The X2222USB has built-in effects which will be heard through the MAIN OUTPUTS. If you want to hear them through monitors that are connected via the AUX channels, perform the following steps:
1.) Use a "Y" TRS 1/4 to 2 MONO TS 1/4 cable and plug the TRS end into the AUX OUT FX port.
2.) Plug the 2 MONO TS ends into a stereo channel (9/10, 11/12, 13/14, 15/16)
3.) On the stereo channel you have chosen, turn down the orange FX knob.
4.) Make sure the PRE button in the AUX section is not selected (unpushed).
5.) Use the channel fader to turn up the effect.
6.) Turn up the AUX (red) knobs to feed the effect into the AUX channels.