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.
What are the symptoms of the disease? The principal symptoms of dengue fever are high fever, severe headache, severe pain behind the eyes, joint pain, muscle and bone pain, rash, and mild bleeding (e.g., nose or gums bleed, easy bruising).