I have a DT300 Amp. I am building a 214L Adire Alignment ported enclosure tuned to 15.4hz. My amp has dip switches on the inside to change the base boost. I figured that i would want it set to flat. But there are three freq to choose from,(to set it flat) 18hz,20hz,23hz. I would have to remove the amp from the enclosure to change them once it's installed. Can someone please tell me which frequency i'd be better off with. I was thinking 18hz just because it is the closest to my tuning frequency( but i may be wrong). Thanks for your help guys.