I'll respond to your PM here in the event in can help others...
If you have input A as your LFE input and output 1 and 6 as your subwoofers (just as an example) this is what you want to set the DCX up for to begin with.
Press the button below the level outputs for channel 1 output. You should be on page 1of8 general settings.
The first setting for this channel is the input it is being fed by. Select A. You can move through the options by using the "param" buttons to go up and down and use the scroll wheel to do side to side stuff.
You can also set the output gain and what this output is labeled as. Leave the gain on 0db for now.
Next do the same for channel 6 (or whatever other output you decide to use) In my setup I opted for channels physically farthest apart on the unit for any hope of better stereo seperation. You're probably not going to be worried about that. I just did it because i could.
Now there are 4 more channels of outputs your not using so go through this first step as outlined above and do the same for each, only set them to input B or C. You just dont want them to be on the same input as what your using.
Now, Go to page 2 of the menu for channel 1. This is where your going to set up the crossover. And the High Pass filter to protect the driver.
The first parameter you need to set is the crossover slope for the high pass. Set it on but24. This is a butterworth type 24db slope. You can play with these settings later on but this is the reccomended filter. You want to set it at 20hz, which is the lowest you can set a crossover filter. After thats done your high pass is ready. This slopes off frequencies below 20hz to protect from over excursion. Since you'll probably be using the sub crossover in your reciever, Go ahead and set the other crossover filter to "off" under type and you can turn the freq to 20khz just for the heck of it. (in the picture i hav it set as a butterworth 18db slope at 69hz because I also have my main speakers hooked to the DCX and i only use 2 channel. If you were not using the recievers crossover for the sub you would want to set it at say 80hz and some kind of slope.
Also, set the Xover adjust mode to free if its not already to keep things simple. (bottom right corner of this display)
You have now basically setup the dcx. that will get you started.
A few more things though...
Your going to want to eq your in room response with the dcx, this is best done with room eq wizard software. Once you get more accustomed to using this thing it will be easy. Also the manual is a good help if perhaps a bit technical. I'll explain a little on the eq page..
you'll probably want to keep the eq to off for now, but at the top we have the first paramter which is NR, I dont know what that stands for but anyway thats the first band of eq. you can have up to 8 or 10 IIRC per channel. Type, just leave on BP, freq is the center frequency of what your are going to eq, next is the gain plus or minus in db, and Q which sets how "big" the eq is. You'll see what i mean by looking at the graph and playing with it.
Next page is Dynamic Eq. Just leave this set to off, (it should look like this screen)
Next page is more dynamic eq stuff. leave this set as it is on this page as well. The main thing is the Thresh, leave it on 0db
Next page is the limiter. also leave this off. as see on this page.
Now we get into something you want to play with which is page 7, containing phase. You can invert the polarity (180 degrees) or adjust it in smaller increments with the phase paramter. Just leave the polarity on normal for now but switch between normal and inverted and see if you hear any difference. For me inverted is much better.
Theres one more page, the delays that i didnt take a picture of, just leave it all off. Now go through and do the same thing for your other output channel.
One more thing is that you want to mute the inputs and outputs your not using. To do this press the mute button which brings you into sort of "mute mode" and then press the main button you hit to get into each channels menu's. A red light will come on for each muted output and input.
As for your hum, you may have to look into something like the art cleanbox or similar. I did not. I was able to kill any humm with using a star grounding system with my equipment. I reccomend trying this before investing in anything else or getting ground loop isolators. the idea is that you hook up an auxillary ground wire to the chassis ground of all your equipment with lengths of wire that are similar and as short as possible. And tie them all together at one central point, in my case its my power conditioner. The idea is that any stray ground currents which usually cause humm due to running through the audio circuitry are instead redirected through this ground wire because of a lower resistance to ground. It may or may not work for you but it is worth a try. Some equipment has ground lugs and others you simply need to attach the wire with a spade or ring lug and secure it with one of the chassis screws.