HI ,THANK You all for the answers
Is all right ,RALF .I don't mind because is about subs . Very interesting discussion specially for me .
A Little complex and complicated explanation for my knowledge I must admit ,
, but because I want to get as much knowledge as I can , I am always eyes and years on everything I am interested .
Now , the answer to my question is somewhere and I miss them
, or steel on his way !?!? . MARIUS