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.

[ingsy]

I have used a 41 in an acoustic recording session of harp and bagpipe and it came out incredible (anyone want to hear it?). 

yes please 

[saneproductions]

I would love it!

[midside]

Ask and you shall receive:

http://www.yourfilehost.com/media.php?cat=audio&file=harpandbagpipe.mp3

Here's a picture of the harp (sorry no rig in this pic):

[ingsy]

that recording sounds great!  nice job.

[BayTaynt3d]

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.

Well, couple of things this thread made me think of.

For starters, sure you could use a card, hyper, or even an omni for mid, but don't think for a minute it's not going to make a HUGE difference in the recording you make cause it will. The reason hypers probably aren't ideal is because they're real narrow in their patterns, meaning they are going to be pretty focused straight ahead. This results in several things. One is, you're probably going to need more side than you would with a card or omni. The other is that hyper is going to be attenuating the more wide sounds. Both of those things combine into much more OFF-AXIS sound being used by both mics. Simply put, off-axis sound doesn't sound as good as on-axis sound, so you better have some damn good mics or everything's going to be colored by that fact alone. Also, depending on the hyper's narrowness and the fig 8's pattern, you may actually end up with some blind spots in the resulting combined pattern, which goes back to my point about needing more side that you would have needed with a card or omni. That would be ESPECIALLY true if you used a shotgun. Remember too about the "proximity effects" of directional mics. The more directional, the more proximity effect.

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!

I don't think that bolded part is true at all. All coincident stereo techniques are mono-compatible (MS, XY, Bluemlin, etc.) because the sound arrives at both capsules simultaneously and doesn't suffer from phase or timing differences. When they collapse these stereo pairs down to mono, they STILL USE BOTH MICS' signals. They don't throw away the side at all, they just downmix the stereo signal to mono and everythings fine. In fact, in most cases today, the downmix to mono doesn't even happen on the recordist's side, it happens on the end-users' side. Think about it this way, you record a concert and broadcast it over cable TV along with the video and the audio is in stereo. As long as they use a mono-friendly stereo signal, for the folks who watch the program on crappy small or old TVs that only have one speaker, it'll still sound OK because the L and R won't be phase-cancelling each other. Also, here's another example, say you're recording a huge symphony from the sweet spot above the conductor's head with a single stereo MS pair. If the mono signal you created was simply only from the one cardiod facing forward, it's sound like ass cause you wouldn't hear much of the symphony from the left or right sides. What they WOULD do is simply mix the MS to stereo, then downmix that to mono where BOTH mics would still be used. Think about it this way, what about XY and Bluemlin? Which mic would you pick for a mono recording in that case? You'd pick BOTH and downmix to mono. Take Bluemlin for example, in a classical or chamber music environment, that setup brings in a lot of the ambience of the hall plus the direct sound of the musiciancs, in your mono downmix, you'd still want all of that in there.

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?).

Yeah, but that said recording would probably have sounded way, WAY better using split omnis or a card pair. Remember, this forum is all about recording music, so don't take this the wrong way, but you'd pretty much never see someone record an acoustic harp and bagpipe in a studio with a shotgun, and there's a really good reason for that. So, shotguns and hypers all have there place, especially for ENG and video work, and even at times for music, but it'll be a rare, rare day that they'll be able to compete with a good card or omni under the right conditions. The difference would be night and day in all likelihood.

Anyway, just some observations from my end...

[musicsherlock]

Some great observations there...

I've actually been re-thinking this whole M/S thing...what is the end result of a good M/S mix?

Matched Hypers...



I think investing in a great pair of Hypers and using the appropriate set-up would minimize alot of post production time...

[Brian Skalinder]

I think investing in a great pair of Hypers and using the appropriate set-up would minimize alot of post production time...

You'd lose the flexibility of defining the stereo image width in post, though.

[BayTaynt3d]

I think investing in a great pair of Hypers and using the appropriate set-up would minimize alot of post production time...

You'd lose the flexibility of defining the stereo image width in post, though.

Which is one of the best reasons to use MS in the first place.   

[BayTaynt3d]

Some great observations there...

I've actually been re-thinking this whole M/S thing...what is the end result of a good M/S mix?

Matched Hypers...



I think investing in a great pair of Hypers and using the appropriate set-up would minimize alot of post production time...

Actually, it's more than just having the flexibility of post-imaging. For example, one of the reasons I'd love to do some MS is b/c of the music I tend to record, and how I record it: acoustic jazz in small venues. Being able to slap a MS on-stage would be fantastic. Think about a scenario I just had the other day: tenor on the left, clarinet in front, and trumpet to the right. Due to circumstances, my stand had to be right in their face, specifically right in the clarinetist's face, he was super-close to the mics, with the trumpet and tenor farther off to the sides. Man, MS would have killed in that situation b/c I would have been able to crank the S and lower the M and just flat-out nail the balance with mostly on-axis sound for everyone. What would you have done their with a pair of hypers? You'd have been screwed with either focusing on the center clarinet and not getting much of the tenor or trumpet, or you'd have angled them out and picked them up great but completely attenuated and colored the clarinetist straight ahead. So, I don't think a pair of hypers would ever come close to the flexibility you could get with MS, especially when you start bringing a hyper, card, sub-card, or omni into the M channel -- you can create all sorts of different patterns with those combos, when with hypers, you're patterns are extremely limited IMHO. And FWIW, I ended up using 18" split 482 omnis in that situation which ended up sounding pretty damn good, heh. Samples are in the first post on my website right now (note: it was split 482s + DI off the bass > R4, and I so wished I had time to set one overhead on the drumkit, but oh well...).

[DSatz]

Hello, BayTaynt3d. Of course it matters what kind of microphone you use for "M"--I was only saying that M/S isn't a technique with a fixed "recipe" in that respect; the "S" microphone must of course be a figure-8, but as I said, any appropriate type of "M" microphone can be used. The original poster makes mono recordings often, and this technique should be a natural extension of that. I'm eager to hear how this will go for him.

Second, you're completely right that off-axis sound is very important; in fact I would say it is far more important than most people realize, until they leave the studio (or the basement apartment) and start to make two-microphone stereo recordings in concert halls, churches, etc. But you seem to assume that all microphones have equally poor off-axis sound quality, and that is decidedly not the case.

This is a little hard to say in one sentence, but: Microphones whose response is primarily based on the pressure gradient (i.e. microphones tending toward a figure-8 pattern) tend to have off-axis response that more closely matches their on-axis response than microphones whose response is primarily based on sound pressure alone (i.e. microphones tending toward omnidirectional). The upshot is that a good supercardioid such as the Schoeps, which has very flat on-axis response and a very "clean" polar pattern (i.e. it is a supercardioid throughout almost its entire frequency range) will have audibly smoother, flatter off-axis response than any cardioid microphone of normal size. That's why it is one of the preferred microphone types in film and video sound. It's not only because it suppresses off-axis sound efficiently--more often than not, people have an exaggerated notion of how narrow a supercardioid directional pattern really is. But mainly, the reason such microphones are used so much is because the sound which is, inevitably, picked up from off-axis still has a very listenable quality to it.

Just so you know, I've made perhaps 2,000 live stereo recordings of classical music concerts and recitals using coincident or near-coincident pairs of Schoeps supercardioids; they've been my "go to" microphones for about 25 years now. In that application the off-axis response is absolutely crucial to the result--the center of the sound source is generally hitting the microphones at a 45-degree angle or a little greater. So any harmful coloration would be immediately evident, if it was really a defect of those microphones as you seem to assume.

When you talk about possible "blind spots in the resulting combined pattern," I can only think that you have a somewhat confused mental picture of how M/S recording works; "blind spots" aren't a problem at all, either in theory or in practice. Similarly, what you said about the mono compatibility of X/Y stereo recording is perfectly true--but please note that when you sum L + R from an X/Y (coincident) microphone pair as you discussed, you get the precise equivalent of M in an M/S pair. Or to put it the other way around: L and R are obtained from an M/S pair respectively by adding (L = M + S) and subtracting (R = M - S) the microphone signals. M is the mono sum to begin with, and S is the difference between the L and R stereo channels. It's exactly parallel to the way FM stereo is broadcast. A mono FM receiver gets only M (= L + R), while a stereo receiver gets M but can also detect a subcarrier which is modulated at the transmitter by the L - R signal (= S). In stereo mode, this S signal is matrixed with M to get L and R.

So the S signal in an M/S recording is simply ignored if you want the compatible mono version of the recording. When you think about it, you'll realize that it must be so. The two lobes of a figure-8 microphone are in opposite polarity, so you can never mix any amount of the S signal into M without causing the result to favor either the left or the right of the original sound picture. Most people who make this mistake have not fully realized the part about the two lobes of the figure-8 having opposite "sign." A figure-8 has a cosine pattern, and the cosine of any angle between 90 and 270 degrees is negative. This isn't obvious from a normal polar diagram but it is an essential fact of any bidirectional microphone (including the supercardioid, by the way--its rear lobe has inverse polarity, too).

--best regards

[sygdwm]

i wish i could comprehend all of that.

[saneproductions]

I really appreciate all of the running commentary on this topic. I certainly didn't expect this amount of response or the richness of detail offered. I can't think of any place in the world I could get this advice. I feel like I should start writing checks!

I am excited to try a M/S recording and I will report back after I do. The concert is on the 18th of this month and I plan to go to a rehearsal the day before and do some tests.

Thanks again!

[midside]

Yeah, but that said recording would probably have sounded way, WAY better using split omnis or a card pair. Remember, this forum is all about recording music, so don't take this the wrong way, but you'd pretty much never see someone record an acoustic harp and bagpipe in a studio with a shotgun, and there's a really good reason for that. So, shotguns and hypers all have there place, especially for ENG and video work, and even at times for music, but it'll be a rare, rare day that they'll be able to compete with a good card or omni under the right conditions. The difference would be night and day in all likelihood.

Anyway, just some observations from my end...

This is turning into an interesting thread, but I must comment on some of these points:
First - You should use caution with the word 'better'.  Better can mean different things to different people.
Second - I would hardly compare an MK41 to a shotgun microphone.
Third - I also wouldn't compare a live location recording to what would be done in a studio.

With all this in mind, if I was to record this again, perhaps I would do something slightly different but I wouldn't go with split omnis.  The room was just too open for this type of recording.  I picked MS with a 41 for a few reasons, two being of high importance:
1. I wanted a very tight, directional upfront sound.
2. I had to nail it that day....

If I was to do it again, perhaps I would try out an MK4 and arrange the performers a little differently...or, just mic each instrument separately and pan a pseudo stereo image in post.

Now, some people do not fully understand MS recording and think that adjusting the mid to side ratio is:
1. more side = wider
2. more mid - narrower
THIS IS NOT THE CASE!
First off, let's assume for explanation purposes that the mid and side recording levels are approximately the same.
You have the widest stereo image possible when the mid to side ratio is 1:1
When you adjust to all M, you have a mono recording of the M cap only.
When you adjust to all S, you have a mono recording of the S cap only.
Everything else is somewhere inbetween.
It obviously sounds more narrow when you adjust heavier on the M cap in post and it is.  But, the thing most people don't understand is that when you adjust heavier on the S cap (past 1:1) that the image is not getting wider, it is actually getting narrower but with more information from the sides.  It might sound wider, but that is just because of the extra room ambiance.
For instance, if you have one musician on the left and one on the right, and you want to hear them in the proper place, then a close to 1:1 will be the most accurate (depending on the caps used).  If you adjust to the S cap only, then both musicians will be placed equally on the left and right (mono from the side cap).

So, if you really want to make it sound wider than it is (in post), then the best thing to do is lower the gain of the mid (in your audio editor), or raise the gain of the side.  Then, matrix 1:1.  That will give you the truest wider stereo image.

MY MAIN REASONS FOR USING M/S:
I must admit, that while I love the sound of MS, it is (of course) not always the best method to use.
As we all know, different recording situations call for different techniques.
I use M/S a lot because I record mainly in the field and usually do not have a second chance....it's quite easy to get quality material, then 'fix it up' in post.  Just pick your M cap, get in a good location or arrange performers (if you can), get good levels and record.
Later on, if I think the room is too boomy or hollow, etc., I go with more mid.
The waves S1 shuffler is a great tool (works with LR recording too).  (If you use MS techniques and you don't know what shuffing is...then NOW is the time to learn!)
You can also isolate mastering effects (EQ, de-hisser, multiband dynamics, etc.) on the mid or side channel before you matrix it.....
M/S really gives you many great post benefits.  Plus, I can fit two caps in a tiny little rycote for outdoor work.  Great set-up for 'run and gun' or 'no take 2' situations.

Remember, recording techniques/equipment are just tools and there is no replacement for knowing how to use your tool.

With all that said, if I was going to record a symphony in a good sounding room, M/S would NOT be my first choice....I would probably run split omnis from overhead

[midside]

p.s. don't forget to look here:

http://groups.google.com/group/rec.audio.pro/search?hl=en&group=rec.audio.pro&q=ms&qt_g=Search+this+group

[DSatz]

midside (gee, with a name like that, it's no surprise to see you in this discussion)--when BeyTaynt3d says that an omni or cardioid would have sounded "better" than a supercardioid, he's being opinionated, of course.

But I think there's a very real basis for his opinion. There is something hugely desirable about the sound and feel of a well-made recording when omnidirectional (i.e. pressure) microphones are used. The stereo image may be only a vague, wandering mist, but if you change to a "right-brained" listening mode in which you are receptive mainly to tone color, there can be sensual goodies galore. For many musicians, that is the only mode in which they ever listen or even consider listening. For them, localization is but a parlor trick; who cares where everybody was exactly on the stage? They like the fact that real space is being bypassed or abolished.

I can see their point very well, but I hear both ways at the same time, and I don't want to abandon all spatial perspective completely. To discuss this would carry us even farther away from M/S, so let me just say that lately I've become keen on using wide cardioids for stereo recordings when room acoustics allow. You can get about 75% of those sensual pressure-transducer "goodies," while with proper setup you can also have a clear, stable stereo image. (A sphere stereo microphone can also give you "the best of both worlds" in this way--that's a fascinating way of recording.)

Interestingly, it appears that European engineers use omnidirectional microphones for studio recording more often than American studio engineers do. (I mean pressure transducers--not the "omni" setting of a multi-pattern microphone such as a U 87, which synthesizes its "omni" pattern by summing the signals from two back-to-back cardioids.) Typical American studio engineers never look at any pattern other than cardioid; their fidelity to the cardioid pattern is often greater than their fidelity to their wives.

--dre, can I encourage you to ask whatever questions are on your mind about this stuff? When you're really interested in something is always the best time to learn. If need be, we can start another thread to avoid hijacking this one, or we can latch on to an existing thread if you know of one that's more similar to what you want to talk about. (My guess is, it has to do with directional patterns and maybe polar diagrams.)

--best regards

[saneproductions]

Don't worry about hijacking, I am all ears!

[BayTaynt3d]

There is something hugely desirable about the sound and feel of a well-made recording when omnidirectional (i.e. pressure) microphones are used. The stereo image may be only a vague, wandering mist...

You can get plenty of stereo image with good placement and omnis using the right size split or a j-disc or better yet 3-omnis in decca. And sure, hypers can make a good recording, I even said I use them, but the chances of them making a better recording than omnis or cards in a classical or chamber music situation in a decent hall are slim to none IMHO, which is why they are rarely used in those situations (except when multitracking and getting reinforcement of certain sections, but even then I doubt it).

And for the record, points taken earlier, so thanks for the clarifications. And I never said anything about Schoeps being defective, they obviously make some of the best mics out there, we all know that, so that had nothing to do with my comments whatsoever. But regardless of how good the off-axis is, it's still off-axis and it won't be as good as on-axis, so that was my main point. I'm also not sure I agree that XY summed to mono gets you the same thing as the M in MS, unless that M is something like a sub-card, I think the XY summed will have a larger coverage to its overall pattern (not to mention the differences from the on- vs. off-axis aspects of MS vs. XY). Now maybe I'm missing some of the phase cancelling that might occur when summing the XY to mono, but don't think so. I'm also under the impression that a 50-50 MS pattern using a card for mid ends up with more of a 66 degree hypers pattern than it does the equivalent of XY (which is traditionally 90 but not necessarily). But I get the point about summing MS to mono and ending up with M only, so I guess I missed that one, I was more focused on the overall mono-compatibility of all coincident techniques, which don't necessarily result in the same outcome.

[John Willett]

There are only two condenser fig-8 microphones on the market (that I know of) that are truly symmetrical single diaphragm microphones.

Most are made from back-to-back cardioids or a single diaphragm with a single back-plate that makes the pattern non-symmetrical.

The two that are truly symmetrical are the Sennheiser MKH 30 and the Neumann KM 120.

Both these have a front plate as well as a back plate so the polar-pattern is truly identical on each side.  The MKH 40 has an active front plate which drastically reduces IM distortion - the KM 120 has a front plate for acoustic purposes only to give a truly symmetrical polar-pattern.

By contrast, the Schoeps does not have a front plate and you can see the result in the published polar-pattern - the front is different from the back.  For most uses this doesn't really matter - but as a side mic. in an MS array it will make the left/right signals slightly different.

I hope this helps.

John

[DSatz]

John, what you have said here about Schoeps figure-8s is simply mistaken as a matter of fact, so perhaps you will want to revise the way in which you understand the issues which you are discussing. If the backplate of a single-diaphragm figure-8 capsule is acoustically transparent (e.g. Schoeps MK 8), that microphone's bidirectional symmetry can be as close to perfect as manufacturing tolerances allow.

On the other hand, if a figure-8 capsule has two backplates and they differ, its pattern will be lop-sided. How do you explain the fact that Sennheiser uses the two-backplate approach for their MKH-series microphones with all the other patterns, too, if this technique supposedly produces an ideal bidirectional pattern every time? Dr. Hibbing and Mr. Griese from Sennheiser gave an interesting paper at the European AES Convention in 1981 (available as preprint 1752 from the AES) about their reasons for using this approach--mainly, that it can reduce certain types of non-linear distortion in the capsule itself, as you mentioned.

I recommend reading this paper--you'll see that it isn't about pattern symmetry, which in practice is quite similar for all three of the manufacturers that you mentioned.

--best regards

P.S.: Incidentally, the dual-backplate, push-pull construction principle was introduced first by Schoeps several decades ago. They then stopped using it, and to the best of my knowledge, Sennheiser is now the only manufacturer of such microphones.

[muj]

P.S.: Incidentally, the dual-backplate, push-pull construction principle was introduced first by Schoeps several decades ago. They then stopped using it, and to the best of my knowledge, Sennheiser is now the only manufacturer of such microphones.

Dear Mr.Satz Sanken microphones use this principle today with their titanium caps and nevaton microphones.

[midside]

Muj,
Can you please tell me more about the mic in your avatar?

[muj]

Muj,
Can you please tell me more about the mic in your avatar?

it's the prototype predecessor of schoeps mstc54/64 . I just used it as a avatar as it has some twisted sexual undertones to it 

please visit schoepsclassics.de

[musicsherlock]

Muj,
Can you please tell me more about the mic in your avatar?

 I just used it as a avaatar as it has some twisted sexual undertones to it 

kinda like this bad boy...

[Chuck]

Muj,
Can you please tell me more about the mic in your avatar?

it's the prototype predecessor of schoeps mstc54/64 . I just used it as a avatar as it has some twisted sexual undertones to it 

please visit schoepsclassics.de

I'm not so sure it looks 'sexual" to me... I see it more as a TV antenna... but on second thought... 

[DSatz]

midside, Muj's avatar is half of a tube stereo microphone built by Schoeps for the French broadcasting organization (ORTF, now known as Radio France). It uses the 17 cm, 110-degree arrangement which is well known today. I saw this type of microphone used in Paris to record an orchestra concert when I was there in around 1976, and I took some photos of the arrangement which I still have; this microphone was not just a prototype.

I believe Muj's photo may be taken from the "Schoeps Classics" Web site, specifically the page on "unique objects, prototypes and discontinued models." As he says, it has MK 5 capsules; these were originally introduced as successors to the M 934 B two-pattern capsule with improved specifications and no need for the "phase ring" of the older model when used in its cardioid setting.

Muj, thank you for mentioning Sanken condenser microphones as having a push-pull transducer design. Is there a particular model or group of their models which follow this approach?

--best regards

[midside]

Thanks for all the info and for hipping me to the schoeps classics website....lot's of fun vintage pics!
If you don't mind me hijacking this thread just a little...I am curious as to why they made a three pattern switchable dual cap microphone:
http://www.schoepsclassics.de/1969_cmts.htm
I understand that this would work great for MS, XY and blumlein but the use of the omni position would have very little versatility.  I suppose you can use 1 omni cap and leave the other off....or, you can use the onmi with the 8 in MS but this is rare.  I also suppose you can record 1 omni and 1 card for a mono channel and pick the best sounding one later......just thinking......

[John Willett]

John, what you have said here about Schoeps figure-8s is simply mistaken as a matter of fact, so perhaps you will want to revise the way in which you understand the issues which you are discussing. If the backplate of a single-diaphragm figure-8 capsule is acoustically transparent (e.g. Schoeps MK , that microphone's bidirectional symmetry can be as close to perfect as manufacturing tolerances allow.

Sorry - No, I am not mistaken.

The backplate may be acoustically transparent, but the acoustic conditions are different each side of the diaphragm and the Schoeps published polar pattern for the fig-8 clearly shows the differences.



It's very clear that the rear is different from the front at high frequencies.

On the other hand, if a figure-8 capsule has two backplates and they differ, its pattern will be lop-sided. How do you explain the fact that Sennheiser uses the two-backplate approach for their MKH-series microphones with all the other patterns, too, if this technique supposedly produces an ideal bidirectional pattern every time? Dr. Hibbing and Mr. Griese from Sennheiser gave an interesting paper at the European AES Convention in 1981 (available as preprint 1752 from the AES) about their reasons for using this approach--mainly, that it can reduce certain types of non-linear distortion in the capsule itself, as you mentioned.

I recommend reading this paper--you'll see that it isn't about pattern symmetry, which in practice is quite similar for all three of the manufacturers that you mentioned.

I know Manfred Hibbing and I have read the paper (and I know Jörg Wüttke of Schoeps as well).  The backplate and frontplate are identical so there is no lopsidedness. The symmetrical capsule approach only really works with RF condenser microphones which have a low impedance capsule, it is not practical with AF condenser microphones which have an extremely high impedance capsule. Yes, the symmetrical capsule vastly reduces IM distortion, which is why it is used for all the range.  Neumann use a frontplate in their fig-8 for the acoustic purpose of making the polar-pattern truly symmetrical (it is not wired electrically), this was explained to me by Stephan Peus the designer.

The MKH 30 and AK 20 both have identical patterns to the front and rear.

MKH 30


The Neumann link is HERE (click on the magnifying glass to get the diagrams).

I do know what I am talking about and I do know all three designers and have spoken to them several times.  I'm not knocking Schoeps at all, just pointing out a fact that is clear in their published specifications.
 
John

[muj]

kinda like this bad boy...
[/quote]


yep that's beach ball harry 

[muj]

Muj, thank you for mentioning Sanken condenser microphones as having a push-pull transducer design. Is there a particular model or group of their models which follow this approach?

--best regards

Most of the sanken line ...like cu-31 . 30, cm7 cm9 check out their website.

nevaton also have one with push-pull design going on , it's the mc49 . a pic is here and pdf file
http://www.russian-mics.com/downloads/nevaton_mc49.pdf

[muj]

Thanks for all the info and for hipping me to the schoeps classics website....lot's of fun vintage pics!
If you don't mind me hijacking this thread just a little...I am curious as to why they made a three pattern switchable dual cap microphone:
http://www.schoepsclassics.de/1969_cmts.htm
I understand that this would work great for MS, XY and blumlein but the use of the omni position would have very little versatility.  I suppose you can use 1 omni cap and leave the other off....or, you can use the onmi with the 8 in MS but this is rare.  I also suppose you can record 1 omni and 1 card for a mono channel and pick the best sounding one later......just thinking......

you mean this one ? 

[midside]

yep, that one.

[DSatz]

midside, the CMTS stereo microphones used specially adapted matched pairs of MK 6 three-pattern capsules from the CMT series. I owned two of these microphones at various times back in the 1970s; they were manufactured through most the 1980s, even after the rest of the CMT series was discontinued.

An omni can very well be the mid microphone for an M/S pair; given unity-gain matrixing, you'll have the equivalent of X/Y cardioids. I'm no great fan of X/Y cardioids myself, but a lot of people sure use them, so I hope that this helps explain the design choice. Also, stereo microphones in general are occasionally used either as a "failsafe" way of "backing up" the placement of a single microphone (imagine if you were miking a world leader for a live broadcast and one channel went out for whatever reason--a bad cable, perhaps, but there's no time to find out. You can't exactly interrupt and say, "please hold on a moment while I get another microphone"). Finally, there is a technique called "Straus-Paket" recording in which the signals from a concident cardioid and omni are recorded onto two tracks, and then the mix between them can be varied during playback to produce any result along the range from cardioid to wide cardioid to omni "retroactively."

John Willett, some figure-8 microphones are not well suited to be the "S" microphone in an M/S pair. Some Royer ribbons (not the ones they sell for classical music, but some of the models that are more "pop" oriented), for example, have different-sounding fronts and backs; the company admits this freely, says that it is an intentional aspect of their design, and recommends using one side versus the other for different applications. That's certainly one approach to marketing, but it would make me think twice before using that type of microphone for M/S.

However, please note that all the polar diagrams which you reproduced showed no difference whatsoever between front and back below 16 kHz--and 16 kHz is at the upper limit of the frequency response for this type of capsule. Furthermore, since the the published curves of different manufacturers are not drawn the same way, they cannot be compared directly; we must still compare actual microphones. But mainly I object to the fallacy of presenting a plausible explanation for a proposed phenomenon (a "back story," if you will) as if it were any evidence that the phenomenon itself is real. This fallacy is so rampant in the audiophile universe that I have become quite allergic to it. I'm sorry to be "getting on your case" but you made an overly categorical claim, and while you've said many interesting things and you clearly do "know what you're talking about," you still haven't backed up your claim with any particular evidence about actual microphones so far. That's what it would take, I think.

--best regards

[John Willett]

.....some figure-8 microphones are not well suited to be the "S" microphone in an M/S pair. Some Royer ribbons (not the ones they sell for classical music, but some of the models that are more "pop" oriented), for example, have different-sounding fronts and backs; the company admits this freely, says that it is an intentional aspect of their design, and recommends using one side versus the other for different applications. That's certainly one approach to marketing, but it would make me think twice before using that type of microphone for M/S.

Agreed, I have no problem with this.

However, please note that all the polar diagrams which you reproduced showed no difference whatsoever between front and back below 16 kHz--and 16 kHz is at the upper limit of the frequency response for this type of capsule. Furthermore, since the the published curves of different manufacturers are not drawn the same way, they cannot be compared directly; we must still compare actual microphones. But mainly I object to the fallacy of presenting a plausible explanation for a proposed phenomenon (a "back story," if you will) as if it were any evidence that the phenomenon itself is real. This fallacy is so rampant in the audiophile universe that I have become quite allergic to it. I'm sorry to be "getting on your case" but you made an overly categorical claim, and while you've said many interesting things and you clearly do "know what you're talking about," you still haven't backed up your claim with any particular evidence about actual microphones so far. That's what it would take, I think.

I agree partly, but Neumann do specifically have a passive but otherwise identical front plate in order to make the capsule truly symmetrical both sides.  It's to do with the acoustic impedance of the capsule and how the soundwaves impinge on the capsule.

I have discussed this with both Stephan Peus at Neumann and Manfred Hibbing at Sennheiser.

The Schoeps is slightly different at high frequencies - how important that is in the real world is debatable, Jörg Wüttke obviously thinks it is not important - personally I want identical characteristics both sides at all frequencies.

Personally I use the MKH 30/40 for my MS recordings, but I do also have some Neumann KM-D series and will, no doubt, get the KK 120-D head when it becomes available (I have the KK 183-D now with KK 131-D on order).

[Gutbucket]

...An omni can very well be the mid microphone for an M/S pair; given unity-gain matrixing, you'll have the equivalent of X/Y cardioids...

Just to clarify, this is equivalent to coincident cardioids facing directly to either side, 180 degree angle between them.  Not the typical 90 degree or so X/Y angle most would be familiar with.

[DSatz]

Gutbucket, right--with 1:1 matrixing, that's what you'd get. However, it's a perfectly usable arrangement for stereo music recording, under any circumstances in which an orchestra or other ensemble could reasonably be picked up in mono using a single omnidirectional microphone.

That's the perspective from which to understand this design choice, I think. When this type of microphone was developed, engineers in the European broadcasting organizations still took great care to maintain mono compatibility because stereo receivers weren't universal yet. The "Walkman revolution" hadn't happened yet, either; few people listened to radio through headphones. LPs were still being issued as dual inventory--you could buy either the stereo or the mono version of many records (e.g. the Beatles). So "intensity stereo" (i.e. coincident miking) was how European broadcasters and record companies mainly recorded classical music.

As you may know, Schoeps' multi-pattern capsules are single-diaphragm designs which switch their directional patterns mechanically (acoustically), rather than by varying the polarization voltage on a pair of membranes. The company already made a three-pattern (omni/cardioid/figure-8), side-addressed capsule called the MK 6. Its pattern-switching mechanism is very complicated, but there isn't a very large market for stereo microphones, so it would have been prohibitive to develop a new mechanism to include other patterns (such as supercardioid and/or wide cardioid) which we might like to have in a stereo mike. The initial prototype version of the CMTS simply had a pair of these 20-mm-diameter MK 6 capsules mounted on a 30-mm-diameter body, but that looked a little odd, so they adapted the capsules to 30 mm housings and produced the microphone that way. Thus it is what it is.

--Just as a final comment, though I've said it before on this board: X/Y cardioids with only a 90 degree included angle is a generally poor choice for music recording, the Røde NT4 notwithstanding. A cardioid pattern isn't as sharply directional as people often believe or wish it to be. If you only spread a pair of cardioid microphones to 90 degrees and don't space them apart, the resulting recording will be about 3/4 mono. All the direct sound sources will crowd in toward the center of the image in playback, as compared to where they were during the actual recording.

If mono compatibility isn't a requirement and you want to use cardioid microphones, an "ORTF" arrangement gives a far more even, realistic distribution of sound sources within the stereo image in most cases.

But if for some reason it is necessary to record X/Y with cardioids, I'd strongly suggest angling them farther apart. 120 degrees might be a good starting point, particularly with smaller microphones which don't lose much high-frequency response off-axis. The point at which two ideal cardioids would cross at their half-power points would be with slightly greater than 130 (!) degrees of spread between them, ideally.

--best regards

[Gutbucket]

Well put and informative. 
Agreed on the lackluster 90deg X/Y. I'm not a big X/Y fan, even with wider angles, generally preferring spaced techniques.

...The point at which two ideal cardioids would cross at their half-power points would be with slightly greater than 130 (!) degrees of spread between them, ideally...

Good to know, I've assumed it was closer to 120 deg. I suppose this varies somewhat between different cardioid mics.

[DSatz]

Gutbucket wrote:

> I suppose this varies somewhat between different cardioid mics.

Well, cardioid is cardioid is cardioid--the sensitivity is proportional to (1 + cos theta) / 2, where theta is the angle of sound incidence relative to the 0-degree axis of the microphone. But many "cardioid" microphones are cardioid only in the midrange, and their variability in pattern is itself ... variable.

Large-diaphragm microphones generally lose their high-frequency response off-axis, so at those frequencies they are more narrowly directional than cardioid--sometimes quite considerably so. As a result you can get rather dull sound from the center of the image if you angle an X/Y pair of them at what would otherwise be your optimum. Smaller microphones disturb the physical sound field proportionately less; one inch, for example, represents half a sound wavelength at 6 to 7 kHz.

Meanwhile, microphones using the common dual-diaphragm arrangement (regardless of size) tend to become less directional at low frequencies, broadening out to more of a "wide cardioid" pattern at 100 Hz and below. Unfortunately this means that any X/Y recording made with such microphones will be nearly mono in the bass. 20, 30 or 40 years ago that was helpful for cutting stereo LPs that would track easily on cheap turntables, but not very many of us need to worry about that any more.

That characteristic robs stereo recordings of the sense of spaciousness which they could otherwise have. When an X/Y stereo recording has been made with dual-diaphragm cardioids, it's sometimes worthwhile to run it through an M/S matrix "backwards" to derive sum and difference signals, boosting the low frequency content in the difference channel a few dB while reducing it in the sum channel by a similar amount, then rematrixing to left/right stereo.

Better yet, don't use large, dual-diaphragm microphones as cardioids for X/Y stereo in the first place; it's almost a recipe for a worst-case outcome. If a person must use cardioids for X/Y stereo, then small, single-diaphragm cardioids (that are still cardioid at low frequencies) are preferable for the reasons I just explained; there are quite a few good kinds available.

But X/Y generally works even better with good supercardioids or, in those rare and wonderful cases where the geometry and reverberation balance conspire to allow it, with figure-8s ("Blumlein"). X/Y just barely works at all as a stereo recording method with cardioids, and as I said, ORTF or other "slightly spaced" stereo recording arrangements give a much more even distribution of apparent sound sources in playback.

--best regards

[Gutbucket]

... it's sometimes worthwhile to run it through an M/S matrix "backwards" to derive sum and difference signals, boosting the low frequency content in the difference channel a few dB while reducing it in the sum channel by a similar amount, then rematrixing to left/right stereo.
...

I've tried this with good results. One related thing I haven't tried but I'm curious about is the 'Blumlein Shuffler' technique for converting low frequency phase differences into level differences when using spaced mic techniques.  Every try it?

Apologies for the threadjack.

[muj]

David,

how would you run a pair of SDC which are not flat, but may have a good hf boost. an X/Y would from my experience accentuate the hf amount in the recording.

[DSatz]

> [H]ow would you run a pair of SDC which are not flat, but may have a good hf boost?

I don't see where the high-frequency boost changes things very much--if it sounds good, leave it in; if it's too much, cut it back with a good equalizer. Or am I missing the point of your question?

[Massive Dynamic]

But if for some reason it is necessary to record X/Y with cardioids, I'd strongly suggest angling them farther apart. 120 degrees might be a good starting point, particularly with smaller microphones which don't lose much high-frequency response off-axis. The point at which two ideal cardioids would cross at their half-power points would be with slightly greater than 130 (!) degrees of spread between them, ideally.

Having an LSD2, I often run coincident cards instead of Blumlein or M/S. Should the included angle be varied based on the distance to the loudspeakers and the distance between them? Any rule of thumb?

[muj]

> [H]ow would you run a pair of SDC which are not flat, but may have a good hf boost?

I don't see where the high-frequency boost changes things very much--if it sounds good, leave it in; if it's too much, cut it back with a good equalizer. Or am I missing the point of your question?

nope---I should definately try it and see what's up. I usually go omnis, but have started to back to more directional mics.


 

[saneproductions]

I am waiting on my recorder to arrive and I still need to order a second mic. I also moved, so it has been kind of hectic. I still plan to pursue this type of recording. I really appreciate all of the advice!!

Mike