Infinity REF687F 6x8" 2-Way Car Speakers

The Infinity REF687F is a pair of 6x8-inch, two-way coaxial car speakers designed to replace factory door or rear-deck speakers with clearer, more capable sound. It is a practical option for vehicles that use the common 6x8-inch speaker format and need an upgrade without converting to a separate-component system. The pair combines a dedicated woofer and centrally mounted tweeter in each speaker.

With 60 watts RMS and 180 watts peak power handling per speaker, the REF687F can work with many factory or aftermarket receivers and can also be paired with appropriately matched amplification. Its 93 dB sensitivity rating supports useful output from modest power. The 3-ohm nominal impedance is engineered to work with the resistance present in typical factory speaker wiring.

Infinity uses a Plus One polypropylene woofer cone with a hi-roll rubber surround in the REF687F. The enlarged cone architecture provides more active cone area than conventional designs of a similar size. This supports low-frequency output while the rubber surround is intended for durable excursion control.

A 1-inch textile edge-driven dome tweeter handles high frequencies and is designed for smooth, detailed upper-range reproduction. The tweeter level can be adjusted by up to +3 dB, allowing the high-frequency output to be tailored to the speaker location and vehicle cabin. This can be useful when speakers are mounted low in doors or behind restrictive factory grilles.

The REF687F is part of Infinity's Reference speaker line and is suited to a staged audio upgrade. It can serve as a direct speaker replacement first, then be retained if the system later receives a higher-power amplifier, sound treatment, or an added subwoofer for deeper bass. Its compact, optimized frame is designed around fitment in standard factory speaker locations, but vehicle-specific clearance should always be checked before installation.

Key Features

• 6x8-Inch Coaxial Design: Combines woofer and tweeter in each speaker for a straightforward replacement upgrade.
• 60W RMS Power Handling: Supports continuous power from compatible receivers or amplifiers.
• Plus One Woofer Cone: Provides increased cone area for efficient, controlled low-frequency response.
• Textile Dome Tweeter: Delivers clear high frequencies with a smooth listening character.
• Adjustable Tweeter Level: Offers a selectable +3 dB setting for installation-based tuning.
• 3-Ohm Nominal Impedance: Helps the speakers work effectively with common factory wiring systems.

Design & Installation

The REF687F uses polypropylene woofer cones, hi-roll rubber surrounds, textile dome tweeters, and an optimized compact basket. Its two-way coaxial construction places the tweeter within the woofer assembly, reducing the number of separate components needed for installation. The Reference-series Plus One cone architecture is backed by Harman patent number 7,548,631.

Confirm that the vehicle accepts a 6x8-inch speaker and verify the 7-1/4 by 5-inch cutout, 2-7/16-inch mounting-depth, and 8-11/16 by 5-5/8-inch external-dimension requirements before ordering. The package includes two coaxial speakers, foam mounting tape, and an owner's manual; mounting hardware, adapters, wiring harnesses, and grilles may be required depending on the vehicle. Observe speaker polarity and use an amplifier or receiver whose output is appropriate for the 60-watt RMS rating.