This audio amplifier circuit diagram is based on the Texas Instruments TPA3001D1 audio amplifier integrated circuit . The TPA3001D1 is a class-D audio amplifier capable to deliver a maximum output power of 20 watts into an 8 ohms impedance speaker with 10% THD . Also TPA3001D1 audio amplifier accepts low impedance down to 4 ohms and a wide input voltage range from 8 to 18 volts  .
With a 1% THD the TPA3001D1 can provide an output power of 15 watts into a 8 ohms load impedance .

This audio amplifier circuit diagram require few external components and can be used in applications like self powered speakers ,  LCD Monitors/TVs and others .
The TPA3001D1 audio amplifier also has many other features like : short-circuit protection , low supply current , shutdown control , high efficiency, no heat sinks required
The output of the TPA3001D1 may be driven into clipping to attain a higher output power than is possible with no distortion. Clipping is typically quantified by a THD measurement of 10%. The amount of additional power into the load may be calculated with PO(10% THD) =PO(1% THD) * 1.25
For example, consider an application in which the audio ic drives an 8-Ω speaker from an 18-V power supply. The maximum output power with no distortion (less than 1% THD) is 16 W, which corresponds to a maximum peak output voltage of 16 V. For the same output voltage level driven into clipping (10% THD), the output power is increased to 20 W.
D1 and D2 diodes are Schottky diodes ( Vfm = 0.5 V at 1 A, Vr = 30 V ) B130–13 type or similar .