I was at a sound system competition today and it caught my attention a little bit. There was a tiny jetta that hit 145db with one sub, and my 15's that i found in my basement hit only 138. what are the dimensions and the needed cu ft in order to build a proper enclosure?

 

You probably need to go to a sound forum to find that information. Or google you speakers and find out what cubic feet you need. Every speaker has different specs.