Did I make a mistake? Live sound question

[Mbira]

Hey guys,
I have an issue that I'm trying to work out.  My band has played well over 800 shows in the last 10 years.  I have run sound many, many, many times from the stage.  So I don't consider myself new to this at all....

Anyway, we have four marimbas that are on stage and those acoustic instruments are also being combined in the FOH with electrinica, synths, drum machines, and vocals.  We all run in-ears.  The acoustic marimbas have four mics each for three marimbas and five mics on the bass marimba.  So 17 hot mics on stage plus vocals and a guitar amp and the line outs for the synths, etc.

After last weeks gig with a FOH sound guy at a club once again went awry with the soundguy just not being able to hang with the complexity of the setup, I got sick of it and decided to simplify things for the sound man. 

So I created these "mic racks" that we fasten under the marimbas so each marimba has it's mics that go into a submixer and then oout of the sub-mixer we feel one output into our in-ear monitor mixer and we just hand the sound person an output.  So then instead of setting up 17 mics, we just hand the sound person four xlr cables. 

To my question: 
I just picked up four of these  Behringer line mixer/splitters and so I just plug the mics (SM57s) into the mixer and then go out into the preamp of our  monitor board and the other end would go into the snake of the FOH and into a preamp. 

Did I mess up by using line mixers instead of getting a mixer with preamps? 
I seem to be getting a pretty high noise floor from this system and some interference/noise.  I don't know what my best course of action should be now.  I can't spend hundreds of dollars (x17) on individual transformer balanced DIs, etc for each mic....what should I do?  I am noticing a sort of high pitch whining sound coming out of one of the channels from one of the mixers, but the whine goes away if I turn off a specific DIFFERENT mixer....wtf??

 

[PRR]

> Did I mess up

Yes.

SM57 with loud sounds and short cords can be mixed with 1K pots and 1K mix resistors. Could cost $99 with jacks and box.

You also messed the URL somehow.
https://www.sweetwater.com/store/detail/MX882

 

[PRR]

At that store, ART MX821S - Mic/Line Mixer $185 seems to be your value-price *Eight Mike Inputs* mixer.
https://www.sweetwater.com/store/detail/MX821S

 

[Mbira]

I need to be able to split 4 channels into two independent outputs, so an 8 channel mixer won't work (I would still need four of them). 

My less wordy question:
Is it fine to mix four sm57s in a line mixer without a preamp and then have the preamps after the mix stage, or should I be going into preamps before the mix stage and then feeding line level in to the boards?

 

[PRR]

> going into preamps before the mix stage

That.

 

[Mbira]

> going into preamps before the mix stage

That.

Well dang-now I'm confused....what about the 1K pots and 1K mix resistors?

 

[JohnRoberts]

Mixers with 16 mic preamps are pretty cheap these days...

Have you ever experimented with combining some mics passively to reduce the input count?

JR

 

[Mbira]

I got a QU-Pac and split the signal after the preamps.  Seems to work well and it's nice to be able to tweak the onboard gates and eq as well.