"Cascading" two SC48

[mariojorgeandrade]

Hello.
In a Brazilian Forum, one person described a real situation, an open air big concert, no rehearsals and only a line check, several acts playing together, about 80 input channels and two SC48 at the F.O.H.
(If anyone is interested, the thread is here, but is in Portuguese:
http://gigplace.ning.com/group/usuar...e-outras-venue)
He told he looked in the manual for cascading options, hadn't found anything and simply plugged the first 48 channels in the first SC48, the rest of the channels in the second one, the mains of the fist one in the last two channels of the second one and there he went.
I told him it's not possible to cascade, or to make the two SC48 act as one, that he should have used a D-Show or Profile with two Stage Racks instead.
But I was wondering if someone ever faces a situation like that, what could be done to ease the engineer's job.
First of all, at least the "master" should have a IO16 installed, to spare some input channels.
First, for the mains, the outputs of the "slave" SC48 could return in two TRS inputs of the master one and be patched directly to the output matrix, via the matrix mixer. Or maybe the AES/EBU I/O could be used for that purpose instead, with the addition of the Word Clock Connection.
I imagine 8 audio groups coming from the slave console into 8 TRS or XLR inputs of the master, using 8 channels, each one patched to each subgroup. That part is really optional.
Maybe 4 auxes could be enough for 4 effects, being taken from the slave
Into 4 more channels of the master, each sent to its respective aux, which
are then patched to an fx plugin and each returned in an fx return, everything almost standard, so far.
The most difficult part are: VCAs, Snapshots and the solo bus.
In the unlikely use of snapshots in a situation like that, one could simply
Use two footswitches taped closely together and advance the snapshots stepping on both at the same time.
For the VCAs, I’m affraid nothing can be done to link them, any ideas here?
Unfortunatly, I believe that for the solo bus, the problem will be the same: Maybe no way of doing this, any more comments here?
Maybe ising the GPI, I’m not sure, but I believe it’s not possible.
Well, maybe in a situation like that, the best approach would be two
Engineers mixing, each in one SC48 and only the Mains connected together.
But, it would be interesting if we could do a Cascade –like link of the two SC48.
Any comments will be appreciated.
Thanks in advance.
Sincerely,
Mario Jorge Andrade
Recife - Brazil