I'll do my best here to try and provide all the information and make it clear.
I had my buddy install the WS-420 in my boat so I could have all the benefits it provides. ie the ability to independently adjust towers from interior and the ability to yell at tubers from a 100 yards away.lol.
I have about a 3 year old Sony Marine deck
http://www.onlinecarstereo.com/CarAudio/ProductDetail.aspx?ProductID=14678. I have a Hifonics Zeus 5 channel 1000watt amp as well as a 200watt Clarion Mono Amp. The Tower speakers are the older Kicker KB6000.
Originally we tried putting the tower speakers alone on the Clarion Amp but it didn't really make a difference.
On the Hifonics Amp are:
The 2 pairs of cabin speakers share a channel.
The Sub on another Channel
The Tower speakers on another channel.
Clarion Amp:
Currently has the bow speakers on them.
Because the deck only has 2 sets of pre-outs 1 set of RCA's has 2 "Y" splitters to share a channel to the Clarion Amp. I don't remember what channels share...I believe interior share with bow speakers on the Clarion Amp.
Ultimately the issue I am having is I just can't get the tower speakers to go really loud. The interior speakers go just as loud if not louder when playing with the volume on the EQ itself. Are the older Kicker KB6000 the problem or is it gain/power/setup issues.
One minor issue I am also having is when I flip the switch on my tower lights I can hear a click in the speakers. The lights are grounded and powered on a different switch.
Any insight would be much appreciated. If you need more details or better explanations I will try my best.