I have a Polk Audio box with two 12" subs and want to know the best way to face it for SPL contests. This is how I have it facing right now.



Thanks.

 

It really depends on the rules of the SPL sound-off.
Some contests (local no-points shows mainly) allow for "outlaw" sound-offs where there is very little requirement on where the mic/meter is placed in the car. In this case, most competitors are going to put the meter on the vent of the enclosure itself or as close to it as possible, because this is where the pressure levels will most likely be at their highest.
IASCA and USACi events usually have specific guidelines as to where the competitor is allowed to place the mic/meter. Most of the time, these guidelines require that the mic/meter be at the front seat level or even in the front seat itself. If this were the case, your best bet would be to drop the rear seats and point the enclosure forward and center it as much as possible. This would center the flow from the vent directly at the windshield in between the two front seats. This would most likely be where the pressure levels will be at their highest, yet still within the guidelines of qualified events.

 

the 4 times I have gone through a USACI event they have always put the meter in the upper corner of the passenger floor board, where a speaker pod would be.
move the box around and see for yourself what is the loudest and then go with that.

 

Thanks for the advice, I will try facing it forward with the rear seats down and see how that works.