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

[Scooter123]

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. 

[acidjack]

Interesting topic! 

I'll leave the more technical aspects to others, but I'd guess the main advantages are lower power requirements, and lower noise, as you pointed out. 

I think AES is an XLR-type digital connector, if I read my USBpre2 correctly.  I've never had anything that used it so haven't thought about it much. 

Neumann has a similar product line out there now, I believe.  Based on what BLee's rig came with cap-wise, the Schoeps one can use all existing Schoeps caps (he has 41s and 22s I believe)

My immediate view is that lots of people will be "against" this technology because it doesn't offer the natural, more analog sound we all know and love.  And I believe you're right that it would take away the ability we all have to "customize" the sound of our mics using different pres and A/D converters.  Of course, as with past technological leaps, these objections will likely be supplanted by a combination of convenience and by technological fixes that mimic what we liked about the old tech (for example, you can already mess around with tools in Izotope or Audition to mimic some of the sonic characteristics of different pres.  I know page has worked pretty hard, for example, to find software methods to mimic the sound of the Sax). 

At least insofar as BLee's rig is concerned, I think the most annoying thing would be having the bodies set to one sampling rate. But then, if you are running that type of rig, running out of disk space due to using 24/96 shouldn't be your main concern.

And while the iPad control is cool, not sure I want to add an $800, breakable, stealable iPad to an already high-cost mix.  OK, I mean, I would, but it is another thing to "carry around" if you go that route. 

I would imagine the transition will be slow as long as the cost differentials are high.  If anything, it might drive the price of analog bodies down a bit in the used market.

[hi and lo]

The AES type connection is a balanced, digital signal. It's better than unbalanced SPDIF connections for mostly the same reasons as analog balanced vs. unbalanced connections. Longer cables runs, better shielding, etc.
Neumann also makes a digital series of microphones and maybe others that I am unaware of.

You can use any Schoeps capsule intended for use with the Collette series including the MK4

Since I've never heard these mics in comparison to the standard analog versions, I couldn't possibly comment on their sound quality or really their advantages. I assume the main advantage is simply consistency in sonic quality, which could also be a disadvantage depending on how you look at it.

[hi and lo]

And while the iPad control is cool, not sure I want to add an $800, breakable, stealable iPad to an already high-cost mix.  OK, I mean, I would, but it is another thing to "carry around" if you go that route. 

It works with the iPhone too!

[acidjack]

And while the iPad control is cool, not sure I want to add an $800, breakable, stealable iPad to an already high-cost mix.  OK, I mean, I would, but it is another thing to "carry around" if you go that route. 

It works with the iPhone too!

Oh, good.  Now back to plotting that kidnapping I was planning so I can buy one of those rigs! 

[page]

--I assume no preamps are necessary

Correct, if you are staying digital post-body in the chain.

--Low phantom power requirements, only 10v, is there a battery box that might supply this?

I think they have a box if you're doing D>A for use with a system that won't accept the AES mic standard and it provides power (because your recorder/mixer doesn't).

--What recorders are currently available for the connection?

Nothing under $4k. This is all pimp stuff right now.

--What are the advantages of digital mikes?

Supposidly the noise floor of the mic>recorder is lower than mic>preamp>recorder and (paraphrasing the official schoeps blurb) "more low level-type details are preserved".

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

Supposidly they are optimized for these mics, as acidjack puts it;

My immediate view is that lots of people will be "against" this technology because it doesn't offer the natural, more analog sound we all know and love.  And I believe you're right that it would take away the ability we all have to "customize" the sound of our mics using different pres and A/D converters.  Of course, as with past technological leaps, these objections will likely be supplanted by a combination of convenience and by technological fixes that mimic what we liked about the old tech

correct, we see part of that now in the plugins for the neve1073 units that are being offered. While they are not exact, it's fairly close. Likewise, if you really have a good understanding of what a piece of gear does, you can work toward mimicing (and I use that term specifically instead of replicating) it's sound. Sometimes you can do well, sometimes you can't.

It will be different, not necessarily better or worse, but different. The optimized gain settings in terms of noise I think is one of the most intriguing things.

I think AES is an XLR-type digital connector

correct. This uses an offshoot of that technology, but the connector should be the same IIRC.

And while the iPad control is cool, not sure I want to add an $800, breakable, stealable iPad to an already high-cost mix.  OK, I mean, I would, but it is another thing to "carry around" if you go that route. 

It works with the iPhone too!

Oh, good.  Now back to plotting that kidnapping I was planning so I can buy one of those rigs! 

yep, that was the one thing I thought of. (iphone use). Some production companies might use it for wifi-control on a production set, but really, we would juse use teh ifons 

[H₂O]

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

[hi and lo]

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

Resampling on the digital input? How could this possibly be a good thing? I would have hoped each digital microphone would lock to the recorders sample rate.

[H₂O]

I don't think resampling is as much of an issue here as you are dealing with very high end gear.    Note that most all the ultra high end recorders (i.e. Zacomm, Nagra (don't know for sure), AATON, etc) all resample on there digital inputs.

If you don't resample you have to have 1 master clock and standard AES (that AES42 mode 1 is modeled after - assuming for compatibility sake) is one way so the mics would need a Word Clock in (or you could lock on to one digitial mic (if you where running just one digital mic)). 

Mode 2 AES42 is bi directional (one cable handles control and clock to the mic and digital signal back from the mic)

[H₂O]

Also note that running Active cables with a digital Mic (cmd2) as with tube mics (i.e. m222) although is supported by Schoeps slightly defeats the purpose of digital mics as it adds an Analog FET and attenuator into the signal path.

Berhnard gave me a hard time of running actives with my M222's.

[H₂O]

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

[Gutbucket]

Yeah, I've long thought a standard Ethernet jack and good old cat5 cabling with Power Over Ethernet would be the obvious way to go for digital mics(substitute hardened/industrialized versions of LAN cableling & jacks for more pro applications.. Neutrik makes some those I think, plenty of other manufacturers do for industral automation LANs).  It works for prosound PA applications with large numbers of channels using CobraNet for example, and there are other similar competing digital audio + control networks that use Ethernet hardware.

Substituting USB for Ethernet could work pretty much the same way I'd think.

In a similar vein, I wonder why we've been offered active digital input monitors and controllers for several years now that are digitally linked and controlled via an Ethernet link, but none I have seen distribute digital audio over the same cat 5 link. See the JBL stuff , Dynaudio, etc.  They always require an individual audio input to each speaker in the setup via analog inputs or AES/SPDIF connectors on every speaker, in addition to the control link of daisy chained cat5.  If the big PA guys can do 32 channels or more of digital audio over cat5, why not the studio monitor guys?

[H₂O]

I don't think USB is robust enough for this purpose.   I would think you would need some sort of networking topology to truely make this work (I am thinking something like VoIP enabled network to replace all the cables on stage for example)

I know mLAN was an idea by yamaha about 10 years ago so I don't know if this would ever catch on.

A network topology could add security, resiliency, error correction, etc with everything in the digital realm.

[rastasean]

Just please, please don't put the microphones online and/or make them wireless... some genius decided it would be a good idea to make insulin pumps be wireless and its been hacked.
http://www.technewsworld.com/story/73020.html
http://blog.mhhealthsearch.com/2011/09/can-wireless-medical-devices-be-hacked/

[Gutbucket]

Wireless would be cool.  Or completely independant all-in-one mics that sync and SRC reclock when uploaded.  Scatter them around and collect them all afterwards.