After installing 10 inch Alpine type R in sealed box in boot I was a little concerned about securing Safely. The thing is a bit of a lump and I didn't want it moving around when cornering or indeed entering the cabin in an accident. Also didn't want to drill mounting holes in boot floor. The solution was to use a couple of Thule mini roof straps anchored around the sub box and around diagonal chassis braces In my Octy Vrs mk 1. An ideal way of locating Sub safely with easy removal should the need arise.

i use to use velcro stick a few strips along the bottom and it should stay in place

I have heard of people using Velcro. But this Sub is a seriously heavy piece of kit and wanted peace of mind that's it's not going anywhere.

i use to have 2 12" subs in a single box that was big and i used velco just get some strong stuff

I secured mine to my rear brace with a couple of exhaust clamps