On 12/06/2012 10:37 PM, Augustine Leudar wrote:
Hi all,
I am looking for economical ways of building a 256 channel out system which
will be connected to 256 speakers for a wavefield synthesis system. I do
not need a desk - or even inputs.
You can get an RME HDSPe MADI FX for around £1000 which will do 192 channel
out.
Question 1
anyone know how to do a 256 channel system ? - can you expand the rme with
an extra 64 channels somehow ? They would all need to be controlled by the
same clock so they were perfectly synchronised - perfect timing is even
more important than usual in WFS systems.
as mentioned by someone else, rme hdsps can be ganged. _but_ i've seen
weird timing issues with an old hdsp madi pci and a hdsp madi pcie -
they would be in perfect sync, but with random offsets of plus/minus
several hundred samples, apparently randomly after each reboot.
chances are this bug has long since been solved, but do measure it and
complain to rme loudly if you still see it.
Question 2 -
Does windows still only support 254 channels ?
honestly, for a system like that, i wouldn't think about windows even
for a split second. there is really only one sane system choice, and
that is clearly linux. for your frontend and user experience, by all
means go with windows if it suits you, but for the backend machine(s)?
never.
Question 3 :
Can anyone think of a cheaper way of doing this:
RME ADI 648 MADI Breakout MADI to ADAT (64 channels each) 4 * £ 1,749.00
RME HDSPe MADI FX £1099
32* behringer ADA8000 ADAT converters : £4800
yes. swap the MADI to ADAT bridge for a directout exbox, and if you can,
the behringers for directout andiamos (as mentioned by fons before).
as others mentioned before, directout madi gear can be set to "start
addresses", so that when you chain two 32ch andiamos, the first one will
pick out ch 1-32 from its input and insert its AD into channels 1-32 of
the output, and the second one can then deal with the upper half.
Total £12,966 (ish)
I was thinking if I could cut down on the madi to adat boxes or DA
converters - is there something which uses D-SUB 25 out for example ? Some
sort of Madi-analogue converter with lots of outs maybe ?
the andiamos have dsub outs.
when you design the installation, be very wary of the "last mile" of
adat cabling - it's a very weak link. make the toslink cables short,
ideally put them in a separate conduit so they don't get stressed when
you have to revisit the other wiring, and don't coil them, it
deteriorates the signal rapidly. if you have to coil them, the larger
the bending radius, the less signal damping you'll get.
adat sync loss was (and still is afaik) the bane of the wfs system at tu
berlin.
disclaimer: i'm personally acquainted with the directout developers, and
they have helped me out with gear loans several times.
in any case, their stuff is excellent and i can totally recommend it.
best,
jörn
--
Jörn Nettingsmeier
Lortzingstr. 11, 45128 Essen, Tel. +49 177 7937487
Meister für Veranstaltungstechnik (Bühne/Studio)
Tonmeister (VDT)
http://stackingdwarves.net
_______________________________________________
Sursound mailing list
Sursound@music.vt.edu
https://mail.music.vt.edu/mailman/listinfo/sursound
