Ok guys... Just finished installing an Alpine Marine SWR-M100 sub in my boat. First off this things rocks with only a couple hundred watts running it. So here's my challenge. It's mounted under my rear seat on my 272. Its a free air sub so it's not enclosed in the back. The issue is it hits so hard that it vibrates the front of the seat where it is mounted. I have found that you can push up against the seat base and the vibration stops. So here's my thought. Can you run bolts down through lip on on the seat base safely (ie not hitting anything mounted underneath) and tighten it up so the vibration is very minimal?

Depends where you are running them through...The fuel tank is in the center between the bolsters runs the full length of the center of the boat to the bulkhead by the engines.

I don't know how much room you have to play with under there. I had the same problem in a previous 302. From the inside I caulked the sides and bottom of the entire panel. It worked.

That's what I figured Irish... gotta figure out something...

Problem with free air's...Even with enclosures you can get it to rattle though. Alot of aiir moving in a small space.

Agree Irish but I found if I hold the front of the seat base still using my foot I get minimal vibration. Just trying to figure out how to accomplish the same thing using bolts.