Niles Content -"Real World Power The SI-2150 delivers 150 watts per channel at 8 ohms and 270 watts per channel at 4 ohms. You'll get tremendous bass and dynamics from every pair of speakers connected. Niles Content -"Turn-On Modes The Niles SI-2150 Amplifier features three turn-on modes: 1. Music Sense, 2. External Voltage Trigger, 3. Manual Turn-On via the front panel switch. You can configure the Niles SI-2150 Amplifier to interface with any kind of system and have the unit automatically turn on. Niles Content -"Bridged Mode The Niles SI-2150 Amplifier can be operated in a bridged mono configuration. In this configuration, the SI-2150 delivers 550 watts. Bridged mode is perfect for subwoofer, rock speakers or any applications requiring high power output. Niles Content -"Independent Level Controls Each amplifier channel features an independent level control enabling precise volume matching to the rest of the system. These level controls can also limit volume to prevent abuse of the system. Niles Content -"Freedom from Fan Noise The oversized heat sinks inside the System Integration Amplifiers allow the amplifier circuitry to stay cool even when operating into low impedance loads without the distracting noise created when using fan-cooled amplifiers. Niles Content -"Current for Reactive Loads The high current design of the Niles SI-2150 Amplifier assures that even unusual and reactive loads are handled with ease. Cutting edge digital power supplies provide more than ample current to your system. Niles Content -"Freedom from Cross-Talk The Niles SI-2150 Amplifier is powered via its own independent power supply. This increases the isolation between channels and eliminates cross talk, guaranteeing you absolute silence as the backdrop to your music. Niles Content -"Control Output A 12 Volt DC output is provided whenever the amplifier is on, allowing you to operate voltage triggered devices like motorized screens and curtains.