efficiency ratings = output potential

[30hrtz 10+ year member]

There used to be an explanation on the JL website about why that spec meant about nothing. What it is good for is giving you an idea of how big a box it will need to get low. The lower the efficiency spec generally the smaller the box requirement for good low end extension. Part of Hoffman's Iron Law. If you want to get fairly loud down low, a higher number in efficiency is usually a bad thing.

YA I agree on that one.like the p3 12s i had, rating was like 85 i think and they took a very small box compared to others and they hit low,so ok thats a good rule of thumb though.guess thats why spl rated subs have a very high efficiency # but you have to keep them tuned high like solo x's say to tune above 50hz.I'm glad you pointed that out cause i never really put the two together.thanks