Im not tuning for extreme SPL.
I also will only run in intended frequency ranges.
As for the slopes etc, heres some model:
First the 4th Order. Notice the pass band is narrow and VERY peaky:
Now heres the 6th Order box. I consider this to be more musical, which is my goal here. By leveling out the chambers and not making peaking frequencies I try to keep the dip in the middle as low as possible:
And for yucks, heres the vented box. Notice the port gain:
Now heres the sealed. Smooth man, smooth...
