STX Audio SX402 4-Inch 2-Way Coaxial Car Speakers

The STX Audio SX402 is a pair of 4-inch 2-way coaxial car speakers intended for compact factory-speaker replacement locations. Their standard 4-ohm impedance makes them suitable for use with compatible factory radios and aftermarket head units. They are designed for installations where space is limited, including select door, dashboard, and rear-deck positions.

This speaker set is suited to drivers looking to refresh worn or basic factory speakers without moving to a separate-component system. The coaxial format places high-frequency reproduction within the same compact speaker assembly as the main cone. This helps simplify installation in locations originally designed for a single full-range speaker.

The SX402 uses an injection-molded black cone with a rubber edge surround to support controlled cone movement. Its stated 85 Hz to 22 kHz frequency-response range covers midrange and upper-frequency duties for a small coaxial speaker. The 88 dB sensitivity rating is intended to support use with compatible low- to moderate-power car-audio systems.

STX Audio specifies a 1-inch aluminum voice coil and a 10 oz magnet structure for each speaker. The pair is rated at 80 watts RMS and 350 watts maximum power. Match the speakers with an amplifier or head unit that can operate safely with a 4-ohm speaker load, and set gain conservatively to avoid distortion.

Black steel baskets and included grilles give the SX402 pair a coordinated Street Series appearance. These speakers can be used as replacements in compatible 4-inch positions or as part of a modest full-vehicle speaker upgrade. Confirm mounting diameter, depth, terminal clearance, and vehicle-specific fitment before purchase or installation.

Key Features

• 4-Inch Coaxial Format: Fits compact speaker locations where a separate tweeter system may not be practical.
• 2-Way Design: Combines main-cone and high-frequency reproduction in each speaker assembly.
• 4-Ohm Impedance: Works with compatible factory and aftermarket car-audio equipment.
• 80W RMS Per Pair: Provides a continuous-power reference for compatible amplifier matching.
• Rubber Edge Surround: Supports controlled cone movement during normal music playback.
• Included Matching Grilles: Adds protective coverage and a coordinated installed appearance.

Design & Installation

Each SX402 speaker uses a black injection-molded cone, rubber edge surround, 1-inch aluminum voice coil, 10 oz magnet, and black steel basket. The supplied grilles feature gold accents that complement the Street Series styling. This construction is configured in a compact 4-inch 2-way coaxial layout.

Before installation, compare the vehicle opening, mounting depth, mounting-hole pattern, and terminal clearance with the speakers, as vehicle fitment is not universal. Use secure mounting hardware, observe correct positive and negative speaker polarity, and avoid exceeding the system's clean power capability. The pair can be used with compatible factory or aftermarket head units and should be powered by equipment stable at 4 ohms.