Need help on building a passive personal monitor mixing system

[thefunkybeat]

Here's the deal:

I run sound at a church with some talented musicians who are VERY particular about their monitor mixes.  I've been finessing all the monitor mixes for over a year, saving every change on our digital board and I still get someone flailing their arms at me from stage every service over the dumbest things - "the children's choir vocals aren't quite loud enough in the drummers floor monitor", etc.  With a band this size and this demanding there really should be another person JUST doing monitor mixes, but the budget for the staff and equipment required just isn't there. 

I'd like to get an inexpensive personal monitor mixing solution in place and here's how I'd like to do it, but I'm not sure it's quite this easy... (please let me know):

I want to send 6 to 8 mono stems to the stage (drums, vocals, horns, keys, etc...), split them out passively with some kind of mult (just wire to wire hi to hi to hi, lo to lo to lo, ground to ground to ground) to four different 6 to 8 channel passive mixers (just jacks, wire, and pots) that will feed into four powered floor monitors.  Would this work?

So, questions I have:

[list type=decimal]
[*]How many jacks is too many on a mult?  I think AES standard is 4 jacks to a mult on a patchbay?  Can I go 8 without huge signal  loss or some other problem?
[*]Can I build an 8 channel passive mixer with a pot on each channel?  I've seen 4 channel versions of passive mixers like this and was wondering if I could just add 4 more channels to the circuit without much of a problem.
[/list]
I have a gut feeling that this may be too much passive to work and there would need to be an amplifier chip in there somewhere, but if it would work and still sound ok to the average musician I'd love it.  There's just too much going on during service to cater to every little monitor change they want by myself.  It's driving me crazy and I'm tired of them looking at me like I'm messing with their monitors just to jack with them when it's THEY who are turning their keyboards, guitars, amps, up and down or standing closer to or further away from the mics and screwing things up for themselves.  I want them to do it themselves and leave me alone so I can mix for the 400 people in the audience, and the 100 people watching online (ALSO separate mixes).

 

[thefunkybeat]

Yes, I searched the forum.
No, I didn't find what I was looking for.
If you are able to find the answers to these question on this forum I would greatly appreciate links.

Thanks.

 

[thefunkybeat]

Also, I realize that I will not actually be using the LO connections and it would be an unbalanced system.

 

[abbey road d enfer]

So, questions I have:

[list type=decimal]
[*]How many jacks is too many on a mult?  I think AES standard is 4 jacks to a mult on a patchbay?  Can I go 8 without huge signal  loss or some other problem?[/list]

It's not a matter of how many jacks, it's a matter of "how much load can I put on these outputs. The answer is : "it depends".
Assuming you use a modern IC-based mixer, one output should be capable of driving a total equivalent impedance of about 1kohm. If the input impedance of each individual mixer is 10kohm, you could use 10 of them.

• Can I build an 8 channel passive mixer with a pot on each channel?  I've seen 4 channel versions of passive mixers like this and was wondering if I could just add 4 more channels to the circuit without much of a problem.

Yes.

[/list]
I have a gut feeling that this may be too much passive to work and there would need to be an amplifier chip in there somewhere, but if it would work and still sound ok to the average musician I'd love it. 

Indeed, you'll need at least one active summing stage. But in fact, you'll almost certainly need to balance the inputs (even if the outputs you distribute are unbalanced) lest you get unacceptable hum. That's basically a small line mixer that you need. I'm afraid you can't do better (and cheaper) than mass-produced pieces like Behringer RX1602, ART MX821S, Samson SM10 or Alesis MultiMix 8 Line.