USB speaker: it is the digital audio signal from the USB port on the motherboard directly into the speaker, and then through the speaker built-in D/A conversion circuit will signal processing and output of the speaker.
On the surface, the advantages of using USB speakers can improve sound quality, because the digital signal will not be interfered in the transmission process, the purity of the signal is good, but the core of USB speakers is D/A conversion circuit, its conversion accuracy has A great impact on the performance of the speaker.
USB speaker power, limited to USB safety gauge (standard is 5V/500mA), is generally 5V/1A, so the power of USB speaker generally in THD+N 10% power does not exceed 3W (5x0.5 =2.5W), more than is through the extraction of USB port current to increase the power, But in 2012 PC a lot of USB port safety restrictions, so IC and USB speaker manufacturers will carry out some power restrictions.…