View Full Version : 2 18" DC lvl 3 18's 4th order help

03-25-2014, 08:34 PM
Hello, starting my first "big" build soon after SBN last weekend. Equipment is 2 DC lvl 3 18 M2's on an AQ-2200d at 1 ohm. I drive a 4 door truck and the plan is a 4th order bandpass in a blowthrough. After consulting forums I'm going with a 2:1 ratio and looking for SQL with the main priority being able to play across a wide passband. My sketch is 2.5 sealed 5 ported with 360 square inches of port tuned to 47.. Dimensions are 19x49x32 Please tell me if I'm on the right track and correct anything if I'm wrong!

03-25-2014, 08:43 PM
I hope it's 2.5 sealed and 5 ported per woofer...

DC recommends a 4 cube sealed box.. I would personally do 7-8 cubes for the sealed portion of the box or you're going to have a super high Fc. I would also shoot for between about 170-260 sq in of port.

Here's the numbers I got.. this is with 8 cubes sealed and ~16 ported. Aeroports assume you're using 4 8" aeros and square/rectangle is simply a 15" by 15" port


03-25-2014, 10:39 PM
Yes I meant 2.5/5 per SUB haha. A good portion of The builds that I have seen we're running about that size, some obviously bigger, for a pure sq build I thought that was right but thank you for the corrections!