I meant amp crossover, may bad. Do you have a subwoofer? If so the amp crossover frequency should be in the 100-120hrtz neighborhood to start. Without a sub you'd want a lower freq setting so you have a good blen for highs and lows. If with sub you should also make sure the amp is set to hi-pass for the speakers and low-pass for the sub, cut the subs freq at around 80hrtz to start.
Play with the hi-low freqs to get a good "blend" between the speakers and the sub if applicable.
Reference "how to set gains" in the how-to section to make sure your getting the most from them and the amp.
Do you have a dedicated battery for the stereo or just one battery?
What size power cable is going to the amp? 8ga, 4ga etc.