Dual 8″ Back-Loaded Horn Subwoofer Enclosure (Digital Plan) – 20Hz Tuning

This Dual 8-Inch Back-Loaded Horn enclosure is a purpose-built design engineered for extreme low-frequency performance and maximum SPL at subsonic frequencies. Designed specifically for content 30Hz and below, this enclosure peaks around 20Hz and has been proven to deliver an impressive 141 dB SPL at 20Hz under controlled test conditions.

Unlike traditional sealed or ported enclosures, this horn-loaded design prioritizes depth, efficiency, and acoustic loading at ultra-low frequencies. It is tailored for a very specific niche of car audio enthusiasts who chase deep, ground-shaking bass rather than broad musical bandwidth.

This enclosure is not designed for mid-bass or higher-frequency playback. Due to its ultra-low tuning and horn path geometry, playing content above ~35Hz at high volume may result in over-excursion, distortion, or permanent damage to the subwoofers.

Performance Highlights

• Proven Output: 141 dB SPL @ 20Hz

• Tuning Frequency: ~20Hz

• Optimized Bandwidth: 30Hz and below

• Design Type: Back-Loaded Horn

• Use Case: Subsonic bass, demo builds, niche SPL systems

⚠️ Competition & Usage Disclaimer

Competition Use Only
This horn-loaded enclosure is a specialized, high-efficiency design intended for competition-level SPL and subsonic demo applications. Horn enclosures place increased mechanical and thermal demands on subwoofers and require proper amplifier tuning, filtering, and system setup.

• Not intended for daily or full-range listening

• Proper low-pass, high-pass, and subsonic filtering is required

• Playback above 35Hz may cause subwoofer damage

• Recommended for experienced builders only

By purchasing and building this design, the user acknowledges the specialized nature of this enclosure and accepts responsibility for proper setup and operation.

Digital Plan Includes

• Complete cut sheets and dimensions

• Internal horn path layout

• Panel orientation and assembly guidance

• 3D reference views for accurate construction

This enclosure is built for enthusiasts who live in the 20Hz world. If you’re chasing extreme low-frequency SPL from a compact dual-8 platform, this design delivers an experience few enclosures can match