neumann km 183 d

Posted: Thu Apr 05, 2007 4:12 pm

Cucco wrote:

Could you lock it to the AES signal in the Nagra?

Not if it was a stereo mic with a single AES output, as I described. Locking to an external source would mean adding an input to the microphone (either AES or dedicated word clock) and then we're running two cables and the elegance is not there any more...

Posted: Thu Apr 05, 2007 5:19 pm

...and running AES signals via long cables is more detrimental than long analog cables. Have tried, es no bueno.

Posted: Thu Apr 05, 2007 5:48 pm

Plush wrote:

Who said I would pay to try the new Neumann set-up? We will not pay to try it or use it.

Please elaborate... Who *did* say that?

Plush wrote:

There is one thing that you guys are missing in the analysis of the advantages of the new digital system. That is that dynamic range is expanded downward with the so called "28 bit" converter and lack of noise.

This means that low level detail should, in theory, be able to be retrieved like never before.

This benefit is the main reason to use the new set-up.

This is a good point.

However, unless I'm misinterpreting the specs and comparing apples to oranges, I see no practical benefit at all. The noise of the KM183d shows no improvement over the KM183; both are rated at 13dB A. The signal-to-noise ratios appear to be the same, too (KM183D = 70dB CCIR4, KM183 = 70dB CCIR 468-3), although I am not sure of the differences between those two CCIR specs, and perhaps that's where the difference can be found. The only apparent difference might be a 5dB *decrease* in maximum SPL for the KM183d, but it is hard to directly compare that figure because, by necessity, one is quoted at 0dB FS (KM183d) and the other at 0.5% THD (KM183).

Please correct me if I'm misinterpreting the specs (it's highly likely, especially those differing CCIR figures), but on the surface I cannot see any benefit here at all. The self-noise is the same, the signal-to-noise ratio appears to be the same, and the digital version possibly has less SPL capability. Are these digital microphones really a step forward?

Specs aside... As I understand it, the bulk of the noise from a microphone is due to the motion of air particles against the diaphragm; it doesn't matter whether that diaphragm goes into an analogue input circuit or the front end of a 28-bit AD converter - *that* noise is already there. The KM183d uses the same diaphragm as the KM183, so it has the same noise burying the same amount of low level detail, but somehow encoding it beautifully into a 28-bit converter. So we get an extra 4 bits, allowing us to encode that noise accurately down to -168dB FS (or thereabouts). Pardon my tongue-in-cheek sarcasm, but with that amount of low level detail I ought to be able to hear each individual air particle approaching, colliding with the capsule, and bouncing away again. Cool!

Whatever theoretical advantage the digital microphone concept has is not immediately apparent in the specifications of the current models - unless I'm misinterpreting the specs, in which case can someone please correct me....

Posted: Thu Apr 05, 2007 6:26 pm

Well all dat dat you done talked about, we gonna find out.
We jus gonna find it out. I'm sort of a smiling skeptic.

Don't dismiss it out of hand, however.
Dynamic range should be improved certainly. Self noise has nothing to do with it. Performance should be that of a true 21-22 bit converter.

Maybe they done cheaped out, maybe they done done it right. We a gonna find out.

Posted: Thu Apr 05, 2007 8:06 pm

Great...so Plushy has turned into JarJar Binks...
Are you planning on getting a pair?

Simmo -

Can the Nagra generate clock over AES and assign it to one leg? Wouldn't that help in the above hypothetic scenario?

Also, the Brownian noise you refer to is one of the components of microphone noise which increases almost exponentially with a decrease in diaphragm size, but it certainly isn't the main factor in microphone self-noise. Active electronics play at least as much of a role. However, in either case, you are right...the noise IS still there and you ARE still amplifying it along with the signal.

Posted: Thu Apr 05, 2007 11:20 pm

Plush aka JarJar Binks wrote:

Don't dismiss it out of hand, however.

With the amount of time I've spent posting all this anti-digital-microphone crap here, it must be obvious that I'm not dismissing it out of hand...

The technology is of great interest to me, especially from a noise point of view. One of the things I have become increasingly interested in lately is recording nature sounds, in particular, the dusk and dawn sounds of jungles and rainforests. This requires very quiet microphones, and my preference for this type of work is omnis, so the KM183d is/was of great interest to me, and it was happily coincidental that this thread appeared (although it appears I have highjacked it).

By putting all this anti-digital-microphone stuff here, I'm looking for compelling arguments to support the technology. So far, all the arguments for it are based on theoretical notions, mathematical predictions and rosy-eyed futuristic visions. What I'm *not* seeing are *significant* improved specifications in the real-world products. I'm hoping I am missing something, and I'm hoping someone much smarter than me (they won't have to be a genius) is going to pop up any moment now and convince me that the KM183d is going to offer a *significant* advantage over the analogue technology.

By 'significant', I mean, 6dB or so less noise, for example - that would be worthwhile. Comparing the KM183d's specs to the KM183's specs is a little underwhelming, and I can buy a selection of very nice analogue microphones that outperform the analogue KM183 for the entry price of the Neumann system.

Oh... here's something I did not mention earlier when comparing the specs of the KM183 digital to the KM183 analogue: the digital version does not have any more noise added downstream from preamps, converters, etc.

How silly of me. Embarassed

Posted: Thu Apr 05, 2007 11:28 pm

Cucco wrote:

Can the Nagra generate clock over AES and assign it to one leg? Wouldn't that help in the above hypothetic scenario?

Not that I'm aware of...

My hypothetical scenario is becoming a bit of a non-issue at the moment. I've been re-visiting the prices I can find for the Solution D gear and it is completely unaffordable for now. However, if I had no equipment at all and was about to purchase a complete system, the Solution D would make more sense. I could buy a much cheaper recorder than the Nagra V because it would only need an appropriate digital input; it wouldn't need good preamps or AD converters.

But for now, it's too complex, too expensive, and too risky.

I think the smartest thing Neumann could do now is release an appropriate recorder to use with the system, and get all those bits and pieces into one box while also removing the need for the laptop but maintaining remote control of microphone parameters. Then it really would be a good solution, and it really would have a chance of succeeding. At the moment there are so many add-ons required to make it work that it reminds me of the Chinese drive-through scene in 'Dude, where's my car?' (...and then? ...and then? ...and then? ...and then? ...and then?).

Cucco wrote:

Also, the Brownian noise you refer to is one of the components of microphone noise which increases almost exponentially with a decrease in diaphragm size, but it certainly isn't the main factor in microphone self-noise.

Thank you for that correction.

Posted: Fri Apr 06, 2007 7:53 am

"O Taste and See"

would be my motto.

Simmosonic's jungle sounds are fully adequately handled by the Nig-Nog and his current mics.

The comparison between the regular mics and the digital mics will eventually be done here.

In that way I can maintain my goal of being a recording scientist, not a guesser. (or a hand wringer)

Posted: Fri Apr 06, 2007 8:02 am

Please let us know as soon as possible what your findings are.

Though I come off as being against the digital mic revolution, I am anything but.

I am VERY excited at the prospect of where this technology might go and what I may be able to gain (or lose in the way of hardware) from it! To be honest, if it even sounds as good as current technologies, I will be pleased so long as I can afford to revamp my entire set up.

Posted: Fri Apr 06, 2007 8:06 am

In fact, I just did the math.

I could afford an initial investment of $17,250, but that would severely limit my recording capabilities to little more than the digital mics in general.

I'm afraid, as I understand their pricing scheme, this would afford me 6 to 7 channels of recording...

I wish they had some kind of say 8 channel interface which was more affordable and you could simply purchase whatever mics you need to go along with that!

Posted: Fri Apr 06, 2007 10:32 am

Plush wrote:

Simmosonic's jungle sounds are fully adequately handled by the Nig-Nog and his current mics.

Ouch? At first I read that as an insult, and here's why:

In Australia in the early '70s we used to get a sitcom from Britain called 'Love Thy Neighbour'. The main character, a white guy called Eddie, used to call his black neighbour, Bill, a "Nig-Nog", which was obviously derived from the word 'nigger'. Eddie also called Bill a 'sambo', a 'jungle bunny', a 'chocolate drop' and a 'darkie'...

That is the only context in which I've heard the word 'Nig-Nog'. I'm assuming you never got that show in the USA, and that your use of 'Nig-Nog' refers to the Nagra. But your comment works just as well with the other meaning, too.

Because this is the *World* Wide Web, not just the *USA* Wide Web, I think it's important to clarify that. Otherwise, combining "Nig-Nog" with your earlier JarJar Binks/Afro-American slave talk post paints an unfortunate picture.

[By the way, my jungle sounds are not "fully adequately handled by my current mics", which is why I'm interested in the digital mics and their noise. But I've already said that a post or two ago... Rolling Eyes

]

Posted: Fri Apr 06, 2007 10:50 am

Cucco wrote:

I wish they had some kind of say 8 channel interface which was more affordable and you could simply purchase whatever mics you need to go along with that!

According to their website, an 8-channel version of the DMI-2 is under development. Go here:

http://www.neumann.com/?lang=en&id=current_microphones&cid=d01_description

...and scroll down to the bottom, under the heading "The DMI-2 Digital Microphone Interface".

I would assume this will be more affordable per channel than the DMI-2. Build an 8-track hard disk recorder into the same box and it's a real digital solution.

Posted: Fri Apr 06, 2007 11:12 am

Well that's definitely positive news!

Hmmm...I wonder if $17K+ would get me:
8 channels and
4 omni mics,
2 cardioid mics
2 fig 8 mics.

I would be content with that as an initial setup and be willing to add later!

Just think -
A laptop and a 1u box, 8 mics and a handful of stands....
I'm in!

Posted: Fri Apr 06, 2007 11:13 am

Does any one here have any contacts within Neumann?

I'd love it if a company rep would come weigh in on this discussion!

Posted: Fri Apr 06, 2007 11:42 am

Cucco wrote:

Hmmm...I wonder if $17K+ would get me:
8 channels and
4 omni mics,
2 cardioid mics
2 fig 8 mics.

Strewth! In Australia, the Neumann importer will sell you a pair of D01s and a DMI-2 as a stereo kit for $24,349 AUD, which is about $19,860 US. They don't have prices for the KM series on their website...

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