it was probally legal. outlaw is done in USACi. probally walled, but in the sense you are thinking of a wall since its bandpass.. i dont think it be 70/80hz cause then its midbass , wheres the fun, and i believe there are cutoff frequencies in the rules iirc. it is walled but in a bandpass mic on the dash leagal as hell and my personal opinion it would be broken by no other then himself he is just a master at what he does.