SRS StuidioSound HD also features a TruVolume function, designed to eliminate volume changes when switching sources. The TH-BC3 uses proprietary algorithms from SRS Labs to optimize bass performance. This model differs from the lower cost TH-BC1 model in that it has an HDMI 1.4 enabled ARC (Audio Return Channel, which allows for simplified wiring since audio can travel in both directions through the HDMI cable), two HDMI inputs, one HDMI output, 3D ready video pass through, a composite video output (for watching movies on your iPod/iPhone), and a push-open iPod/iPhone dock (for streaming and charging). The JVC TH-BC3 sound bar comes with a pre-out for connecting it to a subwoofer.