ESB Audio 4.6C — 4000 Series 2-Way 6.5"/165 mm Coaxial Speaker (pair) | HF Audio Labs

ESB 4.6C — 6.5-Inch Coaxial Speaker

The 4.6C brings 4000 Series driver engineering to the coaxial format — a complete speaker in a single unit for positions where separate tweeter mounting is not practical or not needed. It is designed for builders who want every position in the system, including the coaxial ones, to hold the same standard as the front stage. The problem it solves is the weak link: the secondary speaker that falls behind when the system is driven.

Key Design Features

The 4.6C uses the same die cast aluminum basket construction and N52-based motor design as the 4000 Series component drivers, applied to a coaxial with the tweeter mounted in the woofer's acoustic center. The result is a coaxial that keeps its composure under load — output that stays clean when the system is driven, rather than falling behind the component drivers around it. Sharing the series design also keeps the tonal character consistent from the front stage to the secondary positions — the system sounds like one system.

System Application

Rear fill in 4000 Series builds, factory door locations without practical tweeter positions, and secondary speaker roles supporting a component front stage. Works in OEM integration setups and amplified daily-driver systems. Fits standard 6.5-inch mounting locations and works with factory head units and aftermarket amplification within its power range; the 4000 Series grille is available for exposed installations.

Specifications

Impedance: 4 ohms. Format: 6.5-inch coaxial. Full specifications available on request.

HF Audio Perspective

A coaxial is a format decision, not a compromise — some positions in a well-designed system are simply best served by a complete speaker in one unit. The 4.6C exists so those positions do not become the weak link in a 4000 Series build. Install it solidly, treat the door if it lives in one, and it carries its role at the same standard as the rest of the system.