BOX TUNING QUESTION??

BOX TUNING QUESTION??

IS 38 HZ GOOD ?

WHATS THE RESULT IF YOU TUNE IT HIGHER OR LOWER ?

SAY A SPEAKERS RANGE IS FROM 23-700 WHAT WOULD BE A BETTER FREG TO TUNE THE BOX FOR A SPEAKER LIKE THAT?
http://www.etronics.com/product.asp?stk_code=audaw1205q&store=&catid=369

What do you think of this box with those speakers
http://www.subzoneusa.com/zv_series.htm