I am running 2 FI BL 18's in about 15.5 cubes after sub and port tuned to 32hz. It sounds awesome for daily and really picks up the lows. I have about 200 square inches of port also. I did 147.3 db on TL first time, then a 152.4 on an audiocontrol meter saturday. Now, I was told I should make my box around 10 cubes after sub and port and tune to 35 or 36hz and it would probably meter better and still pick up the lows. Does this sound right or do you have any suggestions? Oh yeah, I am running 2 sundown audio saz-1500d's strapped on them now. Would it matter with a slot port or are aero's better? thanks for any help

Only thing to do is try. If you don't like it you can always put the old box back in.

yea i say make the box smaller.

only reason i would decrease box size is to increase power. retune higher and re-adjust your ssf so i wont bottom out. as long as your not coming near mech limits you have no reason to downsize box