The trick in building a vented box is to get the right size enclosure and the right size vent. You can't be too far off on either of these factors or your speaker's performance will suffer. In particular, using a too-small box or a too-high vent tuning frequency can eliminate bass instead of increasing it.
1 Dengue fever is a disease caused by a family of viruses that are transmitted by mosquitoes. 2  Symptoms include severe joint and muscle pain, swollen lymph nodes, headache, fever, exhaustion, and rash. 3  The presence of fever, rash, and headache (the dengue triad) is characteristic of dengue fever.
The symptoms Potter experienced were textbook. Often mistaken for the flu, dengue symptoms include nausea, fever, debilitating headaches, eye pain, and bloody urine. The rash noticed by Dr. Trout is a telltale sign of dengue hemorrhagic fever. Next page: A Navy officer contracts the fever.