Infinity PRIMUS 603CF 6.5" 2-Way Component Speaker System

The Infinity PRIMUS 603CF is a 6.5-inch, 2-way component speaker system designed to replace factory door speakers with separate woofers and tweeters. It is intended for vehicle owners who want clearer front-stage sound while retaining a practical, vehicle-friendly installation approach. The system includes dedicated in-line crossovers to divide frequencies between the woofer and tweeter.

Each set uses 6.5-inch polypropylene woofers for midrange and low-frequency reproduction, paired with 3/4-inch silk dome tweeters for high frequencies. Its rated frequency response is 55 Hz to 20 kHz, supporting full-range music playback while leaving the deepest bass duties to an optional subwoofer. With 92 dB sensitivity at 2.83V/1m, it is suited to many factory-radio and aftermarket-amplifier upgrade paths.

Infinity rates the PRIMUS 603CF at 60 watts RMS and 180 watts peak per side. Its 3-ohm nominal impedance is designed to draw useful output from compatible car audio amplification. For best results, match the speakers with an amplifier or receiver that is stable at their nominal impedance and can provide appropriate clean power.

Infinity's Plus One woofer cone architecture increases cone area compared with conventional cones in its class. More radiating area helps the woofer move more air for low-frequency and midrange output. The edge-driven silk dome tweeters are designed to extend high-frequency detail while maintaining a smooth, natural presentation.

The PRIMUS 603CF is a component system, so its separate tweeters can be positioned higher in the cabin than the woofers for a more focused soundstage. Compact-fit engineering and multiple included tweeter mounting parts support flush, surface, and starfish-style installation approaches. This makes the set a practical front-speaker upgrade when vehicle-specific fitment and mounting depth have been verified first.

Key Features

• 6.5-Inch Component System: Separate woofers and tweeters support more flexible speaker placement than coaxial designs.
• Plus One Cone Architecture: Increased cone area helps the woofer move more air.
• Silk Dome Tweeters: Edge-driven 3/4-inch tweeters reproduce detailed upper frequencies.
• 60W RMS Handling: Supports amplifier upgrades with appropriately matched clean power.
• 3-Ohm Nominal Impedance: Designed for use with compatible factory and aftermarket car audio systems.
• In-Line Crossovers Included: Direct high and low frequencies to the appropriate drivers.

Design & Installation

The system combines polypropylene woofer cones, silk dome tweeters, and super-rigid vented basket frames. The vented basket design is intended to help move heat away from the motor structure and voice coil during operation. Its all-black presentation is designed to integrate cleanly with many vehicle interiors.

Confirm vehicle-specific speaker location, mounting clearance, and wiring requirements before ordering or installation. Install one woofer and one tweeter per side through the supplied in-line crossover, observing polarity throughout the system. The included flush-mount adapters, surface-mount cups, and starfish tweeter mounts provide several tweeter-placement options; professional installation may be useful when factory wiring or panels require modification.