Large or small diaphram omni's

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HangDawg

HangDawg

bUnGhOlIo
I'm trying to make up my mind between a pair of SP C-4 or pair of M-Audio Solaris' I don't currently have any omni mics which either of these would give me. The Solaris would also give me the benefit of figure-8. I heard the recording Massive Master did with a pair of these and was pretty impressed. I haven't heard the C-4s. What would be the pro/con of large versus small dia omni's?

Oh, there is the price differnce too. The C-4's I can get for $300 versus $475 for the Solaris but there is the figure-8 thing.


Hmmmmmmmmm?:confused:
 
figure 8 is a very useful thing to have around for rejection purposes.

also fun to do the "two vocalists at once" thing.

and of course for stereo micing.

personally i would the m-audio mics cause i think they look cooler. i mean visually. i like my mics to look cool. might just be me but...
 
I asked the same question of Brent Casey at PMI Group (Studio Projects) on Recording.Org.

I got an interesting answer back: the typical LDC that does omni is going to have bass loss issues because both sides of the capsule diaphragm are open to the sound. A true LDC omni is the DPA 4041, which is beyond reach of nearly all of us, price-wise.

True omni capsules are one-side-only, where the rear side of the diaphragm is isolated from the sound. I looked this up in the excellent DPA tutorial docs on Omni vs Cardioid, and confirmed it. The SDC omni such as my C4 will have more robust bass response than a LDC B3 in omni mode.

None of this has bearing on using the Figure-8 mode, and the double sided LDC do this just fine, by design. I was thinking about a matched pair of SP B3 for omni and F8, but it looks more like they would be used mostly for F8. I already own a pair of C4.
 
bgavin said:
I asked the same question of Brent Casey at PMI Group (Studio Projects) on Recording.Org.

I got an interesting answer back: the typical LDC that does omni is going to have bass loss issues because both sides of the capsule diaphragm are open to the sound. A true LDC omni is the DPA 4041, which is beyond reach of nearly all of us, price-wise.

True omni capsules are one-side-only, where the rear side of the diaphragm is isolated from the sound. I looked this up in the excellent DPA tutorial docs on Omni vs Cardioid, and confirmed it. The SDC omni such as my C4 will have more robust bass response than a LDC B3 in omni mode.

None of this has bearing on using the Figure-8 mode, and the double sided LDC do this just fine, by design. I was thinking about a matched pair of SP B3 for omni and F8, but it looks more like they would be used mostly for F8. I already own a pair of C4.
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You should ask Brent Casey if the C4 has a "ture omni capsule" or not.
 
He wouldn't be suggesting something different (and far more expensive) if he felt his cheaper mics were as good. Read it, man!
 
DJL said:
You should ask Brent Casey if the C4 has a "true omni capsule" or not.
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Of course it would be a true omni, since it's a single diaphragm microphone. Why wouldn't it be a true omni? That's just a silly question.
 
Just based on Massive Masters post on the M-Audio's I would go with those. I'm still amazed at how clear everything was.
 
Harvey Gerst said:
Of course it would be a true omni, since it's a single diaphragm microphone. Why wouldn't it be a true omni? That's just a silly question.
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Thanks Harvey, I didn't know it was a silly question and it's good to know ALL single diaphragm omni capsules are "true" omni capsules.
 
<ALL single diaphragm omni capsules are "true" omni capsules.>

Yep, that's true, whether we like it or not.
 
vestast said:
Just based on Massive Masters post on the M-Audio's I would go with those. I'm still amazed at how clear everything was.
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I started thinking, I don't think the boom stands I have will hold one of the Solaris mics up if I use them for drum overheads. I might have to get some new stands.:(
 
HangDawg said:
I started thinking, I don't think the boom stands I have will hold one of the Solaris mics up if I use them for drum overheads. I might have to get some new stands.:(
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I use Atlas SB36W large boom stands.
 
DJL said:
Thanks Harvey, I didn't know it was a silly question and it's good to know ALL single diaphragm omni capsules are "true" omni capsules.
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You might wanna go back and read the big mic thread, starting with the quote from David Satz of Schoeps. It's covered in a lot of detail there. Basically, if it's a single diaphragm mic, it has to be sealed to make it an omni. Pure pressure mics work by responding to pressure, not velocity. Except for a small vent hole (to prevent them exploding when flying), they must be a sealed capsule design to work.

Dual diaphragm capsules can be made to mimic the response of an omni, but, as Brent Casey pointed out in another thread on this forum, it ain't perfect.
 
Harvey Gerst said:
You might wanna go back and read the big mic thread, starting with the quote from David Satz of Schoeps. It's covered in a lot of detail there. Basically, if it's a single diaphragm mic, it has to be sealed to make it an omni. Pure pressure mics work by responding to pressure, not velocity. Except for a small vent hole (to prevent them exploding when flying), they must be a sealed capsule design to work.

Dual diaphragm capsules can be made to mimic the response of an omni, but, as Brent Casey pointed out in another thread on this forum, it ain't perfect.
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Thank you again Harvey... and I guess there are a lot of mics out there that ain't perfect but sound awesome IMO. :)
 
BTW DJL,

I didn't mean to come off insulting, but I assumed you read the big mic thread and understood how true omni's worked. I apologize if my answer sounded condescending.

As Brent casey pointed out in the C4 thread, dual diaphragm multi-pattern mics can "mimic" a pure pressure omni mic to a degree, but it can't be a pure omni, since the back side of the front diaphragm isn't completely sealed, so the low end suffers, and the size of the capsule created interference patterns at higher frequencies. It's closer to the sound of two back-to-back cardioids.

This is true whether it's a Studio Projects mic or a Neumann; it's basically a law of physics, and how the two diaphragms are coupled electronically.

It was wrong of me to assume you knew that. Sorry.
 
Marik said:
<ALL single diaphragm omni capsules are "true" omni capsules.>

Yep, that's true, whether we like it or not.
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Why wouldn't we like it? Thanks
 
DJL said:
No problem Harvey... I appreciate your help.

PS... I'd love to hear your take on the subject of "microphone impulse response" that they are talking about in the http://www.homerecording.com/bbs/showthread.php?threadid=118752 thread. :)
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Bob Cain is a very sharp guy, but impulse modeling (and convolution modeling) is a very touchy subject with a lot of us. My basic take on modeling is that it's a very sophisticated form of eq and that we haven't reached the point at which the needed horsepower to do it right is available at a low price point. In some situations, it can get surprisingly close, but it's not as cut and dried or as perfect as most manufacturers would have us believe.

Is it possible to convolute an SM-57 to make it sound like a U-47? Maybe, but not today. When it does happen, impulse measurements will play an important part in the design. It's one of the most accurate forms of testing available today for electroacoustic devices, such as microphones and speakers.
 
Harvey Gerst said:
Bob Cain is a very sharp guy, but impulse modeling (and convolution modeling) is a very touchy subject with a lot of us. My basic take on modeling is that it's a very sophisticated form of eq and that we haven't reached the point at which the needed horsepower to do it right is available at a low price point. In some situations, it can get surprisingly close, but it's not as cut and dried or as perfect as most manufacturers would have us believe.

Is it possible to convolute an SM-57 to make it sound like a U-47? Maybe, but not today. When it does happen, impulse measurements will play an important part in the design. It's one of the most accurate forms of testing available today for electroacoustic devices, such as microphones and speakers.
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Thanks again Harvey... oh, and I have read the big mic thread a few times and some of it I understand and some of it I don't. As for mic and amp modeling goes... I think there is more to it than EQ... and I've yet to hear one that didn't suck eggs when compared to the real thing (but it can be a fun effect). Anyway, thanks for your take on the subject... and IMO we are in agreement.
 
If you can scrape together a little extra dough, you might want to check out the T.H.E. KA-04 body with the KR-1F omni capsule. The price tag on these is far south of a DPA but will get you close enough for anything but major label work. I have a pair of these and they work fabulously well with a baffle in an OSS arrangement for small ensemble micing. T.H.E. also sells a diffuse field omni capsule for the KA-04 body (plus several other capsules) that has a high frequency rise for recording more distant sources (the HF rise compensates for the high frequency loss that occurs that becomes a factor at distances greater than a few meters, without having to add eq.) I have personally never used this capsule, however. Taylor Johnson is also a nice guy to deal with.
 
Marik said:
<ALL single diaphragm omni capsules are "true" omni capsules.>

Yep, that's true, whether we like it or not.
Click to expand...

That was my thinking also, but the real point is "single sided". Brent (and DPA research papers) state the true omni only has a single side of the diaphragm exposed to the sound. The inside is isolated, or bass rolloff will occur.

The DPA 4041 is far beyond my reach (forever), so it's academic. I was Jonesing for a pair of SP B3 for omni (decca tree) and figure-8 (Blumlein). The B3 quasi-omni thing kinda put me off, and I have to reconsider.
 
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