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Hersteller: Altec Lansing Dateigröße: 862 kb Dateiname: Unterrichtssprache:

Horizontal Off-Axis Response Contours DISTANCE (m) 3.0976 3.304 3.510 3.717 3.923 4.1294 —r- 6 dB m ~o > rr LU z LU 9000 9600 10200 10800 11400 12000 TIME Cps) Figure 12. Energy Time Curve (See Note 9) Figure 9. Q and Dl Figure 11. Vertical Off-Axis Response Contours Figure 13. Time Energy Frequency Curve (See Note 10) NOTES ON MEASUREMENT CONDITIONS 1. Figure 1 measurement was taken with network attenuation set in the "Flat" position. 2. Pink noise signal, one watt calculated using E2/Zmin, 3.16 meter measurement distance referred to one meter. 3. On-axis, one watt calculated using EJ/Zmin, 3.16 meter. Measurement distance referred to one meter, low frequencies corrected for anechoic chamber error. 4. This system rating patterned after the AES method for individual drivers, where the test signal is pink noise with 6 dl3 crest factor over the bandwidth of the system, with power calculated using EVZmin, for two hours. 5 This measurement made under the same conditions as Pressure Sensitivity, but at rated power, and takes into account any power compression effects due to non-linearities in the system 6. Phase response of the system measured at a time corresponding to the energy arrival of the high frequency component, as noted on Figure 12. 7 Distortion components invalid above 10 kHz The percentage distortion at any given frequency may be found by graphically taking the difference between the fundamental and harmonic, adding 18 dB, and applying the formula: percentage distortion = 100 x 10. —dli change/20 8. The axis of rotation for all polar plots is the apparent apex of the high frequency horn. Plots below 200 Hz have not been shown because of their lack of pertinent information. 9. The time window has been chosen to resolve the arrival times of low and high frequency components. Frequency bandwidth of measurement, 800 Hz-2.8 kHz 10. Response decay of the system. Time window is the same as used in Figure 12, Energy Time Curve 11. The loudspeaker system should be connected to the eight ohm tap of amplifiers using transformer coupled output sections. 12. Continuous program is defined as 3 dB greater than the AES rating using a pink noise signal with 6 dB crest factor. 13. Peak power is defined as 6 dB greater than the AES rating using a pink noise signal with 6 dB crest factor. SOUND PRESSURE LEVEL (dB) '/*■20 ’/.-20 FLAT WASHER CENTER OF GRAVITY: A = 6-34“ 16.51 cm B = 11-J4" 28.57 cm Figure 14. Mounting Data MOUNTING INFORMATION FOR FIXED INSTALLATION The loudspeaker system is supplied with 14-20 a ceiling-plane mounting surface). The user must threaded inserts which allow suspension mount- supply eyebolts, hexnuts, washers, "S" hooks, ing in either 50° or 30° angles (referenced to and cables or chains. Figure 15. System Dimensions ARCHITECT'S AND ENGINEER'S SPECIFICATIONS The loudspeaker shall be of the two-way multipurpose type, consisting of a 16" coaxial type loudspeaker and a dividing network having a crossover frequency of 2 kHz with variable high-frequency attenuation. The loudspeaker system shall meet the following performance criteria. Power rating, 150 w (average) of continuous pink noise, band-limited from 80 Hz-15 kHz.Frequency response, smooth and uniformly usable at high levels from 80 Hz-15 kHz. Pressure sensitivity, 100dB SPL at one watt, 80 Hz-15 kHz, measured from one meter on axis. Impedance, 7.2 ohms, minimum. The enclosure shall be of the ported bass reflex type constructed of Va" (1.9 cm) birch plywood damped with sound absorbent glass wool. The finish shall be black spatter-finish polyurethane paint. The dimensions shall be 201/2" (52.1 cm) high by 22" (55.8 cm) wide by 211/2" (54.6 cm) deep. The loudspeaker shall weigh 58 lbs. (26.4 kg). The loudspeaker system shall be the Altec Lansing Model 938-8AD or Model 938-8AE. ALTEC LANSING P.O. BOX 26105, OKLAHOMA CITY, OKLAHOMA 73126-0105, U.S.A. ©1989 ALTEC LANSING CORPORATION PRINTED IN U.S.A. 5/89-3M AL-2565 42-07-027608...

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