The beauty of speaker foam is that it can be cut to size to complete a self-build speaker and help improve the sound quality. As well as the size, you can also pick out the thickness of your speaker foam, before installing it to counter vibrational resonance and reduce any unwanted noise.
Speaker Foam & Foam Components
Speaker foam is mounted on the front or back of the speaker grille to protect the drivers (so the woofers and tweeters). Applying foam also guards the internal components against dust, dirt and moisture (a light shower or the spatter from a spilt drink), and besides helping to improve the performance, has no negative effect on the operation.