Topic: going to 4 mics - Nuemann & Nakamichi should I mix omni & cardoid

[royjratc]

Just bought a pair of Nuemann KM 184 to replace my Nakamichi CM-300 which I had always used with the CP-1 (cardoid)cartridge - Since I'm using a Tascam DR-70D I would like to record using all 4 mics - My question is if I should run the Nakamichi with the omni CP-2 cartridge since the Nuemann are cardoid?

I normally record in a small blues/rock club about 30' back from the stage 7" in the air with my mics pointed at the stacks - I do outside festivals as well - And yes....I'm new to all of this Roy

[morst]

I would be inclined to run your CP-1's and the 184's side-by-side once or twice as a comparison, just so you know what you have now, then branch out from there.

If you have Omni caps, sure, try those instead of the cards on the Nak300's some time.

You might want to mix sources. You might not. Nice thing about having 4 channels is that you can decide later!

Enjoy, experiment, take chances, and please let us know how it goes!
 

[F.O.Bean]

Enjoy, experiment, take chances, and please let us know how it goes!
 

Exactly! I LOVE having the mk4 cards and mk41 supercards running 4 channels, and I can always decide to do a 4 Channel DAUD Matrix if it came out good enough and my capsules were vertically and horizontally aligned

[royjratc]

Thanks guys! I'm heading out Sunday to catch a band and I'm planning on running all 4 - Sometimes the room is quite empty on Sunday- no chatter - If so I'll run my omni catridges - If it's packed I'll run with the CP-1 The band does have a sax playing so I may try to aim a mic right at him instead of just at the pa

[jnorman34]

The boojum/jnorman array is a great to cover your bases in any venue.

[detroit lightning]

When running 4 channels like this w/ the same recording device, how easy is it to matrix them? Thinking about doing the same thing with a Roland R26 - but have always been freaked out by the post-process work in terms of syncing/mixing two sources...

[morst]

When running 4 channels like this w/ the same recording device, how easy is it to matrix them? Thinking about doing the same thing with a Roland R26 - but have always been freaked out by the post-process work in terms of syncing/mixing two sources...

Somewhere between not hard and easy.

If the sources are time-aligned or really close, like on the same mic stand, you might not even have to do anything except fudge relative levels.

I'm a big alignment buff, but if you're within 10 milliseconds, the ear won't hear it. 20 ms is probably ok, but let's be tight. (10 ms is 0.01 sec which is 480 samples at 48kHz)

The time error that sounds the strangest is if you let the crowd mics get AHEAD of a soundboard feed.

I have a widget on my mac called Sound Reference which calculates that 20 ms is about 11 feet at room temperature. Mics on stage (perhaps from a soundboard feed, or maybe stage lip pair) more than 11 feet from the ambient pair will have to be moved over in a workstation for proper sync, but that's on the EASY side. 

PM if I can advise you on specifics, or walk you through it by phone. This week happens to be good for me. Slow work season. 

[Gutbucket]

Omnis need sufficient space between them to perform their best when recording from the audience.  To make the most of your good gear, figure a way to space the omnis at least 2'  to 3' apart if you can.  This simple setup geometry aspect is quite often the most challenging part of using omnis, and commonly compromised. 

If you want to play around with mixing the omni and cardioid channels together, space the omnis at least 3' or more and setup whichever 2-channel stereo cardioid configuration you like in the middle in between them.  Play around with different cardioid microphone configurations to figure out what you like best in combination with the omnis.   It's quite likely that you'll end up preferring a different cardioid configuration in combination with the omnis than what you would choose if using just the cardioids on their own.  Even if you don't care much for X/Y stereo using cardioids by itself, give it a try it in combination with the spaced omnis.  The two complement each other very well, combining to help each other where the other is weak without undue interference, and 3' spaced omnis + PAS X/Y cardioids (pointed at stacks) can be a super useful combination for audience recording.

[Gutbucket]

But run a few side-by-side comparisons of both sets of cardioids in identical stereo configurations as morst suggested, before jumping into omni configs and 4-channel combinations.  That will give you a solid basis of comparison for the differences between the Nak and Neumann cardioids.  It's also likely to be easier to setup than figuring a way to get the omnis 3' apart (or more). 

Give the spaced omnis plus center x/y pair thing a try for an outside festival where the spaced omnis should really shine.  And once you've figured out a way to rig a sufficient omni split, go ahead and try the same setup inside.  The omnis will be more room-acoustics dependent, so you might just end up using less omni level and a bit more X/Y level in the mix depending on the room acoustics and audience.  If you discover that the acoustics simply won't support using omnis from your recording location in the room, try substituting the other pair of cardioids for the omnis and keep the configuration the same: Forward-facing A-B spaced cardioids + PAS X/Y cardioids in the middle.  Then experiment with angling the A-B spaced cardioids increasingly wider while leaving the center pair PAS.  The better the acoustics, the further apart you'll likely be able to point the A-B cardioids.  Outdoors, and if the acoustics are good indoors, this 4-cardioid spaced/coincident configuration becomes optimized in many ways when the the A-B cardioids are facing directly to either side, 180 degrees apart.  That can be a very useful alternative when you are unable to space the omnis 3' or more.   Might work well inside too, although depending on room acoustics you may find you need to use less angle on the A-B mics indoors.  I suspect you'll probably want the brighter sounding cardioid pair in the center and the darker/bassier pair spaced, but try it both ways.

[royjratc]

Thanks Gutbucket - To date I've just been running all 4 as cardoid on a 2' bar - Just did Grey Fox & got some nice results! Looks like I should get a bigger bar to try the omni! The Naks definitely are bassier and I've been running them on the outside with the Nuemans on the inside. At Grey Fox I pointed everything at the stack - went to another festival where I had the Nuemans in (as close as I could get it) XY pattern. Thanks all for the suggestions - I'm brand new to this hobby or "obsession" as my wife puts it!

[heathen]

Thanks Gutbucket - To date I've just been running all 4 as cardoid on a 2' bar - Just did Grey Fox & got some nice results! Looks like I should get a bigger bar to try the omni!

I'll suggest an idea that is not my own creation, but may suit your case: space the omnis vertically.  Until you get that bigger bar, maybe run your cards how you usually would and then clamp the omnis a couple feet lower on your stand.  (Obviously this assumes you have a clamp.)

[Gutbucket]

Thanks Gutbucket - To date I've just been running all 4 as cardoid on a 2' bar - Just did Grey Fox & got some nice results! Looks like I should get a bigger bar to try the omni! The Naks definitely are bassier and I've been running them on the outside with the Nuemans on the inside. At Grey Fox I pointed everything at the stack - went to another festival where I had the Nuemans in (as close as I could get it) XY pattern. Thanks all for the suggestions - I'm brand new to this hobby or "obsession" as my wife puts it!

Cool. Since you now have that as a data point, the next time you are at a similar outdoor thing like Grey Fox, try that current setup with the same bar and the Neumans in X/Y pointed at the stacks, but with the Naks pointing straight out to each side 180 degrees apart and see how you like that mixed together.  Also try pointing the Naks backwards for a few acts, say with each pointed directly away from the PA stack on the opposite side, so that the cardioid's null is pointed at the PA stack.   If you wan't to use a near-spaced point-at-stacks config for the Neumanns instead of X/Y, the backwards facing Naks should also work well with that.

One step at a time.  Have fun with it, you can make the most of what you have and develop a good understanding of how things work and interact with each other before buying more gear!  I'm a big fan of wide-spaced omnis, but they can be a hassle to setup and run, and they tend to impair the view from behind, so be kind.

I'll suggest an idea that is not my own creation, but may suit your case: space the omnis vertically.  Until you get that bigger bar, maybe run your cards how you usually would and then clamp the omnis a couple feet lower on your stand.  (Obviously this assumes you have a clamp.)

I've suggested this before as a three mic technique to get enough spacing between the main pair and a single omni for tapers without a wide omni bar.  I think it may work well for that when appropriate.  I've never tried it though, and was mostly just tossing the idea out there for folks to think about and try.  The aim is to decorrelate the ambient room sound between the omni and main pair to a lower frequency (a good thing), making the ambience sound more open, diffuse and less monophonic.  One would put one omni up as high as the stand goes, and clamp the main mics at their normal height.  Think of it sort of as a modification of the old popular Dead taping technique of using two shotguns with a single omni (the 3-mic Nak thing) by spacing the omni directly upwards.  Would only require a high enough stand and a clamp, and only reaches higher without increasing the stand areal horizontal "footprint".

It would be harder to do with two omnis for a lot of reasons- You want both omnis as far from each other as possible, and I suspect you'd also want each equidistant from the main pair  To do that the stand would need to be quite high with the cardioid pair in the middle and one omni mounted down low, making the low omni susceptible to picking up a lot of audience chatter.  The frequency and level balance between the omnis would be different not only because they have different perspectives, but also because the lower one would be closer to the ground placing it in a different low-frequency boundary layer condition with respect to the ground (more very low bass in the bottom one, less low bass and more ambient clarity in the top one).  Plus it would not really produce stereo bass in a left/right sense anyway.   Maybe it would work with both omnis above the main pair, with one at the top and one in the middle, but you'd need like a 15' tall stand to get 3' or more between each mic location and seems more trouble than its worth.

But for a single omni added to a near-spaced stereo pair I think its a viable option to try as long as a taller stand is cool.

[royjratc]

"but with the Naks pointing straight out to each side 180 degrees apart and see how you like that mixed together.  Also try pointing the Naks backwards for a few acts, say with each pointed directly away from the PA stack"

Wow I never would have thought of pointing the mics away either at 180 degrees or with the backs facing the stack - Forgive my ignorance but it sounds counter intuitive - Why would this help? Heading out to Peach in a couple weeks & can try it there! Thanks!

[Gutbucket]

It's about making the best of a situation that allows for it.  We're using four microphones instead of two, which allows us to do things we otherwise could not do with just two.  We can take advantage of that instead of simply duplicating what we would have done if we only had two microphones to begin with.

Most think of stereo as being mostly about left/right.  After all we are recording left and right channels most of the time.  Point one mic left-ish and one right-ish. Yet a deeper and more fundamental aspect is the balance between direct-sound/reverberant-sound.  And even at the level of left/right-ness, there are are other equally important stereo aspects such as the sense of width, openess, center/side-ness, etc.

Omni microphones are often considered to sound natural and open compared to directional microphones.  But it can be difficult to use them optimally because we have no control over directivity and recordings made with them can sound distant, muffled, boomy, etc. unless we can put them in the optimal spot in an optimal sounding room.  By using more than two directional mics and arranging them in such a way that the combined coverage of all of them together approaches omnidirectionality, we get a very natural, open "you are there" type sound but with directionality.  We gain control over left/right/front/back/side-to-side balance of things in ways we can't using just a pair of omnidirectional mics or just a pair of directional mics.  It gives us some control and differentiation over direct/reverberant, front/back, left/right, and center/sides, with improved left/right imaging as well.


Here's an analogy which might help-
Consider a two channel Mid/Side microphone setup.  The Mid microphone faces directly forwards and records the up-front mono component of the sound- ideally dominated direct sound from the stage and PA.  But the Side microphone faces sideways, recording the stereo ambience and width components of the sound- more or less everything except the direct sound coming from directly forward. It wouldn't work if the Mid and Side microphones were both pointed directly forward.

The PAS Neumann pair (X/Y or near-spaced) is analogous to the Mid microphone, focusing on the direct sound from the stage and PA.  It just has some added stereo directionality to it.  The sideways or backwards pointing Naks are analogous to the Side microphone, recording the spatial aspects of the sound, basically focused on everything else except the direct sound.  The Neumann pair then does it's job best partly by excluding most everything except the direct sound (thus PAS), and the Nak pair makes it's contribution partly by excluding the direct sound and maximizing the ambient difference signal (thus pointed 180 degrees apart to maximize the difference between them, or directly away from the PA to minimize the direct sound pickup as much as possible).  We get some control over the direct/reverberant balance by how much of the Nak pair we mix in with the Neumann pair, similar to adjusting the Mid/Side ratio of a M/S pair, but we have much more flexibility in doing so, and other stereo aspects like left/right and mono/wide can be addressed and adjusted separately.

The better sounding the room, the more leeway we have to not focus on the direct sound alone, and the more open natural and convincing the recording will sound.  In a crappy sounding concrete box music club we might need to try and exclude everything but the direct sound as much as possible just to get something decently listenable which isn't all mud, boom and reverb.  But in a good sounding space there is no reason to sacrifice everything else.  Outdoors we are free of room problems for the most part, so setups which record in a more overall omnidirectional way (in a well managed omnidirectional way, determined by how we point and space the directional microphones) can make for much better recordings which we can't make in lesser environments. 

Sure you can use the same microphone setup outdoors you'd use in the concrete box club, and it will probably sound somewhat better, but the point is that it could sound a whole lot better!  I look at this the other way around-Figuring a setup appropriate for a perfect acoustic is my starting point. Figuring a setup used for crappy music clubs is a modification of that, doing whatever is necessary to make a good sounding recording in a non-optimal situation.   

[morst]

Bands who record their own live shows directly often point a mic into the crowd from either downstage corner in order to get some room ambience and crowd response on an otherwise-dry board feed.

Also, pointing mics back can be some great fodder if you want to make a multi-channel surround mix, perhaps to go with a video?

Gutbucket has great ideas, and covered my potential issue with the over/under omnis - the low one may pick up more crowd, and as he rightly points out, potentially more bass.