TPA3122D2 IC is used as a class D audio amplifier and can deliver up to 15W of power at 10% distortions. The real advantage of using a class D amp, especially TPA3122 is the fact that this IC doesn’t need a heatsink because it has a high efficiency. Another great thing about it is that you can buy a $20 built-it-yourself kit or even cheaper from ebay but you need to be careful not to buy a fake one.
I discovered this IC while searching for an audio amplifier circuit that I need for the 2 x 10W/4Ω speakers received from my brother-in-law. I think that TPA3122 can provide enough power for what I need even though it can output only 8W with 1% distortions on a 4Ω speaker (something that some of you might find too low). The main reason I would choose this instead of a class A or B IC is the fact it doesn’t need a heatsink, so the whole amplifier will be lighter in weight and cheaper.