Is speaker foam ring important for car speakers?Yes! A high-quality speaker foam ring can greatly improve bass dramatically in the doors. After testing we found that it can make the overall frequency response smoother and reduce unwanted rear reflections. This is the quickest and simplest solution for enhancing midbass. A piece of foam looks expensive but completely worthed?Can any kind of foam be used to make speaker rings?No, the material for speaker foam ring must have good water resistance, high density and high elasticity. Otherwise, it will mold and damage your car speaker. Our fast ring foam is made of high rebound and high-density EVA, which is more expensive and eco-friendly than PVC. It's waterproof, odorless and resistant to high and low temperatures. Therefore, long-term exposure can maintain elasticity and does not emit unpleasant toxic gases, which is an ideal material for making speaker sponges.It's a laser-cut foam product with industrial-grade, peel away adhesive backing. So the installation is very simple and convenient. The fast foam ring is 25mm wide and 25mm thick. It has better sound reinforcement and noise reduction than other inferior fast foams, which can greatly improve the sound quality and service life of your car.