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.
Symptoms, which usually begin four to six days after infection and last for up to 10 days, may include. 1  Sudden, high fever. 2  Severe headaches. 3  Pain behind the eyes. 4  Severe joint and muscle pain. 5  Fatigue. 6  Nausea. 7  Vomiting.
Many people, especially children and teens, may experience no signs or symptoms during a mild case of dengue fever. When symptoms do occur, they usually begin four to 10 days after you are bitten by an infected mosquito. Signs and symptoms of dengue fever most commonly include: 1  Fever, as high as 106 F (41 C). 2  Headaches. 3  Muscle, bone and joint pain. 4  Pain behind your eyes.