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.
Once infected, a person experiences a severe, flu-like illness. Symptoms include high fever, muscle and joint aches, severe headache, nausea, vomiting and rash-just to name a few. In some patients severe Dengue Fever (a.k.a. Dengue Hemorrhagic Fever) can form. Symptoms include severe abdominal pain, persistent vomiting, shock, leaky capillaries, and circulatory system failure.