what size box do i need?

every org has diffrent rules.     Also never heard of a MX sub from RE     There are the SE SX XXX MT from what I know...... Your biggest thing is going to be below the window line and in the designated "cargo" compartment, if it has rear seats then you have to be behind the rear seats. That rule will be for usaci and Db Drag.   The other orgs you will have the research the rules to find out USACi will be listed on Soundoff.org DB drag rules will be at DBDRAG.com IASCA is Sound Quality except NSPL which is quite small from what I have seen this year MECA is Drive by SPL, I dont know any of the rules. Sorry2009 0-1000 Trunk WR 154.0DB 2009 1001+ Trunk WR

2007 USACI World Champion

2007 World Record

2006 USACI Finals 2nd Place

You just might want to double check on that....I just spoke with RE about a week ago and thier product names were not changing.   The only thing they had were RE,SE,SX,XXX,MT     The MT is an SPL designed only sub. Not for daily driving uses, it has been done but I would not suggest it. As far as the SX18 I havent heard one in person but I have heard a few XXX18 and it was insane for street use. It was being powered by a memphis 4KW     The recomended box for it is quite large for SPL, but you said you plan to use it on the street...I would recomend making the box so you can change the port to go from street to comp use.2009 0-1000 Trunk WR 154.0DB 2009 1001+ Trunk WR

2007 USACI World Champion

2007 World Record

2006 USACI Finals 2nd Place

It depends on if you plan to run street beat in usaci, outlaw SPL in USaci (which is classed by amp power at 4 ohm)    or db drag you need to be alot more specific with what you are trying to run in for a class I dont know the best way to describe how to make an interchangable port system, besides to say recess the port so that it has a 3/4 or 1 1/2 inch lip around the box where you can bolt diffrent ports into Street beat you can come above the window line and up to the B-pillar. Outlaw SPL you have to be in the "Cargo compartment" which is behind the rear most seats and under the window line Street Beat 3 (which is the class the 18 would fall into) has a record of 139.7db    This is using a comercially availible cd and a avearage of the SPL using music for a full 30 seconds Outlaw has scores ranging from 158.5-144.1db with a tone, depending on what voltage you are running and what the rating of you amp/amps are at 4 ohm More info like what amps you are running and if you plan to run a street beat class or outlaw SPL would help alot2009 0-1000 Trunk WR 154.0DB 2009 1001+ Trunk WR

2007 USACI World Champion

2007 World Record

2006 USACI Finals 2nd Place

is outlaw only able to run @ 4 ohm or can i run a 1 ohm load at lets say 3000watts?

just found a new box ive never herd of, whats a transmission line box?

for an Outlaw run, you can run at any impenance you wish, amps are just classified by thier 4 ohm rating, list your amp model and brand and I will look at the spec and list the classes you would fit into. Street beat you can use as much power you want, but you have to use a commerically availible cd, with music for a averaged 30 second run.   Classes are split by sub size. again list what your complete setup is going to be and I could make some better suggestions2009 0-1000 Trunk WR 154.0DB 2009 1001+ Trunk WR

2007 USACI World Champion

2007 World Record

2006 USACI Finals 2nd Place