I. Manufacturing Process
The speaker's aluminum alloy shell has a cylindrical structure. Leveraging the advantages of integrated aluminum profile molding, and balancing the regularity of the acoustic cavity with production efficiency, the core process employs aluminum profile extrusion + CNC precision machining + surface treatment. The specific process is as follows:
1. Raw Material Selection: 6063 aluminum alloy is preferred (excellent hot extrusion formability, good surface treatment effect, and acoustic conductivity suitable for speaker cavity requirements); for higher structural strength, 6061-T6 aluminum alloy can be selected, using solid aluminum rod blanks for hot extrusion.
2. Profile Extrusion Molding:
◦ A custom-made cylindrical profile mold is used. The aluminum rod is heated to 480~520℃ and extruded into an integrated cylindrical profile through an extruder at a pressure of 80~120MPa. This directly forms the reinforcing ribs, grooves, and other structures of the shell, ensuring uniform cavity wall thickness (deviation ≤0.1mm).
◦ After extrusion, the material undergoes online quenching and artificial aging (T5/T6 treatment) to eliminate extrusion stress, prevent bending deformation, and improve structural rigidity.
3. CNC Precision Machining:
◦ The material is cut to length using a CNC saw (tolerance ±0.2mm), followed by precision machining of the end face on a CNC lathe to ensure flatness. A three-axis CNC machining center is used to drill and tap the sound outlet holes, wiring holes, and mounting holes, and to mill the grooves. Micro-cutting technology is used on thin-walled areas to avoid deformation.
◦ Laser engraving is applied to the marking area to clearly display brand, parameters, and other information. Edges are chamfered and deburred (R0.3~0.5mm) to improve the user experience.
4. Surface Treatment:
◦ Anodizing: A 10~15μm thick layer of natural/black anodizing is applied to enhance corrosion resistance and wear resistance. The matte anodized surface reduces sound wave reflection and optimizes acoustics. Brushed anodizing can also be used to create a radial metallic texture and enhance the appearance.
◦ Electrostatic Powder Coating: Powder coating is applied to the outdoor speaker housing, with a coating thickness of 20-30μm. Custom matte and metallic finishes are available to enhance weather resistance and protect against sun and rain.
◦ Sandblasting: Fine sandblasting is applied to the exterior of the cavity to increase surface adhesion. An oxidation process can also be used to create a delicate matte texture.
5. Inspection and Trial Assembly: Roundness, aperture, and other precision indicators are checked using a 2D measuring instrument. The housing is then assembled and trial-fitted with components such as speaker units and crossovers to test the cavity's sealing performance and acoustic resonance.
II. Manufacturing Accuracy
The housing must match the regularity of the speaker's acoustic cavity and the assembly precision of its components. Key specifications are as follows:
1. Dimensional Accuracy:
◦ Inner Diameter Tolerance of the Cylinder: H7 grade (+0.018/0mm), ensuring an interference/transition fit with the speaker unit.
◦ Sound outlet/mounting hole position tolerance: ≤0.05mm, hole diameter tolerance ±0.03mm, ensuring precise assembly of audio components.
◦ Housing length tolerance: ±0.1mm, wall thickness uniformity deviation ≤0.1mm, preventing cavity deformation from affecting sound quality.
◦ Slot size tolerance: ±0.02mm, ensuring a secure snap-fit connection with the panel and grille.
2. Geometric Tolerances:
◦ Cylindricity of the inner wall of the cylinder: ≤0.05mm/100mm, ensuring the regularity of the acoustic cavity and reducing sound wave reflection interference.
◦ Perpendicularity of the port end face to the axis: ≤0.03mm, ensuring a tight fit after speaker installation and preventing sound leakage.
◦ Parallelism of the slot to the housing axis: ≤0.03mm, preventing panel misalignment during assembly.
3. Surface Finish:
◦ Inner wall roughness Ra 1.6~3.2μm, reducing sound wave scattering and loss within the cavity.
◦ Outer surface (after oxidation/spraying) roughness Ra 1.6μm, ensuring visual and tactile quality.
◦ Mounting and fitting surface roughness Ra 0.8~1.6μm, improving the fit and sealing with accessories.
III. Industry Applications
This type of aluminum alloy speaker housing, due to its lightweight, regular cavity design, and high mass production efficiency, is widely used in various audio equipment fields. Key application scenarios include:
1. Consumer Audio Equipment:
◦ Desktop Speakers/Bluetooth Speakers: The small cylindrical housing meets portability requirements, and the heat dissipation of the aluminum alloy material prevents the built-in amplifier's heat from affecting sound quality.
◦ Home Theater Speakers: The center/surround speaker uses an aluminum profile housing; the integrated cavity reduces resonance and improves sound reproduction.
2. Professional Audio Equipment:
◦ Stage Audio: High-power stage monitor speakers with aluminum profile housings offer high strength and excellent heat dissipation, suitable for long performances. The integrated profile structure also facilitates modular assembly.
◦ Conference Audio: Conference room wall-mounted speakers with aluminum profile housings feature a lightweight design for easy installation, and the anodized layer resists dust and oil corrosion.
3. Outdoor Audio Equipment:
◦ Outdoor Bluetooth Speakers: The weather resistance and impact resistance of the aluminum profile housing make them suitable for outdoor scenarios such as camping and cycling. The powder coating protects against UV rays and rain.
◦ Public Address Systems: Public address speakers in parks and squares use aluminum profile housings. Their corrosion resistance and easy cleaning properties make them suitable for complex outdoor environments.
4. Car Audio Equipment:
◦ Car Audio Aftermarket Systems: Car subwoofers feature aluminum profile cylindrical housings. The lightweight design reduces the vehicle's weight, and the metal cavity reduces vibration interference during vehicle operation.
