I am finally in an interesting position to be able to get a nice main pair of omnis, but... I don't wish to overpay for hype and marketing, yet I aim at something really nice, since I have an opportunity now that might not happen again, soon.

While checking out the options I noticed how strangely different the published frequency charts are for different high end omni mics...

DPA4006, MKH20 and Schoeps MK2 have "tidy" ruler flat" frequency responses with clear boosts (4006, MKH20 with hf switch on, MK2H/S) and slight attenuation in subs in MKH20, but all very clear, no fluctuations shown in the boosts; while the equally (or even more) praised Gefell M221 and Josephson have weird high end response... and they sound good?

I also looked at Austrian Audio OC818 as an option and Gefell M950 and the same - very variated high end response. Not a simple clean "EQ bump".

Are the latter honest and more detailed and the former only present the simplified - symbolic response?

Especially the MK2 flat line... Like someone simply draw a line with a ruler... no measurement... or even the Line Audio CM3 flat line, or even caridoids MKH40 and fig.8 MKH30 - flat line from 40 to 20k for the latter. (and I do like those mics a lot - some say dark - I say natural and smooth)

Can you enlighten me about those charts?

I am Sennheiser MKH40/30 user, also loved DPA4006A, but thought it can be "not so nice" with higher strings registers, especially violins - hmmm... I know it is also about placement, but...

I always admired Schoeps MK2 recordings...

What to get... how to interpret the charts...

I somewhat closed in on Gefells, seemed interesting, heard some nice recordings, deep, yet clear, maybe a tad on the bright side, not in a bad way it seemd, but the chart scares me and it seems overpriced new at the moment. While there can be nice MKH20 found on the used market and I already like the "family" sound.

What about MK2 - really as flat as its published chart shows? But on MKH20, you can switch to diffuse field easily... I wonder if it sounds equally nice as MK2H, though - when switched...

Anyway... any thoughts appreciated.

Schoeps for me.

Difficulty is deciding between the different omni capsules. MK2s has proved favourite so far. Would like whole set! Balls can be useful too, must get some. Capsule has slight high end lift which my old ears like.

DPA worthy runner up, just a bit too "flat" for my taste, I get something euphonic from the Schoeps.

Big OC818 fan, especially in Cardioid, but too big for my OMNI purposes normally. Prefer SDC.

Never see Sennhesier much...sure they are good.

Gefells get knowing looks but I have not tried that I can recall.

a) don't trust any measurement that you haven't taken yourself!
published specs from all manufacturers are smoothed or were achieved under very specific conditions (anechoic chamber) which are far from real-world experience.

b) if you're into ruler-flat response, go with the smallest capsule diameters which are still acceptable in terms of self noise.

c) if you care less about fr but very much about self noise, modern mdc's/ldc's are the way to go...

...or then digital mics but we're getting into difficult territory when discussing their benefits (and limitations).

Regarding the Gefell M221, note the vertical scale of the frequency response (it is often 1dB per graduation so small variations seem more significant).

Also, as others have said you must consider the amount of smoothing / filtering on the vertical scale, but this is usually not stated. I have a few pairs of Gefell Omnis (M296S and M221). They were supplied with individual sensitivity and frequency response measurements.

I don’t know if Gefell M221 are currently available; they were on extended backorder.

Your post seems focused on frequency response, but the polar response between different Omnis is quite different and each manufacturer has their own ‘sound’. These factors are significant.

Thanks for the replies... What matters is of course the sound - subjective preference, it is a bit difficult to test here... to have them all... I am leaning towards used MKH20s... and a pair of OC818. Seem like affordable, but classy workhorses. Let's be "Sennheiser house" with a touch of Austria.

First check the scales on these... the Josephson 617 and M221 have IEC Type I capsules which are as flat as possible in the free-field. They do have a little peak of less than 1dB in the top octave which is a capsule resonance that is hard to tune out completely. (Also because of the small capsule and the grille design the response off-axis is very close to the on-axis response, that is these are very very omni.)

If you look at the DPA 4006 data sheet you'll see it has the same capsule resonance except that it's larger... more than 2dB! And once you move off-axis, the high end drops off much faster. Personally I like that beaminess at high frequency when working with Jecklin discs, but not everybody does.

It's there on the MKH20 although the data sheet plot is so heavily smoothed by the marketing department that you won't see it. Interestingly, what is the huge benefit of the MKH20 is the low noise floor but because manufacturers won't agree on a common noise spec the data sheet won't tell you that. The MKH20 is a little beamy but less than the 4006.
--scott

The only thing that can affect the polar patterns of different omnis is if the capsules are of different diameters; the larger being more directional in the top octave.

Omni mics from different mfgrs that have the same capsule diameters will have the same polar patterns.

How are your thoughts on M221, there is much less about those mics than the others available online...

I only ever used the vintage Geffels which I liked a lot (especially the UM70) and a newer M300 on occasion - I liked it, but preferred the more beefy and less bright MKH40, which felt more natural, but in direct AB comparison, it sounded like someone cut the high end from MKH40... when the ears adjusted - it was more pleasant listening to MKH40 recordings (to me).

Anyone compared M221 to MKH20 and MK2 in daily use?

It's a different animal altogether. There are a bunch of different microphones using variants of those capsules, including the Josephson 617, the Sonodore, and the AKO 7052PH. MikeW also makes one that is a bit more cheaply made.

I think they are cleaner and more open than the MKH20, 4006, or MK2, but I am severely biased on the subject.

I think most of those companies are willing to provide a demo unit for you to try with a deposit. It is definitely worth trying one of them... they all sound a little different because of the electronics but they are all very close.

Personally what I want is a microphone built with a larger and more beamy version of that capsule but nobody makes a commercial product like that.
--scott

depending on approach/application, it may be more important to have multiple decent mics than just a pair of excellent mics...

...and max. spl may also be a consideration, as well as frequency range, accessories, dealer/distributor/manufacturer reputation with regard to repairs.

Are you looking for something like the Gefell M102 or the Sonodore LDM-54?

I really like the Gefell M221, but I've only used them a few times so far. The M221 seems very true to the source. Compared to my Gefell M296S, the polar patterns are quite different. The M221 is a 1/2" capsule and the M296S capsule is closer to 3/4".

I don't have experience with the MKH20 or MK2.

For cardioids I am also using Senn MKH40.

Wow! Yes, very much like those!

I made some homebrew ones and I was considering making that into a commercial product but it looks like I have been beat to the punch.

I really, really like those 1" measurement capsules for Jecklin discs.
--scott

You can also contact Josephson if you have the c617. They used to offer an adapter to fit the 1" Gefell measurement capsules onto the c617

Bruel & Kjaer designed their 1” measurement capsules in the 50s, so it’s not something new I owm LDM54s and also four B&K 4145 capsules and they are both amazing.

And... they're actually adaptations of the Western Electric 640AA capsule of the 1930s.. same basic construction but slightly different tensioning.
--scott

I must say that I do prefer the mics that have the (marketind dept smoothed or not) flatline response... like Schoeps MK2, Neumann KK131 (those seem really interesting), Sennheiser MKH20 to some extent...

It is really a pity one cannot easily test all the models...

Gefell M221 seem very interesting, but I fear they might be a bit to "open" for me hearing some comparisons of kk131 and C617 - not the same mic, but similar, I guess? And hearing Trptk label catalogue - mostly done with c617 - nice sound, but all sounds in the similar vain - to me it is a bit too open, I miss the warm mids... to detailed, very roomy... but is it the mic or approach? Who knows.

And M221 is over 4k now, for a pair...

Also - a side question... what's the thing with Neumann KK133? Why is that capsule so expensive compared to others? Specs don't tell.

You have to try it. It's flatter than the Schoeps. Because of the nickel diaphragm the impulse response is different. I wouldn't say it has warm mids, but then I wouldn't say the Schoeps has warm mids either.... although I have sure used them in plenty of rooms with warm mids.

You have to try it. It's a cool thing, and it might not be your thing, but you should at least be familiar.

This is also constructed like a measurement capsule (although it's not a measurement capsule). It's got a titanium diaphragm that is made in place rather than being stretched across the capsule. It's a much slower process and I don't think it can be automated very much. Beyond that I don't know but I'd love to take one apart and see. B&K did a couple things when they adapted the Western Electric capsule to make it easier to manufacture and I am curious what Neumann's take on the idea is like.
--scott

I know I will have to test it myself - but this somehow scares me - I do like the roundness of Neumann... in forte passages I don't like c617 that much... It is nice, detailed, fast and open, but I like the roundness of Neumann there... I wonder how M221 is...

Neumann KM131 vs. Josephson C617

The shrillness of strings or flutes, piccolos amd triangles is what I fear, that's why I also don't consider getting 4006 as an universal mic, it can do that... I have heard nasty strings on many commercially released albums, too. Some are obviously not bothered.

I would really like to hear some more classy M221 recording and comparison to MK2 or kk131, MKH20...

If you go to the FB "Classical Music Location Recording" group you can search for M221 and find recordists that use the Gefell M221. They may have recordings posted, and if not you could message them.

The c617set and the Gefell M221 are near identical in performance. Realize that the M221 came out years after Josephson had been selling the c617set with that same capsule. And if the M221 are too expensive, the c617 are more (and if you want the diffraction ball for the c617 that is an extra cost $$ while multiple-sized balls come with the M221)

I would not judge mics based on the TRPTK recordings -- they are going for their own desired sound/mix which is very different from most classical recording goals.

Besides being a titanium capsule, the kk133 also has the added expense of the ball and different shape of the capsule metalwork to accept that (making it the only mic in the series that deviates.) It also has overlap with one of Neumann's other products: the much more expensive M150 -- which uses the same capsule. If you could get the US$8000 mic sound (M150) for $1400 (the price of the KMA + kk184 -- using as an example) that would be a terrible business decision. So the KMA+kk133 is about half the cost of the M150 (without the added expense of tube, tube cable, power supply, etc.)

As Scott notes, that HF bump in the 4006x mics happens mostly on-axis. Therein lies the trick to using them effectively on strings. Many engineers will aim the mic at the source straight-on, simply out of habit. Some, when challenged say, point out that it's an omni mic and the aim "shouldn't matter." Ah, but it does! When using a spaced pair on a single bar, I'll often rotate the bar, re-aiming the mics in the elevation plane, while listening with headphones. The Grace Design stereo bars and the (much cheaper!) Manfrotto ones make that quite easy.

It's only in recent years that DPA's started shipping with a "trapezoidal" grid in addition to the silver and black ones. I recommend trying this grid on strings, it calms things down significantly.

David L. Rick

Schoeps is my favorite microphone manufacture on earth—and the MK 2 capsules are stunningly beautiful and effective. But part of the value of Schoeps MK series is that the initial investment also eventually makes alternate first-quality capsules (financially and aesthetically) compelling.

Trust the sonic quality of Schoeps and a few other manufacturers; but don't read too much into published charts. They are useful, but not at all sufficient.

To answer your question, see: https://www.youtube.com/watch?v=aSAZN-B9DpU


Best wishes,

Ray H.

Why is that so? To use them only a couple of times?

You cannot judge microphones of these level with published measurements and sound samples, acoustics and placement have such a profound impact on the recorded sound that it is impossible to really know how the microphones are imparting those differences one can hear between different recordings; the only way is using them, and many times in different halls. You can’t really know how accurate a published frequency chart is, either; for example, the one shown in Rens Heijnis’ website for the LDM54 is quite different than the one I got from the capsule’s manufacturer, and this one is closer to the measurements I’ve taken myself at home and to what I hear after years using them.

my advice is simple: buy the gear of which you think you will be satisfied with for many years to come!

[i bought my first schoeps mics (mstc) in 1978 and they are still in regular use.]

You won't go wrong with any of the mikes described in this thread... I have a bunch of different high end small diaphragm condensers and they are all good but they are all a little different and having that selection is handy. But for years I only owned two and I did good work with them.
--scott

for many years, i had but a cardioid and an omni pair from two different manufacturers which served me well.
these days, i have a far larger variety to select from but i'd be very hard pressed to mention strict criteria which would lead me to pick specific models in any given situation; except maybe that in reverberant spaces or in live situations, i tend to use more mics with a bit of a hf bump - otherwise, i blame the weather...

I guess the main "thing" that made me consider the differencies more thoroughly, is that I percieved the M221/C617 as a bit different omni than MK2, MKH20, etc, a very accurate and fast response and I thought of getting a pair. But then I had second thoughts about high end response and started checking the specs more and comparing.

I am also a percussionist and not insignificant part of what I do are my (as one friend called it) "intelligent new age" projects. So I thought a mic of this sort might compliment the MH40 and 30 well, to have a bit different "crayon".

Also difficult to decide between MK2, MKH20 and Kk131, not knowing them all well...

I like the low noise of MKH20s and "worhorse" style, with the HF boost switch, the tone and reputation of Schoeps MK2 and as I could hear in some examples, a rich midrange sound of kk131, with smooth highs, but then again - I have that with MKH40/30, too. Maybe some opennes of Gefells wouldn't hurt.

Then there is also the idea of a pair of Gefell M950s and a pair of used MKH20s, but I see the Gefell prices went through the roof lately...

since you mention percussion instruments: i very strongly favour using m/s as main mics when recording/amplifying percussion (heavy) ensembles to avoid transient smearing.

my standard rig is schoeps mk-4v/mk-8; if high spl is a concern, i'm using neumann kk-84/kk-120 with km-d 'preamp' bodies.

no omnis, sorry...