The Infinity Primus 603F is a 6.5 inch 2-way coaxial car speaker designed for improved clarity and bass over factory speakers. It pairs a Plus One polypropylene woofer with an edge-driven tweeter to deliver clear vocals, crisp highs, and extended low-end response.

Build features include a vented cooling basket frame for reduced thermal stress and a low-impedance voice coil described by Infinity as true 4-ohm architecture to safely draw extra power from factory radios, aftermarket stereos, or external amplifiers. Power handling is 50 watts RMS and 150 watts peak, impedance 3 ohm, frequency response 55-20,000 Hz, sensitivity 92 dB.