Audio Systems: head unit cuts off at high volume, sony cdx s2000, gauge wire

Question
I have a Sony CDX-S2000 CD/radio driving 4 Alpine STM-6666 2-way marine speakers rated at 100w peak, 30w RMS. Unit is installed in a Mastercraft ski boat used in fresh water.
All speaker connections and wiring has been checked for shorts.  The unit temporarily cuts off when turned up past 27+-. Can I jump yellow wire power and ground to my newly installed sub amp that uses #8 gauge wire all the way back to the battery? I want to keep the unit connected to the accessory switch, so my kids won't let it run down.

Answer
Yes, I think it would be alright.  But fuse it so there is not fire in case of accidental shorts.

Also, this will give you more stability of power levels, but it will not reduce the shut downs; they are from turning the system loudness up too high and overloading the power output circuit.  The heat builds up and the thermal sensor is shutting the amp down to protect it.  That is my opinion.

Hope this helps.
Cleggsan