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.
1 Worldwide, 2.5 percent of people infected with dengue fever die. 2  Dengue does not spread from person to person, but it possible to spread via blood transfusion and organ transplants. 3  In 1955 dengue fever was only reported present in 3 countries. 4  Today dengue is present in more than 120 countries.engue Fever Symptoms. Symptoms of dengue fever usually begin to manifest 3-7 days after being bitten by an infected mosquito, in some cases it may be up to 2 weeks before symptoms appear.