Loudspeaker (A1 Mini, 4'' Markaudio CHR70)

High-End Audio meets Brutalist 3D-Design

This project is a high-performance bookshelf speaker designed around the legendary Markaudio Full-Range drivers. By leveraging the mass of a $0.8\text{ mm}$ nozzle and a clever 3-piece interlocking design, this speaker delivers an "unbelievable" soundstage and punch.
 

The design features a unique Accent Ring inlay that not only adds a premium aesthetic but also perfectly masks the glue line between the two main housing halves.

Technical Specifications

• Internal Volume: approx. $5.1\text{ Liters}$
• Enclosure Type: Bass Reflex (Rear Ported)
• Driver Compatibility: Optimized for Markaudio (e.g., CHR-70 or similar 4-inch drivers)
• Wall Thickness: Heavy-duty construction for acoustic rigidity.

Print Instructions

To achieve the necessary acoustic mass and prevent cabinet resonance, follow these settings:

• Nozzle Size: $0.8\text{ mm}$ (Highly recommended for "acoustic deadness" and strength).
• Filament: approx. $1\text{ kg}$ of PLA (Off-White for the body, Black for the Accent Ring and Port).
• Layer Height: $0.4\text{ mm}$ to $0.6\text{ mm}$.
• Wall Loops: 3–4 (with a $0.8\text{ mm}$ nozzle, this creates a massive $2.4\text{ mm}$ to $3.2\text{ mm}$ solid shell).
• Infill: 15–20% Gyroid.
• Orientation: Print the main halves with the open side facing the build plate (Upside down).

Pro-Tip: If printing on a "bedslinger" like the A1 mini, use Silent Mode or reduce outer wall speeds to for the taller sections to prevent vibrations from affecting the surface finish.

Assembly & Sealing (The "Acoustic Marriage")

The secret to the high-end sound is a hermetically sealed enclosure.

1. Preparation: Install M4 Heat-Set Inserts into the front baffle for the driver mounting. This ensures a vibration-proof connection.
2. Internal Damping: Line the internal walls with acoustic fleece (Vlies). Make sure to tuck the speaker cables behindthe fleece to prevent "cable slap" during heavy bass notes.
3. The Accent Ring: Apply a thin bead of 2-component epoxy or high-strength superglue to the shoulder of the lower half. Place the Black Accent Ring on top, then apply glue to the upper side of the ring and join with the top half.
4. Sealing: For absolute air-tightness, I recommend coating the internal seams with a thin layer of wood glue or epoxy before the final assembly. A "leaky" speaker loses its punch!
5. Final Marriage: Use weights (like a soldering station or books) to compress the parts while the glue cures.

Hardware Needed

• Drivers: Markaudio Full-Range (Champagne finish recommended).
• Inserts: 4x M4 Heat-set inserts per box.
• Connectors: High-quality binding posts (Screw terminals).
• Amplifier: Works beautifully with Class-D amps like the Aiyima A07 Pro or all-in-one streamers like the Technics SA-C600.

The Result

Expect a "glittering" high-end resolution and a surprisingly deep, controlled bass. The $0.8\text{ mm}$ layers give the speaker a raw, industrial "brutalist" look that contrasts beautifully with the refined champagne driver.