looks like typical computer speakers to me.... those THD figures are probably lies...... what you have here is a "system" that is probably 10 to 15 watts total, with 5 watt speakers, and the subwoofer driver might be rated at 10 watts. the power supply is most likely 12V DC, as that's common for computer speakers. you could probably get away with disconnecting the power transformer and connecting the battery in place of it. if you want to see how some of these manufacturers come up with their fictional power ratings, there's an article here: **broken link removed**