Amp issues SV211 Kicker KX300.4

[homer12]

My amp that powers in boat and sub speakers wants to cut out when it gets turned up to a certain point and then gets extremely quiet while the tower speakers on separate amp stay normal. If I keep the volume mid to low it doesn’t do this. Any ideas on if I have an amp issue or wiring issue and where I should start? I will replace amp if need be but don’t want to do it and still have the issue.
Also, I’ve had the boat and setup for 6 years with no changes. This just started recently

[MLA]

How many speakers and how are they wired, and how the woofer wired and whats its final impedance? When the issue happens, is the amp's protect light coming on? Sounds like either the amp is possibly getting hot, but more so like the impedance on one channel is dropping too low.

[homer12]

Thanks for the response. Impedance is something I am not familiar with. I can say that the way it’s wired is boat speakers (6) on one channel and sub (1) on the other. I’d agree about the getting hot piece but it’s never really acted this way in 6years. Is there a way to measure the impedance or where can I research? Wondering if it’s a wiring issue or speaker wires are old and need replacing from corrosion buildup…

[homer12]

Also, the night I investigated it after it was going out that day I didn’t find anything and protect light never came on. The next day is when I realized I have to turn it up to a certain volume before it happens.

[homer12]

Boat speakers I believe are wired in parallel off 2-channels for right and left. Is that right?

[MLA]

There is no good way to power 7 drivers on a single 4 channel amp. So I would speculate that the amp is driving the woofer and the 4 main cabin speakers. In this case, that would most likely have all 4 chnls at their minimum impedance of 2 ohm. A failing speaker could be pulling down the impedance lower, putting the amp in protect mode.

[homer12]

MLA thanks so much for the help. To clarify, the amp is running the sub bridged on 2-channels and the boat speakers L R on 2 channels.
So, maybe I should disconnect each speaker one at a time and test to see if I have a bad one perhaps.
This appears to be a car audio amp too so not sure if it could fail in a boat but isn’t new. I’m thinking amp needs replacing.