M-S With A Wide Cardioid?

[mosrite]

Hi Folks,

Just interested to know if anyone has tried MS with a wide cardioid as the Mid mic?

How was the imaging compared to with a standard cardioid?

Any issues to speak of?

I have an MK21 pair that I use at the moment but would like to expand on it to get more precise imaging when required. I was hoping that just buying the MK8 capsule and using it with one of my MK21's might prove more pin point than the MK21 pair in a modified NOS. Any thoughts?

Cheers,

[fifthcircle]

Sure... why not?

I've done M-S with the full range of patterns in the center. More often than not, I'll go with something that is directional (hyper, fig-8, card), but in large ensemble settings when I have flanking mics, I'll go for a wider pattern. Gives you more of the spaced omni sound and the imaging isn't as good, but it still works for a large group (gives better imaging than 3 plain omnis across).

I'm not sure I'd use this for a smaller group, but it also may work well for m-s as a spot pair.

--Ben

[mosrite]

Cheers Ben.

But I guess that the imaging will suffer and there might not be any advantage (imaging wise) over the pair of wide cardioids in a modified NOS?

[d_fu]

I don't think the M channel has much, if anything, to do with imaging. It's the S channel spread that does this. M is just mono, and with a wide cardioid or even omni, there will be a some more sound from the sides and rear, but it's still just mono...

[DaveD]

Originally Posted by mosrite

I have an MK21 pair that I use at the moment but would like to expand on it to get more precise imaging when required.Cheers,

Hi Rab. You probably know this already, and probably beside the point, but two MK8s in blumlein will give you very precise imaging. Bit pricey though

[davebl@dircon.c]

I think the imaging will be unafected but the overall impression may be that the sound is more imediate as the broad cardioid is more omni.

Its a very good move in my opinion.

[davebl@dircon.c]

To add to the MS question, I use M/S all the time for films sound recording mostly with more hyper cardioid mics Sennheiser MKH 30/40 or 30/60 mostly. The best imediate sound is from a 30/20 pair if the mic placment is right.

What is apparent is that SDC mics seem to perform far better than LDC's. I used a 414 pair agains a MKH30/40 ones and the diference in imaging was massivly improved over the 414's. Apart from I dont like 414's anyway, the 414's sounded wolly by comparison and the imaging was very poor.

If I had used a 30/20 then I think there would have been a further improvment.

Im wrestling with this question at the moment as to weather to go Omni Schoeps or Gefell, may MKH 30 for a new tree set up. Broad cardioid may be a good move too.

[fifthcircle]

Originally Posted by d_fu

I don't think the M channel has much, if anything, to do with imaging. It's the S channel spread that does this. M is just mono, and with a wide cardioid or even omni, there will be a some more sound from the sides and rear, but it's still just mono...

Sure it does- has to do with the way it sums out.

If you think of it this way- M-S is going to sum out to 2 microphones of the same pattern at 90 degrees, each 45 degrees off axis of the source. So M-S with a cardiod gives you basically X-Y, M-S with 2 Fig 8 gives you blumlein. Now, we know that it doesn't sound exactly the same because of the nature of on and off axis of the microphones used.

That is why I use the omni only in large settings. It really does not image the way a cardiod, fig-8 or hyper cardiod will image. It is kind of an "accurate mono" kind of sound. Great when you have flanks on an orchestra or wind band, but not so much when it is the only mic on a chamber ensemble.

With a sub-cardiod in the center, you'll have the net effect of two subs at 90 degrees. You'll have imaging, but you'll likely get a better one if either the subs are moved apart or if you go with a more directional mid.

--Ben

[roonsbane]

M/S with an omni will yield extremely precise imaging. I have had the pleasure of having it up while in my video monitor from stage someone walks out on stage between pieces. The imaging is uncanny. As that person walks across. There they are! precisely where I see them on camera. Also, it's by no means a boring image the way I usually feel about M/S with a cardioid or Y/Y. it's for this reason that I only use X/Y (often panned to the same spot or at least way in) to spot individual instruments within a bigger main array picture. I don't use this M/S on small groups because I usually prefer a-b with omni's. These small groups can often be complimented by a looser spacious A-B image. The thing this M/S omni array will not allow you to do is dry up the image the way it would if you favor the Mid with an M/S with cardioid. If you want to experiment and worry about covering your ass, try a Decca tree with the Omni M/S in the front. I use the Schoeps MK2H/MK6 combo.

Have fun experimenting.
Cameron

[liuto]

Originally Posted by fifthcircle

Sure it does- has to do with the way it sums out.

If you think of it this way- M-S is going to sum out to 2 microphones of the same pattern at 90 degrees, each 45 degrees off axis of the source. So M-S with a cardiod gives you basically X-Y, M-S with 2 Fig 8 gives you blumlein. Now, we know that it doesn't sound exactly the same because of the nature of on and off axis of the microphones used.

That is why I use the omni only in large settings. It really does not image the way a cardiod, fig-8 or hyper cardiod will image. It is kind of an "accurate mono" kind of sound. Great when you have flanks on an orchestra or wind band, but not so much when it is the only mic on a chamber ensemble.

With a sub-cardiod in the center, you'll have the net effect of two subs at 90 degrees. You'll have imaging, but you'll likely get a better one if either the subs are moved apart or if you go with a more directional mid.

--Ben

It seems to be a bit more complicated than you stated:
MS with omni and figure eight will result in two patterns fixed at an angle of 180 degrees but with varying pattern, depending on the ratio of omni and eight.
MS with two eights will result in two eights at a varying angle, dependent on the ratio between M and S eight.
If you use cardioid as a center the resulting patterns will vary again in their angles and also the patterns will vary from cardioid to eight in the extreme settings. The angle of 90degrees is one special case, if the amount of M and S is about the same.
Regards
Hermann Platzer

[d_fu]

Originally Posted by fifthcircle

M-S with 2 Fig 8 gives you blumlein.

Does it? How so?

[liuto]

Originally Posted by d_fu

Does it? How so?

http://www.sengpielaudio.com/Stereo-Matrix01.pdf
http://www.sengpielaudio.com/Koinzid...Niere-Acht.pdf
http://www.sengpielaudio.com/Koinzid...Kugel-Acht.pdf

These papers perfectly show the (theoretical) equivalence of MS and XY.
Best regards
Hermann

[d_fu]

Originally Posted by liuto

These papers perfectly show the (theoretical) equivalence of MS and XY.

I'm aware of that. I was referring to Blumlein / MS with Fo8s.. But I see it's mentioned in the first pdf...

[Yannick]

Accuracy of imaging has nothing to do with the M pattern - not in this simplistic way.

Changing the M pattern however does have several consequences:

1. for equal S levels, the recording angle changes from very wide (M=omni) to narrow (M=8). You could look at the M pattern as a consequence of a. the largeness of the source b. the acoustics (as less S level often results in a drier pickup).

2. angular distortion changes in function of the M pattern. fig8 has the least angular distortion (as Blumlein has), M=omni tends to the sides of the (big?) source being pulled into the L and R speakers, not unlike a big AB setup (or decca tree).

In this sence, M=wide cardioid does result in a less perfect imaging, but if this is the correct choice, who will argue (eg. you could use this to make the center of the stage appear wider - ie. more precise. Compared to a cardioid M where the sides of the stage would be more precise, but the center (woodwinds) too compressed etc. etc.)

Lastly, choice of the M pattern can be a consequence of the tonal quality of this pattern in this hall.

And then we could go on and talk about vertical angles (eg pointing a too wide pickup above the source, so you pickup more ambience and get a complete spread between the speakers) but that gets more complicated, I don't even remember where I put that paper.

[fifthcircle]

Originally Posted by liuto

It seems to be a bit more complicated than you stated:

You're absolutely right... This is what I get for posting at the end of a long day when I'm really tired... I think things have been clarified-

Thanks!

--Ben