1、INCH-POUND MIL-DTL-25547C 21 June 2002 SUPERSEDING MIL-L-25547B 6 February 1975 DETAIL SPECIFICATION LOUDSPEAKER, PERMANENT MAGNET LS-211/AIC-13 This specification is approved for use by all Departments and Agencies of the Department of Defense. 1. SCOPE 1.1 Scope. This specification covers one type
2、 of loudspeaker, designated loudspeaker, permanent magnet, LS-211/AIC-13. This loudspeaker is a horn type unit with a frequency response of 200-7000 Hz, nominal 16 ohms voice coil impedance, and a 20 watt peak power output (see 6.1). 2. APPLICABLE DOCUMENTS 2.1 General. The documents listed in this
3、section are specified in sections 3 and 4 of this specification. This section does not include documents cited in other sections of this specification or recommended for additional information or as examples. While every effort has been made to ensure the completeness of this list, document users ar
4、e cautioned that they must meet all specified requirements documents cited in sections 3 and 4 of this specification, whether or not they are listed. 2.2 Government documents. 2.2.1 Specifications, standards, and handbooks. The following specifications, standards, and handbooks form a part of this d
5、ocument to the extent specified herein. Unless otherwise specified, the issues of these documents are those listed in the issue of the Department of Defense Index of Specifications, and Standards (DoDISS) and supplement thereto, cited in the solicitation (see 6.2). SPECIFICATIONS FEDERAL A-A-52024 -
6、 Compass, Magnetic: Surveyors and Transit, Pocket; with Optional Ball and Socket Joint or Ball and Socket Head, and Jacobs Staff. STANDARDS FEDERAL FED-STD-595 - Colors Used in Government Procurement. Beneficial comments (recommendations, additions, deletions) and any pertinent data which may be of
7、use in improving this document should be addressed to: Defense Supply Center, Columbus, ATTN: VAI, P.O. Box 3990, Columbus, OH 43216-5000, by using the Standardization Document Improvement Proposal (DD Form 1426) appearing at the end of this document or by letter. AMSC N/A FSC 5965 DISTRIBUTION STAT
8、EMENT A. Approved for public release; distribution is unlimited.* Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-DTL-25547C 2 DEPARTMENT OF DEFENSE MIL-STD-130 - Identification Marking of U. S. Military Property. MIL-STD-202 - Test Methods for E
9、lectronic and Electrical Component Parts. MIL-STD-810 - Environmental Engineering Considerations and Laboratory Test. (Unless otherwise indicated, copies of the above specifications, standards, and handbooks are available from the Standardization Document Order Desk, 700 Robbins Avenue, Building 4D,
10、 Philadelphia, PA 19111-5094.) 2.3 Non-Government publications. The following documents form a part of this document to the extent specified herein. Unless otherwise specified, the issues of the documents which are DoD adopted are those listed in the issue of the DoDISS cited in the solicitation. Un
11、less otherwise specified, the issues of documents not listed in the DoDISS are the issues of the documents cited in the solicitation (see 6.2). AMERICAN NATIONAL STANDARDS INSTITUTE (ANSI) ANSI/NCSL Z540-1 - Laboratories, Calibration, and Measuring and Test Equipment. (Applications for copies should
12、 be addressed to the American National Standards Institute, Inc., 1430 Broadway, New York, N.Y. 10017.) AMERICAN SOCIETY OF AUTOMOTIVE ENGINEERS (SAE) AMS-QQ-A-250/2 - Aluminum Alloy 3003, Plate and Sheet (Application for copies should be addressed to the American Society Of Automotive Engineers, 40
13、0 Commonwealth Drive, Warrendale, PA 15096-0001.) INTERNATIONAL ORGANIZATION for STANDARDS (ISO) ISO 10012-1 - Equipment, Quality Assurance Requirements for Measuring Equipment Part 1:Metrologic Confirmation System for Measuring Equipment. (Application for copies should be addressed to American Nati
14、onal Standards Institute (ANSI), 11 West 42ndStreet, New York, NY 10036.) (Non-Government standards and other publications are normally available from the organizations that prepare or distribute the documents. These documents also may be available in or through libraries or other informational serv
15、ices.) 2.4 Order of precedence. In the event of a conflict between the text of this document and the references cited herein, the text of this document takes precedence. Nothing in this document, however, supersedes applicable laws and regulations unless a specific exemption has been obtained. 3. RE
16、QUIREMENTS 3.1 First article. When specified (see 6.2), loudspeakers shall be subjected to first article inspection in accordance with 4.4. 3.2 Materials. Materials shall be as specified herein. However, when a definite material is not specified, a material shall be used which will enable the loudsp
17、eaker to meet the performance requirements of this specification. Acceptance or approval of any constituent material shall not be construed as a guaranty of the acceptance of the finished product. 3.2.1 Aluminum. Aluminum shall conform to SAE-AMS-QQ-A-250/2, Alloy 3003, or equivalent. * * Provided b
18、y IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-DTL-25547C 3 3.2.2 Recycled, recovered, or environmentally preferable materials. Recycled, recovered, or environmentally preferable materials should be used to the maximum extent possible provided that the ma
19、terial meets or exceeds the operational and maintenance requirements, and promotes economically advantageous life cycle costs. 3.3 Design and construction. 3.3.1 Dimensions. The dimensions of the loudspeaker shall be as shown on figure 1. 3.3.2 Width of air gap. The air gap for the voice coil in the
20、 permanent magnet shall be such that the difference between the minimum width of the radial air gap and the maximum thickness of the voice coil shall be at least 0.014 inch. 3.3.3 Weight. The weight of the loudspeaker shall not exceed 1.6 kilograms. 3.3.4 Color. The loudspeaker color shall be luster
21、less gray, color #36270 in accordance with FED-STD-595. 3.3.5 Terminal board. The voice-coil lead wire of the loudspeaker shall be brought to a terminal board on the mounting plate of the loudspeaker assembly, as shown on figure 1. The terminal board shall be covered with a metal protective shield w
22、ith a grommet to permit the entry of a 5/16-inch diameter cable. The terminal board shall be constructed of a suitable high-grade insulating material and shall contain a minimum of two screws which will accept a No. 6 wire terminal. 3.4 Voice coil impedance. When loudspeakers are tested as specified
23、 in 4.6.2, the impedance of the voice coil, mounted in a complete loudspeaker assembly, shall be 16 3.2 ohms. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-DTL-25547C 4 Inches mm Inches mm .001 .005 .180 .250 .312 .03 .13 4.57 6.35 7.92 3.875 4
24、.97 5.375 6.80 7.5 98.43 126.24 136.53 172.72 190.50 NOTES: 1. Dimensions are in inches. 2. Unless otherwise specified tolerances are .015 (.38 mm) for three place decimals and .06 (1.52 mm) for two place decimals. FIGURE 1. Outline drawing loudspeaker LS 211/AIC-13.Provided by IHSNot for ResaleNo r
25、eproduction or networking permitted without license from IHS-,-,-MIL-DTL-25547C 5 3.5 Voice coil polarity (see 4.6.3). When tested as specified in 4.6.3, the polarity of the voice coil shall be determined and the positive terminal of the voice coil shall be marked with a red dot. The marking shall n
26、ot interfere with the electrical connections and shall not be impaired by soldering or unsoldering operations. 3.6 Stray magnetic field. When tested as specified in 4.6.4, the loudspeaker shall not cause a deflection of more than 5 on a magnetic compass. 3.7 Sensitivity. 3.7.1 At sea level. When lou
27、dspeakers are tested as specified in 4.6.5.1, the average sensitivity above a reference level of 0.0002 dyne per square centimeter for each of the indicated frequency bands, shall be not less than the values shown in table I. TABLE I. Sensitivity. 3.7.2 At altitude. When loudspeakers are tested as s
28、pecified in 4.6.5.2, the sensitivity measured at an altitude of 15,000 feet, shall not differ by more than 3 dB from the sensitivity measured at ground level (see 4.3). 3.8 Frequency response. When loudspeakers are tested as specified in 4.6.6, the frequency response shall be within the limits speci
29、fied on figure 2, except that sharp peaks and dips may extend beyond these limits provided the width of the extension is not greater than 0.1 octave at the limit, and the number of extensions does not exceed 1 peak or dip per octave below 3,000 Hz, and 3 peaks or dips above 3,000 Hz. 3.9 Directional
30、 characteristics. When loudspeakers are tested as specified in 4.6.7, the sound pressure measured 4 feet away from the loudspeaker in a free field at the indicated angles in all four quadrants with respect to the principal axis shall not deviate from the sound pressure measured on the principal axis
31、 by an amount greater than the values shown in table II for a frequency of 1,000 Hz. The same input signal shall be applied for both on-axis and off-axis sound pressure measurements. TABLE II. Directional characteristics. 3.10 Linearity. When loudspeakers are tested as specified in 4.6.8, the acoust
32、ic output of the loudspeaker shall not deviate from a linear function of the input voltage by more than 1 dB. 3.11 Distortion. When loudspeakers are tested as specified in 4.6.9, the harmonic distortion in the acoustic output shall not exceed the values given in table III.Frequency band Average sens
33、itivity Hz 500 - 800 800 - 1250 1250 - 2000 2000 - 3200 3200 - 5000 500 - 5000 dB 97.0 102.0 103.0 106.0 103.5 103.0 Frequency (Hz) Maximum sound pressure deviation (dB) Off-Axis Angles 15 30 1,000 -3.0 -6.0 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IH
34、S-,-,-MIL-DTL-25547C 6 0 = 95dB 2dB FIGURE 2. Frequency response.Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-DTL-25547C 7 TABLE III. Distortion. 3.12 Acoustic quality. When loudspeakers are tested as specified in 4.6.10, there shall be no buz
35、zes, rattles, or other spurious sounds that would impair the quality of reproduced audio signal in the output. 3.13 Dielectric withstanding voltage. When tested as specified in 4.6.11, there shall be no arcing or breakdown of the voice coil insulation. Following the test, the loudspeaker shall meet
36、the following requirements: Voice coil impedance variation: Not more than 1 ohm maximum from the initial measured value. 3.14 Life. When tested as specified in 4.6.12, the loudspeaker shall meet the following requirements: a. Voice coil impedance variation: Not more than 1 ohm maximum from the initi
37、al measured value, except when measurements are made immediately after hot and cold exposures of the last cycle (see 3.4). b. Sensitivity variation: Not more than 3 dB from the initial measured value (see 3.7.1). c. Frequency response: As specified in 3.8. d. Dielectric withstanding voltage: As spec
38、ified in 3.13. e. Visual examination: There shall be no visual or mechanical failures (see table VIII). 3.15 Endurance. When tested as specified in 4.6.13, loudspeakers shall meet the following requirements: a. Voice coil impedance variation: Not more than 1 ohm maximum from the initial measured val
39、ue, except when measurements are made immediately after hot and cold exposures of the last cycle (see 3.4). b. Sensitivity variation: Not more than 2 dB from the initial measured value (see 3.7.1). c. Frequency response: As specified in 3.8. d. Dielectric withstanding voltage: As specified in 3.13.
40、e. Visual examination: There shall be no visual or mechanical failures (see table VIII).Frequency Signal input range 3.9 volts 8.8 volts Hz 500 - 1,000 1,000 - 6,000 Percent 9 3.5 Percent 14 5 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-DTL-2
41、5547C 8 3.16 Temperature cycling. When tested as specified in 4.6.14, the loudspeaker shall meet the following requirements: a. Voice coil impedance variation: Not more than 1 ohm maximum from the initial measured value, except when measurements are made immediately after hot and cold exposures of t
42、he last cycle (see 3.4). b. Sensitivity variation: Not more than 3 dB from the initial measured value (see 3.7.1). c. Frequency response: As specified in 3.8. d. Dielectric withstanding voltage: As specified in 3.13. e. Visual examination: There shall be no visual or mechanical failures (see table V
43、III). 3.17 Vibration. When tested as specified in 4.6.15, the loudspeakers shall meet the following requirements: a. Voice coil impedance variation: Not more than 1 ohm maximum from the initial measured value, except when measurements are made immediately after hot and cold exposures of the last cyc
44、le (see 3.4). b. Sensitivity variation: Not more than 2 dB from the initial measured value (see 3.7.1). c. Frequency response: As specified in 3.8. d. Dielectric withstanding voltage: As specified in 3.13. 3.18 Shock. When tested as specified in 4.6.16, the loudspeakers shall meet the following requ
45、irements: a. Voice coil impedance variation: Not more than 1 ohm maximum from the initial measured value, except when measurements are made immediately after hot and cold exposures of the last cycle (see 3.4). b. Sensitivity variation: Not more than 2 dB from the initial measured value (see 3.7.1).
46、c. Frequency response: As specified in 3.8. d. Dielectric withstanding voltage: As specified in 3.13. 3.19 Pressure cycling. When tested as specified in 4.6.17, the loudspeakers shall meet the following requirements: a. Voice coil impedance variation: Not more than 1 ohm maximum from the initial mea
47、sured value, except when measurements are made immediately after hot and cold exposures of the last cycle (see 3.4). b. Sensitivity variation: Not more than 2 dB from the initial measured value (see 3.7.1). c. Frequency response: As specified in 3.8. d. Dielectric withstanding voltage: As specified
48、in 3.13.Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-DTL-25547C 9 3.20 Explosive decompression. When tested as specified in 4.6.18, the loudspeakers shall meet the following requirements: a. Voice coil impedance variation: Not more than 1 ohm
49、maximum from the initial measured value, except when measurements are made immediately after hot and cold exposures of the last cycle (see 3.4). b. Sensitivity variation: Not more than 2 dB from the initial measured value (see 3.7.1). c. Frequency response: As specified in 3.8. d. Dielectric withstanding voltage: As specified in 3.13. e. Visual examination: There shall be no visual or mechanical failures
