Infinity PRIMUS 683F 6 x 8" 2-Way Coaxial Speakers

The Infinity PRIMUS 683F is a pair of 6 x 8-inch, 2-way coaxial car speakers designed to replace compatible factory door or rear-deck speakers. It is suited to drivers who want a straightforward upgrade in clarity and output while retaining a compact, vehicle-friendly speaker format. Each speaker combines a polypropylene woofer and a centrally mounted silk dome tweeter.

With 50 watts RMS and 150 watts peak power handling per speaker, the PRIMUS 683F can work with many factory radios as well as appropriately matched aftermarket amplification. Its 3-ohm nominal impedance is designed to make effective use of available amplifier power. The 92 dB sensitivity rating supports useful output from modest-power systems.

The sound system is built around Infinity's Plus One woofer cone architecture, which increases usable cone area compared with conventional cones in its class. More cone area can support stronger low-frequency output and sensitivity within the speaker's operating range. The specified frequency response is 65 Hz to 20 kHz at -6 dB.

An edge-driven 1/2-inch silk dome tweeter handles high frequencies, while the crossover point is specified at 5 kHz with a 6 dB-per-octave slope. This coaxial arrangement keeps the woofer and tweeter together in one speaker assembly. It is a practical format for replacing full-range factory speakers where a separate component system is not required.

The PRIMUS 683F uses a vented basket frame intended to help move heat away from the voice-coil area during operation. Its compact mounting profile is designed for installations with limited space. The package includes two speakers, mounting hardware, pigtail cables, a foam gasket, brand stickers, and an owner's manual.

Key Features

• 6 x 8-Inch Coaxial Design: Combines woofer and tweeter in each speaker for a compact replacement upgrade.
• Plus One Woofer Cone: Provides increased cone area for efficient midbass and low-frequency output.
• Silk Dome Tweeter: The 1/2-inch edge-driven tweeter reproduces the upper-frequency range.
• 50W RMS Power Handling: Matches well with modest factory or aftermarket amplifier power.
• 3-Ohm Nominal Impedance: Designed to draw effective power from compatible car audio amplifiers.
• Vented Basket Frame: Helps dissipate heat around the motor and voice-coil assembly.

Design & Installation

The PRIMUS 683F pairs a 6 x 8-inch polypropylene woofer with a 1/2-inch silk dome tweeter in an all-black coaxial assembly. Infinity's Plus One cone architecture and vented basket frame are integral to its design. The basket is engineered to support cooling around the voice-coil area during higher-output use.

Confirm the vehicle's speaker opening, mounting depth, mounting-hole pattern, and factory grille clearance before purchase. The installation diagram specifies a 2-5/16-inch mounting depth and a 2-11/16-inch overall depth; use the included screws, speed clips, foam gasket, and 18 AWG pigtails as appropriate for the installation. For amplified systems, select an amplifier channel with power output suited to the 50W RMS rating per speaker.