These work horses just got better.With improved circuit board design, superior quality components and more heat sink mass you can expect a little extra UMPH compared to previous models. Built-in high/low- pass crossovers match the output to your specific speakers perfectly, while a switchable bass boost brings down the house. There are platinum-plated RCA inputs as well as speaker-level inputs for integration with virtually any audio system. A system distress indicator and 3-way protection circuitry keep this amp calm, cool, and collected even under extreme loads. Other features include fully variable low-pass and high-pass filters, and RCA preamp outputs for easy system expansion.