Wow:P! Thanks for the replys! to 144dbFiBl15 I have a Laurel medalist 35 from nissan. The year of the car is 2002!  I dont know from where i should start building my new system very well. But I was thinking to put 2subs of 15 or 12, 4 selenium horns  2 selenium super tweeters 1amp for the horns and 1 for the subs. 1sub batery 1or 2 capacitors. Enclousure type wegde  And it can have until H=46cm W=82cm D1=73cm  D2=33cm Internal vb=199liters Im trying to study more about audio but im not finding too mutch thing :/ . Do you know some where i can study?  Wow! And the Btl are so loud like that? O.o The subs that i allready had  were a carozzeria 800w and a boss 300w! so i have no ideia what a BTl 15 will sound like:o hum. One more question. About the Btl what do you mean with *tight tolerance in the motor gap*? ________________________________________________________________________________ ______. To Ryan J - abxx What amp do you think that matches with it?  ________________________________________________________________________________ ______. To johnecon2001 Thanks for that!  I try to read it but there are a lot of words i didnt get it :S My english its not very good :X