4.1 Channel Subwoofer Amplifier The S-299 HiFi Audio Amplifier can be connected with four 4-8 40W passive speakers, the rated power is 40Wx4, peak power up to 800W. 4.1 channel amplifier, the S-299 amplifier can contact an active SUB subwoofer and four passive speakers, and the active subwoofer has no power limit. This makes it the perfect addition to a home theater, audio PC setup and car audio system. HiFi Amplifier The S-299's improved circuit board with 2 integrated YD7377 audio processing chips and a powerful transformer ensures high output power. Hi-Fi Amplifier-The lossless decoding and minimal distortion ensure pure sound quality, and the treble and bass controls allow you to finely tune the sound, whether you want deep bass or clear treble, this amplifier will fulfill your desires.