Hey Gang,
A friend of mine just GAVE me an Echo Audiofire 4 to compliment my Audiofire 12.
Since all of my inputs are analogue can I just link the 2 together via firewire? The Audiofire 4 does NOT have word clock while the 12 does. Wondering if this will work as my project studio has a 16 channel snake.
Thanks in advance for any advise.

If I remember, the audiofire series will share the driver under ASIO since they are designed for that.  I'd check their forum or instructions to get it to work.  I may be wrong, or it may be two of the same exact units.
 
The only way to be really sure is just to hook the two up and see if they find each other.
 
@

Do the units have SPDIF inputs and outputs. If so then you can link them to provide a clock signal from one to the other. FireWire does not carry the clock signal but if the driver provides for concatenating the devices then they might work.

The AF 4 has SPDIF while the AF 12 has Word Clock.
I posed this same question on Gearslutz.com forum & it has been suggested that I send Word Clock from one of these: http://www.sweetwater.com/store/detail/SyncGen?utm_source=CSE&utm_medium=PPC&zmap=SyncGen&zmac=7&zmas=1&zmam=89202644&SID=0
From this ART unit I can send SPDIF & Word Clock to each unit via their proper connections. I have one on order.
Is there any benefit to also sending Word Clock signal to my pre-amps as well? Some of them have W.C. or SPDIF inputs, some of them don't.

Before you spend any money just try it in Sonar and see how ASIO presents the 2 devices. Sometimes the driver does the synchronising for you. What you do need is for the driver to show you all the inputs and outputs of the 2 units. If that doesn't happen then synchronising the clocks through SPDIF or an external unit like the ART Syncgen won't matter.

You may be able to get it to work under WDM/KS. It always depends on how well the WDM drivers are written. WDM does allow for multiple drivers and devices being addressed simultaneously, however you may still need to do external synchronisation. Just try the software routes first.

Synchronisation is only required for AD/DA conversion. If your preamps have ADDA that is being used then you HAVE to synchronise their clocks with ALL your equipment.

When I say being used I mean; some preamps provide digital as well as analog outputs. If you're using the digital outputs then that unit will need to be clocked to your Audio Interface.

As a rule there can must be only one master clock in any circuit of digitally connected devices