Building My 8-Inch Full-Range Passive Cubes
I recently finished a pair of 8-inch full-range passive cube speakers, built with a focus on clarity, natural tone, and solid construction. This project combines precision laser cutting, layered cabinet design, and a great-sounding Dayton Audio full-range driver.
Design & Volume
Each cube was designed as a sealed enclosure with an internal volume of about 13–15 liters — ideal for the 8-inch Dayton full-range driver.
This sealed design provides tight, accurate bass and smooth midrange response, perfect for small rooms or near-field listening.
Dual-Layer Cabinet Construction
To get the best of both worlds — strength and damping — I used a two-layer cabinet:
- Outer Layer: 18mm birch plywood, laser-cut for perfect precision and finished with clear varnish to highlight the wood grain.
- Inner Layer: 12mm MDF, cut to match the exact dimensions and glued firmly to the inside of the plywood shell.
This combination adds stiffness from the plywood and internal damping from the MDF, reducing cabinet resonance and keeping the sound clean.
I bonded the layers using Sikaflex, which acts as both a strong adhesive and a vibration-absorbing sealant.
Assembly Process
After cutting all parts on the laser, I glued the MDF inserts into the plywood panels and clamped them overnight. Once cured, the box felt incredibly rigid and inert.
Then, I joined all panels together with another layer of Sikaflex along the edges, forming a perfectly sealed cabinet.
Internal Acoustic Treatment
Inside, I added acoustic damping material — a mix of acoustic foam and polyester fiber — to absorb reflections and standing waves.
I covered the back and side panels while leaving space around the driver for proper air movement.
Finishing Touches
The outer plywood surface was lightly sanded and varnished, giving a clean, natural look with visible grain texture. The varnish not only enhances appearance but also adds durability and moisture protection.
I installed the Dayton 8-inch full-range driver, wired directly to gold-plated terminals with 16AWG copper wire for clean signal transmission.
Listening Impressions
When powered up, these cubes sounded tight, open, and well-balanced.
The dual-layer cabinet really paid off — no audible box resonance, just smooth sound from top to bottom. The sealed design keeps bass controlled and precise, while the full-range driver delivers a natural midrange and airy highs.
They perform beautifully with acoustic, vocal, and instrumental tracks — a perfect balance between handcrafted build quality and audiophile clarity.
