Turbosound LMS-D26, LMS-D6, LMS-D24 user manual Turbobass Directivity, Bass Enclosure arraying

Page 38

user manual

TA-890

Turbobass Directivity

The Aspect series TA-890L bass bin and the TSW-218 subwoofer are “Turbobass” devices, comprising horn-loaded drivers. Whilst this horn loading does aid in tuning the device and adding some sensitivity, the relationship between horn length and the bandwidth covered by the enclosures means that each source is effectively an omni-directional point source.

Therefore any LF pattern control experienced when using an Aspect system derives from adjacent enclosures within an array or from the relationship of a left to right stack

Bass Enclosure arraying

Aspect bass enclosures are most efficient when ground stacked in a block. Not only do they benefit from improved coupling when there are no air gaps between them, but they also couple to the ground. However, some of this energy may be absorbed by nearby obstructions such as barriers or a tightly-packed standing audience. Sound pressure levels may also be excessive for members of the audience if they are able to get too close to the enclosures. When stacking on the stage or on a platform, particularly outdoors, it is preferable to close the gap between the platform and the floor with sheets of plywood. This results in increased sound projection into the audience and less leakage backstage.

Aiming - directivity of the stack

The directivity of the bass stack will depend on its dimensions and curvature. A tall thin stack will disperse a lot in the horizontal plane and become narrow in the vertical plane whereas a wide stack will narrow in the horizontal plane. There is usually an optimum compromise between the two so that a smooth transition can be obtained between the effect of the coupling of the two stacks down the centre line of the room and the effect of the individual stacks beaming on their axis. Also adding some curvature to the stack will help to increase the directivity of the stack especially in stopping beaming at higher frequencies.

TA-890 user manual Page 38

Image 38

Contents Aspect TA-890 System TA-890 TA-890 TA-890 Amplifier Rack Signal Wiring Output Connections EC Declaration of Conformity ProductsTurbosound Polyhorn IntroductionTurbosound Aspect System Concepts TA-890 Aspect TA-890 Turnkey System Concept LMS-D24, LMS-D26 and LMS-D6 Loudspeaker Management Systems Power AmplifiersLoudspeaker Management System LMS Concept Amplifier RacksTA-890L Low Frequency Enclosure Digital ControllersAspect Loudspeaker Components TSW-218 Subwoofer TA-890H Mid-high EnclosureTA-890 Transportation Aspect Flying Systems Flying and Stacking OverviewSetting up a Venue Overview Gigmate Acoustic SimulationRunning Turbosound GigMate / Ease Focus for the first time System Setup Designing a system TA-890 TA-890 Changing the system Theatre-style venue 3-wide flown cluster @ 1kHz Safety Notes on Rigging Sample Certificate of Load Test Wide and Narrow Flybar Settings Flying HardwareSingle A-System Flybar FB-890/1A TOP View Bottom View Figue 3. Triple ‘A’ System Flybar FB-890A/3W FC-890 Flying Chains TS-890 Tilting StrapsTA-890 Four-wide hang using MB-890 and FB-890/2A Integral Flying Hardware ‘A’ System FlygearDrop Link Connecting Flying Chains to the CabinetConnecting Cabinets ‘A’ System Swing LatchSetting Vertical Angles ‘A’ System Attaching the Tilt Straps Attach buckleAiming directivity of the stack Turbobass DirectivityBass Enclosure arraying TA-890 Typical Left to Right problem ABC DEFCreating Directional Bass arrays Bass in a lineFanned bass Bessel Array General observations of long lines of bassEnd firing array Summing up Ground stacking LMS Series Loudspeaker Management Systems General features & facilities UnpackingMechanical Installation IntroductionLMS-D6 Front Panel Functions Mains Power LMS-D6 Rear Panel FunctionsAC Power Fusing Voltage SettingSafety Earthing Powering UpAudio Connections Input and Output Connector WiringTime correction for loudspeaker driver placement Features LMS-D24 and D26 Loudspeaker Management SystemsFront Panel Functions TA-890 Rear Panel Functions Starting up Selecting a Factory PresetOperating the LMS-D24 and D26 Creating a CrossoverA Freq Width Gain EQ1 100Hz 1.4Q 0.0dB Navigation and Viewing ParametersOut1 Freq Width Gain EQ1 100Hz 1.4Q 0.0dB NavigationPreset Recall PresetsPreset Name Store My System Preset StoreDSP Processing Layout Input DSP block diagramOutput DSP block diagram Stereo / Mono FormatsDSP Processing Input ChannelsA Freq Shape HPF 20.0Hz LR24 Parametric filters Parametric EqualisationHigh and Low shelving filters Gain and Polarity DelayOutput Channels Out1 Freq Shape LPF 2.50k LR24 High and Low Pass FiltersOut1 Freq Slope Gain EQ- 100Hz 12dB 0.0dB Limiters RoutingUtilities Utility functionsAudio Input Connectors AMP-890 Aspect System Amplification Rack Racking, Cables and ConnectionsOptions Input ConnectionsAmplifier Rack Signal Wiring Output ConnectionsMid-High Outputs Break-out Cables NL4 bass Break-out cables NL8 mid-high Extension CablesMains Connections T-45 High Efficiency Audio Power Amplifiers General Features & FacilitiesFront Panel Functions T-25 Front Panel Functions T-45 Mechanical Installation Voltage Range Audio Connections & ControlsInput Impedance Gain and Sensitivity SettingsPolarity Attenuation & Gain Setting Damping FactorLong Speaker Lines Cooling SystemMaintenance To rotate the horn moulding from ‘A’ mode to ‘B’ mode To rotate the horn moulding from ‘B’ mode to ‘A’ mode Removal of the high frequency driverRemoval of the high-mid frequency driver General Maintenance Removal of the low-mid frequency drive unitsPaintwork TA-890 Technical Specifications Warranty Serial NumbersTA-890