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Old March 21st, 2009, 06:54 AM   #1
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What About Using an Omni?

I was recording sound for a friend's indoor production. I used mostly an MKH-60, which sounded good and not reflective b/c the studio's ceilings were quite high.

But things got a little tricky while booming amongst multiple actors. I kept rotating the mic to catch the dialogue, but esp. with three actor scenes, it became quite challenging.

I know lavs offer an alternate solution. But I've continued to think about the challenges of booming three actors who are somewhat far way from each other. Why not use a wider pickup pattern, like an MKH-50 (super-cardiod)? ... But then why not go even wider with an MKH-40 (cardiod)? ... But then why not just use an MKH-20 (omni-directional)?

I realize an omni is sensitive from all angles, but isn't that what I would want when trying to record three actors at varying distances? The set is quiet, so there isn't a lot extraneous noise. So why not boom with an omni in this situation, esp. if lavs are ruled out for some reason?

Thanks much for any input.

Last edited by Peter Moretti; March 21st, 2009 at 08:25 AM.
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Old March 21st, 2009, 09:57 AM   #2
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You ask the question like you are limited to a certain mic. You're not. Use whatever works! You can use certain mics, or you can throw up another boom if you like.

In terms of booming, you should try and learn the scene and do rehearsals so you know who talks next. It makes it lot easier.
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Old March 21st, 2009, 10:09 AM   #3
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I was recording sound for a friend's indoor production. I used mostly an MKH-60, which sounded good and not reflective b/c the studio's ceilings were quite high.

But things got a little tricky while booming amongst multiple actors. I kept rotating the mic to catch the dialogue, but esp. with three actor scenes, it became quite challenging.

I know lavs offer an alternate solution. But I've continued to think about the challenges of booming three actors who are somewhat far way from each other. Why not use a wider pickup pattern, like an MKH-50 (super-cardiod)? ... But then why not go even wider with an MKH-40 (cardiod)? ... But then why not just use an MKH-20 (omni-directional)?

I realize an omni is sensitive from all angles, but isn't that what I would want when trying to record three actors at varying distances? The set is quiet, so there isn't a lot extraneous noise. So why not boom with an omni in this situation, esp. if lavs are ruled out for some reason?

Thanks much for any input.
You're overlooking that each mic has an optimum working distance and the less directional the mic, the closer you need to work it to get good quality sound. An omni needs to be within about 8 inches of the speaker's mouth and a cardioid about 12 inches to get the clear sound you get at 18-24 inches with a hyper or short 'gun. That makes the difference between a mic that's in-frame and one that's not in most dialog situations. A single omni or cardioid positioned to cover all three actors will be too far away from any one of them to give you very good results.
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Old March 21st, 2009, 10:13 AM   #4
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Peter,
If you have an omni you could try it and see how the sound compares to the other mics you are using but you may find that the distance is still a problem. As Jeffrey said limiting yourself to one mic may be the issue in this case depending on the blocking of the scene. It is not always possible to get all the sound with just one mic. Maybe you can add a second boom into the system so you can pick up the dialog of the farthest person. Or use a lav or some other combination of mics. This is one of the tricky parts of staging a complex scene. A lot of people would be doing both boom and body mics recording them separately in a situation like this.
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Old March 21st, 2009, 10:39 AM   #5
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Peter,
If you have an omni you could try it and see how the sound compares to the other mics you are using but you may find that the distance is still a problem. As Jeffrey said limiting yourself to one mic may be the issue in this case depending on the blocking of the scene. It is not always possible to get all the sound with just one mic. Maybe you can add a second boom into the system so you can pick up the dialog of the farthest person. Or use a lav or some other combination of mics. This is one of the tricky parts of staging a complex scene. A lot of people would be doing both boom and body mics recording them separately in a situation like this.
Exactly why sound guys get paid the big bucks. ;) Use what you need to get the job done whether it's boom, lavs, etc. What people always forget is that you can use plant mics too. Hang mics off C-stands, tape them to walls, hide them in objects, etc.

With experience you'll know what works and what doesn't.
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Old March 21st, 2009, 11:50 AM   #6
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For stationary dialog scenes with multiple actors I have used 2 or even 3 cardioids or hypers hanging from above, usually by the cable and taped to whatever (light fixtures, ceiling, air vents). Omni would work if you can get it close enough. If the location is quiet, it can be further away than the "rule" says as there is no other sound to be picked up.
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Old March 22nd, 2009, 06:07 AM   #7
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Thanks for the replies guys. BTW, my solution was to lav the farthest away person in one of the three person scenes, but the idea of using an omni intriges me. What I'll probably do is rent an MKH-20, 40 and 50 and compare them to my 60.

As for distance from the mic, I've looked at the sensitivity and noise specs for the 20 (omni), the 40 (cardoid) and the 50 (super/hyper-cardoid). What I found is that they are essentially identical, with omi being slightly less noisy. I would take this to mean that as long the set is truly quiet, I should be able to place an omni, cardoid and super/hyper cardiod about the same distance from the talent and get approximately the same sound.

The real change in noise and sensitivity occurs in the jump to the MKH-60. The 60 is almost twice as sensitive and about a third less noisy. And the MKH-70 improves considerably more in term of sensitivity and noise.

BTW, I realize I'm only looking Sennheisers in this comparison, and these observations may not hold for other manufacturers' designs.

So if I can get close enough and the set is quiet enough, an omni may be an option.

That said, again, real world testing is what I have to do. And thanks everyone for all the input. I'll keep ya posted. ;)
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Old March 22nd, 2009, 07:11 AM   #8
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...
So if I can get close enough and the set is quiet enough, an omni may be an option.

That said, again, real world testing is what I have to do. And thanks everyone for all the input. I'll keep ya posted. ;)
The set must be REALLY quiet - like professional recording studio grade quiet. Don't forget too that in addition to self-noise and ambient noise pickup issues, the timbre of the sound has to match from character to character and shot to shot. If you're going to intercut between your three-shot establishing shots, closer two-shots and individual character closeups, as you usually would, the sound quality of the voice of a given person as recorded in the three-shot needs to be identical to the quality recorded when you shoot him closer in the other coverage shots. If you're going to use omni's for the longer shots and other mics or lavs for the close shots, just like you need to have the same colour rendering on the visuals in shots that need to intercut, you can't allow any qualitative differences in the sound rendering between the mics from shot to shot either.
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Old March 22nd, 2009, 07:48 AM   #9
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Steve,

Thanks, I've continued my pondering. I think a more accurate conclusion for me to draw is that a cardiod pattern may be a good choice for the indoor booming of multiple talent, even when just going back and forth between two actors.

In terms of Sennheiser models, I've heard many people say to use a 50 indoors, which is a super or hyper cardiod depending on whom you talk to.

But if I'm going to go with a 50, why not a 40? Sensitivity and noise are identical. The 50 has a tighter pattern, but that also means less off-axis pickup of the talent.

I guess it's a balancing act between the location's noise and reflectivity and the importance off-axis pickup of the talent's voices. It just seems that a cardioid could actually do a better job, even though a hyper/super-cardiod is often recommended.

I'm saying this b/c looking at the specs, the somewhat longer "reach" of a 50 vs a 40 seems solely the result of increased off-axis rejection. A 50 is not any more sensitive or less noisy than a 40. On the other hand, the 60 and 70 do have significant increases in sensitivity and decreases in noise. Their reach is not solely attributable to off-axis rejection, they have what I would categorize as truly longer reach.

Again, I will have to test this out, as real world experience always trumps conclusions drawn from reading the specs.

And thanks :) for your input.
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Old March 22nd, 2009, 11:11 AM   #10
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Steve,

Thanks, I've continued my pondering. I think a more accurate conclusion for me to draw is that a cardiod pattern may be a good choice for the indoor booming of multiple talent, even when just going back and forth between two actors.

In terms of Sennheiser models, I've heard many people say to use a 50 indoors, which is a super or hyper cardiod depending on whom you talk to.

But if I'm going to go with a 50, why not a 40? Sensitivity and noise are identical. The 50 has a tighter pattern, but that also means less off-axis pickup of the talent.

I guess it's a balancing act between the location's noise and reflectivity and the importance off-axis pickup of the talent's voices. It just seems that a cardioid could actually do a better job, even though a hyper/super-cardiod is often recommended.

I'm saying this b/c looking at the specs, the somewhat longer "reach" of a 50 vs a 40 seems solely the result of increased off-axis rejection. A 50 is not any more sensitive or less noisy than a 40. On the other hand, the 60 and 70 do have significant increases in sensitivity and decreases in noise. Their reach is not solely attributable to off-axis rejection, they have what I would categorize as truly longer reach.

Again, I will have to test this out, as real world experience always trumps conclusions drawn from reading the specs.

And thanks :) for your input.
Just remember, it's not just sensitivity that's important. Sensitivity to off-axis deals with levels but the character of the sound is also important. If the level remains usable but the tonality and subjective quality of the sound changes depending on the speaker's position relative to the mic you'll still have problems in post.
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Old March 23rd, 2009, 06:46 PM   #11
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Originally Posted by Peter Moretti View Post
Thanks for the replies guys. BTW, my solution was to lav the farthest away person in one of the three person scenes, but the idea of using an omni intriges me. What I'll probably do is rent an MKH-20, 40 and 50 and compare them to my 60.

Hi Peter,

Here's a test that might help. These are recordings of the Sennheiser MKH-20, MKH-40 and MKH-50 as well as the MKH-416.

Microphone Polar Patterns - Video Examples to learn from at DVcreators.net

I recorded these with the SD 302 directly into an HPX500. The room is about 25'x30' with 8' ceilings, low ply commercial carpeting. We hung a few moving blankets around the jib to help deaden reflections, you "hear" the room most with the omni for sure.
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Old March 24th, 2009, 03:20 AM   #12
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Wow, that's awesome.

The omni indeed sound more hollow b/c of the room reflections. The cardioid seemed to be the best compromise. I was surprised that the 416 didn't pickup more reflections, as interference tube shotguns are apt to do. Perhaps the sound blankets helped.

THANKS AGAIN!
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Old March 25th, 2009, 08:05 AM   #13
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The 416 has a very narrow pattern, which makes your job tough. I'd use a hypercardiod and put a lav on the hardest person to reach. That way you only have to cover two people.
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