Firewire audio interfaces & such

An anonymous friend, who still prefers that quaint old techology, email, writes: I’ve got a tech question for the computer gurus over at krunk audio (that would be you). I’m just assuming you know more about digital audio than I do these days. Is it safe/advisable to run both one’s audio interace and one’s audio recording HD off the same firewire interface? I’m finally in a position to spring for a computer recording setup, and I’m thinking of doing it by having an Edirol FA-101 and an external HD both into the firewire. That way I can have all the audio hardware and storage outboard, and move freely between my laptop and desktop for recording/mixing. Any glowing pearls of wisdom you have would rock…

OK, great question. FireWire is Apple’s trademark, so let’s refer to the standard by its official name, IEEE 1394. 1394 offers maximum bandwidth of 400 Mbps. What kind of bandwidth are you trying to push? That’s simple, in 24 bit 96 kHz mode, you have a maximum of 10 tracks. Your bandwidth would then be:

24 x 96,000 x 10 = 23,040,000 bps
= 21.97 Mbps

This means you have oodles of available bandwidth on the same bus. For realtime applications, IEEE 1394 offers an isochronous mode, which is clocked at either 100, 200, or 400 Mbps with no dropouts. This makes it ideal for both audio and video. The FA-101 also can do 6 tracks at 192 kHz. If you do the math, the bandwidth requirement is only a little higher. You should be able to plug that 1394 drive into either your PC or the second connector on the FA-101 without any problems.

Now, some questions for you! I see this unit listed at about US $500, but it doesn’t seem to come with any software. If you don’t already have good DAW, software, remember that purchase will drive your price way up. The Digidesign Digi 002 Rack is more than twice as expensive, but comes with Pro Tools LE and a few plugins.

Also, what are you planning on plugging into this thing? Did you notice that inputs 3-6 run at +4 dBu, which is the pro input level, rather than -10 dBu which is prosumer. Your synths & such might not like that. Only inputs 7-8 are selectable to -10 or +4 dBu. The SP/DIF I/O is optical only (kind of lame).

Personally, I would stay away from Edirol and stick with a company that specializes in audio and has lots, and lots of users, like Digi or even Tascam, which has some neat looking new stuff. But whatever you wind up getting, we want a full report, and of course, lots of audio to hear!






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