ESB Audio 3.65 — 3000 Series 2.5"/65 mm Cone Widerange (pair) | HF Audio Labs

A Widerange Driver for 6x9 Systems and Custom Installations

The ESB 3.65 is a 2.5-inch (65mm) widerange driver with a frequency range of 130 Hz to 22 kHz. It is the upper-frequency driver in the 3.69K2.5 speaker system and is also available as a standalone component for custom installations.

The 3.65 is designed to cover both midrange and high-frequency content as a single driver — an approach that works well in 6x9 two-way systems and in custom builds where a single driver needs to handle a broad frequency range without a separate dedicated tweeter.

Design

The 3.65 uses a pressed paper cone with a CNC-machined aluminum center plug. The aluminum plug was incorporated to help linearize high-frequency output and extend the driver's usable frequency range by managing energy distribution at the upper end of its bandwidth.

A rubber surround supports excursion control. The driver uses an N42 neodymium magnet for the motor system.

Specifications: 4 ohm nominal impedance, 60W nominal power handling, 120W transient, 130 Hz to 22 kHz frequency response, 86 dB sensitivity at 2.83V/1m.

System Application

The 3.65 is used as the upper-frequency driver in the 3.69K2.5 system alongside the 3.69 woofer. As a standalone driver, it works well in A-pillar locations, sail panels, and upper door positions in custom builds where a single wide-bandwidth driver is the preferred approach.

HF Audio Perspective

A widerange driver that covers both midrange and high frequencies in a single unit simplifies the installation while still providing meaningful performance across a broad frequency range. In a 6x9 two-way system, the 3.65 allows the 3.69 woofer to focus on low-frequency performance while the widerange driver handles everything above it.

The 3.65 is not a substitute for a dedicated tweeter and midrange in a high-performance front stage. It is the right driver for systems and applications where its broad bandwidth and practical installation profile provide the best solution.