Topic: what mix of mic-types?

[nicegrin]

I was wondering what mix of mic types one (you) would prefer (most of the times) to make a greatsounding matrix mix of two recordings of the same concert (assume both recordings are made in moderateley big to big arenas infront of the soundboard)

a, cardiods + hypercardiods
b, omnis + cardiods
c, omnis + hypercardiods

What mix would you prefer most and least of these 3? (assume that all 3 mics are high quality mics!)

   

[Nick's Picks]

anything with omni's.

IMO, multi-channel just muds up an all ready less than stellar recording environment.
two sets of directional mics make it worse.  so a pair of directional mics w/a pair of omni's is typically considered one of the better approaches.

If you are talking about mixing 3 mics...
then i'm in favor of either 2 omni's w/a center channel of card or hyper mixed...

or even better, two hypers w/a center omni mixed.

[wklitz]

I'd go with the omni's & hyper's (something I haven't done yet, but seems more usueful than anything else).........although I did just make a great recording with 2 Schoeps MK4V's and Schoeps M/S (using the MK21 and MK8) that definitely complimented each other and combined were much better than each source on it's own.

I have in the past liked my 414 omni's with the Schoeps Cards.

I have done 4 cardioids only because I could and we wanted an easy way to compare..but no real noticeable difference between the 2 sources other than both Schoepsnbox and myself arguing which sounded superior (I liked mine, he liked his)

[easy jim]

My favorite for open mic 4 tracks have been either:

from PA only
1) m/s center pair + split omni
2) m/s center pair + near-coincident cardioid
3) XY cardioid center pair + split omni

[Tim]

I don't understand why folks are mixing NC pairs of cards together or NC pairs of cards and hypers.

Think about what you are trying to accomplish, what sound are you looking for?

I'm generally uninterested in 4 mic mixes but the really good ones I have heard (Oade Bros, some Ben Morrisson and Mike Falcon Merle Fest tapes) are all coincident center pair and split omni's. With that you get the precision imaging and tight center image and you retain the ambience and spaciousness of omni's. It's a best of both worlds scenario that way

[DSatz]

Tim, good question. When the same frequency range from the same sound source is picked up by multiple microphones some distance apart, and then you mix their signals together, you get as much interference as you get reinforcement between the microphones. The path lengths between the sound sources and the microphones differ, so their arrival times differ; that causes some frequencies to be cancelled out. It's a big no-no in sound mixing. The technique used to avoid this is generally known as the "3-to-1 rule" and is explained here:

http://www.crownaudio.com/mic_web/tips/mictip6.htm
http://www.shurenotes.com/issue6/article.asp?flash=true

People should be wary of complicating their setups just because they have the extra equipment to do so. More can easily become less that way.

Let me suggest a new strategy (hmm, what movie is that line from?). Directional microphones tend to roll off at the lowest audio frequencies; what if we just let them do that, or even cut them off deliberately at some frequency such as 50 or 75 Hz--then mix in the outputs of two spaced pressure omni microphones at those low frequencies only. That way you could have the stable stereo imaging of a coincident or closely spaced pair of directional microphones, plus the spaciousness and gut-slamming low-frequency response of the pressure (omni) transducers, without either pair of mikes interfering with each other.

--best regards

[rdfager]

I've been experimenting with this lately.  I've had good results with a pair of omnis run Healy method and a pair of directional mics all on the same stand.  To my ears this adds an openness to and augments the low end of the directional microphone recording.  I mix the omnis in pretty low though, just enough to hear a difference.  My results when splitting the omnis has not been as good, probably because of the exact reasons that DSatz outlined.  I love the sound of split omnis.  I just haven't had good luck mixing them with another pair of mics.  

There's some good info on this topic on the Oade Bros website - http://www.oade.com/Tapers_Section/threefourmic.html

[Tim]

I like what you two are saying...

[easy jim]

I like what you two are saying...

Well...it's all in the mixing too.  Sometimes, what would never sound good as an on-the-fly 4 track -> stereo recording may be made to sound really good through well-done post-mixing.  A 4-mic mix made on-the-fly and captured to 2 track stereo is a recipe for phase issues and/or muddiness.  Post-mixing affords the oppportunity to align tracks if necessary, correct phase inversions, and set appropriate levels in a more controlled monitoring environment.

[Jammin72]

Wow, not the responses I was expecting to see but some great thoughts.

[CQBert]

Just to be different...

Bluemlien + Hyper
Split Omni + Hyper


CQBert

[wbrisette]

I tend to like using two omnis in the mix. I use two cards in the middle, and 2 omnis split. There are a lot of examples of this up on Archive.org that I've done. Look for DEVA or Earthworks QTC-1 for most of them.

Wayne

[nicegrin]

Tim, I endorse the question that you're asking. When the same frequency range from the same sound source is being handled by microphones that are spaced some distance apart, and you mix the signals together, you get as much interference as reinforcement between the microphones. The path lengths between the sound sources and the microphones differ, so their arrival times differ. That's usually a big no-no in sound mixing. (3:1 rule, anyone?)

Let me suggest a new strategy (hmm, what movie is that line from?). Directional microphones tend to roll off at the lowest audio frequencies; what if we just let them do that, or even cut them off deliberately at some frequency such as 50 or 75 Hz--then mix in the outputs of two spaced pressure omni microphones at those low frequencies only. That way you could have the stable stereo imaging of a coincident or closely spaced pair of directional microphones, plus the spaciousness and gut-slamming low-frequency response of the pressure (omni) transducers, without either pair of mikes interfering with each other.

--best regards

Nice strategy! Would be interested to hear where the magic cutpoint might be! Any suggestions? 

[DSatz]

nicegrin, my impression is that people here were talking about recording onto four separate channels from four microphones--then later, mixing those four signals down to two. If that's the case, the decision can be made entirely by ear in "post-production" while listening comfortably through a good playback system. And then not only the turnover frequency, but also the relative gain would be a variable worth playing with.

It's kind of like adjusting the output level and turnover frequency of a subwoofer--but in this case the "subwoofer" signal is part of what's being fed to your main loudspeakers, unless you happen to choose the same turnover frequency for both.

(With apologies for possibly causing thread drift: Between you and me and our 10,000 closest friends here, I think the whole idea of combining the deep bass from both channels into one subwoofer is unfortunate. It's true that at low frequencies we can't localize sound sources very well--but that's not the point. If a stereo recording is made with spaced microphones and has strong, independent--"decorrelated"--information in the two channels at low frequencies, you want that information presented from distinctly separate points in the room. Doing so will never recreate the same acoustical conditions as in the original space, but there will be a better reminder or remainder of those conditions in the playback.)

--best regards

[KLowe]

split omnis or sub cards NOS
with a mid'side in the middle

[wbrisette]

nicegrin, my impression is that people here were talking about recording onto four separate channels from four microphones--then later, mixing those four signals down to two.

I use to do a lot of my 4 channel mixes onto DAT using a Wendt X4 ENG mixer. It wasn't until I bough the Deva 3.5 years ago that I started doing four+ channel mixes in post. The key is you have to use a mixer, have a nice set of headphones/earphones (I use the ER-4S when doing this), and realize that you can't put in any delay or fix any sort of issues, so you get one chance at it.

Wayne

[Nick's Picks]

Let me suggest a new strategy (hmm, what movie is that line from?). Directional microphones tend to roll off at the lowest audio frequencies; what if we just let them do that, or even cut them off deliberately at some frequency such as 50 or 75 Hz--then mix in the outputs of two spaced pressure omni microphones at those low frequencies only. That way you could have the stable stereo imaging of a coincident or closely spaced pair of directional microphones, plus the spaciousness and gut-slamming low-frequency response of the pressure (omni) transducers, without either pair of mikes interfering with each other.

--best regards

interesting approach.
its like bi-amping a speaker in reverse.