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.
What is dengue? Dengue is an illness caused by a virus that is spread through mosquito bites. Symptoms include fever, headache, nausea, vomiting, rash, and pain in the eyes, joints, and muscles. After you are bitten by an infected mosquito, symptoms can take up to 2 weeks to develop but usually end in a week.