Also, do not install the port(s) on the back due to air-restrictions from the rear seats. See more ideas about speaker enclosure, speaker box design, subwoofer box design.

We do not recommend modifying the rear deck by cutting sheetmetal to accomodate these ports. Explore Rowen Enriquezs board 'Speaker Enclosures', followed by 123 people on Pinterest. To minimize turbulance at the ends of the vent, we recommend to 'round-off' the inside edge of the interior part and all edges of the external parts to equlize air flow accross the thickness of the wood (see diagram.) If your enclosure is located in a trunk pressed against the back seat with the woofers facing the tail-lights, it is common to 'fire' the ports up through the rear deck. The inherent design of these vents utilize some of the enclosure walls as part of the vent length. Some enclosure designs are based upon 'slot' vents. If the box design requires a bend or 'elbow' in the port, always measure down the 'middle' of the vent to determine the correct cut length. This applies to all common types of vents (circular, rectangular, square, Aeroport, etc.) Remember, the important guideline is not to block the openings of the port(s) and to position multiple ports on the same side. A transmission line loudspeaker is a loudspeaker enclosure design which uses the topology of an acoustic transmission line within the cabinet, compared to the simpler enclosures used by sealed (closed) or ported (bass reflex) designs. If small enclosure design prohibits you from placing ports in their optimum location, do the best you can.

Obstructing the output of the vent may change the tuning frequency and increase port turbulence (noise). Single 12-Inch Ported Subwoofer Box Car Audio Stereo Bass Speaker Sub Enclosure. For optimum performance, keep the port one vent-diameter away from the back and sides of the enclosure. Scosche SE69KT 6x9 Single Car Speaker Box Enclosure with Gray Carpet. Do not block the opening of any port(s) and always position multiple ports on the same side of the enclosure. If this is not possible, installing ports on the side or back of the enclosure are good alternatives. Best acoustic coupling is accomplished when the port(s) are installed on the same side as the woofer(s).

Car speaker enclosure design