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Gazwas

Rotationally symmetrical polar pattern?

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Hello Everyone I’m new here and hoping to learn more about the mysterious subject of capturing quality audio. Apologies first then if my questions sound stupid or amateurish. 
 

I’m a photographer who’s played with video for quite a few years but have only recently realised the upmost importance of capturing quality audio to catapult production values. 
 

I’ve just received my beautiful new Schoeps CMC1 MK41 and was wondering if there is a correct orientation for the microphone to get the best polar pattern. Schoeps make a big point of the CMIT5U having a “rotationally symmetrical polar pattern” but nothing about MK series capsules having the same. When I screw the capsule to pre-amp the logos don’t match up so there seems no obvious correct way up.

 

Should I not worry about orientation as sound is not effected or should I always try and get the MK41/polar pattern logo on the top in the shock mount? And is this the is same for any other microphone that doesn’t advertise rotational symmetry?

 

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Let me offer you a second CMC1, including full windshields, if you hear any difference in a blind test !

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38 minutes ago, cineli said:

Let me offer you a second CMC1, including full windshields, if you hear any difference in a blind test !

 

Thanks for the reply - so no difference and just some marketing speak from Schoeps.

 

You do some great mounts by the way and while looking at the pictures of your E-OSIX-CMC1U mount (thinking of buying one) the photographer in me noticed the microphone was twisted and what sparked my question.

 

7 minutes ago, FrankH said:

Laces out, logo on top, always. 

 

I think I may do the same in the absence of any technical information from Schoeps but as @cineli said above would anyone really hear a difference when micing dialogue? Might fire an email over to Schoeps and ask.

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It doesn’t matter and no, it’s not marketing speak. As you noticed, you were talking about the CMIT on the one hand, and about the CMK641 on the other. Those are two very different microphones. 
For the CMK641 it doesn’t matter where the logo is and Schoeps make the point in the manual that the logo from the capsule and from the preamp don’t necessarily align. Point it nicely at the sound source and it’ll sound nice. 

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2 hours ago, Constantin said:

IAs you noticed, you were talking about the CMIT on the one hand, and about the CMK641 on the other. Those are two very different microphones. 
For the CMK641 it doesn’t matter where the logo is and Schoeps make the point in the manual that the logo from the capsule and from the preamp don’t necessarily align.

 

Seems like after doing a little more digging the direction of the capsule can matter on the Colette series and it depends on the capsule. MK4V, MK41V and MK8 are all classed are vertically aligned capsules and need to be positioned correctly. The others Schoeps capsules are class as axially aligned so orientation doesn't matter. 

 

Thanks everyone for your input.

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50 minutes ago, Gazwas said:

MK4V, MK41V and MK8 are all classed are vertically aligned capsules and need to be positioned correctly


yes of course, those capsules are differently oriented, and I didn’t say that it doesn’t matter for any Colette capsule, I was specifically speaking about the MK41, as per your question 

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Consider the Pearl and Milab mics that have rectangular capsules, which have different patterns vertical versus horizontal.    The same is true for ribbons.  The differences with both relate to off-axis sound pickup.    Anything on axis 0º will sound the same with either orientation, it's the sound of 90º/etc that's going to change.  

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1 hour ago, Constantin said:


yes of course, those capsules are differently oriented, and I didn’t say that it doesn’t matter for any Colette capsule, I was specifically speaking about the MK41, as per your question 


I did say I was still learning so sorry if my response are annoying. Thanks so much for your input and at least now I’ve one less thing to worry about. 

16 minutes ago, EmRR said:

Consider the Pearl and Milab mics that have rectangular capsules, which have different patterns vertical versus horizontal.    The same is true for ribbons.  The differences with both relate to off-axis sound pickup.    Anything on axis 0º will sound the same with either orientation, it's the sound of 90º/etc that's going to change.  


Brilliant explanation thank you!

 

Makes perfect sense now that it's the off axis sound that changes rather than the on axis. 

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15 hours ago, Gazwas said:

I did say I was still learning so sorry if my response are annoying. 


Then you might consider to be careful with statements such as this: 

 

23 hours ago, Gazwas said:

 just some marketing speak from Schoeps.

 

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3 hours ago, Constantin said:


Then you might consider to be careful with statements such as this: 

 

 

 

I'm not sure what is so offensive about that comment about marketing speak as don't all companies do it?

 

Any way, for anyone interested I've had a reply back from a a member of Schoep's support department and it would seem the MK41 is indeed rotationally symmetrical just like the CMIT but obviously this is omitted for the feature list for some reason. Possibly not to confuse users with difference capsules - I've no idea? 

 

Hope that helps someone who might be wondering the same.

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Gazwas, the rotational symmetry of Schoeps' CMIT microphones is a feature that truly differentiates them from some competing brands. For other microphone or capsule types, however, such as omnis, cardioids and supercardioids that aren't "side-facing", rotational symmetry is the usual situation that users assume implicitly.

 

Have you ever seen someone set up a pencil-type cardioid, aim it at the sound source, then rotate the mike until the logo (or whatever) was face up? That's not common practice, because it's widely understood that it makes no difference. When it does make a difference, it's the manufacturer's responsibility to say so, and to provide some way of showing how the microphone should be oriented.

 

To my mind, if something isn't a distinguishing feature, it would be misleading to emphasize it in the sales literature--as if implying that other people's microphones aren't exactly the same way.

 

--best regards

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12 hours ago, DSatz said:

Gazwas, the rotational symmetry of Schoeps' CMIT microphones is a feature that truly differentiates them from some competing brands. For other microphone or capsule types, however, such as omnis, cardioids and supercardioids that aren't "side-facing", rotational symmetry is the usual situation that users assume implicitly.

 

When you say side facing do you mean shotguns?

 

While looking at shotgun microphones I've never seen this statement made about any other competing microphone but equally, I've never seen any of the competition mention you have to use them the correct way up hence my confusion in the original question.

 

I've seen a YouTube video by Ty Ford where he rotated a MiniCMIT microphone to test this feature but in converse, tests done by numerous other YouTubers on anything from Rodes to DPA's or Sennheiser's there has never been mention of making sure the shotgun microphone was rotationally aligned.

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37 minutes ago, Gazwas said:

 

When you say side facing do you mean shotguns?

 

While looking at shotgun microphones I've never seen this statement made about any other competing microphone but equally, I've never seen any of the competition mention you have to use them the correct way up hence my confusion in the original question.

 

I've seen a YouTube video by Ty Ford where he rotated a MiniCMIT microphone to test this feature but in converse, tests done by numerous other YouTubers on anything from Rodes to DPA's or Sennheiser's there has never been mention of making sure the shotgun microphone was rotationally aligned.

Side facing, sometimes called 'Side Address'. Not seen a 'Side Address' shotgun mic - hard to imagine. Fair to work on the principle a manufacturer does their best to make the polar pattern of a 'Side Address' (or any other mono) microphone, rotationally symmetrical at 0º to the axis of the polar pattern - unless otherwise stated (I would have thought anyway).

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4 hours ago, daniel said:

Fair to work on the principle a manufacturer does their best to make the polar pattern of a 'Side Address' (or any other mono) microphone, rotationally symmetrical at 0º to the axis of the polar pattern - unless otherwise stated (I would have thought anyway).

 

Forgive me If I'm not understanding what you said above correctly but if all manufacturers try and make mono microphones symmetrical why has it been suggested above this is such a unique feature of the Schoeps CMIT microphones?

 

The DPA 4017 for example is arguably as good as the CMIT off axis however, in my knowledge it is not referred to in the specs as a rotationally symmetrical microphone?

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2 hours ago, Gazwas said:

The DPA 4017 for example is arguably as good as the CMIT off axis however, in my knowledge it is not referred to in the specs as a rotationally symmetrical microphone?


Every manufacturer sets their own priorities for their specs. You will notice that often specs between two manufacturers, or sometimes even two mics from the same manufacturer, have different properties listed. Sometimes it’s tricky to find out the exact differences and sometimes it’s really obvious. 
Some manufacturers are really proud of what they have achieved and so they will put it in their specs. Another manufacturer worked on that same issue on their mic, but they believe that they haven’t quite gotten it to perfection as they see it, so they leave it out of the specs, because they also think that nobody is going to able to notice. Or maybe the other manufacturer just doesn’t think this particular feature is that much of a big deal. 

So any end-firing small condenser mic with one round capsule is rotationally symmetrical. Unless they messed the mic up badly. 
A shotgun is different because of the interference tube before the capsule which affects the sound from the sides and various other angles. It move the soundwaves out of phase, so to speak, from the direct sound. This is achieved by lengthening the path of the sound entering from the sides before it reaches the capsule. I find it easy to imagine how a small rotation if the mic can change the point of entry of soundwaves into the mic and causing to take a different path to the capsule and thereby altering the sound slightly when compared to the previous version. 
If you manage to build a shotgun mic that will always sound exactly the same no matter how you rotate the mic you should be really proud. Then again, this would also be somewhat difficult to prove and also it‘d be difficult to assess how important this feature might actually be. 
But every manufacturer can decide that for themselves. 

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All the standard (axial address) capsules like the MK41 have a naturally occurring 'rotationally symmetrical polar pattern' without Schoeps having to do anything to achieve it. The designers of the interference tube of the CMIT however probably put a lot of work into the rotationally symmetrical polar pattern for that mic, however, so felt justified in advertising the "rotationally symmetrical polar pattern" of their endeavours! As such I would expect them to say,

" You can position the logo however you like - we have engineered a rotationally symmetrical polar pattern into the CMIT"!

 

But it's probably easier to get to the switches if they are on the top.

 

Seriously though, when interference tubes were first developed, the holes being along the top had an effect on its 'rotational symmetry'. It's a new term for me (in advertising, not in understanding it's meaning) but they're just making a point that they took this aspect of the design for their very late entries to the interference tube canon seriously.

 

Jez

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Thanks for all the replies. 
 

I’m no trying to make out Shoeps are doing anything wrong here or a dislike for their microphones as I’m in love with my CMC141. I just didn’t understand the significance of this CMIT feature over its direct competition. 
 

When I think of the more recent shotgun microphones like the Sennheiser 8060 and DPA 4017 which both offer modularity (capsule amd pre-amp) I can’t imagine either of those being anything other than rotationally symmetrical also. Surely a crude screw thread wouldn’t be best practise if they where not symmetrical. 

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I took apart one of the early interference tube classics several years ago - the Sennheiser 805 - and was surprised to find that beneath the meticulously machined upper slots of the outer casing was an inner tube with small round holes (albeit also meticulously positioned and varying in diameter at the 'horn' so to speak). So I had a second physics lesson. I wonder what the massive Electrovoice looked like up close or indeed inside?

 

But the point is that in such a 'simple' (or at least early) design pointing the slots (actually holes) upwards tended the 'unwanted' ambient sound (to be cancelled by the interference tube) to be the more random outdoor noises from the air rather than the stuff bouncing from below. One might assume that the sound from either side might be the stuff we really want the interference tube to prioritise in general use but whilst the outside appearance of IT mics has certainly become more slotty over the decades I've never dared taking another one apart. (Said 805 stopped working shortly after my investigation)!

 

All told, I'm not sure what benefit exactly a rotationally symmetrical polar pattern has in a shotgun, but they apparently achieved it so good on them! I'm happy to report that my Schoeps omni boasts a rotationally symmetrical polar pattern whilst my Schoeps figure of eight does not!

 

Jez

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20 hours ago, The Immoral Mr Teas said:

I took apart one of the early interference tube classics several years ago - the Sennheiser 805 - and was surprised to find that beneath the meticulously machined upper slots of the outer casing was an inner tube with small round holes (albeit also meticulously positioned and varying in diameter at the 'horn' so to speak). So I had a second physics lesson. I wonder what the massive Electrovoice looked like up close or indeed inside?

 

But the point is that in such a 'simple' (or at least early) design pointing the slots (actually holes) upwards tended the 'unwanted' ambient sound (to be cancelled by the interference tube) to be the more random outdoor noises from the air rather than the stuff bouncing from below. One might assume that the sound from either side might be the stuff we really want the interference tube to prioritise in general use but whilst the outside appearance of IT mics has certainly become more slotty over the decades I've never dared taking another one apart. (Said 805 stopped working shortly after my investigation)!

 

All told, I'm not sure what benefit exactly a rotationally symmetrical polar pattern has in a shotgun, but they apparently achieved it so good on them! I'm happy to report that my Schoeps omni boasts a rotationally symmetrical polar pattern whilst my Schoeps figure of eight does not!

 

Jez

 

The 416 also uses the tube with consecutive holes of varying diameter. I boomed for a mixer once that claimed the slots on the 416 mattered which way they pointed but I could never hear a difference.

I tried to open up my CMIT to see what it uses but the interference tube is fully enclosed with the capsule. A flashlight didn't reveal any of the holes behind the slots like on a 416 though.

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2 hours ago, Patrick Farrell said:

 

The 416 also uses the tube with consecutive holes of varying diameter. I boomed for a mixer once that claimed the slots on the 416 mattered which way they pointed but I could never hear a difference.

I tried to open up my CMIT to see what it uses but the interference tube is fully enclosed with the capsule. A flashlight didn't reveal any of the holes behind the slots like on a 416 though.

 

Patrick, thanks for the heroic investigation! I-tubes have obviously got more slotty over the decades but have we been duped?!? Even all my 1970s/1980s early learning literature on the theory of I-tubes (possibly all BBC but maybe Europe/USA too) to my memory seemed to talk of slots rather than holes (and I recall no mention at all of the widening of the holes at the bell).

 

If any manufacturers of I-tube mics are listening could they butt in and explain what the hidden changes have been since the 1960s? Especially Schoeps for the first CMIT since you failed Patrick!! As an aside, Al's recently posted 1978 December magazine in 'general' has some mention in the later pages of the newly released Neumann KMR 81 (I think) talking of similar "why we looked at IT mics" issues back then.

 

What's inside yr mics folks?!?

 

Cheers Patrick, Jez

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