Flat omnis?

[BrianHanke]

Why don't more manufacturers make omni mics with flat frequency responses? I can think of only four off the top of my head:

- Neumann KM131
- Schoeps MK2
- The AKG CK92 capsule
- Most Earthworks models

Is that really it, or am I leaving a few out? I'm very curious… Feel free to add to the list!

It seems to me that a true omni with a flat response is a very useful thing. All the models I listed are quite pricey and are often only available through special order in the States. Are there any cheaper omnis out there that don't have a high-frequency bump? I've looked at Shure, Oktava, Rode, Audio-Technica...

[hughesmr]

Are you asking in general, or limiting it to cheap mics? Not clear.

Anyway, these qualify if you omit "cheap":

Sennheiser 8020
DPA4003/4006TL/4006 (using free-field grid)
Josephson c617 Set

[BrianHanke]

Good additions to the list, thanks! It's an interesting state of affairs when Neumanns are actually the more affordable option!

Are there any low to mid range alternatives out there?

[jnorman]

brian - i just went through this search also. the AKG CK62 for the C460 and C480 bodies is a nice flat omni. the AT4049 is also pretty flat (they have just re-released the omni capsule to go with the new 4051b body) - my AT4051s are still some of my favorite mics ever, and i will likely pick up a pair of the omni capsules for them soon. the new AT4022 omnis are fairly flat, but more of a mid field than near field - but you can get pretty near flat with them slightly off axis ( i really liked the 4022s i had, and there is a clip of them you can hear of flute and piano in the thread about ORTF vs spaced pair). the beyer mc910 is also sort of mid field, and will probably work okay off axis. john willet uses his km183d's (which are diffuse field) pointed straight up to use them in the near field, though he just bought a pair of the ak31 caps for them - caps are interchangeable on the km183D system he uses, making them the equiv of km131s. recordings from the km131s are as good as anything i have heard. ivo sedlacek uses the schoeps cmc6/mk2 near field omnis to very nice effect, but are so spendy... i didnt really love my DPA 4006s, and wound up trading them off for 4011s (cards). my friend down in south oregon was not too enamoured of the josephsons he bought - he is using manley ref LDC's now.

[BrianHanke]

Good point about moving the mics a bit off-axis! I have the KM131s and I think they're ideal. I'm just curious why flat omnis in general seem to be limited to the most expensive brands?

The AT4049b does look flatter than I remember. I'm generally not a fan of ultra-small diaphragm mics like Earthworks because of the self-noise and I find they sound a bit “hard” for some reason...

[7rojo7]

4051s are awesome for the price, I had them in the early 90s. an engineer brought in some B&Ks and we put them up side by side and there wasn't much difference. we use dthe B&Ks because he brought them. these were cards though. just a comment on the quality

[BrianHanke]

It seems like the Audio-Technicas are the closest one can get to flat in that price range. Oktava MK-012s have a big HF bump, as does the Shure KSM141. I rented an AT4050 a while ago and was really impressed with it, but of course it isn't a true omni.

[BrianHanke]

Does anyone have experience with the Lauten Torch? They look really interesting: vacuum tube design, interchangeable capsules and a relatively flat omni response.

[aracu]

There is a relatively new, very small sized Sonodore.

[BrianHanke]

Originally Posted by aracu

There is a relatively new, very small sized Sonodore.

Now that is flat! The price is mighty high though: nearly $3000 per mic!

[7rojo7]

Do they make pads for the 405n series? That was my only problem, they ended up on gtr alot. maybe the AKG pads would work. never tried. Maybe with a mod you could extend the DR. Not true omnis? Enlighten me.

[BrianHanke]

Originally Posted by 7rojo7

Do they make pads for the 405n series? That was my only problem, they ended up on gtr alot. maybe the AKG pads would work. never tried. Maybe with a mod you could extend the DR. Not true omnis? Enlighten me.

Not sure what you mean. I believe all the 40-series mics have 10dB pads, don't they? The 4050 is a large diaphragm mic, so it "fakes" an omni response by combining the signals from two capsules placed back to back. The AT4049b is a true omni though...

[jnorman]

7ro - the new 4051b has a pad built in.

[sonare]

Single diaphragm capsule = true omni (pressure transducer)-- of course the mere fact that it is a SDC does not mean it is omni-- but it must be a single diaphragm to be a pressure transducer-- a device that responds to a difference in pressure. These can have LF response down to 5 or 6Hz.

Anything else (such as dual diaphragms) = not a "true" omni LDCs are usually dual capsule, therefore respond to a pressure gradient and only electrically hear both sides ("omni")

The SDC are usually flatter, but the smaller the diaphragm greater the noise-- simple physics. This is why the DPA 4060 is really flat, really omni, and has a higher noise figure.

Rich

[Teddy Ray]

Attachment 1: Gefell MK221 with Josephson C617

Attachment 2: Gefell 296

[mathieujm]

Originally Posted by BrianHanke

Why don't more manufacturers make omni mics with flat frequency responses?

The problem is that, except with the very small capsules (Earthwork), flat omni are not... flat. Yes they are flat on axis but not at all off axis.

But frequently omni are used to have realistic ambience where off axis sound is much important, so the compromise found by the manufacturers is this bumb in the high. When it's well done the off axis response go higher than for flat omni and provide more sence of space and the direct sound is well integrated with the reflected sound. So not flat omni are more "flat" at a distance than the real flat one which should become very dull when they are not used close to the source.

A few years ago, I made a compareason of the "linear" and "distant" MBHO omni capsules (KA100LK and KA100DK). I found that the LK was unusable in classical concert situations (but great to record in good acoustics in the near field). The problem was that the compromise for the bump of the DK version was not so good for me (and probably recording with omni is so difficult when the acoustic is not optimum !)

JMM

[Gaston69]

Dpa 4060
dpa 4006

[7rojo7]

Then I'm confusing this with another mic by AT, all these numbers
well I forget the model number but I'm talking about an SDC made by AT that has swappable capsule and then that means I've never heard the 4050. Grey hair, glasses and now alzheimers. Last time I used them was in 94, but they were reliable.
I was confused about the true omni thing but now I'm just confused, thanks for the explaination anyway, it's 101 kind of stuff.
Seems to me my CCM5lgs have a bump some where up top when set to omni, but it's needed if you use them with some distance and not as spots. If need be a little dip around 8k - 12k flattens it out for spot use. The card setting works on an acoustic principle and sounds really nice too

[d_fu]

I use and like the KM 131 (got them veeeery cheap, though - but they are well worth their price).

But the AKG CK62 is certainly worth considering.
I've got the (discontinued - shame) diffuse field version, which is a very nice mic. The difference is just the front grill.

[mljung]

Originally Posted by BrianHanke

Oktava MK-012s have a big HF bump

Really..!?
My set of MK-012 omnis are pretty dark, bordering to "muffled".

DPA 4006 with nose cones pointing straight up is pretty close to perfect omni all the way round [not top/bottom] this could be a way of getting a near-perfect omni with less noise than say DPA 4060.
[that said for all other reasons than noise I really like the 4060]

::
Mads

[BrianHanke]

Originally Posted by mathieujm

But frequently omni are used to have realistic ambience where off axis sound is much important, so the compromise found by the manufacturers is this bumb in the high.

Very interesting, thanks! There's definitely a set of compromises inherent in any microphone design. For my purposes though, having flat on-axis response is very useful for getting in close to acoustic instruments.

Originally Posted by d_fu

I use and like the KM 131 (got them veeeery cheap, though - but they are well worth their price).

Originally Posted by d_fu

But the AKG CK62 is certainly worth considering. I've got the (discontinued - shame) diffuse field version, which is a very nice mic. The difference is just the front grill.

I wish I could have gotten mine very cheap too! The AKGs look really interesting. I'd love to give them a try sometime...

Originally Posted by mljung

My set of MK-012 omnis are pretty dark, bordering to "muffled".

Well, according to the frequency response chart they have bump of 7 or 8 dB up there. I'm sure that doesn't tell the whole story about how they sound though…

On a related note, it looks like I'm going to get a chance to demo the Lauten Torches that I mentioned earlier. I'm very curious to see how they sound, especially since there's so little info about them floating around here.

[mljung]

Originally Posted by BrianHanke

Well, according to the frequency response chart they have bump of 7 or 8 dB up there. I'm sure that doesn't tell the whole story about how they sound though…

I see Brian - just checked the response curve that came with my MK-012: they have a "flat lift" of about 2 db from 3-9 kHz [straight line] an extra 2 db tiny bell at 10 after which it rolls of slowly to -3,5 db at 20kHz. Off axis it rolls of quite steep above 5 kHz.
Quite a difference from your chart, it seems!

::
Mads

[BrianHanke]

Originally Posted by mljung

I see Brian - just checked the response curve that came with my MK-012: they have a "flat lift" of about 2 db from 3-9 kHz [straight line] an extra 2 db tiny bell at 10 after which it rolls of slowly to -3,5 db at 20kHz. Off axis it rolls of quite steep above 5 kHz.
Quite a difference from your chart, it seems!

::
Mads

Wow, interesting! Perhaps they've changed the design in the current model? I'm going by the chart on the Oktava website.

[Ozzie62]

No one has mention the Sennheiser MKH20. This is one of the flatter microphones in Sennheiser lineup.

[John Willett]

Originally Posted by BrianHanke

Why don't more manufacturers make omni mics with flat frequency responses? I can think of only four off the top of my head:

- Neumann KM131
- Schoeps MK2
- The AKG CK92 capsule
- Most Earthworks models

Is that really it, or am I leaving a few out? I'm very curious… Feel free to add to the list!.

Sennheiser MKH 20: First Attachment

Sennheiser MKH 8020 (NB: the dark blue bit is ultra-sonic above 20kHz): Second Attachment

There is a Neumann 131 head for the digital KM-D series as well as the analogue KM 131.

Sennheiser K6 + ME62: Third Attachment

You have also forgotten DPA

[Harvey Gerst]

For your consideration:

audix TR40A

[BrianHanke]

Originally Posted by John Willett

Sennheiser K6 + ME62

This is the first I've heard about this particular model. It looks like it fits my criteria: relatively flat response and more affordable than the top-of the line options already mentioned. Seems to be in the same price range as the AT4049b.

Is this mic used for recording music? I notice the info sheet lists the primary application as recording speech. How does it compare with the two MKH models?

Originally Posted by Harvey Gerst

For your consideration: audix TR40A

Flat and inexpensive for sure, but the noise figures put me off a bit, just as with Earthworks...

[Teddy Ray]

Originally Posted by BrianHanke

This is the first I've heard about this particular model. It looks like it fits my criteria: relatively flat response and more affordable than the top-of the line options already mentioned. Seems to be in the same price range as the AT4049b.

Is this mic used for recording music? I notice the info sheet lists the primary application as recording speech. How does it compare with the two MKH models?

Flat and inexpensive for sure, but the noise figures put me off a bit, just as with Earthworks...

Yes, the earthworks are way, way too noisy for any "acoustic" recording application..at least in my opinion..same with the 4060.

[John Willett]

Originally Posted by BrianHanke

This is the first I've heard about this particular model. It looks like it fits my criteria: relatively flat response and more affordable than the top-of the line options already mentioned. Seems to be in the same price range as the AT4049b.

Is this mic used for recording music? I notice the info sheet lists the primary application as recording speech. How does it compare with the two MKH models?

The K6 series was the replacement for the K3 series.

It's a good value for money range, in fact it's an excellent range that is often overlooked for recording because Sennheiser don't classify it as a recording mic - it is certainly not in the MKH league, but is nevertheless an excellent little mic.

[aracu]

How about T.H.E. omnis, or the Milab multipattern mic?