L-Acoustics V-DOSC Operator'S Manual Download Page 8

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L-ACOUSTICS V-DOSC Manual Version 4

6/29/2005

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LIST OF FIGURES

Figure 1: Wavefront interference versus a sculptured V-DOSC wavefront.................................................... 12

Figure 2: Wavefront Sculpture Technology Conditions 1 and 2 Illustrated.................................................... 13

Figure 3: Coplanar Symmetry of V-DOSC ..................................................................................................... 15

Figure 4: Cylindrical versus spherical wave propagation................................................................................ 16

Figure 5: V-DOSC Array ................................................................................................................................ 17

Figure 6: V-DOSC System Block Diagram ..................................................................................................... 20

Figure 7: LR System Configuration ................................................................................................................. 21

Figure 8: LR System Plus Offstage Fill Configuration..................................................................................... 22

Figure 9: V-DOSC system loudspeakers plus accessories.............................................................................. 23

Figure 10: V-DOSC Rigging Accessories ......................................................................................................... 25

Figure 11: V-DOSC Subwoofer Options......................................................................................................... 26

Figure 12: Subwoofer Rigging Accessories ...................................................................................................... 26

Figure 13: L-ACOUSTICS LA48a Power Amplifier......................................................................................... 27

Figure 14: Amplifier Rack Options and Accessories........................................................................................ 28

Figure 15: Signal distribution and cabling......................................................................................................... 30

Figure 16: Loudspeaker cabling options .......................................................................................................... 32

Figure 17: V-DOSC Enclosure - Front and Rear Views................................................................................... 33

Figure 18: V-DOSC BUMP2............................................................................................................................ 34

Figure 19: BUMPDELTA ................................................................................................................................. 35

Figure 20: SB218 Subwoofer – Front and Rear Views .................................................................................... 36

Figure 21: BUMPSUB SB218 Flying Bar .......................................................................................................... 37

Figure 22: V-DOSC PADO4a Amplifier Rack Panel........................................................................................ 40

Figure 23: V-DOSC PADO2a Amplifier Rack Panel........................................................................................ 40

Figure 24: PADO4a amp rack wiring............................................................................................................... 41

Figure 25: PADO2a amp rack wiring............................................................................................................... 42

Figure 26: L-ACOUSTICS Amplifier Rack RK124a loaded with 4 x L-ACOUSTICS LA48a amplifiers........... 43

Figure 27: L-ACOUSTICS Amplifier Rack Options ......................................................................................... 44

Figure 28: L-ACOUSTICS RK122a amplifier rack channel assignments and cabling....................................... 46

Figure 29: L-ACOUSTICS RK124a amplifier rack channel assignments and cabling....................................... 46

Figure 30: L-ACOUSTICS RK122a amp rack channel assignments for 2-way, 3-way stereo presets ............ 47

Figure 31: L-ACOUSTICS RK124a amp rack channel assignments for 2-way, 3-way stereo presets ............ 48
Figure 32: CO24 Control Output Panel.......................................................................................................... 49

Figure 33: MD24 Multi Distro Panel................................................................................................................ 50

Figure 34: CO6 Control Output Panel............................................................................................................ 50

Figure 35: Spectral balance for SUB/LOW versus MID/HI Sections ............................................................... 53

Figure 36: Spectral balance for SUB/LOW versus MID/HI Sections (V6 presets and earlier)......................... 53

Figure 37: Infra preset time alignment procedure........................................................................................... 55

Figure 38: 4W preset time alignment procedure ............................................................................................ 55

Figure 39: X preset time alignment procedure ............................................................................................... 56

Figure 40: X AUX preset time alignment procedure...................................................................................... 56

Figure 41: 5W Infra preset time alignment procedure .................................................................................... 57

Figure 42: 5W X preset time alignment procedure ........................................................................................ 57

Figure 43a: Horizontal V-DOSC isocontour averaged from 630 Hz - 16 kHz ............................................... 63

Figure 43b: Horizontal V-DOSC isocontour averaged from 32 Hz - 630 Hz ................................................. 63

Figure 44: Constant Curvature Array Examples. ............................................................................................ 65

Figure 45: Defining Cutview Dimensions ........................................................................................................ 67

Figure 46: Parameters for the ROOM DIM Utility Sheet in ARRAY ............................................................... 68

Figure 47 (a): Cutview showing non-constant enclosure site angle impact spacing........................................ 69

Figure 47 (b): Cutview showing constant enclosure site angle impact spacing ............................................... 69

Figure 47 (c): Plan view representation of non-constant (a) versus constant spacing (b) arrays .................... 69

Figure 48: ARRAY 2004 Geometric Data for V-DOSC................................................................................... 71

Figure 49: ARRAY 2004 Geometric Data for dV-DOSC................................................................................. 73

Figure 50: ARRAY 2004 spreadsheet calculation example .............................................................................. 75

Summary of Contents for V-DOSC

Page 1: ...Version 4 June 2005 V DOSC OPERATOR MANUAL ...

Page 2: ...L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 2 of 158 ...

Page 3: ...ion are also discussed in this document MANUAL ORGANIZATION The Introduction gives a brief presentation of V DOSC and explains why specialized training is necessary to work with the system Chapter 1 presents the fundamentals of Wavefront Sculpture Technology and introduces the elements of the V DOSC system standard Chapter 2 describes V DOSC array performance and coverage prediction Chapter 3 disc...

Page 4: ...stem this in itself was a radical innovation in its day and even now provides speed and flexibility that captive rigging systems can t equal That s what new what s old is that V DOSC remains the reference that other line arrays are compared to and has become a modern day classic But V DOSC is not just a speaker it is a standard system and through the V DOSC Network a worldwide service including hi...

Page 5: ...ORIES 24 SUBWOOFER ENCLOSURES 26 SUBWOOFER RIGGING ACCESSORIES 26 AMPLIFICATION 27 AMPLIFIER RACKS 27 SIGNAL DISTRIBUTION AND CABLING 29 LOUDSPEAKER CABLING 31 1 2 V DOSC SPECIFICATIONS 33 1 3 V DOSC RIGGING SYSTEM 34 1 4 SB218 SUBWOOFER SPECIFICATIONS 35 1 5 SB218 RIGGING SYSTEM 37 1 6 POWERING V DOSC 38 1 7 V DOSC AMP PANELS 40 1 8 V DOSC AMPLIFIER RACKs 43 1 9 COMB CONNECTORS 45 1 10 CO24 CONTR...

Page 6: ...OVERAGE MODELING USING ARRAY 2004 66 CUTVIEW SHEETS 67 V ARRAY1 V ARRAY2 Input Data 67 Optimization Procedure 69 Output Data 70 dV ARRAY1 dV ARRAY2 Input Data 72 dV DOSC PICK POINT UTILITY 72 H ISOCONT SHEET 74 Input Data 74 Optimization Procedure 74 Output Data 74 2 4 V DOSC COVERAGE MODELING USING SOUNDVISION 76 SOUNDVISION EXAMPLES 80 SOUNDVISION STADIUM EXAMPLE 80 SOUNDVISION ARENA EXAMPLE 82 ...

Page 7: ... Procedures 129 6 2 Recommended Maintenance Tools 129 6 3 Spare Parts 130 6 4 Recommended Installation Tools 131 7 SPECIFICATIONS 132 7 1 V DOSC ENCLOSURE SPECIFICATIONS 132 7 2 SB218 SUBWOOFER SPECIFICATIONS 134 7 3 RIGGING STRUCTURES 135 V DOSC BUMP2 Bumper 135 SB218 BUMPSUB Rigging Bar 136 7 4 CO24 MD24 Line Assignment Summary 137 7 5 CO24 Control Output Panel Line Assignments 138 7 6 MD24 Mult...

Page 8: ...ier rack channel assignments and cabling 46 Figure 29 L ACOUSTICS RK124a amplifier rack channel assignments and cabling 46 Figure 30 L ACOUSTICS RK122a amp rack channel assignments for 2 way 3 way stereo presets 47 Figure 31 L ACOUSTICS RK124a amp rack channel assignments for 2 way 3 way stereo presets 48 Figure 32 CO24 Control Output Panel 49 Figure 33 MD24 Multi Distro Panel 50 Figure 34 CO6 Con...

Page 9: ...urations 95 Figure 73 Hybrid flown stacked subwoofer configurations 96 Figure 74 Hybrid flown stacked subwoofer example 96 Figure 75 L R Subwoofer arraying techniques 98 Figure 76 Centre subwoofer line array a without and b with electronic delay processing 99 Figure 77 Electronic delay processing examples using a 4 or 6 channel DSP 100 Figure 78 LCR Subwoofer arraying techniques 101 Figure 79 Larg...

Page 10: ...r amplifier ratings 38 Table 2 Load and Power Ratings for V DOSC 39 Table 3 PADO4a COMB Wiring Chart 41 Table 4 PADO4a Internal Amp Rack Wiring Chart 41 Table 5 PADO2a COMB Wiring Chart 42 Table 6 PADO2a Internal Amp Rack Wiring Chart 42 Table 7 V DOSC preset DSP output channel assignment and COMB connector summary 45 Table 8 2 way 3 way stereo preset DSP output channel assignment and COMB connect...

Page 11: ...peakers were typically assembled in fan shaped arrays according to the nominal horizontal coverage angle of each enclosure in an attempt to reduce coverage overlap that causes chaotic interference With this type of arrangement the optimum clarity available in one direction could only be provided by the individual enclosure facing in this direction Attempts at flattening the array to achieve greate...

Page 12: ... the curvature of the wavefront radiated by each source and the source separation WST coupling conditions can be summarized as follows An assembly of individual sound sources arrayed with regular separation between the sources on a plane or curved continuous surface is equivalent to a single sound source having the same dimensions as the total assembly if and only if one of the two following condi...

Page 13: ...rtion to the listener distance geometrically this is equivalent to shaping variable curvature arrays to provide equal spacing of individual enclosure site angle impacts on the audience listening plane 5 Limits exist concerning the vertical height of each enclosure the minimum allowed listener distance and the angles that are allowed between enclosures The key to satisfying WST conditions at higher...

Page 14: ...t possible at higher frequencies since the wavelengths become progressively smaller than the physical separation between the acoustic centres of horn and driver assemblies Neither of the first two WST criteria can be satisfied and as a result interference occurs throughout most of the high frequency range see Appendix 1 By comparison a V DOSC array is a full spectrum coherent loudspeaker system ev...

Page 15: ...e software tools to be used for horizontal coverage prediction Psychoacoustically coplanar symmetry is largely responsible for the exceptional stereo imaging properties that are characteristic of V DOSC Other practical benefits of the coplanar symmetric configuration include the fact that there is no need to fly mirror imaged L R arrays plus rigging issues are further simplified since the enclosur...

Page 16: ...at must be evaluated using specific calculations Aside Conventional modeling techniques cannot accurately simulate WST based systems such as ARCS KUDO dV DOSC or V DOSC For WST based products L ACOUSTICS has worked with the developers of EASE and CATT to integrate proprietary SOUNDVISION modeling techniques into these industry standard room acoustics modeling programs When curved V DOSC arrays are...

Page 17: ... the reverberant energy in the room and focus more energy on the audience we can effectively move back the critical distance in a given room while offering more of the audience a nearfield listening experience Given the well defined vertical coverage of V DOSC the benefits of WST become immediately obvious in comparison with conventional systems when working in difficult reverberant rooms Finally ...

Page 18: ...mmended by a recognized CVE see below or an official V DOSC Network representative CERTIFIED V DOSC ENGINEER CVE The higher level of qualification is Certified V DOSC Engineer or CVE In addition to satisfying the mission statement for QVTs the CVE has further expertise in the areas of sound design and system measurement as well as extensive real world experience with V DOSC The CVE has a complete ...

Page 19: ... overview of system connection and signal flow This is followed by an identification of the individual elements of the system and more detailed descriptions in Sections 1 2 through 1 7 Please note that specific multi conductor connector selection for system drive remains open for the user to define although L ACOUSTICS does offer a specific connector type that is supplied with turnkey systems L AC...

Page 20: ...L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 20 of 158 Figure 6 V DOSC System Block Diagram ...

Page 21: ...L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 21 of 158 Figure 7 Example LR System Configuration ...

Page 22: ...L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 22 of 158 Figure 8 Example LR System Plus Offstage Fill Configuration additional distributed front fill or stereo infill system recommended ...

Page 23: ...rs Constructed of rugged cordura material and padded for extra protection 3 dV DOSC Active 2 way loudspeaker enclosure meeting WST criteria with coplanar symmetric arrangement of loudspeaker components Used with V DOSC for down fill up fill long throw offstage fill stereo in fill or distributed front fill Note for full details see the dV DOSC user manual available for download on www l acoustics c...

Page 24: ...24 BUMP251 BUMP25 BUMP26 BUMP27 8 SPACER Used with ANGLE STRAPS to provide the desired spacing between V DOSC enclosures when stacked or flown Part Codes SPAC251 1 3 SPAC25 2 SPAC26 3 SPAC27 4 SPAC28 5 5 for use with corresponding BUMPxx 9 CHARIOT Transportation chariot for 2 x BUMP2 2 x BUMPSUB ANGLE straps ratchet straps screwjacks shackles and other rigging accessories 10 dV BUMP Flying bumper ...

Page 25: ...L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 25 of 158 CHARIOT dV DOWN dV BUMP Figure 10 V DOSC Rigging Accessories ...

Page 26: ...vel low frequency extension Optional removable front dolly not shown recommended for touring applications 15 dV SUBCOV Protective cover for dV SUB enclosures comes in pairs SB218 dV SUB SUB COV dVSUB COV Figure 11 V DOSC Subwoofer Options SUBWOOFER RIGGING ACCESSORIES 16 BUMPSUB Flying bar for rigging up to eight SB218 enclosures deep in a vertical line array 17 dV BUMP2 Flying bumper for rigging ...

Page 27: ...nnector for loudspeaker connection in parallel with 4x Speakon connectors two male 19 pin CA COM connectors for signal distribution input through COMB connector for selecting 2 way 3 way or subwoofer operating modes 4x male XLR and 4x Speakon fanouts on the internal side for connecting to amplifier inputs and outputs Note PADO stands for PATCH DOSC 23 PADO4a AMP PANEL Amplifier panel supplied with...

Page 28: ...L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 28 of 158 RK12U PADOSEC RK122a PADO2a COMB CONNECTOR RK124a PADO4a Figure 14 Amplifier Rack Options and Accessories ...

Page 29: ...or return snake 100 m 325 ft length fitted with 84 pin MASS connectors at each end used for connecting CONTROL OUTPUT panel typically located at FOH to MULTI DISTRO panel for signal distribution to the amplifier racks 30 PCMCIA CARDS Contain OEM factory preset data for programming DSP units PCM224V PCM226V and PCM366V for XTA DP224 DP226 and BSS 366 respectively Other approved DSPs are programmed ...

Page 30: ... 6 29 2005 Page 30 of 158 CO24 CONTROL OUTPUT MD24 MULTI DISTRO CO6 CONTROL OUTPUT MC28100 MULTI DOM30 CROSS LINK DOM2 AMP LINK DOMF LINK BREAKOUT DOMM LINK BREAKOUT DOMP LINK EXTEND PCMCIA CARD Figure 15 Signal distribution and cabling ...

Page 31: ...way fill loudspeaker cable 4 conductor 4 mm2 conductor cross section 7 m 20 ft length equipped with 2x NL4 Speakon connectors for connecting dV DOSC or other 2 way fill enclosures to PADO2a or to PADO4a using DO2W and CC4FP 43 SP25 F CABLE 2 way fill loudspeaker cable 4 conductor 4 mm2 conductor cross section 25 m 80 ft length equipped with 2x NL4 Speakon connectors for connecting dV DOSC or other...

Page 32: ...CS V DOSC Manual Version 4 6 29 2005 Page 32 of 158 DO 7 V DOSC LINK CABLE DO7 V CABLE DO25 V CABLE DOSUB CABLE DO10P EXTENSION SP 7 SP7 SP25 DOFILL DO3WFILL DO2W DO3W CC4FP Figure 16 Loudspeaker cabling options ...

Page 33: ... of the isophasic radiating elements is greater than 80 percent of the target radiating area high section All components of a V DOSC array are symmetrically arranged with respect to a plane vertically bisecting the array coplanar symmetry and provide 90 degree horizontal coverage 6 dB points independent of the number of vertically arrayed enclosures Crossover points are 200 Hz between low and midr...

Page 34: ...rovide up to a maximum of 5 5 degrees between enclosures at 0 75 degree angular resolution Cabinets are physically connected while lined up on the floor and the complete array is flown all at once in comparison with other systems where cabinets are flown row by row The only external parts needed are ANGLE STRAPS and SPACER blocks these accessories are used to adjust the angle between enclosures in...

Page 35: ...motor per point for a 4 enclosure array 1 0T motor per point for a 5 to 10 enclosure array 2 0T motor per point for an 11 to 16 enclosure array BUMP2 can also be used for stacking V DOSC In this case the BUMP2 is inverted upside down and the first enclosure of the array is stacked on the bumper Since the depth of the BUMP2 is larger than that of a single enclosure this allows for better front to r...

Page 36: ...coil 9 mm peak excursion capability weatherproof cone body diecast aluminum frame massive vented magnet structure and utilize advanced high temperature adhesives in their assembly Loudspeaker components feature low thermal power compression long term reliability and low distortion output The SB218 is constructed of 24 mm baltic birch and is internally braced with steel corner plates and joints tha...

Page 37: ...each side of the SB218 two per loudspeaker on each side 4 total per SB218 The BUMPSUB flying bar is rated for up to 8 subwoofer enclosures at a 5 1 safety factor Note It is recommended to preattach shackles and fittings to the chains prior to flying Lay the chain out flat and remove any twists Shackles and double stud fittings are then attached every 13 chain links i e with a separation of 11 open...

Page 38: ...an RK124a amplifier rack loaded with 4 x LA48a amplifiers numbered 1 4 from top to bottom nominal impedance loads and amplifier channel assignments when powering a single V DOSC cabinet are 1 x 16 ohms for the high frequency channel Amplifier 1 Channel A 1 x 8 ohms for the mid frequency channel Amplifier 2 Channel A 2 x 8 ohms for both low frequency channels Amplifiers 3 4 Channel A When powering ...

Page 39: ...200 V DOSC LOW SECTION AMPLIFIER V DOSC MID SECTION AMPLIFIER V DOSC HI SECTION AMPLIFIER REC D POWER OUTPUT REC D POWER OUTPUT REC D POWER OUTPUT LOAD REC D LA 48a LOAD REC D LA 48a LOAD REC D LA 48a ohms POWER ohms POWER ohms POWER 2 3000 2900 2 4800 2900 2 0 dB do not use 2 7 2250 2700 2 7 3600 2700 2 7 0 dB 0 dB 4 1500 2300 4 2400 2300 4 3200 2300 0 dB 0 dB 0 dB 5 3 5 3 5 3 2400 1800 0 dB 8 75...

Page 40: ...espectively lines 5 and 6 are assigned to 2 way fill low and high respectively Figure 23 V DOSC PADO2a Amplifier Rack Panel The V DOSC PADO2a amp panel is suitable for use with 2 LA48a power amplifiers and allows for connection of loudspeakers input signal and output signal loop through The panel has a single female 8 pin CA COM connector for loudspeaker connection that is in parallel with 4 x Spe...

Page 41: ...L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 41 of 158 Table 3 PADO4a COMB Wiring Chart Table 4 PADO4a Internal Amp Rack Wiring Chart Figure 24 PADO4a amp rack wiring ...

Page 42: ...L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 42 of 158 Table 5 PADO2a COMB Wiring Chart Table 6 PADO2a Internal Amp Rack Wiring Chart Figure 25 PADO2a amp rack wiring ...

Page 43: ...B channels respectively Using separate COMB connectors for both channels it is possible to assign the A channels and B channels independently When fully loaded with 4 x LA48a plus PADO4a the RK124a rack can power up to 6 x V DOSC 8 x SB218 subwoofers or 12 x dV DOSC In terms of construction the amplifier rack is made of a lightweight aluminum space frame with heavy duty bracing internal shock moun...

Page 44: ...58 4 x LA48a plus PADO4a 4 x LA48a plus 2 x PADO2a Master Rack Slave Rack Figure 27 L ACOUSTICS Amplifier Rack Options a 4x LA48a plus PADO4a b 4x LA48a plus 2x PADO2a c Master Rack with DSP CO6 Control Output 2x LA48a PADO2a d Slave Rack with 2x LA48a PADO2a ...

Page 45: ...nic arc delay processing of subwoofer arrays or for powering passive enclosures SUB T1 signal line 1 SUB T2 signal line 2 SUB T3 signal line 3 SUB T4 signal line 4 SUB T5 signal line 5 SUB T6 signal line 6 For complete details regarding CA COM line assignments PADO2a and PADO4a wiring plus COMB connector wiring please refer to Tables 3 and 5 in the preceding section DSP output channel assignments ...

Page 46: ...ments and cabling for V DOSC presets Operating modes amplifier rack channel assignments and cabling plus loudspeaker enclosure combinations for the L ACOUSTICS RK124a amplifier rack PADO4a plus 4 x LA48a are as follows V DOSC HI V DOSC HI SUB SUB 2W HI 2W HI V DOSC MID V DOSC MID SUB SUB 2W LO 2W LO V DOSC LO V DOSC LO SUB SUB 2W HI 2W HI V DOSC LO V DOSC LO SUB SUB 2W LO 2W LO 3 WAY SUB 2 WAY 3 W...

Page 47: ...ched 1 1 2 2 3 3 etc This helps eliminate potential sources of error due to mispatching and in addition it is not necessary to repatch DSP outputs when changing between stereo 2 way and 3 way presets Operating modes amplifier rack channel assignments and cabling plus loudspeaker enclosure combinations for the L ACOUSTICS RK122a amplifier rack PADO2a plus 2 x LA48a are as follows 2 WAY STEREO PRESE...

Page 48: ... 25 DOFILL DO7 or 25 DOFILL DO7 or 25 DOFILL or or or or DO2W CC4FB SP7 25DO2W CC4FB SP7 25 DO2W CC4FB SP7 25 DO2W CC4FB SP7 25 3 3 dV DOSC ARCS XT 3 3 dV DOSC ARCS XT 3 3 dV DOSC ARCS XT 3 3 dV DOSC ARCS XT 3 WAY STEREO PRESETS RK124 RK124 HI A HI B SUB A SUB B LO A LO B SUB A SUB B SUB A SUB B SUB A SUB B SUB A SUB B SUB A SUB B 3W A SUB A 3W B SUB B DO10P DO3W DO10P DO3W or or DO10P DO10P DO7 o...

Page 49: ...stem application in detail since small and medium systems will adhere to the same channel assignment standards and are considered as subsets of the large scale setup A large scale V DOSC system typically consists of Left Left L L Left L Right R and Right Right R R V DOSC arrays Each of the four arrays can have associated 2 way dV DOSC downfill enclosures and SB218 subwoofers Therefore each L L L R...

Page 50: ... LINK cables and similar connections are performed for the A and D lines to accommodate Left Left and Right Right arrays as necessary Separating signal distribution lines to individual L L L R and R R arrays is also an effective way to avoid potential ground loop problems 1 12 CO6 CONTROL OUTPUT PANEL The CO6 Control Output panel is a scaled down 6 channel version of the 24 channel CO24 panel that...

Page 51: ...andard A lot of engineering and real world testing goes into determining optimum V DOSC presets detailed polar measurements and weighted spatial averaging are used to determine component equalization crossover points and time alignment delays for example As a result V DOSC presets give the user an optimum starting point system tuning should be done using band attenuation subwoofer time alignment a...

Page 52: ... impact dV SUB subwoofers can be added to create a 5 way system X INFRA modes A summary of operating bandwidths for the various presets is given in Table 9 Individual presets are discussed in the following section along with further details concerning LO HI equalization subwoofer time alignment techniques and sub low gain scaling procedures Table 9 SUB LOW OPERATING BANDWIDTH SUMMARY 3 WAY PRESETS...

Page 53: ... earlier 3 WAY STEREO PRESETS 3WX PRESET The 3WX preset features a 30 Hz high pass filter for the V DOSC low section combined with optimized low frequency shelving equalization With the 3WX preset significant LF energy can be obtained from V DOSC itself and for some applications classical music or speech reinforcement V DOSC can be used without additional subwoofers For larger systems there is the...

Page 54: ...ows HI presets BAND PRESET X X AUX INFRA 4W SUB 4 dB 6 dB 6 dB 6 dB LOW 0 dB 0 dB 2 dB 2 dB MID 5 dB 5 dB 5 dB 5 dB HIGH 5 dB 5 dB 5 dB 5 dB Recommended gain scaling procedures for different cabinet ratios are summarized as follows 2 1 V DOSC SB218 ratio scale subwoofer gain by 2 dB or low section by 2 dB 1 5 1 V DOSC SB218 ratio standard gains 1 1 V DOSC SB218 ratio scale low gain by 4 dB Followi...

Page 55: ...gn SB218 peak 1 dip1 peak 2 with V DOSC low section Figure 37 Infra preset time alignment procedure 4W PRESET The 4W preset features an 80 Hz crossover between SB218 subwoofers and the V DOSC low section 4W presets provide a flatter overall response contour that is considered more suitable for classical music or speech reinforcement Although the 80 Hz HPF for the V DOSC low section does not fully ...

Page 56: ...s with negative polarity X PRESET Align SB218 dip1 peak 2 with V DOSC low section Figure 39 X preset time alignment procedure X AUX PRESET The X AUX preset extends the V DOSC low section down to 30 Hz while ground stacked SB218s are run from 25 80 Hz with negative polarity to account for the phase shift due to the overlap in operating bandwidths SB218 25 80 Hz with negative polarity V DOSC low 30 ...

Page 57: ...n For the 5W INFRA preset AUX SUB drive can be implemented using the SB218 DELAY ARC 60 Hz or SB218 LCR 60 Hz presets subs with positive polarity 5W INFRA PRESET Align SB218 peak1 dip2 peak2 with dV SUB V DOSC low section Figure 41 5W Infra preset time alignment procedure 5W X PRESET The 5W X preset features identical operating bandwidths for the V DOSC low section and dV SUBs 30 200 Hz while grou...

Page 58: ...esholds can be lowered to match the rms power handling for individual sections according to the tables below Table 10 Recommended Limiter Threshold Settings LIMITER THRESHOLDS CALIBRATED TO RECOMMENDED POWER AMPLIFICATION 2 x RMS Power Handling for Sub Low Mid and 4 x RMS Peak Power Handling for Hi ENCLOSURE NOM LOAD RMS POWER PEAK POWER REC D POWER EQUIV Vrms dBu EQUIV LIMITER MODEL ohms W W W vo...

Page 59: ...ay A 1 B 27 dV SUB A dV DOSC LO A dV DOSC HI A dV SUB B dV 3W SB118 LO 3 way A 1 B 28 SB118 A dV DOSC LO A dV DOSC HI A SB118 B dV 3W SB118 HI 3 way A 1 B 29 SB118 A dV DOSC LO A dV DOSC HI A SB118 B dV 3WX SB118 LO 3 way A 1 B 30 SB118 A dV DOSC LO A dV DOSC HI A SB118 B dV 3WX SB118 HI 3 way A 1 B 31 SB118 A dV DOSC LO A dV DOSC HI A SB118 B dV 3W SB218 LO 3 way A 1 B 32 SB218 A dV DOSC LO A dV ...

Page 60: ... i AUX dV HI 5 way A 1 B 27 V DOSC LO A V DOSC MID A V DOSC HI A dV DOSC LO A dV DOSC HI A SB218 B V DOSC X AUX dV LO 5 way A 1 B 28 V DOSC LO A V DOSC MID A V DOSC HI A dV DOSC LO A dV DOSC HI A SB218 B V DOSC X AUX dV HI 5 way A 1 B 29 V DOSC LO A V DOSC MID A V DOSC HI A dV DOSC LO A dV DOSC HI A SB218 B V DOSC i ARCS LO 4 way A 2 B 30 SB218 A V DOSC LO A V DOSC MID A V DOSC HI A ARCS LO B ARCS...

Page 61: ...V DOSC LO B 5 1 MODULES V DOSC i LO SB218 A V DOSC LO A V DOSC MID A V DOSC HI A FULL A V DOSC i HI SB218 A V DOSC LO A V DOSC MID A V DOSC HI A FULL A V DOSC 4W LO SB218 A V DOSC LO A V DOSC MID A V DOSC HI A FULL A V DOSC 4W HI SB218 A V DOSC LO A V DOSC MID A V DOSC HI A FULL A V DOSC X LO SB218 A V DOSC LO A V DOSC MID A V DOSC HI A FULL A V DOSC X HI SB218 A V DOSC LO A V DOSC MID A V DOSC HI...

Page 62: ... LO A V DOSC MID A V DOSC HI A SB218 B V DVS SB i H 5 A 1 B 29 SB218 A dV SUB A V DOSC LO A V DOSC MID A V DOSC HI A SB218 B V DVS SB X L 5 A 1 B 30 SB218 A dV SUB A V DOSC LO A V DOSC MID A V DOSC HI A SB218 B V DVS SB X H 5 A 1 B 31 SB218 A dV SUB A V DOSC LO A V DOSC MID A V DOSC HI A SB218 B DV 2W 80 LO 3 A 3 B 32 FULL A dV DOSC LO A dV DOSC HI A FULL B dV DOSC LO B dV DOSC HI B DV 2W 80 HI 3 ...

Page 63: ...contour that is obtained by taking the average of individual 1 3 octave polar plots over a 630 to 12 5k Hz bandwidth and then re formatting the information on a linear scale Unlike a standard polar plot which corresponds to the SPL versus angle referenced to the on axis level at a given frequency the isocontour is more useful for practical coverage prediction Note The 630 12 5k Hz bandwidth is sel...

Page 64: ...istances this tilt in tonal balance is offset by air absorption in open air situations and by both building material absorption and air absorption indoors resulting in spectrally balanced sound over the largest area possible This is an important benefit of V DOSC and WST since both SPL and tonal balance are more even with distance Since the flat array configuration maximizes energy and intelligibi...

Page 65: ...0 x 15 coverage arrays 4 versus 8 enclosures for the 8 enclosure array there will be a 6 dB increase in the unweighted SPL since there are twice as many 15 loudspeaker components and a 3 dB increase in the A weighted SPL since twice as much mid high energy is focused over the same solid angle Finally when comparing the 4 enclosure 90 x 7 5 array versus the 8 enclosure 90 x 15 array it is interesti...

Page 66: ...rmed enclosure site angle impacts The direction of each enclosure is calculated according to the user input angles All angles are referenced with respect to the site angle of the top enclosure which should be aimed at the rearmost part of the audience Cutview sheets are used to shape the vertical isocontour of either V DOSC or dV DOSC arrays to match the audience area Note Cutview sheets V ARRAY1 ...

Page 67: ...he listening level cell 1 2 metres for a seated audience 1 8 metres for standing Figure 45 Defining Cutview Dimensions Although detailed blueprints are not necessarily required the more information that can be obtained on a venue for defining the audience geometry the better Typically plan and section views are available for most venues upon request In situations where such documentation is not av...

Page 68: ...o determine exact array tilt angle limits NOTE Always refer to the MECHANICAL DATA cells in ARRAY 2004 to verify that safe rigging conditions apply with respect to load distribution The designer then chooses the angular spacing between enclosures from the available values in the pull down menu 0 75 1 3 2 3 4 5 5 The red lines show the aiming directions of all enclosures where each line is aligned ...

Page 69: ...gle impacts have equal spacing between them In this case the SPL decreases by 3 dB when doubling the distance see Figure 47 for details Figure 47 a Cutview showing non constant enclosure site angle impact spacing for an 8 enclosure constant curvature V DOSC array 3 degrees between all enclosures Figure 47 b Cutview showing constant enclosure site angle impact spacing for an 8 enclosure variable cu...

Page 70: ...mall gap between the top V DOSC enclosure and the bumper and therefore a difference between site angle 1 and the BUMP2 site angle For this reason always attach a laser and or remote digital inclinometer to the top of V DOSC enclosure 1 not the V DOSC bumper in order to accurately measure the true focus of the top enclosure Also tabulated are continuous A weighted SPL estimates throughout the cover...

Page 71: ...the vertical coverage angle perfectly matches the nominal value Some beaming vertical coverage narrowing may occur at F3 especially when the array is of constant curvature type Further theoretical details related to the calculation of F1 F2 and F3 are given in Appendix 6 Finally MECHANICAL DATA gives an estimate as to the rear versus front motor and rear rotating leg versus BUMP angle strap load d...

Page 72: ...ress on rear and front pins for the top enclosure to dV BUMP attachment not including dV SUB 4 a pick point calculation utility is included for single point hangs 5 angular spacing between enclosures is chosen from the following available values 0 2 3 75 5 5 7 5 for dV ANGLEP1 or 1 3 4 5 6 5 for dV ANGLEP2 Note The site angle for dV DOSC enclosure 1 is equal to the dV BUMP site angle provided that...

Page 73: ...L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 73 of 158 Figure 49 ARRAY 2004 Geometric Data for dV DOSC ...

Page 74: ...0 VU 4 dBu and the Continuous A weighted SPL is tabulated corresponding to the SPL that would be obtained along the isocontour for each array The Console Output Signal can be increased until the amount of headroom available in the system goes to zero and the user has an indication as to the peak A weighted SPL that will be available along the isocontour Further increases in the Console Output Sign...

Page 75: ...L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 75 of 158 CUTVIEW SHEET HORIZONTAL ISOCONTOUR SHEET Figure 50 ARRAY 2004 spreadsheet calculation example ...

Page 76: ...bution Optimum SPL contours are highlighted within the displayed 6 dB coverage pattern filled circles corresponding to the 3 dB coverage pattern in order to facilitate the implementation of multiple source installations For offstage LL RR V DOSC or dV DOSC arrays or distributed sound reinforcement design using coaxial loudspeakers the goal is to align the filled circles in order to have even cover...

Page 77: ...rage predicted in impact mode The A weighted SPL average provides a more strict representation of system coverage since there is more emphasis on higher frequencies while the unweighted mapping is more omnidirectional due to the inclusion of lower frequency information in the average Note For color versions of SOUNDVISION figures see the V DOSC manual PDF file available for download on www l acous...

Page 78: ... 00 29 06 05 V DOSC MANUAL V4 0605 doc 78 158 250 Hz 4 kHz 500 Hz 6 3 kHz 1 kHz 8 kHz 2 kHz 10 kHz Figure 52 Plan view SPL mappings at octave band frequencies for 12 V DOSC 30 metre throw distance enclosures perpendicular to target plane ...

Page 79: ...ANUAL V4 0605 doc 79 158 Impact Coverage Unweighted SPL Map A Weighted SPL Map 1 10 kHz SPL Map Figure 53 Impact coverage and SPL mappings unweighted A weighted 1 10 kHz bandwidth for 12 V DOSC 30 metre throw distance enclosures perpendicular to target plane ...

Page 80: ...terdam Arena NL shows the coverage of different elements of a stadium system consisting of four main arrays 15 V DOSC 3 dV DOSC four distributed front fill arrays 3 dV DOSC one centre cluster 6 dV DOSC eight distributed balcony fill arrays 6 dV DOSC Figure 54a Stadium example rear perspective view of full system impact coverage Figure 54b Stadium example plan view of full system impact coverage LL...

Page 81: ...DOSC MANUAL V4 0605 doc 81 158 FULL SYSTEM FOH OFFSTAGE FILL LL L R RR FOH SYSTEM L R BALCONY FILL SYSTEM 8 x 6 dV DOSC OFFSTAGE FILL SYSTEM LL RR FRONT FILL SYSTEM 4 x 3 dV DOSC Figure 55 Stadium example rear perspective view of 1 10 kHz SPL Mappings ...

Page 82: ...Palais Omnisport de Paris Bercy POPB Paris France shows the coverage of different elements of an arena system consisting of two main arrays 15 V DOSC 3 dV DOSC two offstage fill arrays 12 dV DOSC eight distributed front fill enclosures 112XT Figure 56 Arena example rigging plot Figure 57 Arena example plan view of full system impact coverage ...

Page 83: ...C Manual Version 2 00 29 06 05 V DOSC MANUAL V4 0605 doc 83 158 Figure 58 Arena example rear perspective view of full system impact coverage Figure 59a Arena example rear perspective view of full system SPL map 1 10 kHz ...

Page 84: ...COUSTICS V DOSC Manual Version 2 00 29 06 05 V DOSC MANUAL V4 0605 doc 84 158 Full System dV DOSC Offstage LL RR FOH L R 112XT Front Fill System Figure 59b Arena example plan view of 1 10 kHz SPL mappings ...

Page 85: ...stem trim height should be selected to provide a 4 1 ratio between the throw distances to the furthest and closest members of the audience Such a trim height tends to make it easier to satisfy WST Condition 4 and thus obtain optimum SPL distribution Offstage coverage is another consideration when selecting array trim height in general the best results are obtained when the top V DOSC enclosure has...

Page 86: ... directly in front of the system will shadow the following rows acoustically An additional technique to avoid build up for the closest members of the audience is to install the system further upstage the initial distance attenuation loss to the first few rows will help provide better SPL distribution throughout the entire audience without the need to attenuate the mid or high sections of lower enc...

Page 87: ... be selected by considering the on axis cutview only always consider the audience coverage off the main axis especially from 35 to 45 on the offstage side It is important to check that you are not lacking in offstage coverage and require additional fill systems see Multiple Arrays It is also common to have two sections of the audience area that have different slopes for example the transition betw...

Page 88: ...ge These effects are due to the path length difference interference effects that are inherent in any left right system which in turn produce frequency and position dependent peaks and dips Tradeoffs Between Intelligibility and Stereo Imaging The left right configuration has the advantage of being able to reproduce effects of spatialization and localization The area over which these effects is audi...

Page 89: ...ys panned offstage up to 20 degrees for speech reinforcement L R arrays can be panned offstage up to 70 degrees to optimize coverage and intelligibility For theatrical sound reinforcement the 120 degree coverage of dV DOSC is well suited to centre cluster applications since there is a good match between C system coverage and overall L R coverage for the typical 12 15 metre L R array separation tha...

Page 90: ...dible comb filtering interaction is lessened since the overlap region between the two arrays is reduced In some situations more overlap may be desirable and cross panning arrays will help provide stereo to a greater portion of the audience while de correlating the signals between adjacent arrays to further reduce audible interference effects i e arrays can be run in cross panned stereo and fed as ...

Page 91: ...can cover any type of audience and an additional advantage of multiple arrays is improved resistance to wind effects in open air situations Beyond the basic solution of coverage problems multiple source arrays open up many possibilities for creating a spatial soundscape thus providing a powerful tool for sound design and creativity see the example below Figure 68 Stereo dV DOSC offstage fill syste...

Page 92: ...me applications subwoofers are used as an effect and are not driven with the same signal as the V DOSC system separate auxiliary send The other option is to use subwoofers as a low frequency extension of the V DOSC array and drive subs with the same signal 4 way mode All presets 4W INFRA X X AUX will function with aux sub drive or in 4 way mode however the user should be aware of the operating ban...

Page 93: ... Figure 69 Flown V DOSC and ground stacked subwoofer configurations As illustrated in Figure 70 for flown V DOSC and ground stacked subwoofer configurations time alignment of subwoofers is required due to the geometric path difference between the two systems The distance from the measurement microphone to the subwoofers is dSUB while the distance to the flown V DOSC system dV DOSC dSUB PATH DIFFER...

Page 94: ... radiated by the flown V DOSC system due to the 80 Hz high pass filter In order to benefit from the available resources of the V DOSC low section the INFRA preset is recommended An additional benefit of the INFRA preset is that time alignment is more forgiving for a greater part of the audience due to the longer wavelengths at 60 Hz and subjectively the subs become more of a delocalized effect due...

Page 95: ... Improved low frequency summation impact and throw Improved time alignment since the physical path length difference problem of ground stacked subwoofers versus flown V DOSC is no longer an issue Overall this improves low frequency summation and coherency Elimination of local low frequency buildup for the audience down front in the first few rows Adding several ground stacked subwoofers per side o...

Page 96: ...art and used as part of a distributed front fill system see Fig 78f A central line array of SB218s will radiate omnidirectionally into half space vertically this is of interest for indoor venues in order to obtain low frequency impact throughout the tribune section of the audience Horizontal coverage of the central line array can be improved with additional electronic delay processing see Section ...

Page 97: ...ns and basic guidelines are made in the following Figures 75 a b c and d show techniques for optimizing low frequency tonal balance over the audience while 75 e shows a non recommended configuration In Figure 75 a ground stacked L R subwoofers are arranged in a block with minimum frontal surface area and are physically separate from the flown V DOSC arrays either INFRA 4W or X AUX presets are reco...

Page 98: ...al Version 4 6 29 2005 Page 98 of 158 a L R subwoofer array blocks b L R column line arrays c L Wrap L R subwoofer arrays d Curved L R subwoofer arrays e L R horizontal line arrays Figure 75 L R Subwoofer arraying techniques ...

Page 99: ...rption this problem is likely to occur with any ground stacked configuration A good technique for controlling the directivity of a central ground stacked horizontal line array is to use delay processing to electronically arc the array Electronic delay processing in this manner will decouple sections of the array so that tonal balance is improved up close while at the same time low frequency covera...

Page 100: ...system equals the SPL from the ground stacked subwoofers iii duplicate the time alignment settings for R subwoofers and FOH R iv if applicable time align LL and RR to L and R respectively using a measurement location in a representative location where the coverage of the main and off stage fill systems overlap Figure 78 b shows a hybrid ground stacked LR flown C configuration In this case a stereo...

Page 101: ...a Ground stacked LCR b Ground stacked L R Flown C c Flown L R ground stacked C d Flown L R stereo infill C e Flown L R centre line array with electronic delay processing f Flown L R distributed ground stacked subwoofers Figure 78 LCR Subwoofer arraying techniques ...

Page 102: ... can be applied to compensate for the physical placement of the centre line array and time align the system with the instrument backline kick drum monitor sidefills or monitor front line as desired This predelay is also applied to the relative arc delays T2 T3 and T4 that are calculated based on their physical XY coordinates Once electronic delay processing has been applied to all subwoofer arrays...

Page 103: ...anual Version 4 6 29 2005 Page 103 of 158 Figure 80 Geometric coordinates for the SUB ARC utility spreadsheet in ARRAY2004 Figure 81 Large format arena configuration 4 delay taps Rammstein World Tour 2004 5 Black Box Music ...

Page 104: ...Version 4 6 29 2005 Page 104 of 158 Figure 82 Large format open air festival configuration Festival of Humanity France Potar Hurlant Figure 83 Large format stadium configuration Red Hot Chili Peppers 2004 European Tour Rat Sound ...

Page 105: ... 110 degree K LOUVER setting or dV DOSC will provide adequate coverage for the closest members of the audience however image localization and coverage can be further enhanced with the addition of a dedicated front fill system Front fill can be provided via stacked stereo infill systems using dV DOSC ARCS or KUDO loudspeakers Alternatively a distributed approach can be adopted using dV DOSC or MTD ...

Page 106: ...gure 85 Flown offstage fill system options As discussed in Section 3 1 stacked systems improve image localization for the audience by lowering the perceived image to stage level and geometrically a stacked system can provide more extended vertical coverage than a flown system For these reasons stacked offstage fill systems or a hybrid flown stacked approach can be of interest for arena sound reinf...

Page 107: ...nd the delay For example main L R V DOSC arrays can be focused to provide coverage up to 120 metres and delay positions installed at 90 metres and focused to provide coverage from 100 150 metres 3 Time alignment of delays should be performed at a measurement point located on the axis of the delayed source and the reference source If the delay time is set so that the two sound waves arrive at the s...

Page 108: ...8 Figure 88 Flown and stacked delay systems sound design D Tramontani A Francais resp Figure 89 Stacked dV DOSC delay system Dream Concert 2002 sound design Ki Sun Choi Seoul Sound Figure 90 Flown V DOSC delay system Radiohead Oxford 2003 sound design F Bernard ...

Page 109: ...ower the height adjustment blocks to the minimum position Mount the screwjacks on the corners of BUMP2 by sliding the blocks into the locating slots on BUMP2 and then lower the screwjacks Note For greater stability when tilting the stacked system downwards the front pair of screwjacks can be omitted and the front of BUMP2 laid directly on the stacking surface Conversely when tilting the system upw...

Page 110: ...erance variations in enclosure construction and spacer block placement Use a digital inclinometer to determine the effect of these tolerance variations and minimize their impact The same procedure is followed for all other enclosures of the array until stacking is completed NOTE it is easier to place spacer blocks between enclosures as the array is built instead of inserting them afterwards The co...

Page 111: ...nd if necessary use plywood sheets or steel plates under individual screwjack feet in order to help distribute the load The maximum downward or upward tilt angle of the bumper is 12 degrees When stacking on scaffold platforms install 2 rear screwjacks only for downwards tilt and ratchet strap the BUMP2 to the platform for improved stability see Figure 91 Figure 91 Stacked V DOSC offstage fill syst...

Page 112: ... of 1 05 meters 43 and the desired onstage rotation angle for the array Alternatively three points can be used along with a swivel shackle for connecting the delta plate to the rear BUMP2 point this allows for pan adjustment of the flown array see Fig 19 Rigging points should be equipped with 0 5T chain motors for a 4 enclosure array 1 0T motors for a 5 to 10 enclosure array 2 0T motors for an 11 ...

Page 113: ...L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 113 of 158 Figure 93 SOUNDVISION installation report data Figure 94 ARRAY 2004 installation data ...

Page 114: ...is convenient to perform a last minute check to confirm that all values are correct In addition when the array is flown all angle strap labels will be visible from the rear this is useful as a check and makes for a cleaner installation see Fig 95 i Connect all enclosures to the amplifier racks using V CABLEs and V LINK jumpers between enclosures for parallel operation NOTE it is best to connect ca...

Page 115: ...cally making it easier to attach angle straps This is acceptable for smaller systems for larger arrays it is recommended to fly the system flat so that the load distribution between front and rear motors is equal As a reference attach angle straps from flytrack hole 3 to hole 3 between cabinets to provide the correct inter enclosure angles When using the 0 75 degree angle strap to obtain 5 5 degre...

Page 116: ...L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 116 of 158 a b c d e f g h ...

Page 117: ...L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 117 of 158 i j k l m n o p ...

Page 118: ...L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 118 of 158 q r s t u v w x ...

Page 119: ...L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 119 of 158 y z aa bb cc dd Figure 95 Photo sequence showing the steps involved in flying V DOSC ...

Page 120: ...ferent i e if the system is pointing upwards or downwards Note DO NOT OVERTIGHTEN RATCHET STRAPS especially if the array is tilted upwards In general the goal is to simply take the slack out of the angle straps Overtightening ratchet straps can increase the angle between enclosures up to 1 additional degree per cabinet by closing the gap at the rear of the enclosures similar to what happens for a ...

Page 121: ... Since front and rear chain motors can run at different speeds once you are at trim you must reset the focus angle of the array using either the remote inclinometer or by referring to a laser mounted on the top enclosure Repeat this process to ensure that the vertical coverage and focus of Left and Right arrays are exactly matched Trim and Site Angle Adjustments After the ratchet straps have been ...

Page 122: ...ats of the audience when the light can be seen through the gap separating the first and the second enclosures the angle of the array is correct Under daylight conditions outdoors the trim angle can be visually checked from the rearmost audience section flashlight not required If the gap between the top and second enclosures is clearly visible then the focus is correct Note Bushnell Rangefinder gla...

Page 123: ...ressure levels Hearing loss or damage can occur with prolonged exposure to high SPLs Please operate your system responsibly at all times An SPL meter on the mix console is highly recommended as a reference Prior to describing system operation and tuning procedures subjective criteria and system setup objectives are first considered 5 1 SYSTEM TONAL BALANCE V DOSC and dV DOSC presets have been spec...

Page 124: ...gineer At lower frequencies array coupling and room related effects will typically require equalization in the 120 300 Hz range and it is important to walk the room and or perform spatial averaging measurements to ensure that system equalization adjustments are valid throughout the coverage region of a given array Due to system phase coherency small equalization adjustments are highly audible i e ...

Page 125: ...l shape of the frequency responses at these locations is similar before proceeding to perform detailed equalization Measurement Instruments Equalization adjustments can be performed using a real time analyzer RTA however more sophisticated measurement tools such as MLSSA WinMLS TDS SMAART or SpectraFOO allow the user to obtain better results provided these instruments are properly used of course C...

Page 126: ...surement systems such as MLSSA WinMLS and TDS allow the user to apply a time window to remove such reflections from the measurement however this can be at the expense of low frequency resolution depending on the length of the time window When placing the microphone on the floor if the floor is absorbent e g thick carpet or grass in open air situations the measured response may display a high frequ...

Page 127: ...at the back of the venue Perform any required trim and angle adjustments if necessary 5 Using your measurement system at the mix position compare Left versus Right polarity and frequency response channel by channel as a final system check All responses should be identical within 1 dB except for the high band where larger deviations are acceptable 2 to 3 dB Beware of wind effects which can affect H...

Page 128: ...spatial average of all measurement locations If a given measurement location is in close agreement with the spatial average re place the microphone at this location and use this as a reference for conducting system eq Another useful approach invert the spatially averaged measurement curve then use this as a target while electrically sweeping the equalizer Alternatively sweep the system equalizer w...

Page 129: ...ntenance procedures include refoam grilles repaint cabinets replace stacking runners replace protective covers for rotating legs 6 2 Recommended Maintenance Tools APPLICATION V DOSC SERVICE TOOLS V DOSC SERVICE TOOLS USA only As Required 2 Phillips screwdriver 2 Phillips screwdriver LF Speaker Mount 5 mm hex key 3 16 allen head socket driver hex key LF Speaker Terminals 13 wrench 13 wrench MF Spea...

Page 130: ...tor Line 19 conductor CC 19B FF Speakon Connector Line 4 conductor CC 4 F Speakon Connector Panel Mount 4 conductor CC 4 ER COMB Connector 25 pin CC 25SUBDM COMB Connector 37 pin CC 37SUBDM DKIT upgrade kit for 1 x COMB Connector DKIT Accessories Locking Pin 4 5 mm diameter for U Pins CA GOUP45 Lanyard for CA GOUP45 CA_EL45 Locking Pin 6 mm diameter for dolly board CA GOUP6 Lanyard for CA GOUP6 CA...

Page 131: ...ps and set site angle Laser Levels Laserline XPRO or equivalent one for each array required FOR DISTANCE MEASUREMENTS Laser Rangefinder Binoculars Bushnell Yardage Pro or equivalent Laser Rangefinder Leica Disto Classic or Hilti PD22 or equivalent 20 m 50 ft tape measure for setting array trim height PORTABLE COMPUTER SOUNDVISION Excel for ARRAY 2004 WinMLS SMAART or MLSSA measurement software sou...

Page 132: ... main axis 70 3 dB points symmetrical about main axis Vertical Coverage Angle defined by the array System Data Continuous SPL Continuous SPL flat array maximum curvature 1 enclosure 134 dB 134 dB 2 enclosures 140 dB 139 dB 5 degrees vertical coverage 4 enclosures 146 dB 143 dB 15 degrees vertical coverage LF 2 x 15 weather resistant loudspeaker 3 voice coil bass reflex MF 4 x 7 weather resistant l...

Page 133: ...L ACOUSTICS V DOSC Manual Version 4 6 29 2005 Page 133 of 158 Figure 97 V DOSC Enclosure Line Drawing ...

Page 134: ...inuous 136 dB peak 2 enclosures 136 dB continuous 142 dB peak 4 enclosures 142 dB continuous 148 dB peak Impedance 4 ohms Components 2 x 18 cone bass reflex 4 5 edgewound copper voice coil Material Baltic birch plywood Sealed screwed cabinet construction Finish Maroon gray Grill Black epoxy perforated steel with acoustically transparent foam Features Integrated flying hardware handles Dimension Wx...

Page 135: ...Manual Version 4 6 29 2005 Page 135 of 158 7 3 RIGGING STRUCTURES V DOSC BUMP2 Bumper Dimension WxHxD 1262 mm x 140 mm x 1100 mm 49 5 8 x 5 4 8 x 43 3 8 Weight 61 5 kg 135 6 lbs Figure 99 V DOSC Flying Bumper Line Drawing ...

Page 136: ... 61 493 1087 5 540 61 601 1325 6 648 61 709 1563 7 756 61 817 1801 8 864 61 925 2039 9 972 61 1033 2277 10 1080 61 1141 2515 11 1188 61 1249 2754 12 1296 61 1357 2992 13 1404 61 1465 3230 14 1512 61 1573 3468 15 1620 61 1681 3706 16 1728 61 1789 3944 SB218 BUMPSUB Rigging Bar Dimension WxHxD 1420 mm x 140 mm x 40 mm 55 7 8 x 5 4 8 x 1 5 8 Weight 12 kg 26 5 lbs Figure 100 SB218 Flying Bar Line Draw...

Page 137: ...STU 11 A STU 12 C5 C STU 12 C STU 13 B4 B ABC 13 B ABC 14 D4 D ABC 14 D ABC 15 B3 B DEF 15 B DEF 16 D3 D DEF 16 D DEF 17 B2 B GHJ 17 B GHJ 18 D2 D GHJ 18 D GHJ 19 B1 B KLM 19 B KLM 20 D1 D KLM 20 D KLM 21 B6 B NPR 21 B NPR 22 D6 D NPR 22 D NPR 23 B5 B STU 23 B STU 24 D5 D STU 24 D STU 25 REMOTE OUT M 25 REMOTE IN F 26 REMOTE IN F 26 REMOTE OUT M 27 REMOTE OUT M 27 REMOTE IN F 28 REMOTE IN F 28 REM...

Page 138: ...6 2 A P 2 WAY FILL HF LEFT LEFT 29 GND A6 1 A N 2 WAY FILL HF LEFT LEFT 28 RED A5 3 A U 2 WAY FILL LF LEFT LEFT 27 YELLOW A5 2 A T 2 WAY FILL LF LEFT LEFT 26 GND A5 1 A S 2 WAY FILL LF LEFT LEFT 25 RED B4 3 B C HF LEFT 24 ORANGE B4 2 B B HF LEFT 23 GND B4 1 B A HF LEFT 21 GREEN B3 3 B F MID LEFT 20 BLUE B3 2 B E MID LEFT 19 GND B3 1 B D MID LEFT 18 GREEN B2 3 B J LF LEFT 17 BROWN B2 2 B H LF LEFT ...

Page 139: ...BROWN C5 2 C T 2 WAY FILL LF RIGHT 26 GND C5 1 C S 2 WAY FILL LF RIGHT 25 GREEN D4 3 D C HF RIGHT RIGHT 24 WHITE D4 2 D B HF RIGHT RIGHT 23 GND D4 1 D A HF RIGHT RIGHT 21 GREEN D3 3 D F MID RIGHT RIGHT 20 YELLOW D3 2 D E MID RIGHT RIGHT 19 GND D3 1 D D MID RIGHT RIGHT 18 GREEN D2 3 D J LF RIGHT RIGHT 17 ORANGE D2 2 D H LF RIGHT RIGHT 16 GND D2 1 D G LF RIGHT RIGHT 15 WHITE D1 3 D M SUB RIGHT RIGHT...

Page 140: ... WAY FILL LF RIGHT 27 BROWN C T 2 WAY FILL LF RIGHT 26 GND C S 2 WAY FILL LF RIGHT 25 GREEN D C HF RIGHT RIGHT 24 WHITE D B HF RIGHT RIGHT 23 GND D A HF RIGHT RIGHT 21 GREEN D F MID RIGHT RIGHT 20 YELLOW D E MID RIGHT RIGHT 19 GND D D MID RIGHT RIGHT 18 GREEN D J LF RIGHT RIGHT 17 ORANGE D H LF RIGHT RIGHT 16 GND D G LF RIGHT RIGHT 15 WHITE D M SUB RIGHT RIGHT 14 YELLOW D L SUB RIGHT RIGHT 13 GND ...

Page 141: ...A P 2 WAY FILL HF LEFT LEFT 29 GND A N 2 WAY FILL HF LEFT LEFT 28 RED A U 2 WAY FILL LF LEFT LEFT 27 YELLOW A T 2 WAY FILL LF LEFT LEFT 26 GND A S 2 WAY FILL LF LEFT LEFT 25 RED B C HF LEFT 24 ORANGE B B HF LEFT 23 GND B A HF LEFT 21 GREEN B F MID LEFT 20 BLUE B E MID LEFT 19 GND B D MID LEFT 18 GREEN B J LF LEFT 17 BROWN B H LF LEFT 16 GND B G LF LEFT 15 WHITE B M SUB LEFT 14 BLUE B L SUB LEFT 13...

Page 142: ... Pm resulting from the addition of the two speakers at point M is calculated as If both sources radiate the same pressure P and the real part of the complex sound pressure at M is considered at time t t1 d1 c the expression simplifies to where the path length difference d2 d1 δd From the simplified expression it is seen that the second source causes a frequency dependent phase shift given by δϑ 2π...

Page 143: ...hen considering multiple V DOSC arrays since in effect the main and offstage V DOSC arrays act as 2 coherent sound sources When a separation of 6 8 metres is maintained between the 2 V DOSC arrays this shifts the first octave wide cancellation seen in Figure 102 fo down to approximately 15 25 Hz and this cancellation becomes inaudible since it is shifted below the operating bandwidth of the V DOSC...

Page 144: ...s arriving at an observation point M is δd 2n 1 λ 2 where n is an integer We can therefore conclude that discrete sound sources produce a totally incoherent wavefront due to comb filtering effects as soon as the path length difference between the sources to a given point M is greater than λ 2 half a wavelength Let s consider a line array or column of discrete sound sources providing almost equal p...

Page 145: ... constructively at M Maintaining the same frequency and therefore the same ring spacing and moving the position M closer to the array means that the radius of curvature of the rings is decreased therefore fewer sources fall within the ring Moving the listener position further away the radius of curvature increases and more sources fall within the constructive ring Now let s draw all circles with r...

Page 146: ...e of the array for this given frequency The goal for the sound designer is to clearly identify an area where the wavefront is coherent not just for a given frequency but for the whole operating bandwidth of the sound source How can we achieve this goal The first step is to minimize the distance between sound sources By doing this for a given frequency we have a better chance of maximizing the numb...

Page 147: ...front of the sound sources into a flat isophasic ribbon with no more than 20 discontinuity of the radiating area In the AES journal paper Wavefront Sculpture Technology these two WST Criteria were re derived based on an intuitive approach using Fresnel analysis and in addition it was shown that The deviation from a flat wavefront must be less than λ 4 at the highest operating frequency this corres...

Page 148: ... 13 m Figure 108 Front view of V DOSC array and vertically stacked DOSC waveguides We have to fulfill the first WST criterion at higher frequencies since it is not possible to satisfy the second criteria as wavelengths are too small to have the acoustic centres of high frequency compression drivers with less than λ 2 separation over the entire HF bandwidth 1 3 18 kHz This is achieved by mounting a...

Page 149: ...al times of every possible wave path to be the same value at the rectangular exit of the device The internal plug is a truncated conical piece that looks like a tomahawk This plug and its outer housing are precisely constructed according to specific ratios between depth height and cone angle in order to produce a flat constant phase wavefront Tight manufacturing tolerances are obtained through the...

Page 150: ...NDRICAL near field Fresnel and SPHERICAL far field Fraunhofer zones can be expressed as where H height of the array in m F frequency expressed in kilohertz dborder extension of the cylindrical soundfield with respect to the source in m In the Fresnel region the wavefront is cylindrical and expands only in the horizontal dimension nominally 90 for V DOSC The height of the wavefront is equal to the ...

Page 151: ... H 5 4m Dv deg 63 124 72 125 125 53 34 250 125 53 26 17 500 53 26 13 8 5 1k 26 13 6 4 4 2 2k 13 6 4 3 2 2 1 4k 6 4 3 2 1 6 1 1 8k 3 2 1 6 0 8 0 5 16k 1 6 0 8 0 4 0 3 At 1 kHz a flat V DOSC array of 8 enclosures H 3 6 m radiates a wavefront that is cylindrical over a distance of 19 m Beyond this distance the wavefront becomes spherical and the coverage angle is 6 i e the wavefront at 1 kHz is defin...

Page 152: ...ual to 2 3 of N x A This defines the minimum vertical coverage angle and is termed the beaming frequency F3 The vertical coverage angle then increases back to the nominal value at F2 defined by For frequencies higher than F2 the vertical coverage angle is constant For example a constant curvature array of 8 V DOSC with 4 between all enclosures provides constant 28 vertical coverage above F2 794 Hz...

Page 153: ...stances given in the table below ARF is set to 80 since this is the limit for satisfying WST Condition 1 and the maximum angles are calculated for two minimum listener distances dmin 10 or 20 metres Table 22 WST Criteria Number 5 For front loaded 15 systems such as V DOSC it is seen that the maximum allowed angle is 4 8 degrees for dmin 10 m and 6 0 degrees for dmin 20 m This explains why the maxi...

Page 154: ...fly track sections can be laid out according to the indicated double stud fitting plunger plunger spacing to provide a fast test jig for checking angle strap values and labeling When testing angle straps they should fit the test jig with a tolerance variation of 1 mm to 2 mm Note For full details on angle strap calibration issues refer to Technical Bulletin TB0402 Angle Straps Figure 114 Angle str...

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