James ST21
Brian Long
Introduction
The ST21-4 is a 21" subterranean subwoofer designed for high SPL bass output in outdoor environments. It features a powerful 21" transducer, optimized for maximum excursion and SPL, delivering exceptional low-end performance for outdoor audio applications.
Product Gallery
Features, Specifications, and Manuals
Features
- All-copper toroidal transformer (70V models)
- Direct burial, compression bandpass subwoofer design
- Marine grade
- Available in a selection of standard or custom colors
- TAA Compliant
Specifications
| Specification | Details |
|---|---|
| SKU | ST21 |
| Speaker Woofer | (1) 21" (534mm) Aluminum |
| Frequency Response (+/- 3db) | 18Hz - 120Hz |
| Sensitivity | 91dB (2.83V/1m) |
| Enclosure | Aluminum |
| Nominal Impedance (Ohms) | 4 ohms |
| Dimensions (WxHxD) | 24.0" x 24.0" x 24.0" (609.6mm x 609.6mm x 609.6mm) |
Manuals and Documents
- ST21 Data Sheet (PDF) - Sales & Data Sheets
- James Standard Colors and Upgraded Finishes (PDF) - Sales & Data Sheets
- Tech Note Landscape System Output Bass (PDF) - Sales & Data Sheets
- Subterranean Installation Guide (PDF) - Instructions
- ST21 cad file (PDF) - Drawings & Images
- ST21 cad file (DWG) - Drawings & Images
- Sonance DSP Speaker Presets Sonance DSP SpeakerPresets 2026.08.03 (ZIP) - Ease Files & Speaker Presets
- PowerZone Connect Speaker Preset Library BlazebySonance SpeakerPresets 20260819.1 (ZIP) - Ease Files & Speaker Presets
- PowerZone Connect PRO Speaker Preset Library SpeakerPresets 20260819.1 (ZIP) - Ease Files & Speaker Presets
- James ST21 Product Page - Official manufacturer product information, documentation, and support resources.