Version 3.
FOREWORD This manual is intended for sound engineers who are responsible for the installation and operation of the dV-DOSC sound reinforcement system. It is also intended to provide interested sound designers, consultants and installers with information regarding the fundamental principles of Wavefront Sculpture Technology® and how these principles are embodied within dV-DOSC.
TABLE OF CONTENTS INTRODUCTION .....................................................................................................................................9 WAVEFRONT SCULPTURE TECHNOLOGY™ FUNDAMENTALS .........................................................................9 The Sound Reinforcement Problem ..............................................................................................................9 Wavefront Sculpture Technology Background.........................................
Optimization Procedure..............................................................................................................................66 dV-DOSC Single Point Hang Utility .....................................................................................................................67 dV-DOSC Downfill / Upfill Simulation.........................................................................................................68 Output Data ...................................................
5. MAINTENANCE AND INSTALLATION TOOLS ...........................................................................137 5.1 Recommended Maintenance Procedures ....................................................................................................137 5.2 Recommend Maintenance Tools.................................................................................................................137 5.3 Spare Parts ........................................................................................
Figure 42: Horizontal dV-DOSC isocontour........................................................................................................60 Figure 43: Defining Cutview Dimensions.............................................................................................................64 Figure 44: Parameters for the ROOM DIM Utility Sheet in ARRAY ....................................................................64 Figure 45: ARRAY 2004 Geometric Data for dV-DOSC..................................
LIST OF TABLES Table 1: Maximum rated dV-SUB / dV-DOSC combinations - with extension bar .............................................36 Table 2: Maximum rated dV-SUB / dV-DOSC combinations - without extension bar ........................................36 Table 3: dV-DOSC Power Handling and Recommended Power Amplifier Ratings.............................................37 Table 4: L-ACOUSTICS LA24a MLS Settings for use with dV-DOSC.................................................................
INTRODUCTION The small ''d'' in dV-DOSC refers to the mathematical terminology for the derivative function since dVDOSC can be considered as a derivative of V-DOSC. dV-DOSC provides the same benefits of Wavefront Sculpture Technology as V-DOSC except in a much smaller format. We hope this manual will help you to understand the basic theoretical principles behind how the dVDOSC system works.
Figure 1: Wavefield interference for a conventional sound reinforcement system compared to a sculptured dV-DOSC wavefield Wavefront Sculpture Technology Background As early as 1988, a preliminary system named "Incremental" had proven the feasibility of Wavefront Sculpture Technology. From this experimental concept, further theoretical research was conducted by Professor Marcel Urban and Dr.
Figure 2: Wavefront Sculpture Technology Criteria 1 and 2 Additional conditions were published in the Audio Engineering Society journal paper ''Wavefront Sculpture Technology'', JAES Vol. 51, No. 10, October 2003.
First V-DOSC, Now dV-DOSC V-DOSC is the first loudspeaker system designed based on the principles of WST and can be considered as the first modern generation line source array. Note: the “V” in V-DOSC refers to the Vshaped acoustic lens configuration employed for the mid and high frequency sections. It should be stressed that there is a big difference between a WST-based line source array (such as V-DOSC, dVDOSC, KUDO or ARCS) and other line arrays on the market today.
The internationally patented1 DOSC waveguide is the core technology contained in dV-DOSC. Essentially, the DOSC waveguide allows fulfilment of the first WST condition for frequencies higher than 800 Hz, i.e., the wavefronts generated by individual DOSC waveguides are planar and their combined radiating surface area accounts for at least 80% of the total surface area.
Figure 3: Cylindrical versus spherical wave propagation Aside: Conventional modeling techniques cannot accurately simulate WST-based systems such as ARCS, KUDO, dVDOSC 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. V-DOSC and dV-DOSC DLLs are available for download on: www.l-acoustics.
Summary of dV-DOSC Applications As a full range two-way system, dV-DOSC can be used for speech reinforcement in corporate applications, houses-of-worship, television or theatrical productions. In some cases, dV-DOSC can be used standalone for limited bandwidth musical reinforcement (note: for extended bandwidth sound reinforcement, the use of subwoofers is recommended). Another possibility is the use of dV-DOSC in A/B systems for theatre.
dV-DOSC TRAINING AND QUALIFICATIONS V-DOSC and dV-DOSC are innovative systems which are based on a completely new approach to sound reinforcement. These systems can provide predictable results to the extent that no other existing system is capable of, however, achieving the desired results requires following a methodical procedure which may at first seem unusual to some sound designers and engineers.
1. THE dV-DOSC SYSTEM STANDARD dV-DOSC is a complete, self-contained FOH sound reinforcement system consisting of dV-DOSC enclosures and accessories, rigging hardware, dV-SUB, SB118 or SB218 subwoofers, approved digital signal processors with OEM factory presets, L-ACOUSTICS LA24a or LA48a power amplifiers, power amplifier racks, PADO2a or PADO4a panels, CO6 or CO24/MD24 signal distribution panels, loudspeaker and signal distribution cables.
Figure 5: dV-DOSC 3-way system configuration
Figure 6a: dV-DOSC 4-way system configuration (option 1 COMB connector / cabling) dV-DOSC dV-SUB Manual V3.
Figure 6b: dV-DOSC 4-way system configuration (option 2 COMB connector / cabling) dV-DOSC dV-SUB Manual V3.
1.1 dV-DOSC SYSTEM COMPONENTS LOUDSPEAKER ENCLOSURES dV-DOSC Active 2-way loudspeaker enclosure, meeting Wavefront Sculpture Technology criteria, with coplanar symmetric arrangement of loudspeaker components FLIGHT-dV Flight case for transport of three dV-DOSC enclosures dV-DOSC FLIGHT-dV Figure 7: dV-DOSC plus accessories FLIGHT-dV RIGGING ACCESSORIES dV-BUMP Bumper for rigging dV-DOSC and/or dV-SUB.
dV-ANGLEP1, dV-ANGLEP2 Rear angle bar used to form convex (positive curvature) arrays. Available angles include: P1: 0, 2, 3.75, 5.5, 7.5 degrees P2: 1, 3, 4.5, 6.5 degrees dV-ANGLEN Rear angle bar used to form concave (negative curvature) arrays or for downwards tilt of stacked dVDOSC systems. Available angles include: 0, -2, -3.75, -5.5 and -7.5 degrees dV-ANGLESS Front and rear angle bar used to rig dV-SUB to dV-SUB (i.e., SS=sub to sub) dV-ANGLESD Front angle bar used to rig dV-DOSC to dV-SUB (i.e.
SUBWOOFER ENCLOSURES dV-SUB Dual-vented bandpass-loaded, triple 15” subwoofer for high SPL, low frequency extension. Optional removable front dolly (not shown) recommended for touring applications. dV-SUBCOV Protective cover for dV-SUB enclosures (comes in pairs) SB118 Dual-vented bandpass-loaded, single 18’’ subwoofer for high SPL, extended bandwidth. Optional removable front dolly (not shown) recommended for touring applications.
SUBWOOFER RIGGING ACCESSORIES BUMPSUB Flying bar for rigging up to eight SB218 enclosures deep in a vertical line array dV-BUMP2 Flying bumper for rigging up to six dV-SUB enclosures deep in a vertical line array (also an alternative to dV-BUMP for rigging dV-DOSC and/or dV-SUB) BUMPSUB dV-BUMP2 Figure 10: Subwoofer Rigging Accessories AMPLIFICATION L-ACOUSTICS LA24a Compact, light weight two-channel power amplifier (2 rack units, 10 kg), 1100 watts per channel into 8 ohms, 1500 watts per channel into 4
AMPLIFIER RACKS RK12U 12 rack unit amplifier rack (empty). Light-weight aluminum space frame construction, internal shock mounting, standard rack rails, provision for rear support of amplifiers, transparent lexan doors that store inside the rack, high impact resistance polyethylene cover (no external case required). Recessed Aeroquip flytrack sections for flown applications.
PADOSEC RK12U PADO2a COMB CONNECTOR RK122a PADO4a RK124a Figure 12: Amplifier Rack Options and Accessories dV-DOSC dV-SUB Manual V3.
SIGNAL DISTRIBUTION AND CABLING CO6 CONTROL OUTPUT PANEL Control Output Panel for use with a single 2 in x 6 out (or 3 x 6) digital signal processor (DSP) to create a compact, modular drive rack or for mounting in RK12U amplifier racks along with amplifiers and a DSP unit for standalone master rack packaging.
MD24 MULTI DISTRO CO24 CONTROL OUTPUT CO6 CONTROL OUTPUT MC28100 MULTI DOM2 AMP LINK DOM30 CROSS LINK DOMF LINK BREAKOUT DOMM LINK BREAKOUT PCMCIA CARD DOMP LINK EXTEND Figure 13: Signal distribution and cabling dV-DOSC dV-SUB Manual V3.
LOUDSPEAKER CABLING DO7 Loudspeaker cable, 8 conductor, 4 mm2 conductor cross-section, 7 m (20 ft) length, equipped with male/female CA-COM connectors (for use with DOFILL or DO3WFILL) DO25 Loudspeaker cable, 8 conductor, 4 mm2 conductor cross-section, 25 m (80 ft) length, equipped with male/female CA-COM connectors (for use with DOFILL or DO3WFILL) DOSUB SUB CABLE Subwoofer loudspeaker cable, 5 m (16 ft) length, with male 8 pin CA-COM connector and four NL4 Speakon connectors (for connecting 4 x subwoofers
DO7 DO25 DOSUB CABLE DO10P EXTENSION SP7 SP25 CC4FP SP.7 DOFILL DO3WFILL DO2W DO3W Figure 14: Loudspeaker cabling options dV-DOSC dV-SUB Manual V3.
1.2 dV-DOSC SPECIFICATIONS Figure 15: dV-DOSC Enclosure - Front and Rear Views dV-DOSC contains two 8" loudspeakers (connected in parallel) and a 1.4" exit compression driver mounted on a custom DOSC waveguide. The 8'' loudspeakers are individually rated at 16 ohms and connected in parallel to provide a nominal impedance of 8 ohms. The nominal operating bandwidth for the 8'' section is 100 Hz to 800 Hz.
1.3 dV-DOSC RIGGING SYSTEM dV-DOSC features a convenient rigging system where rear mounted angle bars are used to control the angle between enclosures, i.e., cabinets pivot about the front mount points and selecting the desired hole on the rear angle bars adjusts the angle between enclosures. When dV-ANGLE P1 or P2 bars are used, convex (positive curvature) arrays can be constructed ranging from flat up to a maximum of 7.5 degrees between cabinets in increments of approximately 1 degree.
Figure 18: dV-BUMP and dV-BUMP2 rigging bumpers Maximum recommended flown configurations are summarized as follows: dV-BUMP or dV-BUMP2 (NO EXTENSION BAR) (SINGLE OR TWO POINT HANG FROM CENTRAL SPREADER BAR) - maximum 24 dV-DOSC enclosures dV-BUMP or dV-BUMP2 + EXTENSION BAR (SINGLE POINT HANG FROM REAR EXTENSION BAR) - maximum 12 dV-DOSC enclosures dV-BUMP or dV-BUMP2 + EXTENSION BAR (2 POINT HANG FROM FRONT POINT AND EXTENSION BAR REAR POINT) - maximum 12 dV-DOSC enclosures Figure 19: dV-DOWN Up to 6 d
1.4 dV-SUB ENCLOSURE DESCRIPTION Figure 20: dV-SUB dV-SUB contains three 15'' loudspeakers mounted in a vented bandpass configuration. Individual 15'' loudspeakers are rated at 8 ohms and connected in parallel to provide a nominal impedance of 2.7 ohms. Note: The two side firing 15'' components are wired internally in polarity opposition so that a positive signal causes cone movement in the same direction for all components, i.e.
1.5 dV-SUB RIGGING SYSTEM dV-SUB features two sets of recessed side panels on each side of the enclosure that are used in conjunction with three different types of angle bar for rigging purposes. dV-ANGLESS angle bars are used for rigging sub-to-sub in flown or stacked applications. Four dV-ANGLESS are required per two dV-SUB along with 8 dV-PIN25.
dV-SUB rigging is compatible with dV-BUMP and dV-BUMP2 and the rigging system is rated for up to 6 dV-SUB deep. When flown 6 deep, the overall weight of the system is 552 kg (1217 lbs) and pick point hole number #5 on the central spreader bar will produce a dead hang (nominal zero degree site angle). When flying combined dV-DOSC/dV-SUB arrays in a single column, dV-SUB is always flown on top. Under no circumstances should dV-SUB be flown beneath dV-DOSC.
1.6 POWERING dV-DOSC L-ACOUSTICS LA24a or LA48a power amplifiers are specified for use with dV-DOSC. For full technical details please see the LA24a or LA48a user manuals (available for download on: www.lacoustics.com). Both amplifiers have 32 dB gain and the input sensitivities are 1.95 Vrms (8.0 dBu) and 2.3 Vrms (9.5 dBu) for the LA24a and LA48a, respectively.
Table 4: L-ACOUSTICS LA24a MLS Settings for use with dV-DOSC MLS SWITCH SETTING LOAD CONFIGURATION -5 dB -4 dB -2 dB 0 dB 8 ohms Stereo (2 channel) 300 400 700 1100 4 ohms Stereo (2 channel) 600 750 1300 1500 2.7 ohms Stereo (2 channel) 1000 1180 1465 1635 Table 5: L-ACOUSTICS LA48a MLS Settings for use with dV-DOSC MLS SWITCH SETTING LOAD CONFIGURATION -5 dB -4 dB -2 dB 0 dB 8 ohms Stereo (2 channel) 430 520 820 1300 4 ohms Stereo (2 channel) 830 1000 1600 2300 2.
1.8 dV-DOSC AMP PANELS Figure 24: dV-DOSC PADO4a Amplifier Rack Panel The PADO4a amp panel allows for connection of loudspeakers, input signal and output signal loop through and is suitable for use with 4 LA24a or LA48a power amplifiers.
Table 9: PADO4a COMB Wiring Chart Table 10: PADO4a Internal Amp Rack Wiring Chart Figure 26: PADO4a amp rack wiring dV-DOSC dV-SUB Manual V3.
Table 11: PADO2a COMB Wiring Chart Table 12: PADO2a Internal Amp Rack Wiring Chart Figure 27: PADO2a amp rack wiring dV-DOSC dV-SUB Manual V3.
1.9 dV-DOSC AMPLIFIER RACKS Figure 28: L-ACOUSTICS AMP RACK RK12-4 The L-ACOUSTICS RK12U amplifier rack is 12 rack units high and can be loaded with up to four LACOUSTICS LA24a or LA48a amplifiers. Overall external dimensions are 77 cm high (including casters) x 61 cm wide x 58 cm deep (30.3 x 26.4 x 22.9 inches). Clearance from the front rack rail to the front of the rack is 9.5 cm (3.7 in). Clearance from the rear rack rail to the rear of the rack is 6 cm (2.4 in).
4 x LA48a plus PADO4a 4 x LA48a plus 2 x PADO2a Master Rack Slave Rack Figure 29: 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 dV-DOSC dV-SUB Manual V3.
1.10 COMB CONNECTORS COMB connectors are used in conjunction with L-ACOUSTICS signal distribution panels (CO6, CO24, MD24) to route desired signal lines from the 19-pin CA-COM input connectors on PADO2a or PADO4a amplifier rack panels to the appropriate amplifier inputs. Amplifier racks can be conveniently reconfigured without rewiring internally - simply by changing the COMB connector.
Table 13b: dV-DOSC DSP output channel assignment and COMB connector summary (4+2 format presets) DSP OUTPUT 4+2 FORMAT CO6 / CO24 CHANNEL PRESET INPUT COMB CONNECTOR 1 SUB (A) 1 2 LO (A) 2 dV-SUB 3 MID (A) 3 dV-DOSC LO 4 HI (A) 4 dV-DOSC HI 5 2W LO (B) 5 2-way LO 6 2W HI (B) 6 2-way HI 3-WAY SUB 2-WAY* SB118 or SB218 * 2-WAY ENCLOSURES: ARCS, 112XT, 115XT, 115XT HiQ Operating modes, amplifier rack channel assignments and cabling plus loudspeaker enclosure combinations for
To power 2-way fill enclosures or 3-way stereo dV-DOSC, ARCS or XT systems using PADO2a and PADO4a amplifier panels, additional COMB connectors can be employed: 2W(A), 2W(B), 3W(A), 3W(B), SUB(A), SUB(B) or 2W STEREO.
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: HI (A) HI (A) HI (A) HI (B) LO (A) LO (A) LO (A) LO (B) HI (B) HI (B) HI (A) HI (B) LO (B) LO (B) LO (A) LO (B) 2W ST 2W ST 2W (A) 2W (B) (DO10P+) DO2W or DO10/DO25 + DOFILL or DO2W+CC4FB+SP10/25 (DO10P+) DO2W or DO10/DO25 + DOFILL or DO2W+CC4FB+SP10/25 (DO10P+) DO2W or DO10/DO25 + DOFILL or DO2W+CC4FB+SP
1.11 CO24 CONTROL OUTPUT PANEL Figure 36: CO24 Control Output Panel The CO24 control output panel can be used in conjunction with 4 digital signal processors to create a compact, modular drive rack. DSP outputs are patched to the 24 x female XLR patch bay on the internal side of the CO24 panel and assigned to MC28100 MULTI return snake lines. For added flexibility, all MULTI lines are paralleled with individual front panel Left-Left (A), Left (B), Right (C) and Right-Right (D) 19-pin CA-COM connectors.
1.12 MD24 MULTI DISTRO PANEL Figure 37: MD24 Multi Distro Panel The MD24 Multi Distro panel is used onstage for distribution of MC28100 MULTI return snake lines that originate from the CO24 Control Output panel located at FOH. The MD24 panel can be packaged separately and located either stage left or right (depending on physical constraints regarding snake runs) or, alternatively, can be mounted in the amplifier rack that is first in line for patching purposes.
1.14 APPROVED DIGITAL SIGNAL PROCESSORS Digital signal processing units supported by L-ACOUSTICS for dV-DOSC include: XTA DP224, XTA DP226 (or DP6i = fixed install version of the DP226), BSS FDS 366 (Omnidrive Compact Plus), BSS Soundweb and Lake Contour.
1.16 dV-DOSC PRESETS dV-DOSC presets are provided in LO and HI versions with differing amounts of HF shelving equalization. In general, LO presets are flat (smooth) while HI presets have an additional 3 dB of shelving eq (bright). Stereo 2-way dV-DOSC presets offer the choice between two high pass filters for the low section and two shelving eqs for the high section. For dV-DOSC 2W 100 presets, a 100 Hz, 24 dB/octave slope HPF is applied to the low section and the limiter threshold is set at +7 dBu.
Stereo 3-way presets are also provided for dV-DOSC plus L-ACOUSTICS SB118 (single 18'') and SB218 (dual 18'') subwoofers. Two types of presets are provided for each subwoofer: 3W (120 Hz crossover point) and 3WX (80 Hz crossover point). The 3W preset is intended for applications where subwoofers are closely coupled to the dV-DOSC array as an extension of the system and 3WX presets are intended for applications where subwoofers are ground stacked, separate from the flown dV-DOSC arrays.
dV 3W SB118 (120 Hz crossover between SB118 and dV-DOSC low section) dV 3WX SB118 (80 Hz crossover between SB118 and dV-DOSC low section) dV 3W SB218 (120 Hz crossover between SB218 and dV-DOSC low section) dV 3WX SB218 (80 Hz crossover between SB218 and dV-DOSC low section) Figure 40: Time alignment guidelines for 3-way SB118 and SB218 presets dV-DOSC dV-SUB Manual V3.
dV-DOSC + dV-SUB + SB118 INFRA (60 Hz crossover between SB118 and dV-SUB) dV-DOSC + dV-SUB + SB118 X (SB118=25-80 Hz/negative polarity, dV-SUB=30-120 Hz) dV-DOSC + dV-SUB + SB218 INFRA (60 Hz crossover between SB218 and dV-SUB) dV-DOSC + dV-SUB + SB218 X (SB218=25-80 Hz/negative polarity, dV-SUB=30-120 Hz) Figure 41: Time alignment guidelines for 4-way presets dV-DOSC dV-SUB Manual V3.
General Guidelines Regarding System Protection Standard limiter thresholds for dV-DOSC are based on twice the RMS power handling for each section and set at +7 dBu (100 Hz HPF) or +5 dBu (80 Hz HPF) for the low section and +1 dBu for the high section. For additional protection, L-ACOUSTICS LA24a and LA48a output power can be matched to dV-DOSC power handling capabilities using MLS switches (refer to tables 3, 4 and 5 for recommended settings).
PRESET NAME PGM TYPE MEM OUT 1 (Source) OUT 2 (Source) OUT 3 (Source) OUT 4 (Source) dV-DOSC 2W 80 LO dV-DOSC 2W 80 HI dV-DOSC 2W 100 LO dV-DOSC 2W 100 HI 2-way stereo 2-way stereo 2-way stereo 2-way stereo 10 11 12 13 dV-DOSC LO (A) dV-DOSC LO (A) dV-DOSC LO (A) dV-DOSC LO (A) dV-DOSC HI (A) dV-DOSC HI (A) dV-DOSC HI (A) dV-DOSC HI (A) dV-DOSC LO (B) dV-DOSC LO (B) dV-DOSC LO (B) dV-DOSC LO (B) dV-DOSC HI (B) dV-DOSC HI (B) dV-DOSC HI (B) dV-DOSC HI (B) dV-DOSC 3W 80 dV-SUB LO dV-DOSC 3W 80 d
PRESET NAME dV-DOSC 2W 80 LO dV-DOSC 2W 80 HI dV-DOSC 2W 100 LO dV-DOSC 2W 100 HI PGM TYPE 3-way stereo 3-way stereo 3-way stereo 3-way stereo MEM 10 11 12 13 OUT 1 (Source) FULL (A) FULL (A) FULL (A) FULL (A) OUT 2 (Source) dV-DOSC LO (A) dV-DOSC LO (A) dV-DOSC LO (A) dV-DOSC LO (A) OUT 3 (Source) dV-DOSC HI (A) dV-DOSC HI (A) dV-DOSC HI (A) dV-DOSC HI (A) OUT 4 (Source) FULL (B) FULL (B) FULL (B) FULL (B) OUT 5 (Source) dV-DOSC LO (B) dV-DOSC LO (B) dV-DOSC LO (B) dV-DOSC LO (B) OUT 6 (Source) dV-
PRESET NAME USER PGM TYPE 3(A)+3(B) Mem 1 OUT 1 (Source) OUT 2 (Source) OUT 3 (Source) OUT 4 (Source) OUT 5 (Source) OUT 6 (Source) DV 2W 80 LO DV 2W 80 HI DV 2W 100 L DV 2W 100 H 3(A)+3(B) 3(A)+3(B) 3(A)+3(B) 3(A)+3(B) 2 3 4 5 FULL (A) FULL (A) FULL (A) FULL (A) dV-DOSC LO (A) dV-DOSC LO (A) dV-DOSC LO (A) dV-DOSC LO (A) dV-DOSC HI (A) dV-DOSC HI (A) dV-DOSC HI (A) dV-DOSC HI (A) FULL (B) FULL (B) FULL (B) FULL (B) dV-DOSC LO (B) dV-DOSC LO (B) dV-DOSC LO (B) dV-DOSC LO (B) dV-DOSC HI (B)
2-WAY MODULES dV-DOSC 2W 80 LO dV-DOSC 2W 80 HI dV-DOSC 2W 100 LO dV-DOSC 2W 100 HI 3-WAY MODULES dV 3W 80 dV-SUB LO dV 3W 80 dV-SUB HI dV 3W 120 dV-SUB LO dV 3W 120 dV-SUB HI dV 3W 200 dV-SUB LO dV 3W 200 dV-SUB HI dV 3W SB118 LO dV 3W SB118 HI dV 3WX SB118 LO dV 3WX SB118 HI dV 3W SB218 LO dV 3W SB218 HI dV 3WX SB218 LO dV 3WX SB218 HI 4-WAY MODULES dV + dVS + SB118 i LO dV + dVS + SB118 i HI dV + dVS + SB118 X LO dV + dVS + SB118 X HI dV + dVS + SB218 i LO dV + dVS + SB218 i HI dV + dVS + SB218 X LO dV +
2. dV-DOSC ARRAY SPECIFICATIONS dV-DOSC can be modelled using L-ACOUSTICS proprietary SOUNDVISION or ARRAY2004 software. Alternatively, custom DLLs for modeling V-DOSC and dV-DOSC are available for CATTAcoustics or EASE room acoustics modeling sofware. 2.1 COVERAGE IN THE HORIZONTAL PLANE dV-DOSC has a coverage angle of 120° in the horizontal plane from 1-10 kHz with -6 dB points at +/60° off axis.
2.2 WAVEFRONT SCULPTURE IN THE VERTICAL PLANE Flat dV-DOSC Array Flying or stacking dV-DOSC with 0 degree angles between all enclosures produces a flat array that behaves acoustically as a continuous, isophasic line source that radiates a cylindrical wavefront. The cylindrical wavefront expands in the horizontal dimension only and is defined by the section of a vertical cylinder over a given distance.
Constant Curvature dV-DOSC Array For a constant curvature array, the vertical directivity is nominally (N-1) x A° where N is the number of enclosures in the array and A° is the constant angle between each adjacent enclosure. Therefore, a curved array of 9 dV-DOSC enclosures can provide a maximum vertical coverage of 8 x 7.5° = 60° while still satisfying WST criteria. The constant curvature array is the simplest type of convex curvature dV-DOSC array.
2.3 COVERAGE PREDICTIONS USING ARRAY2004 L-ACOUSTICS has developed a fast, easy-to-use prediction spreadsheet named ARRAY2004 that operates under EXCEL. ARRAY2004 can predict coverage for flat, constant curvature or variable curvature dV-DOSC arrays.
Figure 43: 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 available, there are a number of options: use a tape measure or laser range-finder (such as the Leica Disto Basic or Hilti PD22) on site to perform dimensional measurements.
In dV-DOSC ARRAY#1 or dV-DOSC ARRAY#2 cells, the designer enters the number of dV-DOSC enclosures (24 maximum), the offset distance (in the x dimension), elevation of the bumper and the autofocus adjust angle. By default, ARRAY 2004 automatically focuses the top dV-DOSC enclosure to the rear of the audience geometry defined in Cutview 1. Autofocus adjust can be used to adjust the overall focus of the array and DOES NOT CORRESPOND TO THE TILT ANGLE OF THE dV-DOSC BUMPER.
Optimization Procedure After entering all input data (as described above), press the SCALING button to display the defined audience geometry and vertical coverage of the system. The cutview display shows the intersection of individual dV-DOSC enclosure site angles with the audience (square blocks = site angle impacts) and represents the SPL dispersion over the audience. In accordance with WST Condition #4, the best results are achieved when enclosure site angle impacts have equal spacing between them.
dV-DOSC Single Point Hang Utility A pick point calculation utility is included for single point dV-DOSC array hangs. Pick point holes are numbered 0 to 16 from front-to-rear on dV-BUMP or dV-BUMP2. Hole 0 corresponds to the downstage motor point, holes 1-8 correspond to pick points on the central spreader bar and holes 916 correspond to pick points on the rear extension bar.
dV-DOSC Downfill / Upfill Simulation dV-DOSC downfill or upfill enclosures can be conveniently simulated in V-ARRAY1 or V-ARRAY2 sheets using the available cells. Note: For dV-DOSC downfill simulation, autofocus adjust angle = 0 degrees corresponds to the first dVDOSC enclosure as tightly wrapped to the bottom V-DOSC (i.e., a relative site angle of 3.75 degrees). Note: When simulating dV-DOSC downfill or upfill using ARRAY2004 there will appear to be a physical alignment offset with respect to V-DOSC.
Figure 50: dV-DOSC downfill simulation (circuiting issues) For dV-DOSC upfill simulation, an autofocus adjust angle of zero degrees corresponds to the first dVDOSC enclosure as parallel to the site angle of the top V-DOSC. Note: To obtain the 0 degree relative angle, the 3.75 degree hole on dV-ANGLEP1 must be used during installation. For upfill purposes, the 5.5 or 7.5 degree holes can also be selected on dV-ANGLEP1. When using 5.5 or 7.5 degree holes, set autofocus adjust = 1.75 degrees or 3.
Output Data In the columns adjacent to where angle values are entered, the site angles (i.e., what you would measure if you put a digital inclinometer on each enclosure) and the wavepath (throw distance) for each enclosure are tabulated. Note: The site angle for enclosure #1 is equal to the dV-BUMP or dV-BUMP2 site angle provided that the 3.75 degree angle is selected for the top dV-DOSC enclosure.
Figure 52: dV-DOSC mechanical data H-ISOCONT SHEET The H-ISOCONT sheet is used to check horizontal coverage by mapping a projection of the horizontal isocontour of the defined V-DOSC and dV-DOSC arrays onto the user-defined audience area. By matching horizontal coverage to the audience area, H-ISOCONT can be used to check array placement/aiming and stereo imaging as well as determine whether offstage fill, front fill or center cluster arrays are required.
The user can also define the y coordinates for each array (off-center distance) and the azimuth angle in degrees (i.e., aiming or panning angle of the array). Note: to simulate a centre cluster, simply set ''Y location'' equal to zero. Figure 53: dV-DOSC Isocontour Optimization Procedure Typically, the optimization procedure begins by using the V-ARRAY1, V-ARRAY2, dV-ARRAY1 or dVARRAY2 cutview sheets to determine the number of array enclosures, inter-enclosure angles, etc.
CUTVIEW SHEET HORIZONTAL ISOCONTOUR SHEET Figure 54: ARRAY 2004 spreadsheet calculation example dV-DOSC dV-SUB Manual V3.
2.4 dV-DOSC COVERAGE MODELING USING SOUNDVISION SOUNDVISION is a proprietary 3D software program dedicated to the modeling of the entire LACOUSTICS product line - including dV-DOSC, V-DOSC, KUDO, ARCS, XT and MTD enclosures. Designed with a convenient, graphical user interface, SOUNDVISION allows for the calculation of sound pressure level (SPL) and coverage mapping for complex sound system or venue configurations.
250 Hz 4 kHz 500 Hz 6.
Impact Coverage Unweighted SPL Map A Weighted SPL Map 1-10 kHz SPL Map Figure 56: Impact coverage and SPL mappings (unweighted, A-weighted, 1-10 kHz bandwidth) for 12 dV-DOSC (30 metre throw distance, enclosures perpendicular to target plane)
3. SOUND DESIGN 3.1 STACKED OR FLOWN? Although flown systems are generally preferred, there are good arguments to support both solutions and, in some cases, the choice is dictated by the venue itself, i.e., sometimes it isn’t possible to fly the system since rigging points are not available or weight restrictions apply. Stacked Systems improve image localization for the audience since the perceived sound image is lowered to stage level.
Stacking Guidelines The stacking system is rated for a maximum of 12 dV-DOSC enclosures For stacked systems, the well-defined vertical coverage of dV-DOSC allows little margin for error. Whether the audience is standing or seated is an important consideration and the system should be stacked on a riser of suitable height (or on top of subwoofers) so that the system is higher than the listening level of the first row of the audience.
Rigging Guidelines The rigging system is rated for a maximum of 24 dV-DOSC enclosures without the extension bar and 12 dV-DOSC enclosures with the extension bar When simulating system coverage using ARRAY2004 or SOUNDVISION, the goal is to select dVDOSC inter-enclosure angles so that equal spacing is obtained between enclosure site angle impacts over the audience geometry (WST Condition 4).
3.2 ACHIEVING OPTIMUM COVERAGE ARRAY 2004 or SOUNDVISION are convenient simulation tools for optimizing the coverage for a complete system consisting of multiple dV-DOSC arrays and complementary fill systems. Parameters for each array such as spatial coordinates, azimuth angle (i.e.
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 audible depends on the separation of the two arrays and the orientation of the left array with respect to the right array, defined by the intersection of the isocontours for both arrays.
3.2.2 LEFT/CENTRE/RIGHT (LCR) CONFIGURATIONS Although it can be sometimes difficult to negotiate the centre position (from a visual standpoint), LCR systems offer more flexibility in optimizing audience coverage with the potential for improved intelligibility, more even horizontal tonal balance and better image localization compared with standard LR configurations.
3.3 MULTIPLE ARRAY CONCEPTS When the horizontal coverage of a dV-DOSC array (120° nominal, 100° effective) is insufficient, it is not recommended to place a second array directly beside the first one. The best approach is to utilize a second array which is focused on another portion of the audience (typically at 60° - 100° relative to the first array) and spaced at least 6-7 meters (approximately 20 ft) from the first array.
3.4 SUBWOOFERS dV-DOSC is capable of radiating frequencies down to 80 Hz with good vertical directivity control (the low frequency pattern control limit depends on the size of the array). To extend low frequency response to 40 Hz, dV-SUB enclosures are added to create a 3-way system. SB118 or SB218 subwoofers can also be added to further extend frequency response down to 27 Hz and increase the overall unweighted SPL.
3.4.1 Flown dV-DOSC, Ground Stacked SB Subwoofers (3-way system operation) SB218 or SB118 subwoofers are normally ground stacked to take advantage of the 6 dB SPL enhancement obtained due to floor coupling (effectively, there is a mirror image that doubles the number of subwoofers). Various flown dV-DOSC and ground stacked subwoofer combinations are shown in Figure 63 (see also Subwoofer Arraying Techniques).
3.4.2 Physically Coupled dV-SUB/dV-DOSC (3-way system operation) dV-SUBs can be physically coupled with the dV-DOSC array by rigging dV-DOSC underneath, stacking dV-DOSC on top of dV-SUB, flying a separate dV-SUB array offstage with minimum physical separation, or stacking dV-SUB below a flown dV-DOSC array with minimum separation.
The benefits of flown subwoofers include: • Improved low frequency summation, impact and throw. • Improved time alignment since the physical path length difference problem of ground stacked subwoofers versus flown dV-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.
3.4.
3.4.4 Time Alignment: Flown/Ground Stacked Subwoofers As seen in Fig. 64, selection of the time alignment reference location in the vertical plane is always a compromise since the geometric path difference varies with position (note: this also occurs in the horizontal plane and time alignment must be considered in 3D). Time aligning at a distance where the SPL from ground stacked subwoofers equals the SPL from flown dV-SUBs is recommended as an optimum compromise (for time alignment in the vertical plane).
section operating bandwidths, i.e., the 24 dB per octave low pass filter for the SB218 or SB118 generates a phase shift of 180°). The X preset takes full advantage of dV-SUB resources and provides maximum sub/low output.
3.5 SUBWOOFER ARRAYING TECHNIQUES 3.5.1 LEFT/RIGHT CONFIGURATIONS Any L/R subwoofer configuration will have problems with the so-called “power alley” effect, i.e., a build up of low frequency energy in the centre accompanied by uneven low frequency response and impact off-axis in the horizontal plane. This is easy to understand using Fresnel analysis, i.e.
(a) Minimum front surface area L/R ground stacked subwoofer array blocks (b) Vertical column L/R ground stacked subwoofer arrays (recommended for open air festival applications) (c) L-Wrap L/R ground stacked subwoofer arrays (d) Curved L/R ground stacked subwoofer arrays (e) L/R horizontal line arrays Figure 70: L/R Ground stacked subwoofer arraying techniques Figure 71: Flown L/R subwoofers integrated with dV-DOSC offstage fill arrays dV-DOSC dV-SUB Manual V3.
3.5.2 CENTRAL LINE ARRAY WITH ELECTRONIC DELAY PROCESSING A central ground stacked line array optimizes low frequency SPL output since all subwoofers couple acoustically and the mirror image ground plane effect doubles the number of subs. Given the same number of subwoofers, the overall SPL obtained by ground stacking in this manner is higher than any other configuration.
An EXCEL spreadsheet tool to perform delay and offset calculations is available in ARRAY2004 (SUB ARC). Several examples are given in Figure 73 (for further details on the SUBARC sheet please see the V-DOSC manual). HORIZONTAL SB218 (24 TOTAL) HORIZONTAL SB218 (16 TOTAL) T4 T4 T3 T3 T2 T2 T1 T1 T1 T1 T1 = 0 msec T2 = 1.167 msec T3 = 3.036 msec T4 = 5.495 msec VERTICAL SB218 (8 TOTAL) T4 T3 T2 T1 T1 T2 T3 T4 T1 = 0 msec T2 = 0.493 msec T3 = 1.282 msec T4 = 2.
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 overlaps. Figure 74(e) shows a central subwoofer line array with electronic delay processing; Fig. 74(f) shows a distributed ground stacked subwoofer configuration which can also be used with electronic delay processing. For further details on electronic delay processing, please see Section 3.5.2 and the VDOSC manual.
4. INSTALLATION PROCEDURES In the following sections, detailed procedures for stacking or rigging dV-DOSC and dV-SUB are presented. Please follow these procedures carefully and remain safety-conscious at all times. In addition: • Only users with sufficient rigging knowledge should attempt to install any L-ACOUSTICS loudspeaker system intended for overhead suspension. • Users should be familiar with the rigging techniques and safety considerations outlined in this manual prior to installation.
four dV-PIN25 (front first, rear last) to secure the bottom dV-DOSC to dV-BUMP. Verify the tilt angle for the first enclosure and perform any required tilt adjustments using the rear screwjacks. Note : Compensate for the 3.75 degree trapezoidal angle of dV-DOSC versus the actual site angle by using a 3.75 degree angle between the rear of the bottom enclosure and dV-BUMP. The next step is to connect two more dV-ANGLE bars to the rear locator slots of the bottom dVDOSC enclosure using two dV-PIN25.
(i) Place V-DOSC bumper into position (ii) dV-BUMP locator studs mate with holes (iii) dV-BUMP mounted inside V-DOSC BUMP (iv) Insert locator pin (v) Use dV-PIN81 to secure locator pin (vi) Overview of dV-BUMP secured to V-DOSC BUMP (vii) Attach rear screwjacks to V-DOSC BUMP dV-DOSC dV-SUB Manual V3.0 (viii) Select 3.
(ix) dV-ANGLE pre-attached in the 3.75 degree position (x) Front rigging tabs mate with locator slots on dV-BUMP (xii) Then pin rear points - note: by pre-selecting the angle, the tab on dV-ANGLEP1 acts as a stop (xi) Pin front points first using dV-PIN25 (xiv) Stack the second dV-DOSC enclosure (xiii) Pre-attach two more dV-ANGLE bars at desired angle (xv) Pin front points first, rear points last using dV-PIN25 (xvi) Use dV-ANGLE at 3.75 (rear) and 7.
Stacking on top of V-DOSC For dV-DOSC upfill applications, dV-BUMP is attached to the V-DOSC bumper to act as a stacking platform using the same stacking procedures outlined above. For stability reasons, the maximum number of dV-DOSC enclosures that can be stacked on top of VDOSC is 6. Typically, allowable trim height and chain motor clearance issues will be the determining factors with respect to the number of cabinets that can be used.
dV-DOSC dV-SUB Manual V3.
(v) Attach rear dV-ANGLE and mount the first enclosure (vi) Continue to build the stack (vii) Note bridling arrangement in front (viii) Entire system is now ready to fly Figure 76: Stacking dV-DOSC on top of V-DOSC for upfill/longthrow dV-DOSC dV-SUB Manual V3.
Stacking on top of SB218 Subwoofers For this application, four circular pads are provided on dV-BUMP that mate with the stacking runner recesses on top of the SB218 subwoofer. Side notches in dV-BUMP are also available that allow a ratchet strap to be used to secure dV-BUMP to the SB218 for added stability. Start by building a stack of SB218 subwoofers.
dV-DOSC dV-SUB Manual V3.
(v) Ratchet strap secures dV-BUMP to the SB218 (vi) Rear dV-ANGLE pre-attached at desired angle (vii) Bottom dV-DOSC mounted, attached using dV-PIN25 (viii) Pre-attach next set of dV-ANGLE dV-DOSC dV-SUB Manual V3.
(ix) Second dV-DOSC placed into position (x) then secured using dV-PIN25 (front first then rear) (xi) Use dV-ANGLE N instead of dV-ANGLE P1… (xii) for more downwards tilt Figure 77: Stacking dV-DOSC on top of SB218 subwoofers dV-DOSC dV-SUB Manual V3.
Stacking dV-SUB Subwoofers When stacking dV-SUB, the stacking runners on the bottom of enclosures mate with the recesses on the tops of adjacent enclosures while the stack is being built. There are two options for securing a stack of dV-SUBS: 1) use a ratchet strap around the entire stack or 2) use dV-ANGLESS (sub-to-sub) angle bars between adjacent dV-SUB enclosures. Either of these options is recommended, especially if dV-SUB will serve as a stacking platform for dV-DOSC (see the following section).
Repeat the same procedure to stack 3 dV-SUBs high The stack - secured using 8 dV-ANGLESS and 16 dVPIN25 Figure 78: Stacking dV-SUB subwoofers dV-DOSC dV-SUB Manual V3.
Stacking dV-DOSC on top of dV-SUBS There are two options for stacking dV-DOSC: with, or without dV-BUMP. Procedure 1: Stacking without dV-BUMP When stacking on stages or risers, reduced downwards tilt requirements for the stacked dV-DOSC system may allow for the direct installation of dV-DOSC on top of dV-SUB without use of dV-BUMP. Similarly, for stacked field level distributed systems, systems are normally oriented upwards and downwards tilt is not required.
(i) Pre-attach dV-ANGLESD (front) and dV-ANGLESDP (rear) to dV-SUB (ii) Note: The ''fat'' part of dV-ANGLESD and dV-ANGLESDP is oriented towards the center of dV-SUB on both sides (iii) Place dV-DOSC in position (inverted) and secure the front 2 points (iv) Lift dV-DOSC into position and secure with dV-PIN25 dV-DOSC dV-SUB Manual V3.
(v) Pre-select the angle / pre-attach dV-ANGLE P1 or P2 for the second dV-DOSC enclosures and continue to build the stack (vi) The finished stack of dV-SUB and dV-DOSC Figure 80: Stacking dV-DOSC on top of dV-SUB subwoofers (without dV-BUMP or dV-BUMP2) dV-DOSC dV-SUB Manual V3.
Procedure 2: Stacking with dV-BUMP or dV-BUMP2 In this case, dV-BUMP or dV-BUMP2 is placed on top of the upper dV-SUB to serve as a stacking platform for dV-DOSC. dV-ANGLEN bars can be used for downwards tilt and from ground level, stacking 3 dV-SUB enclosures high puts dV-DOSC at a good height so that the bottom cabinet will be angled down into the audience. Typically downwards tilt is necessary to reduce audience shadowing effects and to improve HF penetration into the audience.
(i) dV-BUMP secured to dV-SUB stack using a ratchet strap. dV-ANGLEN preinstalled for rear attachment points (iii) 3 high dV-SUB stack provides a good height as a stacking platform. With the bottom enclosure at maximum downwards tilt, coverage starts from 2 metres onwards. (ii) dV-DOSC installed - note how dV-ANGLEN provides downwards tilt Figure 81: Stacking dV-DOSC on top of dV-SUB subwoofers with dV-BUMP (or dV-BUMP2) dV-DOSC dV-SUB Manual V3.
4.2 FLOWN SYSTEMS Standalone Rigging with dV-BUMP or dV-BUMP2 Flying a dV-DOSC array is fast and easy. When properly prepared and organized, handling time can be significantly reduced in comparison with conventional systems. Installation is optimum when 2-3 people are available although it is possible for a single person to fly dV-DOSC. Preliminary Preparations: All geometrical data for installing the array (i.e.
Referring to the angle values that were pre-calculated using ARRAY2004 or SOUNDVISION, preattach pairs of dV-ANGLE bars at the rear of all dV-DOSC enclosures of the array (while they are still face down in their flight cases). Remember to keep the ball/tab end up as a reference. Be careful to select the correct angle for each enclosure (generally, it is better if one person performs this operation to avoid mistakes).
(ii) Pin the fronts of all dV-DOSC using dV-PIN25 (i) dV-DOSC lined up in FLIGHT-dV cases (iii) Use 3.75 degree for rear when attaching dV-BUMP dV-DOSC dV-SUB Manual V3.
(iv) Pre-attach all rear dV-ANGLE (ball/tab end up) (v) Pre-select the desired angle (vi) dV-BUMP attached, dV-ANGLE pre-attached (vii) Connect dV-DOSC enclosures in groups of three dV-DOSC dV-SUB Manual V3.
(viii) Lower detail between adjacent blocks of 3 dV-DOSC (ix) As cabinets lift off … (x) Pin adjacent blocks of 3 together as the gaps close dV-DOSC dV-SUB Manual V3.
(xi) Note: single point hang from spreader bar section on dV-BUMP (xii) Front view of the flown array (xiii) Single point hang from rear point on extension bar gives 90 degrees coverage with 12 dV-DOSC (xiv) 90 degrees vertical coverage running from parallel to vertical with respect to floor level Figure 82: Rigging dV-DOSC standalone with dV-BUMP (or dV-BUMP2) dV-DOSC dV-SUB Manual V3.
Trim and Angle Adjustments At this point there are only two adjustments left - trim height of the array and tilt angle of the entire flown system. If two motors are used for rigging the system, the front motor is used to set the proper height of the whole array. Controlling the tilt angle is then performed by the relative action of the two chain-motors, i.e., once the proper height has been set the front motor is fixed and activating the rear motor only varies the tilt angle.
Under daylight conditions (outdoors), the trim angle can be visually checked from the rearmost audience section. If the gap between the top and second enclosures is clearly visible then the focus is correct. At long distances, binoculars can help to visualize this gap and for final angle adjustments, a pair of radios is useful while one person walks the room and visually inspects the array while a second person operates the motors.
Once flown, there will be a gap between dV-DOSC and the bottom V-DOSC enclosure. To remove this gap, the two dV-DOWN screwjacks are tightened to firmly secure dV-DOWN and the first dVDOSC enclosure to the V-DOSC enclosure, i.e., as the screwjacks are tightened, the underhung dVDOSC array will swing upwards. Do not overtighten the screwjacks. At this point, the system is ready to be taken up to trim and the installation completed by verifying trim height and focus.
(v) Attach dV-DOWN using U-PIN and locking safety (vi) Preconnect all dV-ANGLE at the rear of dV-DOSC (vii) Pin all dV-DOSC at the rear using dV-PIN25 (viii) Connect ANGLE straps on bottom V-DOSC dV-DOSC dV-SUB Manual V3.
(ix) Raise the ARRAY - note the gap (xi) dV-DOSC flown under V-DOSC (x) Tighten screwjacks to remove this gap Figure 84: Rigging dV-DOSC below V-DOSC for downfill dV-DOSC dV-SUB Manual V3.
Rigging dV-SUB Standalone When rigging dV-SUB standalone, up to 6 enclosures deep can be flown from dV-BUMP or dVBUMP2 (single or two point hang). Please refer to the photo sequence below in addition to the following description of dV-SUB rigging procedures. To fly the system, the first dV-SUB enclosure is located at the rigging location and flipped onto it's stacking runners in the normal orientation. Four dV-ANGLESD are pre-attached to the dV-SUB using 4 x dV-PIN25, in preparation for attaching dV-BUMP.
Lower 1st dV-SUB into position and attach using 4 dV-PIN25 Figure 85: Rigging dV-SUB Standalone
Rigging dV-DOSC Under dV-SUB (3+1 configuration) When rigging small configurations of dV-DOSC under a single dV-SUB (e.g., 1 dV-SUB with 3 dVDOSC underneath), it is possible to fly the system in the same manner as dV-DOSC standalone, i.e., assemble the enclosures while they are face down on their dollies and fly the system as a whole. Note: For larger configurations with more than 3 dV-DOSC flown under multiple dV-SUBs, see the following section for rigging procedures.
Connect the front and rear motors (or single motor) to dV-BUMP. Slowly begin to raise the array. As the array lifts off, there will be a gap between the dV-SUB and dVDOSC. One person on either side can lift/rotate the block of 3 dV-DOSC into position and then secure the front attachment points to dV-ANGLESD using 2 x dV-PIN25. Steady the array as it lifts off the ground in order to prevent it from swinging and continue to lift the array until it is freely floating in air.
(v) Attach rear points only (dV-SUB to dV-DOSC) (vi) Houston - we have liftoff… (vii) Lift dV-DOSC into position, secure front points using 2 x dV-PIN25 (viii) The flown array Figure 86: Rigging dV-DOSC under dV-SUB (small configuration)
Rigging dV-DOSC Under dV-SUB (larger configurations) When rigging larger configurations of dV-DOSC under dV-SUB (e.g., 2 dV-SUB with 6 dV-DOSC underneath), there are 2 possible procedures: 1) fly the system in the same manner as dV-DOSC standalone, i.e., assemble the enclosures face down on the ground and fly the system as a whole or 2) follow the dV-SUB standalone rigging procedure then fly dV-DOSC in blocks of three.
Connect all enclosures to the AMP RACKS using appropriate cables and adaptors (SP and DO2W or DO plus DOFILL) and SP.7 jumpers between enclosures for parallel operation. Long cable runs should be dressed and tied off to dV-BUMP for strain relief. Be careful not to connect more than 3 dV-DOSC enclosures in parallel. Conduct a final inspection to make sure all cabling is correct, proper interenclosure angles have been selected and that all dV-PINs are in place and securely seated.
(i) dV-SUB with dV-BUMP attached using 4 x dV-ANGLESD and 8 dV-PIN25 (ii) Second dV-SUB with 4 x dV-ANGLESS pre-attached (iii) 2 x dV-SUB physically connected (iV) dV-ANGLESD (front) and dV-ANGLESDP (rear) pre-attached
(v) Preconnect the first dV-DOSC to dV-SUB, front and rear. (Do not attach the dV-DOSC #2 to dV-DOSC #1) (vi) All dV-DOSC attached at front, in blocks of 3 at the rear (except for dV-DOSC #1 to #2) (viii) The flown system (2 dV-SUB + 6 dV-DOSC) (vii) dV-DOSC #2 to #1 then blocks of 3 are attached as the array is raised Figure 87: Rigging dV-DOSC under dV-SUB (larger configuration – procedure 1) dV-DOSC dV-SUB Manual V3.
(i) dV-DOSC are pre-attached in blocks of 3 (ii) Flip dV-DOSC onto dV-SUB dolleys to position under the dV-SUB array (iv) dV-DOSC front point attachment using dV-ANGLESD. The array is raised and rear points attached using dV-ANGLESDP (iii) Standalone dV-SUB techniques (see above) are used to fly the dV-SUB array dV-DOSC dV-SUB Manual V3.
(v) The procedure is repeated for subsequent blocks of 3 dV-DOSC Figure 88: Rigging dV-DOSC under dV-SUB (larger configuration – procedure 2) dV-DOSC dV-SUB Manual V3.
SAFETY RULES CAUTION: PLEASE FOLLOW THE GUIDELINES BELOW WHEN FLYING dV-DOSC AND dV-SUB dV-BUMP OR dV-BUMP2 ONLY (SINGLE OR TWO POINT HANG FROM CENTRAL SPREADER BAR POINTS) - maximum 24 dV-DOSC enclosures dV-BUMP OR dV-BUMP2 + EXTENSION BAR (SINGLE POINT HANG FROM EXTENSION BAR POINTS) - maximum 12 dV-DOSC enclosures dV-BUMP OR dV-BUMP2 + EXTENSION BAR (2 POINT HANG FROM dV-BUMP FRONT POINT AND EXTENSION BAR REAR POINT) - maximum 12 dV-DOSC enclosures dV-DOSC FLOWN UNDER V-DOSC USING dV-DOWN - maximum 6 dV-
5. MAINTENANCE AND INSTALLATION TOOLS 5.
5.
6. SPECIFICATIONS 6.1 dV-DOSC SPECIFICATIONS L-ACOUSTICS specifications are based on measurement procedures which produce unbiased results and allow for realistic performance prediction and simulation. Some of these specifications will appear conservative when compared with other manufacturer's specifications. Measurements are conducted under free field conditions and scaled to a 1 m reference distance unless otherwise specified.
Number of Cabinet Cabinet dV-DOSC Weight Weight Cabinets (kg) (lbs) 2 63.6 140.2 3 95.4 210.3 4 127.2 280.4 5 159.0 350.5 6 190.8 420.6 7 222.6 490.7 8 254.4 560.9 9 286.2 631.0 10 318.0 701.1 11 349.8 771.2 12 381.6 841.3 13 413.4 911.4 14 445.2 981.5 15 477.0 1051.6 16 508.8 1121.7 17 540.6 1191.8 18 572.4 1261.9 19 604.2 1332.0 20 636.0 1402.1 21 667.8 1472.2 22 699.6 1542.3 23 731.4 1612.4 24 763.2 1682.
dV-BUMP Net Weight: 22.5 kg without extension bar (49.6 lbs) 32.0 kg with extension bar (70.5 lbs) Figure 91: dV-BUMP – Line Drawing dV-DOSC dV-SUB Manual V3.
6.2 dV-SUB SPECIFICATIONS Frequency response (+/-3 dB) Usable bandwidth Recommended Filtering 40 - 200 Hz 35 - 200 Hz 80 to 200 Hz (4th order low pass filter) 30 Hz (4th order high pass filter) Sensitivity (average SPL over rated bandwidth, freefield conditions, without equalization, equiv to 2.83 Vrms at 1 metre) 104.5 dB SPL (40 - 200 Hz) Long Term Power Rating Amplification Impedance 2400 W recommended 2.
Figure 92: dV-SUB Line Drawing dV-DOSC dV-SUB Manual V3.
APPENDIX 1: HOW DOES dV-DOSC BEHAVE WITH RESPECT TO WST CRITERIA The second Wavefront Sculpture Technology criterion: STEP < λ/2 over the frequency range of operation is fulfilled by a dV-DOSC array at low/mid frequencies. With reference to Figure 93: Acoustic centers between 8" speakers are separated by 25cm horizontally and 23 cm vertically. The 800 Hz crossover frequency utilitized for the low section corresponds to λ/2 = 21.
APPENDIX 2: HOW DOES THE DOSC WAVEGUIDE WORK? The DOSC waveguide is the result of careful analysis of the wave path from the exit of a compression driver, through the waveguide and the resulting wavefront shape at the exit of the device. The wavefront emerging from a conical or constant directivity horn is the result of constant time arrivals for all possible wave paths radiated by the driver exit.
dV-DOSC dV-SUB Manual V3.
dV-DOSC dV-SUB Manual V3.
dV-DOSC dV-SUB Manual V3.
dV-DOSC dV-SUB Manual V3.
