Sorry for any stupid questions that I ask, still learning. If I am putting an AV-15 in about a 142L box what amount of mass should I have on the 18" stryke PRs? I know adding the higher amount will tune it lower, but is there anything I sacrifice for that other than a little bit of SPL. Boominess for example? Any advice would be appreciated. Also most likely to be driven with a Rythmik Audio 380w into 4 Ohms plate amp.