I integrated power amp and a speaker into small carry cooler box.

Step 1: Power Amp PCB

I maked power amp with LM386. I use one LM386 for one channel.
PCB is fixed with double-stick tape.

Step 2: Speaker

In this cooler box, the inside became dual structure. Therefore, I fixed the speaker in an internal housing.
I used a screw for fixation and blocked up the gap with silicon.

Step 3: Waterproofing and Wiring

I thought about waterproofing of a speaker and covered it with Tupper. And I filled up a gap with silicon in the same way.
A battery uses 006P.
A battery is fixed with a board of aluminum like a picture, because I do not enter a gap of a housing of dual structure.