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.
Previous dengue infection increases the risk for DHF in a patient with subsequent dengue infection. Dengue shock syndrome is DHF with signs of circulatory failure, including narrow pulse pressure (. 20 mm Hg), hypotension, or shock, and can result in a case-fatality rate of approximately 10% (8).revious dengue infection increases the risk for DHF in a patient with subsequent dengue infection. Dengue shock syndrome is DHF with signs of circulatory failure, including narrow pulse pressure (. 20 mm Hg), hypotension, or shock, and can result in a case-fatality rate of approximately 10% (8).