Firewire Extender

[luigichelli]

Hi guys, i'm thinking about moving my notebok away from the soundcard/converters/preamps stuff...stacked close to the mics.

Anyone had experiences with a firewire extender?
i found those 2 models:
cheaper 400Mbps over ethernet: CAT5 FireWire Extender (Up to 75m) | Repeater | FireWire Cables | USB & FireWire | LINDY USA

expensive 800Mbps over fiber: Gefen Firewire 800 Extender (EXT-FW-1394B) - IndustrialComponent.com

Here on GS i've only found a thread where someone stated to beware the true extenders, since they could go down to 100Mbps in real world usage.

What about the latency? obviously i don't want any packetloss etc...

Thanks for your help!

[jglamar]

I use the newnex firenex model (400mbps). It works as advertised but feels very flimsy and in fact I had an experience once where FW bus power blew one of the repeaters, which IMO bespeaks poor (or at least cheap) design. The units are so flimsy I gaff them down to a nearby surface lest the weight of the fw cable drag them off. Both the Lindy and Gefen models you list look more well-made than the Firenex, but I've never encountered them in the wild.
Another thing to note about using extenders with your interface at a distance from your laptop is that you will need to consider how to monitor on the far end. Some use an aggregated device but others haven't found that solution stable or trustworthy - in which case, like me, you will end up needing to run some kind of audio cable from the interface to your monitoring position, which is at best a pain and to some degree mitigates the advantages of the fw extenders.
All that having been said, I use mine all the time for classical recording and have never noticed dropouts or loss of signal of any kind. Recording 8-16 channels of 24/96 has never been an issue bandwidth-wise. Latency, I don't know about since it doesn't really affect what I'm doing, just capturing audio.

[luigichelli]

Thanks a lot jglamar!
yeah i was thinking of running the audio cables for monitoring and talkback alongside the ethernet too.....
Or we could try to monitor through the DAW, for example in logic i could select the far interface as the input device, while the usb-close interface as the output device. i'm thinking about jitter and stuff... how the 2nd interface will be clocked?

[jglamar]

Originally Posted by luigichelli

Or we could try to monitor through the DAW, for example in logic i could select the far interface as the input device, while the usb-close interface as the output device. I'm thinking about jitter and stuff... how the 2nd interface will be clocked?

This is precisely the problem - getting the near-end interface to clock properly. As I said, many have success "aggregating" the devices, usually in coreaudio but sometimes through the DAW. Personally I feel better just running the extra cable for monitors, talkback, etc. Your other options would be to run actual clock signal back from the far-end interface to the near-end one (which I have done a couple of times and it works fine - but I think there is a limit to how far you can drive word clock signal over co-ax) or use a long AES run. I use this method often too, and the obvious added benefit is that the AES line can carry 2 channels of audio to your near-end d/a. But not everyone has really long AES cables.

Since I began using fw extenders with the Metric Halo ULN-8 (I record in the MH record panel), I've always dreamed of a small near-end unit that could be inserted in the fw chain without causing any clocking issues, the sole function of which would be to provide monitoring. Basically a fw-based 2-channel d/a.

[luigichelli]

hmmm..maybe the only way to have just one eth. cable for remote recording/monitoring/talkback is an adat over ethernet solution.
like this:
Products

setting pre and converters in one room and having a long run ethernet carrying digital code to a slave interface, using it for recording, monitoring, and talkback...

[jglamar]

If you're ok with the 24/48 limitation of standard adat, and if you have 2 interfaces that will work. Actually I guess you wouldn't need a whole interface on the far end at all - just pres, a/ds, and conversion to adat lightpipe. One of the great advantages using the fw extender is that I have remote control over the uln-8, so I don't have to run up to the catwalks every time I want to change gain. That wouldn't be possible with lightpipe over ethernet.

[jglamar]

Now that I really looked at the products you mention though, the 32-channel version is intriguing. A couple of observations:
First, with multiple toslink connections you could transfer 16 channels of 24/96 over s/mux. Pretty cool.
However, the price for 2 units is not great but still a bit more than your fw over ethernet solution.

[luigichelli]

yeh the price tag is higher than a fw extender (less than other models btw)...
and i think it's possible to duplicate somehow the adat outs to feed for example a backup recorder.

Anyway for now i'll stick like you with a remote fw with some audio cables along.
Last but not the least: this way we got a remote midi in/out too! (usable for remote pre's etc..)

thanks for your help!