Soundstream Technologies EXC 10 Calculating Cylindrical Port Volume, Building The Enclosure

SELECTING AN ENCLOSURE

Sealed Band-pass Enclosure

Sealed band-pass enclosures enclose both sides of the woofer(s). An airtight enclosure is built around the front and back of the woofer and one chamber is ported to a specific frequency.

ProsCons

·	High power handling ·		Low power handling
	within the operating		beyond the tuning
·	frequencies		frequency
	Very high output	·	Poor to moderate
	within the range of		transient response
	the operating	·	Poor low frequency
	frequencies		extension

CALCULATING NET INTERNAL ENCLOSURE VOLUMES When constructing any type of enclosure, you must be aware that the outside dimensions DO NOT represent the true (Net) volume inside. Such things as woofers, ports, thickness of enclosure material, dividing walls, and any internal bracing will reduce the total amount of the actual air space available. The following worksheet has been designed to provide you with the necessary steps to accurately calculate the absolute (Net) internal volume of any given enclosure.

Calculating Cylindrical Port Volume

1.Measure the outside diameter of the port and divide by 2 for the radius.

2.Square the radius and multiply by 3.14 (pi) to arrive at outside port area.

3.Multiply the area by the length of the port inside the enclosure for the port volume.

BUILDING THE ENCLOSURE

·Determine the dimensions of your enclosure.

·Be certain the box you have designed will fit into the location you have chosen. Sometimes making a cardboard box with the same outside dimensions is helpful.

·Use 3/4 inch thick Medium Density Fiberboard (MDF) or High Density Particleboard. It is preferable to cut the wood with a table saw to ensure straight, even joints. If a table saw is not available, a circular saw is acceptable.

·Use a "T' square to verify precise right angle gluing.

·Use a high quality wood glue and air nails or wood screws to assemble the enclosure. Elmer'sâ woodworker's glue and Weldwoodâ work well. To guarantee an airtight box, seal each inside joint with silicone sealant.

·For Sealed Enclosures, stuff the chamber with 50-75% filling (approximately 1.5 pounds per cubic foot) of fiberglass insulation or Dacronâ.

·For Vented Enclosures, staple 1-inch thick fiberglass insulation or Dacronâ to all walls of the enclosure except the baffle to which the woofer is mounted.

∙Use the eight (8) wood screws or T-nuts and bolts to seal the woofer in the enclosure. Progressively tighten each of the bolts or screws to prevent warping the woofer frame.

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