AVIXA CTS-D: Loudspeakers All Possible Questions and Answers with complete solution

Full overlap distributed ceiling system arrangement - Will provide excellent coverage at most frequencies (1.4 dB variation). However, this is a costly approach, and will likely provide more coverage than required. This amount of overlap may also result in some negative interaction with the sound from nearby loudspeakers, such as phase cancellation. This is because a dense overlap pattern may project too much acoustical energy within the space. Distributed Loudspeaker System - Employs multiple loudspeakers that are separated by some distance from each other. This is most commonly done by placing them in the ceiling above the audience area. loudspeaker polar pattern directivity - how much area a selected loudspeakers will cover, typically in ballon plot format representing a specific frequency response Coverage is typically stated at the 6 dB down points with 5 degree markings Speech Reinforcement typical loudspeaker frequency rating - 2000 Hz (2 kHz) What two items do a loudspeaker polar chart indicate? - 1. The radiated energy of a loudspeaker at a given frequency in either the vertical or horizontal plane. Energy radiates outward - but not equally - in all directions from the loudspeaker, and polar plots are used to show the pattern of the energy. 2. The degree off-axis where the radiated energy decreases by 6 dB as compared to the on axis level. These locations are referred to as the, "6 dB down points." Most often, the coverage pattern in equipment specifications is typically stated at the 6 dB down points. Loudspeaker Coverage Formula - This is the formula for the diameter of the circle representing the coverage area of a loudspeaker: D = 2 * (H - h) * tan (C∠ / 2)Where: D is the diameter of the coverage area H is the ceiling height h is the height of the listeners' ears C∠ is the loudspeaker's angle of coverage in degrees. What are common arrangements for distributed ceiling systems - 1. Full overlap 2. Edge-to-Edge 3. Minimum Overlap Edge-to-Edge distributed ceiling system arrangement - Places the loudspeakers such that the furthest extent of their acoustic energy joins at listeners' ear level with the adjacent loudspeaker. This approach is inexpensive, and results in minimum interaction between loudspeakers within the room. However, the arrangement may result in an uneven frequency response, with low spots in the corners of the coverage area. Minimum overlap distributed ceiling system arrangement - One of the most common ceiling arrangement methods. Provides very good coverage at most frequencies with 2 dB of variation, and ensures few or no "low" spots. However, this approach may not produce an entirely even frequency response (since the dispersion patterns vary according to the frequency of the sound). And may also create some negative acoustic interaction between nearby loudspeakers. Each loudspeaker's coverage pattern overlaps about 20% Hexagonal or partial overlap subtypes provides a variation of about 2.6 dB. Square Edge-To-Edge - Employs the non-overlapping concept and is the least favorable in a business communications setting but may be more than appropriate for general paging or simple background music. Maximum to minimum coverage variations for this configuration are around 4.35 dB.Hexagonal Edge-to-Edge - Employs the non-overlapping concept and is the least favorable in a business communications setting. Coverage variations for this configuration are around 5.4 dB. Requires many loudspeakers, which can get expensive. Additional power amplification may be required and additional installation labor can also add to the expense. Coverage variations for this configuration are around +/- 1.2 dB Loudspeaker Spacing (Ceiling Mounted) Center-to-Center Formula - D = r Where: D is the distance between loudspeakers r is the radius of loudspeaker coverage circle Loudspeaker Spacing (Ceiling Mounted) Edge-to-Edge Formula - D = 2 * r Where: D = the distance between loudspeakers r = the radius of loudspeaker coverage circle Loudspeaker Spacing (Ceiling Mounted) Minimum Overlap Formula - D = r * √ 2 Where: D = the distance between loudspeakers r = the radius of loudspeaker coverage circleANSI/INFOCOMM 1M-2009 - Audio Coverage Uniformity in Enclosed Listener Areas, Performance Standard (currently in the process of being revised). is meant to verify that a speech reinforcement or program audio design delivers uniform coverage in the listening area. While designing to conform to this standard requires computer modeling software