Just bought this boat and have a question as to the sound. The boat came with 6 speakers ( 4 round and 2 mounted on wake tower) and a subwoofer. It has a marine head unit and a Pyle 4ch. 1000 watt amp. The sound it produces is no where near what I feel it should be. It does not get very loud! Upon checking the amp, there is only one speaker wire connected to that side of the amp. It goes to one side of channel 3 and one side of channel 4. All the speakers work but the volume is limited. This doesn't make sense to me. Any ideas as to possible problems and solutions?