Within the Red Hat certification program, the RHCA is considered the most complete (and grueling) certification among the seven major Red Hat certifications. In fact, some equate the prestige of the RHCA to that of the Microsoft Certified Master and possibly the CCIE.
A plumbing fixture like a sink can not function properly without a sink vent. When a drain pipe drains it creates a negative pressure in the sink drain; the negative pressure will pull the water out of the p-trap of the sink that's draining and sewer gases can enter your home if a sink vent is not installed.
The trick in building a ported box for your subwoofer is to get the right enclosure size and the right vent size. These measurement can make or break the design. The ventâs placement within the enclosure is also quite important. An equivalent of the ventâs diameter much be left between the port and any inside wall.