There is no fixed standard for the isolation degree of a soundproof box; it mainly depends on the **application scenario** and **noise reduction target, with a common range of 20dB to 50dB. The isolation degree of a soundproof box is a crucial parameter, as it directly determines whether the soundproof box can meet practical needs and avoids the situation where "soundproofing is done but insufficient". 1. Determine the Core Range Based on Application Scenarios Requirements for isolation degree vary significantly across different scenarios. Below are reference ranges for the most common types of scenarios: -Noise reduction for industrial equipment (e.g., water pumps, fans): A range of 30dB to 45dB is usually required. This range can effectively reduce the medium and high-frequency noise generated by equipment operation, ensuring that the noise in outdoor or adjacent areas meets environmental protection emission standards (generally ≤55dB during the day and ≤45dB at night). - Laboratory/test environments (e.g., acoustic testing, precision instruments): Requirements range from 40dB to 50dB, and some high-demand scenarios may require isolation degrees of over 60dB. The goal is to isolate external interference and provide a stable, low-noise background environment for testing. - Civil/small-scale equipment (e.g., household soundproof boxes, small generators):

A range of 20dB to 35dB is generally sufficient. It can reduce the equipment noise from "obviously harsh" (e.g., 70dB) to "slightly audible" (e.g., 35dB to 50dB), without affecting daily rest or work. For product production testing, the isolation degree of the soundproof box is generally 10-15dB lower than the noise of the product itself. Common soundproof boxes use A-weighting. When the external noise is 80dB, the internal noise should be 30-40dB. 2. Key Factors Affecting Isolation Degree

After determining the target isolation degree, the following elements need to be matched through design; otherwise, it will be difficult to achieve the expected results: 1. Material selection for panels: Priority should be given to high-density and high-surface-density materials, such as cold-rolled steel plates with a thickness of 1.5mm or more, and multi-layer composite panels (steel plate + damping layer + sound-absorbing cotton). Single-layer thin panels (e.g., ordinary iron sheets) cannot achieve a high isolation degree. 2. Sealing performance: Gaps in the box (e.g., doors, cable interfaces, ventilation ports) are weak points for soundproofing. Professional soundproof sealing strips and labyrinth-style ventilation structures should be used to avoid "sound leakage", which would lead to a significant decrease in isolation degree. 3. Structural design: "Double-layer box" or "floating vibration isolation" structures should be adopted as much as possible to reduce vibration transmission (solid-borne sound). Especially for low-frequency noise (e.g., motor vibration), simply increasing the thickness of the panels has limited effect.