1, depending on the weight
The formula of sound insulation is directly related to the density of the material, so the sound insulation with high density is better, and the die-pressed door is lighter, which is the root of the poor sound insulation of the die-pressed door. But note: adding soundproof cotton in the middle of the hollow door in the flat plate will be soundproof than the solid wood door.
Step 2 look at the thickness
The thicker the veneer, the better the sound insulation effect. Generally, the veneer of wooden doors should be 8mm thick. At the same time, the thickness and flatness of the surface layer are better, but the cost will increase. However, the surface of the iron fire door is 3mm thick, and the sound insulation effect is also good.
3, look at the flatness
The flatter the wooden door, the better the combination with the door cover, regardless of the structure. As long as the deformed wooden door is soundproof, it will definitely not work.