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.
1 Dengue fever is a disease caused by a family of viruses that are transmitted by mosquitoes. 2  Symptoms include severe joint and muscle pain, swollen lymph nodes, headache, fever, exhaustion, and rash. 3  The presence of fever, rash, and headache (the dengue triad) is characteristic of dengue fever.
Once you are bitten by a mosquito that is carrying dengue fever, the average time for symptoms to begin is four to seven days. 1  While the average incubation period is from of four to seven days, you may experience symptoms as early as three days, or as late as two weeks, after being bitten.ther common symptoms caused by the virus can create hemodynamic changes, or changes that alter the flow of blood in the body. 1  Examples of blood flow changes seen with dengue fever include nose bleeds, bleeding from the gums, and areas of bruising.