sls音箱线阵厂方培训ppt课件

1、RBA - 1线阵列扬声器原理PrinciplesofLine ArraysR Bob AdamsInternational DirectorrbobSLSaudiorbobadamsSLS AUDIOOzark, MissouriSLSaudio线阵列是一种扬声器单元的阵列方式，它可以对声音进展良好的控制，并在产生反响之前提供适当的增益。Line Arrays have been recognized as a loudspeaker design that can provide excellent control and gain before feedback.为了合理得当地运用线阵列

2、扬声器，设计者必需明确扬声器设计和操作的一些根本原理。To properly use Line Arrays, the designer must understand some basic principals of loudspeaker design and operation.为了合理得当地运用线阵列扬声器，设计者必需明确扬声器设计和操作的一些根本原理。To properly use Line Arrays, the designer must understand some basic principals of loudspeaker design and operation.线阵

3、列扬声器 Line Arrays早期的线阵列扬声器 Early Line Array规范的扬声器构造Standard Loudspeaker Construction规范的扬声器是点声源Standard Loudspeakers arePOINT SOURCEdevices规范的扬声器构造Standard Loudspeaker Construction点声源的声学特性POINT SOURCE characteristics 球面波辐射 Spherical wave propagation Spherical = 球状 声波传播以三维的方式进展 Waves spread in 3 dimens

4、ions规范的扬声器构造Standard Loudspeaker Construction球面波的辐射特性Spherical Wave Propagation点声源的声学特性 POINT SOURCE characteristics 声波以三维的方传播 Waves spread in 3 dimensions 当间隔添加一倍时，由于间隔产生的损耗 = -6 dB Loss over Distance = -6 dB per doubling of distance 这就是所谓的平方反比定律Know as the Inverse Square Law 损耗dB = 20*LOG Dft/3.28

5、LossdB = 20*LOG Dft/3.28 规范的扬声器构造Standard Loudspeaker Construction数学的根本原理The Mathematic Fundamentals实际上的点声源： A theoretical point source: 2 X 半径 R = 4 X 面积 2 X the radius R = 4 X the area4 X 面积 = 能量, 或 6 dB 声压级损失 4 X the area = power, or a 6 dB loss of level因此，平方反比定律为：间隔每添加一倍损失6dB Thus the inverse-sq

6、uare law: 6dB per doubling of distanceCourtesy of Ulysses Line Array Research平方反比定律 Inverse Square Law 普通系统 Conventional Systems规范的扬声器构造Standard Loudspeaker Construction普通系统声压级以dB计Conventional SystemSPL in dB100941248丈量点 Measurement Points8288线阵列的特性Line Array Characteristics 柱面波辐射 Cylindrical wave p

7、ropagation 柱体 Cylinder = 纵向的 Strait forward projection 声波以二维的方式传播 Waves spread in only 2 dimensions线阵列利用声波干涉原理加强或减弱来限制声波的辐射角度Line Arrays use the physics of interference effects (summation and cancellation) to restrict wave spreading 线阵列 Line Array柱面波cylindrical wave 线阵列的特性Line Array Characteristics

8、柱面波辐射 Cylindrical wave propagation 当间隔每添加一倍时，间隔所呵斥的损耗=-3dB Less Loss over Distance =-3 dB per doubling of distance只适用于近场 Near Field only数学的根本原理The Mathematic Fundamentals实际上的无限线声源 A theoretical infinite line-source: 2 X 半径 R = 2 X 面积 2 X the radius R = 2 X the area2 X 面积 = 能量, 或 3dB 的声压级损失 2 X the a

9、rea = power, or a 3dB loss of level因此，无限点声源在间隔添加一倍时，只损耗3dB Thus infinite line sources loose only 3dB per doubling of distanceCourtesy of Ulysses Line Array Research平方反比定律Inverse Square Law 线阵列系统Line Array Systems线阵列系统声压级以dB计Line Array SystemSPL in dB丈量点Measurement Points1248100979491线阵列系统声压级以dB计Line

10、 Array SystemSPL in dB1248100979491普通系统声级以dB计Conventional SystemSPL in dB100888294平方反比定律Inverse Square Law比较 Comparison线阵列的特征Line Array Characteristics间隔每添加一倍，间隔引起的损耗=-3dBLess Loss over Distance =-3 dB per doubling of distance只适用于近场Near Field only一个设计者如何决议线阵列的近场或远端场呢？How does a designer determine th

11、e Near Field or Far Field of a Line Array?例：Example线阵列 Line array = 4m高 4m tall近场DNear Field (D) = 25米 25 meters近场 NEAR Field-3 dB SPL 损耗-3 dB SPL loss远场 FAR Field-6 dB SPL 损耗-6 dB SPL lossD=L2f/636近场/远场的概念 Near Field / Far Field Concept一切有限线声源在一定间隔后会转变为点声源All finite line-sources transition into poi

12、nt-sources at some distance我们把这个转变间隔称作该线声源的临界间隔We will call the center of this transition area a line sources Critical Distance这是由于在远间隔的听众看来， 声源更像是一个点而不是线This is because the size of the source, from the perspective of the distant listener, is more similar to a point than a line数学的根本原理The Mathematic

13、FundamentalsFresnel vs. Fraunhofer 近场和远场的比较near-field vs. far-field数学的根本原理The Mathematic Fundamentals根本线阵列扬声器频率耦合的几何学Basic Line Array Geometryfor Frequency Coupling根本线阵列扬声器频率耦合的几何学Basic Line Array Geometry for Frequency CouplingPLH最大耦合波长 H Highest coupling HL = 阵列长度 Length of the arrayH = 两个单元声中心的间隔

14、 Center to Center spacingP = 换能器件的直径 Piston (transducer) diameter = 频带宽度 Bandwidth最大耦合波长 H Highest coupling H为了合理地耦合一切超越5kHz的频率，换能器件必需小于2.676.8cmTo properly couple any frequency above 5 kHz,the transducers must be spaced less than 2.67 (6.8 cm) 这对实践设计来说是完全不现实的Completely unrealistic for a practical d

15、esign线阵列假设建立在一堆简易扬声驱动单元的堆砌上，是不能够在高频下作为线声源运用的 NO line array, based on a simple stack of cone drivers, can perform as a line source at high frequencies垂直1米长的带有一组4 间隔驱动单元的线阵列Vertical polars of a 1-meter line array with a 4 driver spacing4 间隔 = 3384Hz，所以大致看来，1600Hz 的驱动间隔大约为 ，3150Hz 大约为 1 ，6300Hz 大约为 2 .

16、4 spacing = of 3384 Hz, so at roughly 1600 Hz the driversare apart, at 3150 Hz they are 1 apart, and at 6300 Hz they are 2 apart在1 的图里，在第一对突起处，高阶的倾斜分支出如今轴向的上方和下方At 1, the first pair of prominent, high-level gradient lobesappear above and below the main lobe1600 Hz( )3150 Hz(1 )6300 Hz(2 )线阵列未被适当耦合的情

17、况Line Array - not properly coupled辐射不延续 Dispersion inconsistent声压级分布不规律 SPL irregularity线阵列Line Array近场计算的数学原理Heavy Math for Near Field calculation以下公式可以算出线声源的最低频率：To find lowest frequency at which line source behavior will be found:F = C/H2xRR = (FxH2)/C以下公式可以算出线声源转化为点声源的间隔：To find transition dista

18、nce from line source to point source behavior:Where:F 代表频率 F is frequencyC 代表声音的传播速度 C is speed of soundH 代表阵列的高度英尺 H is array height in feetR 代表间隔 R is distance 如何决议必要的阵列高度How to determine the Necessary array height取决于以下各量组成的矩阵： Based upon a matrix of: 竖直的覆盖角 Vertical coverage 传播间隔 Throw distance 传

19、播环境的混响特性 Reverberation 阵列地点 Array location 听众位置的最低点 Lowest listener position 听众位置的最高点 Highest listener position 竖直的覆盖角 Vertical Coverage线阵列必需可以“看到每个听众位置，并且用无妨碍的“投射传播声音。The line array must be able to “see each listener position, and project sound with an unobstructed line of “throw.如何决议必要的阵列高度How to

20、determine the Necessary array height 竖直的覆盖角 Vertical Coverage最低的听众位置Lowest Listener Position听众的最高位置Highest Listener Position阵列的位置Array Location如何决议必要的阵列高度How to determine the Necessary array height 投射间隔Throw Distance阵列位置Array location间隔最远听众位置的间隔 Distance to farthest listener position根本的概测法：线阵列必需有足够的

21、高度来保证将柱形波传送到投射间隔的 处。General Rule of Thumb - the line array must be tall enough to produce a cylindrical waves for of the throw distance如何决议必要的阵列高度How to determine the Necessary array height普通来说，为了保证柱面波，阵列的高度必需大致是所要求最低频率高度的6倍。In general terms, the height of the array must be approximately 6 times the

22、 height of the desired lowest frequency to maintain cylindrical waves留意：这只是阵列的近场，普通是阵列高度的6倍。NOTE: This is only the NEAR FIELD of the Array, generally considered to be six times the array height.如何估计一个线阵列的投射间隔：How to estimate throw distance for a line array:计算所需求的最低频率Determine the lowest frequency ne

23、eded for the application.1130 频率 = 波长1130 frequency = Wavelength (WL)波长乘以6可以算出阵列的高度Multiply the wavelength by 6 to get the height of the array波长 x 6 = 高度WL x 6 = Height (H)高度乘以6可以算出近场的投射间隔Multiply the height of the array by 6 to get the estimated throw distance for the NEAR FIELDH x 6 =阵列的近场投射间隔H x

24、6 = throw distance (D) of the NEAR FIELD of the array例子Example500Hz近场估计的投射间隔Throw distance estimate for 500hz near field 计算运用所需的最低频率Determine the lowest frequency needed for the application.波长乘以6可以算出阵列的高度Multiply the wavelength by 6 to get the height of the array1130 (344.42 m) 500 = 2.26 ft (.69 m)

25、 WL2.26 ft (.69 m) WL x 6 = 13.56 ft (4.16 m) H例子Example阵列高度乘以6可以算出近场的估计投射间隔Multiply the height of the array by 6 to get the estimated throw distance for the NEAR FIELD2.26 ft (.69 m) WL x 6 = 13.56 ft (4.16 m) H13.56 ft (4.16 m) H x 6 = 81 ft (21.7 m)4.16m 阵列的近场the NEAR FIELD of the 4.16m array81 f

26、t (21.7 m)混响对阵列高度的影响Impact of Reverberationon array height概算法 A Rule of Thumb混响对阵列高度的影响Impact of Reverberationon array height对于混响时间 2 秒的空间for rooms with reverb 5秒的空间或者在室外for rooms with reverb 5 seconds or outdoors投射间隔 / 2/ 3 = 阵列的高度 (D/2) / 3 = H概算法 A Rule of Thumb混响对阵列高度的影响Impact of Reverberationon

27、 array height例子Example空间声音反射 = 3.5秒Room Reverberation = 3.5 seconds目的投射间隔 = 188ft57mTarget throw distance = 188 ft (57m) 188 / 2 = 94 94ft / 2 = 47ft 47ft / 4.5 = 10.44ft (3.2m) tall = H2 LS8695 = 9ft (2.74m)对于混响时间在2-5秒之间的空for rooms with reverb 2 5 seconds投射间隔/2/ 4.5 = 阵列的高度 (D/2) / 4.5 = H4000Hz200

28、0Hz500Hz250Hz31.5 Hz = 85.5 ft. 250 Hz = 30 ft. 2 kHz = 11 ft. 16 kHz = 4 ft.对一个100英尺的临界间隔，所需求的阵列长度：Length of Array needed for a 100-Foot Critical Distance010203040506070809085.4560.4242.9030.3321.4515.1710.727.585.363.7931.5 Hz63 Hz125 Hz250 Hz500 Hz1 kHz2 kHz4 kHz8 kHz16 kHz频率赫兹 Frequency in Hertz

29、 (Log Scale)Length of Array in Feet阵列的长度英尺例子 Example例子 Example对一个300英尺的临界间隔，所需求的阵列长度：Length of Array needed for a 300-Foot Critical Distance频率赫兹 Frequency in Hertz (Log Scale)Length of Array in Feet阵列的长度英尺148.00104.6574.3052.5437.1526.2718.5713.139.296.5702040608010012014016031.5 Hz63 Hz125 Hz250 Hz

30、500 Hz1 kHz2 kHz4 kHz8 kHz16 kHz31.5 Hz = 148 ft. 250 Hz = 52.5 ft. 2 kHz = 18.5 ft. 16 kHz = 6.5 ft.Break混响场下的线阵列Line Arrays in Reverberant Spaces混响场下的线阵列Line Arrays in Reverberant Spaces实践的和估算的混响时间RT60Real vs. Apparent Reverberation (RT60) 混响时间是用点声源进展丈量和估计的 Reverberation Time is typically measured

31、 (and predicted) using spherical devices对线阵列扬声系统而言，坚持其低频性能的稳定性是很重要的For line array systems, it is important to maintain consistent line array behaviorat low frequencies.以上观念在混响场中尤为重要especially in very live rooms!混响场下的线阵列Line Arrays in Reverberant SpacesLive room with a point source混响场下的线阵列Line Arrays

32、 in Reverberant Spaces5000hz6只 RLA3阵列5000Hz 具有良好的垂直控制范围6 Box RLA3 array- achieves good vertical control at 5000hz5000Hz混响场下的线阵列Line Arrays in Reverberant Spaces250hz5000hz250Hz在 250Hz 的时候阵列的辐射范围几乎是球状的However, at 250Hz the array is almost spherical混响场下的线阵列Line Arrays in Reverberant Spaces一个真正担忧的问题 不平

33、衡的混响声A real concern unbalanced reverberation 混响场下的线阵列Line Arrays in Reverberant Spaces一个真正担忧的问题 不平衡的混响声A real concern unbalanced reverberation 假设柱面波的传播只需在高频的时候被控制 那么产生 估算的RT60“ 的声音能量也只能影响高频。 If spherical spreading is only controlled in the high frequencies the sound energy that produces the “apparen

34、t “RT60 is also only affecting the high frequencies!STOP54混响场内的线阵列Line Arrays in Reverberant Spaces一个真正担忧的问题不平衡的混响声A real concern unbalanced reverberation *假设柱面波的传播只需在高频的时候被控制那么产生估算的RT60“的声音能量也只能影响高频。 * If spherical spreading is only controlled in the high frequencies the sound energy that produces

35、the “apparent “RT60 is also only affecting the high frequencies!整个房间听起来会“嗡嗡作响The Room will sound “boomy!55混响场里的线阵列Line Arrays in Reverberant Spaces在一个带有中等大小线阵列的混响场里Live room with a mid-size Line Array564m(13.5)高的阵列 500hz4 m (13.5) tall array500hz留意没有传播Notice no spreading实例 Example 线阵列 Line Array574m

36、(13.5)高的阵列 250hz4 m (13.5) tall array250hz留意没有传播Notice no spreading实例 Example线阵列 Line Array58阵列的中心点必需坚持足够近的间隔，来保证高的一致性。Center-to-center spacing MUST be close enough to maintain coherence at high frequencies.这取决于运用。THIS IS APPLICATION DEPENDENT谨记 Remember线阵列 Line Array592000Hz单个点声源w/ 55.8mm (2.2) 中心点

37、间距Single Point source w/ 55.8mm (2.2) center-to-center spacing 建立一个线声源Building a Line Source602000Hz2000Hz两个点声源 w/ 55.8mm 中心点间距Two Point sources w/ 55.8mm (2.2) center-to-center spacing 建立一个线声源Building a Line Source612000Hz2000Hz三个点声源w/ 55.8mm (2.2) 中心点间距Three Point sources w/ 55.8mm (2.2) center-to

38、-center spacing 建立一个线声源Building a Line Source622000Hz2000Hz四个点声源w/ 55.8mm (2.2) 中心点间距Four Point sources w/ 55.8mm (2.2) center-to-center spacing 建立一个线声源Building a Line Source632000Hz1.12m (44)没有波长传播No wave spreading2000Hz四个点声源w/ 55.8mm (2.2) 中心点间距Five Point sources w/ 55.8mm (2.2) center-to-center s

39、pacing 建立一个线声源Building a Line Source642000Hz1.12m (44)没有波长传播No wave spreading2000Hz这看起来很好，但是，当频率比中心点间距还小的时候会出现什么呢？This looks OK BUT, what happens at frequencies smaller than the center spacing?建立一个线声源Building a Line Source656300Hz问题 - 大问题Problems Big Problems6300Hz线阵列Line Array66带有带状驱动单元的换能器with Rib

40、bon TransducersPLH在同一个时间点在每个平面上再生的一切频率All frequencies reproduced on each plane at the Same time传感器之间的间隔更加小了Much shorter distance between transducers传感器之间的频率耦合更高Much higher frequency coupling between transducers相位关系得到极大提升Greatly improved Phase relationships67带状的换能器有着宏大的优势Ribbon Transducers have a eno

41、rmous advantage over the competition由于有等相位的特质due to isophasic properties68只需一个辐射衔接平面波的平的矩形驱动单元被密集地放置在一同时，可以结合为一个真正的线声源系统ONLY a flat rectangular piston Radiating a coherent planar waveSpaced tightly together Can be combined intoA TRUE line source system69合理耦合的声音辐射Properly coupled dispersion延续的，可控的Con

42、sistent and Controlled阵列的位置Array Location 座位的位置SeatingLocations70Proper Loudspeakers是一个线阵列Is it a Line Array ?还是只是“堆砌的音箱？Is it just “stacked upLoudspeakers ?还是orfor Line Arrays71平面阵列 和仿真 Planar Array vs. Emulation72Two compression driversWith sectored waveguidesHigh frequency planarRibbon line source堆叠的音箱Stacked upLoudspeakersThree compression driversWith small aperture longWaveguides三个紧缩驱动单元Three Compression Drivers73Two compression driversWith