Is that to stop rattles when you turn up the volume?
Yes and no. The main one going from floor to ceiling angled towards where my rear view mirror use to be was to stop my windshield from flexing back n forth a minimum an 1/8th" most likely more. It destroyed the seal and water would leak when it rained. The 2nd one was to stop any movement my box would do when playing anything below 30hz.
It did stop quiet a bit of rattle I could hear inside but now it's destroying my doors and hatch even though they have sound deadener. I don't hear it but everyone else sure does