Topic: Digital Microphones and Their Advantages: Is This the Future?

[Brian Skalinder]

some genius decided it would be a good idea to make insulin pumps be wireless and its been hacked.

I suspect the benefits of wireless personal medical devices vastly outweight the miniscule risk of someone actually hacking the devices.

And wireless mics would be cool.

[John Willett]

The setup for sale in the yard sale, a Schoeps rig with a digital body, a CMD2 and a Sound Designs recorder made my mouth water, but more importantly, it left me to ponder whether this is the future of recording.  So I throw out this subject for general discussion, and offer these possible areas of banter:

--I assume no preamps are necessary
--Low phantom power requirements, only 10v, is there a battery box that might supply this?
--What recorders are currently available for the connection?
--What is the connection, I read it is an AES type connector?  What is that, like a SPDIF or Toslink? 
--I read this body can use regular Schoeps caps.  Does this include the mk4 and other caps?
--What are the advantages of digital mikes?
--Are the A/D converters as good as those in our typical bit boxes, Edirol/Rolland, Sound Designs, Tascam?
--Are there any other digital mikes out there that are being used, and with what rigs?

I'm fascinated by this apparent new leap in technology.

--I assume no pre-amps are necessary
Correct

--Low phantom power requirements, only 10v, is there a battery box that might supply this?
Low voltage but 250mA (48V phantom only specs 10mA)
Both Neumann and Schoeps provide connection kits / power adaptors that convert AES42 into AES3 and provide power for the mic.

--What recorders are currently available for the connection?
Sound Devices 788T and AETA 4MinX
You can use other recorders with the Neumann DMI-2 or DMI-2P interfaces, or the Connection Kits from Neumann or Schoeps
I use a Nagra VI and Neumann DMI-2P

--What is the connection, I read it is an AES type connector?  What is that, like a SPDIF or Toslink?
The standard is AES42 - basically AES3 with extras.
The connector is a standard 3-pin XLR - NB: NOT S-PDIF or Toslink
 
--I read this body can use regular Schoeps caps.  Does this include the mk4 and other caps?
It can use all the Schoeps heads and accessories - over 100 items

--What are the advantages of digital mikes?
Send me a PM with your e-mail address and I'll send you pdfs of my two AES papers and a few other things - far too much to write here.

--Are the A/D converters as good as those in our typical bit boxes, Edirol/Rolland, Sound Designs, Tascam?
Better than those you mention

--Are there any other digital mikes out there that are being used, and with what rigs?
There are over 40 different digital mic. options.  Neumann, Sennheiser and Gefell all make AES42 digital microphones as well as Schoeps (Neumann were the first).

I have several digital mics. - I have a pair of Neumann KM-D that I can use with either KK183-D or KK131-D heads.  I also have a Sennheiser MZD8000 that I can use with an MKH 8020 or MKH 8040 stereo pair.

I have two Neumann DMI-2P interfaces that I use with my Nagra VI for recording 4 digital  mics at once.

I have been using and recording with digital mics since 2006.

[OOK]

Here is the portable unit from Neumann....looks pretty straight forward...it operates on 10-18volts....

http://www.neumann.com/?lang=en&id=current_accessories&cid=db_current_accessories&dbid=193

[John Willett]

The technology is not new and first appeared as early as the late 1980's - Go see:
http://www.hauptmikrofon.de/doc/WhitePaperE_AES42_v21_May2010.PDF


Their are different implementations of AES42 (mode 1 and mode 2) that have different requirements to make them work correctly.

Mode 1 mics - (i.e. the Schoeps CMD2's, Neumann (supports both 1 and 2)) you need an AD converter that resamples on the input.   No external control required.  Easier to adapt to AES3 connectors

Mode 2 mics - (i.e. Neumann, etc) Can sync to an external clock, but from what I have read may need some external control on the AES42. Need a processor/controller between the mics and a recorder (i.e. Neumann DMI-2 Portable)
http://www.neumann.com/?lang=en&id=current_microphones&cid=kmd_dmi-2portable

Other items that make using digital mics a challenge:
 - single channel mics (i.e. Schoeps CMD, Neumann, etc) only one of the two   channels on the AES42 connection will have signal - so to do stereo you   need 2 AES42 connectors, or 4 channel you need 4 AES42 connectors
 - 10V Phantom requires 250ma of power or is rated at up to 2.5 W whereas 48V phantom is rate at 10mA or 0.48W - so digital mics may require up to 5 times the amount of power (obviously with less in the chain then the power is taken out of those components)

Two recorders that support AES42 Mode 1 natively with 10V Phantom - SD 788t (4 AES3/42 connectors and Aeta 4Minx (2 AES3/42 connectors) - both retail in the $6K range

Mostly correct - but I would say Mode-2 is better than Mode-1.

With Mode-1 you have to have a sample rate converter to clock.  You say "no external control required" - wrong - a SRC is external control - plus - lots of connection kits and an SRC is far more expensive than a Neumann or RME interface that will clock all the Mode-2 mics.

Mode-2 can work Mode-1 or Mode-2.

If you only have a single mic. (or a stereo pair if you use the Sennheiser MZD800 - which you forgot to mention), all you need is a simple connection kit and no SRC.

I have been using AES42 digital mics for 5 years now and have also written two AES papers on the subject (which I am happy to e-mail to anyone who sends me a PM with an e-mail address).  I also have a copy of an article that describes a recording at Abbey Road where all the mics were digital.

In addition, I wrote up my first recording sessions with digital mics HERE.

I hope this helps.

[John Willett]

Probably the cheapest stereo setup is the Neumann KM184 D's and a Neumann DMI-2 Portable at about $4.2K total or so.

No - I think the cheapest stereo set-up is a Sennheiser MZD 8000 + MKH 8040 (or 8020) Stereoset + Neumann Connection Kit

This is my rig with the MKH 8020 stereoset:



Click the picture for full size

[John Willett]

This is my rig - Nagra VI with two Neumann DMI-2P:



Click the picture for full size

Both the DMI-2P are powered via the Hirose connectors of the Nagra VI.

[H₂O]

I was not aware of the Senheiser mic

Can the DMI-2 support Mode 1 mics?

[bryonsos]

John - those are some sexy rig pics! You might have convinced me to start saving my pennies for a digital rig    Just wondering, how would you rate the battery life of your digital Neumanns vs. analogue ones?

BTW- I've been patiently monitoring this thread, waiting for you to chime in. Great input and insights!

Cheers

[John Willett]

I was not aware of the Senheiser mic

Can the DMI-2 support Mode 1 mics?

Yes - but using Mode-1 you will also need a SRC after the DMI-2.

But using the DMI-2 gives access to the Neumann RCS software control.

The RME unit has built-in SRC as well as Mode-2 control, so you can mix Mode-1 and Mode-2 mics if you wish.

[John Willett]

John - those are some sexy rig pics! You might have convinced me to start saving my pennies for a digital rig    Just wondering, how would you rate the battery life of your digital Neumanns vs. analogue ones?

BTW- I've been patiently monitoring this thread, waiting for you to chime in. Great input and insights!

Cheers

I get about 15 hours from a fully charged battery on my Nagra VI - I guess that powering two DMI-2P it will probably go down to about 7 or 8 hours.  I have never had to test it to destruction yet.

As I said earlier - I'm happy to send PDFs of my papers and a couple of other things I have on AES42 mics to anyone who PMs me with an e-mail address.

[hi and lo]

--Are the A/D converters as good as those in our typical bit boxes, Edirol/Rolland, Sound Designs, Tascam?
Better than those you mention

Forgive me if this is covered in your AES articles, but I would love it if you could elaborate more on this.

[H₂O]

Maybe Schoeps will come out with a VSTD someday

[bryonsos]

John - those are some sexy rig pics! You might have convinced me to start saving my pennies for a digital rig    Just wondering, how would you rate the battery life of your digital Neumanns vs. analogue ones?

BTW- I've been patiently monitoring this thread, waiting for you to chime in. Great input and insights!

Cheers

I get about 15 hours from a fully charged battery on my Nagra VI - I guess that powering two DMI-2P it will probably go down to about 7 or 8 hours.  I have never had to test it to destruction yet.

As I said earlier - I'm happy to send PDFs of my papers and a couple of other things I have on AES42 mics to anyone who PMs me with an e-mail address.

Damn! 15 OR 7 hours sounds pretty good to me. [sound of bryonsos counting pennies] One, two, three...

[page]

--Are there any other digital mikes out there that are being used, and with what rigs?

There are over 40 different digital mic. options.  Neumann, Sennheiser and Gefell all make AES42 digital microphones as well as Schoeps (Neumann were the first).

Have any literature on that? Their site has traditionally been tough for me (as someone who has trouble with just english, let alone other languages), so it may be there and I've just missed it in the German language section/materials.

[John Willett]

--Are the A/D converters as good as those in our typical bit boxes, Edirol/Rolland, Sound Designs, Tascam?
Better than those you mention

Forgive me if this is covered in your AES articles, but I would love it if you could elaborate more on this.

The ADC is matched to the microphone capsule.

The Neumann one is 28-bits (NB: not 24) that uses two converters in a patented way to get true 28-bits.  AES42 specifies 24-bits, but the Neumann is 28-bit in the mic.

The Sennheiser one was compared to the best ADCs on the market and the consensus of opinion was that it came out equal.