The two amplifier chips use the 3V + 5V + GND power pin at the 'top' of the 2x20 header. If using 3W speakers, you can draw a significant amount of current, over 1.5 Amps! Make sure you power your Pi with a good wall adapter like our 2.4A microUSB power plug.
Alternatively, if you really need a lot of power, use a 5V 4A power adapter and then a DC to micro USB adapter
The Bonnet uses 3 data pins and they cannot be changed! Pins #18, #19 and #21 are used. All other pins are available
This is the fun part, you get stereo output - one left and one right channel. Each one is Bridge-Tied-Load so do not connect both outputs together to get more volume!
You can use the JST 4-pin plug in the center if you're going to just plug in one of our enclosed speaker kits:
You can use the terminal block spots on the left & right to connect regular speaker cones. You'll need to solder wires on and such but this way you can use whatever speaker you like! We suggest 8 ohm 1W or 4 ohm 3W. For louder audio, but more power usage, use the 4 ohm speakers. For quieter audio, but less power usage, use the 8 ohm speakers
You can also use other 'audio' devices like sonic transducers! These are devices you can put down onto a surface like a table, to make it into a speaker.