James Loudspeaker ST12-4 - Passive 12" Subwoofer 4 Ohm

Product Overview

The James Loudspeaker ST12 4 Ohm is a passive 12" subwoofer wired for 4-ohm operation, built for commercial AV installations that need substantial low-frequency reinforcement on low-impedance amplifier channels. Its 12-inch driver delivers deeper bass than the 10-inch ST model, making this 4-ohm passive subwoofer a fit for larger theaters, multi-zone systems, and high-end residential spaces. As a passive sub, it runs from an external subwoofer amplifier. The ST12 4 Ohm suits integrators specifying high-output low-impedance bass.

Product Description

The ST12-4 is part of the James Loudspeaker ST subwoofer family, where the suffix indicates electrical configuration. The 12 indicates a 12-inch driver and the -4 indicates 4-ohm wiring suited to standard low-impedance amplifier outputs. Because it is passive, the ST12-4 requires an external subwoofer amplifier, leaving power and signal processing under the integrator's control. It is the impedance counterpart to the 70V ST12-70, which shares the same 12-inch driver but is wired for constant-voltage distribution, and it steps up in displacement from the ST10-4. Within the ST range it scales further to the ST15-4 for the largest rooms. The full lineup is available in the James Loudspeaker collection. This makes the ST12-4 a practical specification for high-output low-impedance subwoofer systems.

Key Features

• 12-Inch Driver — A single 12-inch woofer delivers deeper output than the 10-inch ST model.
• 4-Ohm Configuration — Wired for 4-ohm operation to match low-impedance amplifier channels.
• Passive Operation — Driven by an external subwoofer amplifier for full integrator control.
• ST Family Compatibility — Matches other ST subwoofers for consistent multi-zone specification.
• Scalable Range — Specifies cleanly alongside larger ST models for bigger rooms.

Typical Applications

• High-output low-frequency systems
• Larger commercial AV and entertainment venues
• Multi-zone audio installations
• High-end residential and hospitality spaces

Technical Specifications

Frequently Asked Questions

Does the ST12-4 need an amplifier?
Yes. It is a passive subwoofer and requires an external subwoofer amplifier.

What impedance is it?
It is wired for 4-ohm operation to match low-impedance amplifier channels.

What is the driver size?
The ST12-4 uses a single 12-inch driver.

How does it differ from the ST12-70?
The ST12-70 is the 70V version of the same 12-inch driver, wired for constant-voltage distribution instead of 4-ohm.

How does it compare to the ST10-4?
The ST12-4 uses a larger 12-inch driver for greater displacement than the 10-inch ST10-4.