the SQ is great, very similar to the Brahma and as far as SPL goes it is very similar as well but it will get very loud with less power then the Brahma, thats for the Avalanche but the Atlas is very similar to the avalanche in SQ but just doesnt have the deep bottom end like the Avalanche. I love my Avalanche 15 it is great as a matter of fact I run it over my brahma 15. I just ordered an atlas15, avalanche 12 and another avalanche 15 at those prices you cant beat it at all
