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.
Dengue fever may begin suddenly. Symptoms usually include high fever, severe headache, and joint and muscle pain. Nausea, vomiting, and loss of appetite are also common. A rash may appear 3 to 4 days after the fever begins and may spread from the torso to the arms, legs, and face.