo, the additional center mic makes the Left/Right mic spacing less critical and allows for wider spacings than I'd use otherwise without hesitation.

Do you push the center one forward enough to have the line between the sides and the center be perpendicular to your primary sound target (in an attempt to maintain as much "on axis" phase coherency), or is spacing/clamping more of a concern?

[Walstib62]

Yes, I have run the Nak 3-mic setup. As you say, it helps to spread to L/R pair out and get better separation between the 3. Do you use the same type of mic for all 3? It might be interesting to match the L/R and use a different mic for the center. But I agtee with you. i find myself going more and more to omni's.
I just received 5 NIB (never used) NAK CP-3 caps yesterday. Man, those are gonna make some sick tapes. I'm expecting number 6 today.

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Is anyone using a laser sight type tool to measure distance from a given reference point?

[flipp]

Any one here using the original three channel Nak box?  They came as sets of three.. they knew!

Have used the MX100 a couple of times in one of my favorite local theaters. I set up on the balcony rail both times. Outriggers at 26' AB (in line with and pointed at stacks) with the center mic DFC. First time with cards as outriggers and an omni center. Set levels during sound check and it sounds killer. Would have been the best recording I made except for the promoter's wife and her friends sitting in the first row directly behind the center omni. They talked almost the entire show. I didn't need to know whos kid scored how many goals in their most recent soccer game nor what was on special at the fashion boutiques.    For the ~6 minutes during a 90 minute set when they were quiet the imaging is outstanding. The second time was omnis as outriggers and a card as center blend mic. Results were not good. Not sure why but haven't used this configuration again.

[John Willett]

Recently I've been doing more open recording with three main omnis- two wider spaced and one in the middle, either all in a row, or with the center one a bit ahead

You mean a "Decca Tree"?

[Gutbucket]

Last thing I did this way was recorded a couple weeks ago maybe 20' from the stage.  It was picking up both PA and direct stage sound.  I had ~40" between each mic and the center mic forward somewhat, maybe 18-20" or so.  Sort of the Decca tree thing with small diaphram mics.. in fact it was actually arranged in a tree!  I bought a new DAC/headphone amp from a member here and was listening last night to those raw recordings from the DR-680's SPDIF stereo mix out, using the 680's monitor and pan functions to hard pan channels left, right and center.  This is actually a 5 omni recording that has two additional omnis ~40" back as surrounds.  Mixing in the two surround channels panned hard left/right (no EQ on anything) added a spatial ambience that was nice for some portions like quieter solos with space, applause, audience reaction, sense of air and space, etc, but blurred louder more complex segments slightly.  Yet pulling up the center unequivocally put the shine on for the whole thing.  I've been digging adding center for a while, on both speakers and 'phones, but this was so unquestionably good it motivated me to post something about it.

This Thursday I'll do three at stage lip with no PA, all direct stage sound, with the mics closer together, maybe ~26" or so between each and more or less in-line.  That's a regular gig for a trio where I usually set them up straight across the front of the stage.  Last time I pushed the center one slightly closer and bit higher.  I've yet to come to a conclusion on whether having them all in-line or having the center mic forward works better for that.  Have to do more listening.  This kind of stage-lip setup is a more typical one for me.

My current feeling is that spacing the mics left to right is more important and effects the sound to a greater degree than whether the mics are all in a line or in more in a wedge.  Moving the center forward may be more about fine tuning.  I've seen some Decca trees that are triangular and as deep as they are wide, but I've not gone that far forward. Like most things for most around here it probably comes down to what you can set up from a practical perspective more than anything.

[Gutbucket]

Last spring I ran another Decca tree type arrangement (sans actual tree) which was also about a 2 meter total Left to Right spread, similar to the one a few weeks ago, but farther back from the stage.  Though it ultimately came done to what was practical to setup, I put more thought into what was going on along the lines of William’s Stereo Zoom techniques.  A one meter omni spacing renders something like a 20 degree Stereo Recording Angle for the pair and I had one meter between the Left/Center and Center/ Right pairs, so I pushed the center mic forward in an attempt to line up the edges of those two SRA segments to get what Williams’ terms Critical Linking between them.  Basically I pointed the Left/Center pair 10 degrees to the left and the Center/Right pair 10 degrees to the Right, so that their imaginary edges touched without too much gap or overlap.

I didn’t do a classic walk around test calling out numbers and knocking wood blocks to check how evenly the ‘linking’ distributed sounds arriving from various angles, but the recordings sound very nice - great width and ambience without any wide spaced hole-in-the-middle.

[SmokinJoe]

Have used the MX100 a couple of times in one of my favorite local theaters. I set up on the balcony rail both times. ....  The second time was omnis as outriggers and a card as center blend mic. Results were not good. Not sure why but haven't used this configuration again.

I ran omnis on balcony rail a couple of times.  Not good.  My guess is that in a big reverberant room you get the original sound from the front, then reflections from the sides, and then reflections off the back wall.  Omni's pick all this up equally well, but at different times.  If it was one note, or one hit of a snare drum it might sound like a cool echo.  But when it's a constant flow, it's just becomes sounds tripping over each other time wise.

I don't think gutbucket's really talking about a situation like that.  He's thinking stage lip, or other situations where the reflections aren't a big problem (outdoors).  Too wide a spacing on a pair of omnis sometimes gives you a "hole in the middle" and he is saying you can dial in that hole, or lack thereof,  just the way you want it in post if you have 3 mics recorded to 3 tracks.  It's a good idea, I'll have to try it some day.

[Gutbucket]

Yep, that's pretty much the gist of it. But its more than just control over 'filling the hole' that has me charged up about it.  It's that elusive quality of 'air' and 'prescence', and the seemingly contradictory 'wide but super solid' thing.

You are correct, everything I've used this for indoors has been on-stage or just at stage lip.  The wider spaced Decca tree type setups from a couple weeks ago and earlier this spring were both outdoor concerts with good sound and without problematic rooms.

If it was one note, or one hit of a snare drum it might sound like a cool echo.  But when it's a constant flow, it's just becomes sounds tripping over each other time wise.

That's very similar to what I was hearing last night when playing around with mixing in the two surround omnis.  It got blurred with sounds tripping over each other in the more active sections (heard it most in the drum & cymbal transients) but lent a nice lush but subtle reverberant 'air' when things got more sparce.

[cashandkerouac]

for outdoor shows i really love the results i get from omnis.  i'm going to a run of outdoor shows in september/october and bought a new bar that will allow me to use the exact setup that you are describing.  however, in lieu of a third onmi in the center i'm considering a cardioid pair in between the spaced omnis.  i'll probably try both setups and see which configuration my ears like better.