The default is 24V, 1.2A, which can be used for current flow. The higher the current is, the more heat is recommended.
Choose a 3-5 inch full-range speaker, and you can choose a full-range speaker with a 5-8 inch diameter. You can also choose a speaker with a power below 120 watts and below 8 inches.
1 Pair 1969 Class A Power Amplifier Board 10-15W HiFi Audio Amplificador 2N3055 PCB Assembled Finished board