Minimum Enclosure Size, Insulation | Niles Audio CM8SW manual

Treatment & Placement

Typically, sheetrock encloses the sub- woofer in most installations. Sheetrock has a fairly loud resonant “twang” compared to the rigid non-resonant enclosures of most floor standing subwoofers. None of the following modifications are absolutely necessary, however any one or combina- tion of them will improve the performance of the subwoofer.

Minimum Enclosure Size

The CM8SW will produce magnificent results if the ceiling air cavity above the woofer is a minimum of 1900 cubic inch- es. If the ceiling joists center measure 5-1/2” deep (2x6) and are spaced 14-1/4” apart (16” spacing) you would want the length of the air cavity to be a minimum of 24-1/4”. A larger cavity is fine.

Insulation

Lay a batten of fiberglass insulation (e.g. R-19 un-batted insulation) on top of the speaker. If you have more than one sub- woofer in the room, place the same amount of insulation above each subwoofer. If your enclosure is smaller than the recommended 1900 cubic inches, try packing more insula- tion into the space above the speaker. This effectively increases the enclosure size.

Enclosure Bracing

Insert small pieces of 1x2 or 1x1 scrap wood as wedges between the ceiling sheetrock and the floor above if possible. Do not use too long of a piece as you could create a bulge in the ceiling surface.

Enclosure Lining

Purchase some subwoofer damping mate- rial from a car stereo store (there are vari-

ous brands available, e.g. Dynamat™). Apply the damping material to the bottom of the floor above the CM8SW and to the top of the surrounding sheetrock ceiling beside the subwoofer.

Speaker Placement Techniques

Although the CM8SW has extensive ability to compensate for unusual placements with its crossover switches; placement is still the primary tool for satisfying your particular listening needs.

Maximizing Output

Corner Placement – Placing your subwoofer near a corner will increase the volume of bass sound produced by the subwoofer! This is called the boundary effect. Generally, you can expect a 3dB increase in sound pressure level with corner placement.

Proximity – Place the subwoofer as close as possible to the primary listening posi- tion. Sound dissipates indoors at approxi- mately 4dB to 6dB each time you double the distance from the subwoofer to the lis- tener. Therefore you can expect a 4dB to 6dB increase in output every time you halve the distance from the subwoofer to the listener.

Improving the Stereo Image

Near Satellite

Place the subwoofer(s) as close as possible to the satellite speakers.