Engineer's Corner
2:36 pm
Thu June 12, 2014

TheEC: Logitek Audio's Mosiac Mix Board

Logitek MOSIAC mixer demo in the RIPR studio.
Credit Susan Greenhalgh RIPR

This week Frank from Logitek Audio was in town to provide RIPR with a demo of their MOSAIC mix board.  To turn a phrase, this is not your father's mix board!

Typically when you think of a radio station, you think of a "mix board".  AKA a "mix console", this is a largish device with a bunch of linear faders and on/off buttons and whatnot, and it allows a DJ to mix multiple audio sources at different volume levels in real time; switching between CD players, a turntable/record player, a telephone call, their microphone, a satellite feed or two, etc etc etc.   There's usually a bunch of level meters along the top, and they tend to be pretty big because each physical represents one, or at most two, audio sources.   For an NPR station like RIPR, there can be a lot of sources: five mics, two phones, seven AudioVault outputs (computer-assisted playback), ISDN, Reel to Reel, Flash player, four satellite feeds, two CD players, a Comrex Access AoIP Codec, a regular computer (mostly used for Skype calls) and some other things, too.   

The RIPR Mix Board, a Wheatstone A6000.
Credit Aaron Read RIPR

You end up with a mixer that looks a lot like this pic here, which is, indeed, the mix board in the RIPR studio!

These are well-made analog boards, but they're kinda limited by the technology of their day, which is the late 1990's.   There's stark limits on how many different places you can route a given source of audio.  This gets problematic when you have to multitask a single studio as much as RIPR does (which is a lot, since we've only got one studio!).   And they require a lot of exterior wiring and equipment, too.   Anywhere audio goes to or comes from, there must be a wire devoted to that single purpose.  And if you want EQ, compression/limiting, etc...it's all gotta be done on external equipment.

Enter the Logitek (no relation to these guys) MOSAIC mix console.   Except to call this a "mix console" is really a misnomer.  It's really a "mixing system".   Instead of audio remaining electricity with a given voltage and current as it passes through the system, all audio is converted to data at the source using an "audio engine"  (Logitek calls it the "JetStream").  Once it's all just bits and bytes, it can be managed, routed, folded, spindled and mutilated by the audio engine just like any other computer file. 

This concept is known as "Audio over IP" or "AoIP", similar to "Voice over IP" or "VoIP", which you may have seen in discussing software like Skype.

A typical punchblock wiring scheme in a master control room.

The actual mixing console surface suddenly isn't mixing anything at all.  It's basically just a fancy-looking keyboard and mouse that controls the computer inside the audio engine, telling it to put this satellite feed on the air or route that intercom mic to a certain speaker in the other room, etc etc etc.   The flexibility this offers is so great it's almost hard to really comprehend.  You can route any audio source to any audio destination, any way you want.

And the really cool part is that instead of a wiring scheme like this pic on the left, with thousands of wires running all over creation, through punchblocks and patchbays, that can take WEEKS to modify, never mind install?  

With an AoIP console like the Mosaic, you just have one CAT-5 ethernet cable going to an ethernet switch.  That's it!  It's all just data, so you just need the one wire.   Instead of taking days or weeks to wire up a studio, you can do it in a few hours.

With AoIP, you also can assign any source to any fader.  so instead of needing dozens of faders to accommodate every possible source...you only need enough faders to accommodate the specific mix you're running at a given time.

For example, if you have over forty sources, but at a given moment you're only using maybe a dozen of them, then your AoIP mix console might only have a dozen faders.   You can program each one to be the sources you need before you go live.  Or more commonly, you set up a preset beforehand, and then with a single button pressed, all your sources are assigned to your desired faders and you're ready to rock!
 

Wish you'd told me that BEFORE I did all that wiring!
Credit Aaron Read RIPR

  Plus, as you can see in the pic at the top, the Mosaic has a lot of user-assignable lighting schemes.  Note the blue bar of light by James' hands?  That's assignable to any one of 256 colors.  And you can program it to turn on, off, or change color depending on what state the board is set to.  Are the mics on?  Light is red - don't walk in the door because people are talking.   Are the mics off?  Light is green - it's safe to come in.  Is the studio currently on automation and not in active use?  Light is blue (or off) - do whatever off-air production work you need.   Pretty nifty, eh?

We have a major grant application in to help fund this purchase.  As mentioned, it means completely ripping out all our wiring infrastructure.   Removing punchblocks, patchbays, etc.  All of it is just gone; replaced by the audio engines.   That's a major project.  We'll know more by the end of 2014 if the grant's been approved - keep your fingers crossed!  :)