Simple case for Arylic's Up2Stream Plate Amp 2.1 - Multiroom Wireless 2.1 Plate Amp
The amplifier module can be found here, https://www.arylic.com/products/up2stream-plate-amp-subwoofer
Arylic have a nice range of inexpensive DIY audio modules, I have a few connected to old speakers to stream audio to. This one sits on top a a beer fridge in the backyard.
The project is just a simple case to mount the module. No ventilation was needed, but if you plan to run it at 100% in a hot location you may want to add some.
Speaker cable terminals can be found on Amazon, I just used some I had from a past project. As the size of the terminals may be different I have included a version with no mounting holes.