OK. The Crown amp has a very minimum offering of input connections. Because there is simply a single XLR input socket for each channel, and you will probably want to run each monitor of a seperate channel so that you can control the volume level of each box, here's what you will have to do:
Set the Crown's little mode switch to "Dual". We'll cover the "Bridged" mode later.
You will need to go the local GC or the music store that sold you this gear and get an adapter cable that will take that signal from the Mackie's 1/4" Monitor output and split it to the (2) XLR inputs on the Crown. Make sure that you get the correct "gender" of XLR plugs to do this (male) to plug into the Crown.
Then you need to run UNSHIELDED speaker cables from the Crown to the monitors. The Crown offers (2) different speaker outputs: binding posts (aka, "banana plugs"), and Speakons. The Speakons are probably more expensive, and in either case, you'll need to have the other end of the cables to be whatever is on the monitr boxes-probably 1/4".
I don't recommend running the amp "bridged" because that will force it to operate at what it "sees" as a 2-ohm load. @ 8-ohm parallelled monitors=a 4-ohm load. Each channel will be operating in a "push-pull" configuration @ 2ohms. This is possible, but more distortion, heat, and potential failure are the outcome from this.

Also, if you don't have the manual, you can download the manual and "Hook-up Guide" from Mackie's webite, which may help.

Moonbaby's suggestions should work. Probably need to clarify one thing, however.

"...get an adapter cable that will take that signal from the Mackie's 1/4" Monitor output and split it to the (2) XLR inputs on the Crown."

The Mackie Mixer and Monitor outs are unbalanced. The Crown inputs are balanced.

Mackie's literature is confusing. It states the outputs are TRS, which they are according to the schematics. It also states that they are "unbalanced". Which they are. The sleeve and ring are grounded internally. What an odd thing...

If you didn't need to split the signal, it would be easy. An XLR to TRS cable would do it, since the Mackie shorted pins 1 & 3 internally, with pin 2 as (+).

Since you need to "Y" the signal, if you can find a TRS "Y" cable, you'd simply plug that in, and then plug the XLR to TRS cables into them, and then into the Crown. Problem solved. Ready to rock.

(You DO NOT want a TRS insert cable, where the signal goes out one jack, and comes in the other. Be careful about that.)

IF you cannot find the proper adapters or cables, you can make them.

You could start with a mono "Y" cable from the Mackie output. This will be a TS (tip-sleeve..2-conductor) male plug to two TS covered female jacks, paralleled. (Same signal goes through both jacks).

Then, you'll need two cables that convert the two conductors (+ and -) from the Y cable out of the Mackie to the three conductor XLR input of the Crown. (Cut off the opposite end that DOESN'T plug into the Crown).

You'd probably want the shortest length of cables that will reach from the Mackie to the Crown, so you may just buy some short, short mic cables.

It would be easiest to do this at the 1/4" plug end. You will want to get two quality TS plugs with jackets large enough for the cable to fit through. (Or, you could use two TRS jacks. More later).

According to the Crown manual (which I have linked you to later), the positive will be pin 2 on the XLR plug. So, using a continuity tester in a DMM, etc., make sure you have pin 2 of the XLR chosen, and cut to the proper length to solder to the TIP of the 1/4" male TS plug. (Don't forget to put the outer cover and possibly some strain-relief tubing over the cable before you start soldering stuff).

Now, you'll have the shield and another wire left. These two should both solder to the SLEEVE of the TS plug, effectively shorting pins 1 and 3 on the XLR end. You can check that also with a continuity test.

Given the size of the shielded braid, it MAY even be easier to use a 3-conductor TRS male 1/4" plug. Just do pin 2 to the tip (+), as before. Solder the braid to the sleeve, and the wire that's left to the ring. Solder a very short wire between the sleeve and ring to short those two, and you have the same thing. Check with a test.

I do have to ask why you want to run a 200W at 8ohm/300W@4 ohm amp, instead of the Mackie's 600W? You have 600W monitor, and 600W mains amps in there? Are you already using both sections for mains on 2 sets of speakers? Nothing wrong with that. Just wondering.

You may even want to print this out (and also any corrections that someone calls me on), and print out the manuals to take to the store to explain what you are trying to do. This way, they'll have all the info they need, if they have any idea of what they are doing. (I'd at LEAST print out the Mackie sections stating about 1/4" TRS, unbalanced...and the schematic. That explains it all).

http://www.crownaudio.com/pdf/amps/139441.pdf

http://www.mackie.com/products/808m/index.html

Hope this was helpful. :wink:

Kapt.Krunch

Thanks for the abundance of information guys. My goal is to use the mackie for the mains, and crown for the monitors....

stealthy wrote: Thanks for the abundance of information guys. My goal is to use the mackie for the mains, and crown for the monitors....

Stealthy,

I deduced that much. I was just curious if you are using maybe the 600W Mackie mains side for two PA speakers, and also the 600W Monitor side for two more PA speakers? Are you using both sides?

If not, I was just curious why you would want to lug around an extra, lower-powered amp and cables, when you could just use the Mackie and get more monitor headroom?

I suppose you could be using the Mackie for mains and a pair of monitors, and just wish to have an extra set of monitors for a couple more guys?

Just wondering.

Kapt.Krunch