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.
Symptoms appear 3â14 days after the infective bite. Dengue fever is a febrile illness that affects infants, children and adults. Symptoms range from a mild fever, to incapacitating high fever, with severe headache, pain behind the eyes, muscle and joint pain, and rashes.