help with stereo

This may run long. sorry.
I have a center console fishing boat we ride from. Whatever, it's my boat.
I finally put in some simple tunes but i think it needs tweaking.
The system:
Four Kicker 6.5 round speakers in the hull sides.
One Sony 650 watt 4 channel amp.
One Ipod touch.
That's it. no head unit, no line driver, no EQ.
The amp is four channel and I split the speakers up in what i thought was the correct fashion: front back left and right.
The issue is that at high levels the rear speakers are pounding with more base pressure than they can hold and the front speakers seem not to have that pressure.

Options: I have a pair of 8" subs in ported boxes from my old truck. Can I put all four boat speakers on the two "front" channels and wire the two subs to the "rear channel" and toss the boxes inside the console? Would I just wire on top in parallel or do something fancy with series and maybe bridge the subs? How would i do this?

I feel i missed something basic but have to work with what i have. Eventually I will get a JL CL-RLC line driver to use as a volume control but i will never put a head unit in this boat.

Please advise.
John

Setting the amp to Hi-Pass will cure the issue of over driving the rear 6.5.

Exactly what Mike said above. Set all coaixials to 50 to 60 Hz highpass. It won't audibly alter the deep bass extension of a 6.5" at that low of a frequency but it will dramatically increase the power handling and how loud & clean they will play. Make sure that two-channels of the four channel amplifier are NOT set at or using any kind of bass boost or EQ. Are there any coaming pockets or open cavities next to speakers so that the front and rear speakers are acoustically loading differently?

David
Earmark Marine

Both speakers are set in the liner and have proportionately similar area in the compartment. There are two only dip switches on the amp. One high and one low. The high is adjacent the front speaker connections and the low is next to the rear speaker lugs. I switched the low off yesterday and the the rears went quite.
Help?

OK, Ill take my glasses down he boat and actually read the settings. Is the gain pot what I should be adjusting? Where do i set that?

Originally Posted by baitkiller

OK, Ill take my glasses down he boat and actually read the settings. Is the gain pot what I should be adjusting? Where do i set that?

Yes, the gain needs to be set correctly fallowing a procedure, but thats not what we're referring to here.

What you need to check first is the cross-over filters. Your 4 chnl amp will most likely have two, one for both halves of the amp. It sound like the half running the front speakers is set to "Hi-Pass" as it should, but the rears are set to "Off" or some times called "Full-Pass" . Once the cross-over filters are set correctly, then, as David noted, set the Freq. dials to 50-60 Hz range.

The glasses helped, sucks getting old. Thanks for all the help guys it sounds great now.
John