With the A2s there are two ways to connect a powered subwoofer to them like the S8. The S8 has two inputs and an output, so you could send the audio signal into the subwoofer from your source, and then use the output to connect to the A2s. The other option would be to send the audio signal from your source into the A2s, and then use the opposite connection as an output to connect to the input on your subwoofer. Both inputs on the A2s will act as outputs when audio is sent into either the A or B input.