Re: Really struggling with compressor - limiter
 

It should be showing some gain reduction and/or input output levels on the meters. Explain or take some photos of the 'signal flow'.. how it's patched into the mixer and/or other devices. ) Check the input and output connections, and confirm NOTHING is plugged into 'side-chain' input by mistake. (if it has it) and make sure it's not set for side-chain on the front panel either. (again, if applicable)

Re: Really struggling with compressor - limiter
 

Have you down loaded the instruction / setup manual or have a paper copy?
http://www.behringer.com/assets/MDX1600_P0177_M_EN.pdf

Do you want to use it as a brick wall limiter or a compressor?

Do you want to just stop the peaks or do you want to make the mix easier to ride and produce?

Do you have a basic idea of what a compressor does?

Re: Really struggling with compressor - limiter
 

A big red flag is that you have the threshold set to -30db. For such a high ratio (10:1, not 10db) you shouldn't have the threshold anywhere near that low; it should be somewhere in the range of 0 to 20db, normally more like 10-15dbu.

The fact that you are getting OK audio (not squashed to heck) with these settings, however, probably means that you have other gain issues, and you are not sending pro level signals through it. If you are sending consumer level signals through the compressor then I suppose -30db might be appropriate, but I'm not sure if the equipment is optimized for such low level signals.

At any rate, your basic goal should be to adjust the compressor so that you get a lot of gain reduction leds during the peaks that you want to compress (e.g. audience clapping) and none for the signals that don't need it (normal speech for instance).