The Infinity Reference 3004A is a 4-channel amplifier delivering 75W RMS per channel at 4 ohms, built for upgrading factory radios with clean, controlled power. It can also run at 2 ohms for higher output and bridges the rear channels to drive a sub, all with Class H efficiency for real-world listening levels. Power output (4 channels): 75W RMS x4 @ 4 ohms — ample drive for a four-speaker upgrade in most vehicles. Power output (at 2 ohms): 100W RMS x4 @ 2 ohms — higher current capability for demanding speaker loads. Bridged power (4-ohms): 200W RMS x2 bridged @ 4 ohms — bridge the rear channels to push a sub while fronts handle the speakers. Class H technology: Maintains efficiency across a wide range of output levels, reducing heat and draw at typical listening levels. Filters: Separate high- and low-pass filters on front and rear channels (32–320 Hz, 12 dB/oct) to tailor each path and run full-range fronts with a bridged sub without an extra crossover. Inputs and turn-on: Speaker-level inputs and signal-sensing turn-on support factory radios without an aftermarket head unit. Preamp outputs: Preamp outputs allow passing the signal downstream to a dedicated mono sub amp later. Included adapters: Bare wire-to-RCA adapters included for both preamp and speaker-level inputs. Power wiring & fuses: Recommended 8-gauge power/ground wire; two 30A fuses (one installed, one spare). Dimensions: 12-5/8"W x 2-1/4"H x 7"D. Warranty: 1-year warranty. What’s in the box: Four-channel amplifier; four 30A fuses (two installed / two spares); four speaker wire-to-RCA adapters; mounting hardware; logo badge; owner's manual. In a real-world install, the 3004A powers a four-speaker front/rear setup from a factory head unit, with the option to bridge the rears for sub bass while maintaining clean mid/high performance from the front channels. The OEM-friendly inputs, adjustable crossovers, and downstream preamp outputs provide a scalable upgrade path without replacing the head unit, and the compact form with a sensible 8-gauge wiring recommendation fits a wide range of vehicles.