Check the listing for details. Infinity Reference Series 2 Pairs REF407F 4" Coax 2-Way. Condition: New. Listed at 219.90 USD. This bundle includes 2x Infinity REF407F 4” Two-way Car Audio Speaker. New Reference speakers from Infinity bring the brand's signature sound to more vehicles. With edge-driven textile tweeters for clear highs and adjustable tweeter output control, these speakers offer optimized high-frequency performance. The oversized Plus One™ woofers deliver enhanced bass and midrange response. Designed to fit most factory speaker locations, these speakers come in various standard sizes for easy installation. The audiophile-grade tweeters ensure smooth sound even at high volumes, while the patented Plus One™ cone design provides increased cone area for improved sensitivity and accurate audio reproduction. These Reference speakers also feature optimized frame sizes to fit almost any vehicle. The technic.