James Loudspeaker ST21-4 - Passive 21" Subwoofer 4 Ohm

Product Overview

The James Loudspeaker ST21-4 is a passive 21-inch subterranean subwoofer engineered for high-SPL, deep bass output in outdoor commercial and residential landscape audio systems. This 4-ohm in-ground subwoofer uses a single large 21-inch transducer optimized for maximum excursion to deliver low-end performance across patios, grounds, and exterior gathering areas. It is built for buried installation so the low-frequency foundation of an outdoor system stays hidden from view. Pair it with James landscape satellites and a matched amplifier for a complete exterior audio deployment.

Product Description

The ST21-4 is a subterranean subwoofer designed to be buried below grade, with its 21-inch transducer optimized for maximum excursion and high SPL. This large driver moves substantial air to provide the low-frequency output that landscape satellite speakers cannot produce on their own, filling open outdoor areas with even, impactful bass. As a 4-ohm, low-impedance model, it is intended for a dedicated amplifier channel where a single subwoofer anchors the low end of an exterior zone. The subterranean design keeps the enclosure and driver out of sight, leaving only a discreet ground-level vent in the finished landscape.

In deployment, the ST21-4 fits hospitality grounds, resort landscapes, restaurant and bar patios, and high-end residential gardens where outdoor audio must include convincing low frequencies without visible hardware. It is well matched with James all-terrain landscape satellites for full-range coverage. For above-ground outdoor low-frequency and full-range options, explore the broader James Loudspeaker collection available through Creation Networks. Plan amplifier power and burial location during system design for best in-ground response.

Key Features

• 21-inch subterranean transducer — A single large driver optimized for maximum excursion delivers high-SPL bass in open outdoor areas.
• Buried, hidden installation — The in-ground design keeps the subwoofer out of sight, leaving only a discreet ground-level vent.
• High SPL output — Optimized excursion produces the output needed to fill large exterior spaces with deep bass.
• 4-ohm operation — Low-impedance design suits a dedicated amplifier channel for an outdoor zone.
• Outdoor landscape design — Built specifically for exterior installations and landscape audio systems.
• Satellite pairing — Provides the low-frequency foundation for James all-terrain landscape satellite speakers.

Typical Applications

• Hospitality grounds and resort landscapes
• Restaurant, bar, and cafe patios
• Pool decks and outdoor dining areas
• Corporate and government campus grounds
• High-end residential gardens and outdoor entertainment areas

Technical Specifications

Frequently Asked Questions

How is the ST21-4 installed?
It is a subterranean subwoofer designed to be buried below grade, leaving only a discreet ground-level vent visible in the finished landscape. Plan the burial location and drainage during system design.

How does it connect to an amplifier?
The ST21-4 is a passive 4-ohm subwoofer for a dedicated amplifier channel. Match amplifier power to the size of the outdoor zone and keep the channel's minimum impedance rating in mind.

What speakers pair with it?
It is designed to provide low frequencies for James all-terrain landscape satellite speakers. Creation Networks can recommend a matching satellite and amplifier package for your area.

Is it rated for full outdoor exposure?
Yes. It is engineered specifically for in-ground outdoor installation in landscape audio systems.

How many satellites can one ST21-4 support?
That depends on zone size and amplifier power. Creation Networks can help size the subwoofer-to-satellite ratio for even coverage across your space.

What warranty and support are available?
James Loudspeaker products are covered by the manufacturer's warranty. For current warranty terms, system design assistance, or volume pricing, contact the Creation Networks team via creationnetworks.net.