Tuning box

Gord kindt Bronze Member Username: Sexybrat Post Number: 36 Registered: Jan-07	Posted on Friday, January 19, 2007 - 01:29 GMT this is my box and i want to add a port to tune it to 30hz. wut lenght would i need the port? i have a port its 3" diameter and 10" long with a flare top. any help is appreciated.
Drivingreckless Gold Member Username: Drivingreckless DD 9515f, USA Post Number: 2693 Registered: Apr-06	Posted on Friday, January 19, 2007 - 01:32 GMT http://www.carstereo.com/help/Articles.cfm?id=31
Nathan Scott Bronze Member Username: Nathanscott San Antonio, TX United States Post Number: 23 Registered: Aug-05	Posted on Friday, January 19, 2007 - 01:37 GMT For 15 L5 or L7?
Gord kindt Bronze Member Username: Sexybrat Post Number: 37 Registered: Jan-07	Posted on Friday, January 19, 2007 - 02:02 GMT 15" L7. and also were would be the best place to put the port??
Gord kindt Bronze Member Username: Sexybrat Post Number: 38 Registered: Jan-07	Posted on Friday, January 19, 2007 - 22:43 GMT should i use two ports 3"diameter as opposed to one 3" diameter???