has anyone ever used second skin spectrum and damplifier pro to deaden

[emperorjj1]

you have to remember that every application is different and like everything else in "car audio" the 25% is a rule of thumb per say. Meaning that each car is inherently different and most people that are taking pics and posting builds at least are using it with a sub system. Since the subs purpose is to make vibrations and the sound dampeners purpose is to prevent them; depending on your system and goals more than 25% may be needed. Ultimately 100% is pretty much never needed but it is what it is