Topic: figure 8 mic for M/S stereo setup

[saneproductions]

Hi,

Great forum! This is my first post, I did read the stickies and searched. I have some good sound recording experience and decent ears, but I have never made a stero recording.

I have a Sound Devices 302 mixer (has the ability to decode a M/S stero recording for preview)and a Schoeps cmc6u with mk41 super cardioid capsule (and rycote BBG with jammer and K-Tek KSSM shockmount) for HD and video production. I would like to do a M/S recording of a symphony and have something for general ambience in my projects. I don't have the budget to get the matching Schoeps figure 8 mic right now (and I realize that the super cardioid is not the perfect capsule for the "mid" mic, but I can't replace that right now either). It is my understanding that quality of the "side" mic is not as important as the "mid" mic in this setup. I plan to rent an AKG414 to do a trial run, but I would like something smaller for regular work in/outdoors. I have looked at the ambient emesser as well as the AKG blueline SE300B Power Module and CK94 Bi-directional Capsule. I have also thought of picking up a Rode NT2-A, but it seems unwieldy for field production and wind protection seems difficult. Am I on the right track?

Mike Johnson
saneproductions.com

[eric.B]

hey mike...    Id say both the mid and the side are just as important as one another depending on positioning and environment when recording m/s..  Im sure there are small details here and there that would dictate what microphone to match up with your mk41, but I would think that allmost any decent fig8 cap/mic will sound good.  This means that without a schoeps option in my bag, or the ability to borrow one, Id have NO problem running the 414 with the mk41 for your gig..   

[saneproductions]

So for that gig the MK41/414 will work, great thanks!

Do you have a preference for what I should buy for general use when I do pick something else up?

[eric.B]

sure itll "work"...  its just less than optimal.  shame the mid mic you are going to use is a hyper, but itll still do the job when running m/s I would think..   Unfortunately there are'nt *that* many fig 8 choices when your going on a budget, so I will say the rodes you mentioned or a behringer b2(?) which you can probably pick up for a hundred bucks and just see how it sounds...  hell, id even be curious as to what it would sound like!  Im sure it'd be quite listenable if the gig sounded good and you were in the sweetspot etc..     

[saneproductions]

Ya, I got this mic for dilogue and interviews indoors in film/tv/hd production. I could get more capsules later, which ones would you suggest?

I am really looking at that akg blueline/ck94 because of size. the ambient mic would fit in my BBG though.

Many film video guys use the Sennhieser MKH416 (shotgun) and MKH30 (bi-directional) for foley and ambience. I would think that a schoeps hyper would be better that the 416 for this, but what do I know.

I don't mean to be a pain in the a$$, but I don't ususally do this kind of work and I already have these mics. I just want to play around with this kind of recording for fun. I appreciate you taking the time to anwer my question.

I also have a Rode NT-1a and an oktava MC012 with hyper cap.

[iriewsp]

If you must have a small mic the akg blueline/ck94  will work great for a side mic.   

I would think the 414 would be an incredible match to the scheops in a m/s recording. 
If you like the results of this during your test but still cant afford the 414 I would suggest looking into the Audio Technica 4050 its similar to the 414 in looks and polar pattern options and is less expensive.  And still sounds very good in my opinion.

[saneproductions]

Okay, thanks! I will just rent a 414 as I need it for now, then think about getting something nice in the long run.

[qpwoei]

I am really looking at that akg blueline/ck94 because of size. the ambient mic would fit in my BBG though.

Many film video guys use the Sennhieser MKH416 (shotgun) and MKH30 (bi-directional) for foley and ambience. I would think that a schoeps hyper would be better that the 416 for this, but what do I know.

I don't mean to be a pain in the a$$, but I don't ususally do this kind of work and I already have these mics. I just want to play around with this kind of recording for fun. I appreciate you taking the time to anwer my question.

I also have a Rode NT-1a and an oktava MC012 with hyper cap.

Been for some time now using AKG CK94 as a side mic for nature recordings, and my feelings are mixed if you want to know: sounds good, relatively cheap, and small enough to be accomodated inside a rycote with the companion mid mic; yet it's prone to handling noise, not very sensitive, and a tad too noisy for natural ambiances.

I think for someone recording music, or in general medium to high pressure sounds the CK94 capsule is OK as an option, but forget about it if you are into low level sources. The reasons being that: 1) the final stereo mix is short of lateral sound, way too 'centered'; and 2) if you try to compensate for the few lateral signal (by increasing gain) you'll find the CK94 selfnoise spoils everything.

So you cannot use just any combination of mics to do MS, as they must balance to some extent as regards sensitivity and selfnoise. In my case this is even more difficult because the Sennheiser ME66 I use for M is both sensitive and low-noise, so valid fig-8 options are... MKH30 only, damnit.

Hope this helps, actually it helped *me*
cheers

[saneproductions]

wow! quite an insightful response! I will stay away from the akg then. I know someone with the ambient emesser that will let me try it, I will see if it will work and then... someday I will get something really expensive (right after I get a 416, some blue sky media desk 5.1 speakers and .......)
 

[qpwoei]

To complement my post above, and more specifically: since AKG CK94 is 10 mV sensitive and has 24 dB selfnoise, it can be used with any M mic around 12 mV sensitive and 16 dB selfnoise (or worst, but *not* better). I wish I had this info one year ago

Cheers

[DSatz]

OK, I'm trying to understand some things in this thread. Number one, why are people saying right off that a Schoeps supercardioid isn't the optimal "M" microphone for an M/S pair? The "M" microphone can be any type that would give you a good mono recording by itself; there is no pre-ordained ideal type or pattern for "M". I've seen a few on-line descriptions of M/S that specify cardioid as if it was the Only Officially Correct "M" pattern, but they are simply mistaken both historically and technically.

The main point of M/S, when Lauridsen introduced it in the 1950s, was its guaranteed compatibility between mono and stereo. The mono version of the recording came directly from the "M" microphone; you were supposed to use whatever microphone for "M" you would use for an optimal mono recording. Back then, good engineers all still knew how to make good-sounding mono recordings, and cardioid microphones certainly weren't their only choice for doing so!

As far as the match between "M" and "S" microphones is concerned, the CMC 641 and the AKG C 414 B-ULS (or equivalent) should be excellent together. Both have basically flat, neutral frequency response and clean polar patterns throughout the audio frequency range. The overall frequency response of "M" and "S" microphones ought to be generally similar--otherwise some distortion of the stereo image will result, as different frequencies from the same instrument or voice can have slightly different apparent directions of origin. But you shouldn't have this problem with these two microphones.

Unfortunately, "414" refers to any of over a dozen (!) different AKG microphone models using at least three distinct capsule types, some of which have rather different high-frequency response characteristics from others. I would recommend renting one of the types with basically neutral high-frequency response, rather than one of the types with elevated high-frequency response.

It would be great if you could record M and S directly, without dematrixing them. I don't know whether your recorder lets you monitor in L/R stereo while you do this, but many recorders and preamps do so; it's well worth finding out. If so, you can postpone the dematrixing until you're listening to the playback over your familiar loudspeaker setup at home, and you can then choose the relative levels of M and S that are going into the matrix. This will let you set the stereo soundstage width and the reverberation balance to your liking, with the recording already "in the can." That adjustability "after the fact" is a big part of what makes M/S worth using! Also, this approach cancels out all worries over the M and S microphones' relative sensitivity or noise. Just record the two tracks as usual, setting the gains so that your peaks in both channels leave you a couple of dB for safety below 0 dBFS.

The only other major concern I'd have is your miking distance. Will you have a choice about that?

--best regards

[eric.B]

OK, I'm trying to understand some things in this thread. Number one, why are people saying right away that a Schoeps supercardioid isn't the optimal "M" microphone for an M/S pair? The "M" microphone can be any type that would give you a good mono recording if there were no "S" microphone or matrix in the picture. There is no one pre-ordained ideal type or pattern for "M". I've seen a few on-line descriptions of M/S that mention cardioid as if it's the Only Officially Correct "M" pattern, but such descriptions are simply mistaken both historically and technically.

The whole point of M/S was its guaranteed compatibility between mono and stereo. Since the mono signal came directly from the "M" microphone, you're supposed to use whatever microphone for "M" that you would use for an optimal mono recording. Back then (mid-1950s), engineers still knew how to make good-sounding mono recordings, and cardioid microphones certainly weren't their only choice for doing so. M/S isn't like ORTF (which is always small-diaphragm cardioids at 110 degrees and 17 cm spacing) or Blumlein (which is always figure-8s at 90 degrees); it requires a figure-8 "S" microphone with its null facing front and center, but "M" is not restricted as long as it's coincident with "S" and aimed where the "M" microphone's null is facing.

As far as the match between "M" and "S" microphones is concerned, the CMC 641 and the AKG C 414 B-ULS (or equivalent) should be excellent together. Both have basically flat, neutral frequency response and clean polar patterns throughout the audio frequency range. Now while I just said a moment ago that any appropriate microphone can be used for "M," the caveat is that the overall frequency response of "M" and "S" microphones ought to be rather similar--otherwise some distortion of the stereo image will result, as different frequencies from the same instrument or voice can then have slightly different apparent directions of origin. But you won't have this problem with these two microphones.

Unfortunately, "414" refers to any of over a dozen (!) different AKG microphone models using at least three distinct capsule types, some of which have rather different high-frequency response characteristics from others that are also called "414". I would recommend renting one of the types that has basically neutral high-frequency response, rather than one of the types that has elevated high-frequency response.

It would be great if you could record M and S directly, without dematrixing them. I don't know whether your recorder lets you monitor in L/R stereo while you do this, but many recorders and preamps do so; it's well worth finding out. If so, you can postpone the dematrixing until you're listening to the playback over your familiar loudspeaker setup at home, and you can then choose the relative levels of M and S that are going into the matrix. This will let you set the stereo soundstage width and the reverberation balance to your liking, with the recording already "in the can."

That adjustability "after the fact" is a big part of what makes M/S worth using! Also, this approach cancels out all worries over the M and S microphones' relative sensitivity or noise. Just record the two tracks as usual, setting the gains so that your peaks in both channels leave you a couple of dB for safety below 0 dBFS.

The only other major concern I'd have is your miking distance. Will you have a choice about that?

--best regards

great post!   on par with your others I have read..  nice!  +t

I wasnt suggesting at all that a hyper mid is "wrong".. just perhaps not "optimal" for what he is going to use it for (without knowing the environment you will be working in)..  Ive never run hyper Mid myself, however Ive run card, subcard, and omni as a mid..     Go with the akg 414 (whatever the model) for your symphony, then judge a future purchase from your experience..   

[easy jim]

OK, I'm trying to understand some things in this thread. Number one, why are people saying right away that a Schoeps supercardioid isn't the optimal "M" microphone for an M/S pair? The "M" microphone can be any type that would give you a good mono recording if there were no "S" microphone or matrix in the picture. There is no one pre-ordained ideal type or pattern for "M". I've seen a few on-line descriptions of M/S that mention cardioid as if it's the Only Officially Correct "M" pattern, but such descriptions are simply mistaken both historically and technically.

The whole point of M/S was its guaranteed compatibility between mono and stereo. Since the mono signal came directly from the "M" microphone, you're supposed to use whatever microphone for "M" that you would use for an optimal mono recording. Back then (mid-1950s), engineers still knew how to make good-sounding mono recordings, and cardioid microphones certainly weren't their only choice for doing so. M/S isn't like ORTF (which is always small-diaphragm cardioids at 110 degrees and 17 cm spacing) or Blumlein (which is always figure-8s at 90 degrees); it requires a figure-8 "S" microphone with its null facing front and center, but "M" is not restricted as long as it's coincident with "S" and aimed where the "M" microphone's null is facing.

As far as the match between "M" and "S" microphones is concerned, the CMC 641 and the AKG C 414 B-ULS (or equivalent) should be excellent together. Both have basically flat, neutral frequency response and clean polar patterns throughout the audio frequency range. Now while I just said a moment ago that any appropriate microphone can be used for "M," the caveat is that the overall frequency response of "M" and "S" microphones ought to be rather similar--otherwise some distortion of the stereo image will result, as different frequencies from the same instrument or voice can then have slightly different apparent directions of origin. But you won't have this problem with these two microphones.

Unfortunately, "414" refers to any of over a dozen (!) different AKG microphone models using at least three distinct capsule types, some of which have rather different high-frequency response characteristics from others that are also called "414". I would recommend renting one of the types that has basically neutral high-frequency response, rather than one of the types that has elevated high-frequency response.

It would be great if you could record M and S directly, without dematrixing them. I don't know whether your recorder lets you monitor in L/R stereo while you do this, but many recorders and preamps do so; it's well worth finding out. If so, you can postpone the dematrixing until you're listening to the playback over your familiar loudspeaker setup at home, and you can then choose the relative levels of M and S that are going into the matrix. This will let you set the stereo soundstage width and the reverberation balance to your liking, with the recording already "in the can."

That adjustability "after the fact" is a big part of what makes M/S worth using! Also, this approach cancels out all worries over the M and S microphones' relative sensitivity or noise. Just record the two tracks as usual, setting the gains so that your peaks in both channels leave you a couple of dB for safety below 0 dBFS.

The only other major concern I'd have is your miking distance. Will you have a choice about that?

--best regards

great post!   on par with your others I have read..  nice!  +t

I wasnt suggesting at all that a hyper mid is "wrong".. just perhaps not "optimal" for what he is going to use it for (without knowing the environment you will be working in)..  Ive never run hyper Mid myself, however Ive run card, subcard, and omni as a mid..     Go with the akg 414 (whatever the model) for your symphony, then judge a future purchase from your experience..   

Agreed, and I have also done M/S w/ the 414s with card, wide-card, and omni as the mid pattern.  While hyper is do-able as the mid pattern, I feel if you are that far back that you're better off just running a hyper pair vs. using the M/S technique.

[saneproductions]

Wow, what a great post Dsatz!! I feel very fortunate to get advice from all of you at this forum! To answer questions

I plan to use my mbox with macbook pro as a recorder (line level). I will record dual mono as you suggested.

My mixer has a matrix decoder I can use to get an approximation of what I will hear in post.

I planned on going to a rehearsal and walking around with the hyper on a boom pole to determine when I can hear all of the instruments in the orchestra evenly and choose that as my mic position (hopefully eliminating some of the problems of the hyper).

I realize many people on this forum take this very seriously and have great gear for it (like matching neumann mics). Thanks for helping a beginner out. Like I said, this is not a paid gig or part of my normal work (I have a small HD production company). I think it would be a fun trick to know how to do this. I may even use it to record the room and location ambience on set of some digital shorts I am working on. I read in the manual of my sound devices 302 that it could do it (M/S) and I was like hmmm what is that? Kinda funny. I am just really into audio in my HD projects right now (all mono).

[midside]

I have used an MK41 for the mid cap in many MS recordings and they come out great.
It's all about what you want.
For the record, the 41 is the cap of choice for many camera operators (news and motion pictures) as it helps narrow the field.
I have used a 41 in an acoustic recording session of harp and bagpipe and it came out incredible (anyone want to hear it?).  I picked this cap because I wanted tight directional control.  I shot the pair through the strings of the harp (about 14 inches away) toward the bagpipe (about 5 feet back).  The harp was a little to the right and the bagpipe was a little to the left.  Then, I adjusted everything is post.

p.s. if I were to record a symyphony with an MS pair, I would get real close (maybe even onstage) and use a card (MK4) or a sub-card (MK21) if the room sounded good.