BET ACOUSTICS MASS1015 User manual

Brand: BET ACOUSTICS

Model: MASS1015

Type: User manual

This manual is also suitable for

MASS1015FL3

USER MANUAL

MASS1015

USER MANUAL

1. IMPORTANT NOTE 04

1.1. Precautions and recommendations 04

2. INTRODUCTION: CONCEPT AND DEFINITION OF A LINE ARRAY SYSTEM 04

2.1. Historical introduction 05

2.2. Sound propagation 05

2.3. LINE ARRAY systems as sources of cylindrical waves 06

2.4. Directivity of LINE ARRAY systems 06

3. THE LINE ARRAY BET ACOUSTICS MASS1015 10

3.1. General description of the system 10

3.2. Amplification and processing 13

4. ASSEMBLY AND CONNECTIONS 14

5. CONFIGURATIONS 19

6. TECHNICAL CHARACTERISTICS 20

All numbers subject to variation due to production tolerances. BET ACOUSTICS reserves the right to make changes or

improvements in manufacturing or design which may affect specifications.

1. IMPORTANT NOTE

Congratulations! You have just become the owner of the result of careful design and painstaking

manufacturing. We thank you for placing your confidence in us by selecting our Line Array MASS1015

system.

To obtain maximum use and performance it is VERY IMPORTANT that you read this manual

carefully before using the system and that you take notice of the indications presented in it.

To ensure optimum functioning of the system we recommend that maintenance be carried out by

technical service personnel authorised by us.

1.1. Precautions and recommendations

The Line Array BET ACOUSTICS MASS1015 system is capable of delivering levels of sound

pressure that are capable of damaging the human ear. Protect your hearing when working with high

sound levels near the system.

The BET ACOUSTICS MASS1015 systems are designed to work only with your signal

amplification and processing system, thus providing well-balanced sound together with perfect

functioning. The use of components that differ from those specified can lower the performance of the

system and cause loudspeaker rupture.

All BET ACOUSTICS products are tested and checked before leaving the factory and should

therefore be in perfect condition on delivery.

Carefully unpack the product and observe its condition. If it has been damaged during transport

please check the damage so that you can send a report to the haulage contractor and return the product

immediately. Only consignees can initiate a claim against a haulage contractor if damage has been

caused during transport. The claimant is responsible for keeping all packaging parts for later inspection.

Please ensure that the system is not exposed to sunlight or rain.

2. INTRODUCTION: CONCEPT AND DEFINITION OF A LINE ARRAY SYSTEM

LINE ARRAY: “A group of emitting elements placed close together in a straight line, emitting with

the same phase and amplitude”. As per Harry F. Olson in his work “Acoustical Engineering and

Dynamical Analogies” (New York, 1940

Currently the advantages of line array systems over conventional sound equipment are common

knowledge: greater control of auditive coverage level, increased performance, greater projection,

optimisation of frontal emission and also lower weight and volume to handle.

The purpose of the following sections of this user manual is to provide a simplified view of the

behaviour of line array systems and familiarise the user with the basic concepts of acoustics and

electroacoustics.

2.1. Historical introduction

Although the commercial development of Line Array systems began to expand in the 90s, the

acoustic principles that govern the behaviour of line array systems date back to observations made and

parallelisms introduced more than 150 years ago in the field of acoustics after the study of the behaviour

of polarised light.

The analogy between the behaviour of both types of radiation, light and sound, makes it possible

to establish the basic theories on which are based the minimum requirements that define the behaviour

of sound amplification systems such as the line array.

To understand the advantages of a line array system over a conventional sound system it is

important to keep in mind how sound behaves from the point of view of propagation.

2.2. Sound propagation

There are three basic natural forms of propagation of sound in air, each of which has its own

characteristics as regards form and pressure level attenuation as a function of the distance of the

listener from the sound source:

a) Spherical waves

These are emitted by a point source of sound which sends out a

spherical wave front, which therefore obey the inverse square law:

In this case, the level of sound pressure is attenuated by 6dB SPL for

each doubling of the distance between the listener and the sound

source in open air.

b) Cylindrical waves

These are emitted by a line of juxtaposed sound sources. The sound

emission of the group behaves as a cylindrical wave front with

attenuation with respect to the sound source of 3dB SPL.

Basically with a line array system the behaviour of the wave front for

a given range of frequencies follows this type of propagation so long

as the listener is located within the so-called near field (see section

2.3.).

The propagation of cylindrical waves is clearly advantageous as compared with the type of

propagation of spherical waves.

c) Plane waves:

These are generated, for example, in the interior of pipes with a given length and diameter in which

the acoustics are maintained independently of distance covered by the wave front with respect to the

source of sound emission.

In this case the level of sound pressure is not attenuated with distance. This type of wave is

synthesised in the so-called Kundt tubes, but are infrequent in nature.

2.3. LINE ARRAY systems as sources of cylindrical waves

As was shown in the previous section the conditions under which a line array behaves as a

source of cylindrical sound waves depend on factors such as array length and the frequency used, and

can be expressed in a simplified way with the following formula:

D<H

f/2c

Where

H: array length (determined by the number of sound enclosures

used)

f: frequency

c: sound speed

D: frontal distance between the near region (Fresnel region) and the

far region (Fraunhofer region)

For distances greater than D the wave front emitted by a line array ceases to be cylindrical and

tends to become spherical, with a consequent attenuation of the sound pressure level of 6dB SPL on

doubling the distance from the array.

It is important to keep in mind that the behaviour in the near field of a line array system is in

actual fact qualitatively more complex given that each point located in this region is affected by the

pressure level contributions related to the distance to each one of the components that constitute each

of the acoustic enclosures that make up a line array.

This is why line arrays require suitably adjusted sound signal equalization and processing.

2.4. Directivity of LINE ARRAY systems

The efficiency of line array systems is based on constructive and destructive interference. The

pattern of any sound wave front begins to behave directive when the wavelength () of the sound is

comparable with the dimensions of the emitting surface.

If two acoustic boxes that emit the same frequency, phase and amplitude (see section 2) are

grouped, the resulting pattern of sound emission is different than when they emit separately:

 At points along the axis between them there will be constructive interference with a resultant sound

level 6dB greater than with only one sound source.

 At points outside the axis between them the difference in the distance travelled by the wave fronts

will cause cancellations, resulting in a lowered sound pressure level. This is the so-called

phenomenon of destructive interference or combing.

The graphs included below depict the sound pressure level maps resulting from grouping 8

generic point sources of sound, the centres of each separated by 56 cm.

As can be seen, the directivity of the group of 8 sources differs as compared to that of one single

source, varying as a function of frequency.

Eight point sources of sound emitting in phase with the same amplitude.

Comparison of the vertical coverage as compared with one single point source as a function of frequency.

Eight point sources of sound emitting in phase with the same amplitude.

Comparison of the vertical coverage as compared with one single point source as a function of frequency.

Eight point sources of sound emitting in phase with the same amplitude.

Comparison of the vertical coverage as compared with one single point source as a function of frequency.

As is to be expected, each of the acoustic enclosures that make up the line array consists of

different transducers, each of which is perfectly adapted to a range of frequencies to be reproduced and,

in general, with directive behaviour that varies with frequency and differs notably from the directional

behaviour of a point source.

The vertical directivity of a line array is determined using the following mathematical expression:

According to this mathematical function, the vertical response of a line array group is more

directive as frequency increases, low frequencies being almost omnidirectional.

The number of acoustic enclosures in a line array is related to resultant vertical directivity and is

therefore an important parameter on designing equipment for specific applications.

BET ACOUSTICS makes available to you the simulation program EASE FOCUS with the

corresponding library for predicting the behaviour of the MASS1015 system. EASE FOCUS allows rapid

and efficient determination of the number of acoustic enclosures needed as well as the optimum angle

between them to obtain sufficient and homogeneous sound pressure levels in the entire audience area.

EASE FOCUS can be downloaded free from www.betacoustics.com

3. THE LINE ARRAY BET ACOUSTICS MASS1015

3.1. General description of the system

The BET ACOUSTICS MASS1015 is a three-way line array system consisting of:

 1 15" bass loudspeaker

 1 10" middle frequency loudspeaker

 2 1" compression motors for treble frequencies equipped with waveguides and a 90º diffusor for

horizontal coverage

The system is capable of reproducing an extensive bandpass range, (35 Hz – 18.000 Hz)

sufficient to make it a full range system which makes it possible to do without woofer or subwoofer

support systems. In this manner, a more coherent wave front is obtained as the entire information

bearing frequency range (80–18.000Hz), in addition to the most dense mass motion range (35–80 Hz),

proceed from the same source.

The acoustic enclosures that constitute the system are made from 18-mm thick laminated

phenolic birch wood with sufficient internal reinforcements to prevent undesirable mechanical vibrations,

providing the required robustness for the intended type of application.

With a textured black paint finish, each acoustic enclosure contains a flying system, 4 lateral

handles for transport as well as a frontal protective grille with acoustically transparent foam that protects

loudspeakers from splatter and against entry of foreign objects that occasionally can damage them.

The components and architecture used for each of the ways of the system are described below:

BASS FREQUENCIES

The MASS1015 system uses a 15" bass frequency loudspeaker. As is shown in the diagram, the

loudspeaker is inclined. Thus the distance between the axes of the various stacked acoustic enclosures

is reduced, achieving a greater resultant sound pressure level.

By means of the aperture in the central partition wall of the enclosure the volumetric space is

optimized as regards loudspeaker rear load, creating a labyrinth that creates backward motion for

maximum improvement of the in-phaseness of front and rear emissions.

If access to the loudspeaker is required for maintenance purposes, the protective grille is

removed and the loudspeaker removed from the front of the enclosure.

Main characteristics of the 15" bass loudspeaker:

 Loudspeaker: 15” with a neodymium magnet and 100 mm coil

 Power: AES 1200W – 8 ohms

 Program power: 2400 W

 Sensitivity: 97dB SPL 1W/1m

 Frequency response: 30Hz - 2kHz

MIDDLE FREQUENCIES

For middle frequencies the system is equipped with a 10" loudspeaker with a neodymium magnet

that is hermetically sealed in its own rear chassis, which provides increased pressure that translates into

greater performance at middle frequencies. To support these pressures, the loudspeaker is equipped

with a curvilinear carbon-fibre cone.

As shown in the diagram, the system includes a corrector to reduce the distance between the

axes of the middle frequency wave fronts.

If access to the loudspeaker is required for maintenance purposes, the protective grille is

removed and the loudspeaker removed from the front of the enclosure. The corrector is fastened with

two screws to the loudspeaker itself, which maintains the cases separated.

Main characteristic of the 10" middle frequency loudspeaker:

 Loudspeaker: 10” with a neodymium magnet and a 77 mm coil

 Power: 400 W RMS – 8 ohms

 Program power: 800 W

 Sensitivity: 100dB SPL 1W/1m

 Frequency response: 150Hz - 5kHz

TREBLES

For the trebles 2 compression motors are combined as an optimum solution with a neodymium

magnet with waveguides, thus obtaining maximum coupling between both transducers. Both waveguides

are loaded with a diffuser with 90º horizontal coverage, projecting a wave front that is 10" high.

If the mobile treble motor groups need to be replaced, the protective grille is removed so that they

can be removed from the front of the system.

Main characteristic of the treble compression motor:

 Compression motor with a neodymium magnet and 44.4 mm coil

 Power: 40W AES – 8 ohms

 Program power: 80 W

 Sensitivity: 105dB SPL 1W/1m

 Frequency response: 700Hz - 20kHz

 Filter recommended: 1.5kHz

3.2. Amplification and processing

MASS1015 is a line array system which works straight out of the box. The basic configuration

includes 3 acoustic enclosures per channel. The corresponding amplification and processing of this

basic configuration is provided by a single flight case. This flight case consists of:

 1 BET ACOUSTICS DPA1000 power amplifier (treble): 635W RMS / 4 ohms

 2 BET ACOUSTICS DT6800 power amplifier (middle, bass frequencies): 1794 W RMS / 4 ohms

The BET ACOUSTICS power amplifiers are fully protected against subsonic frequencies, output

DC and overheating. Moreover, they include an efficient ANTICLIP circuit and forced, intelligent back

to front ventilation.

 1 processor with 2 inputs and 6 outputs that provide the following functions:

o Values for cut-off frequencies and optimum slopes for each of the three ways

o Independent equalization for each of the three ways

o Phase-adjustment delays for the different transducer systems

o Limitation/compression needed to effectively control the dynamics of each of the three

ways.

If more than three additional acoustic enclosures per channel are required for a given application,

it is sufficient to add a second flight case, and so on successively until the required final number of

acoustic enclosures has been obtained. In any case, 20 acoustic enclosures per flying column should

not be exceeded, given the load capacity of the system.

Please refer to section 5 for further information regarding BET ACOUSTICS MASS1015 line

array configurations.

4. ASSEMBLY AND CONNECTIONS

The acoustic enclosures of the MASS1015 system have been carefully studied and designed for

rapid, efficient and secure assembly, disassembly and storage of a line array:

 Handling and operation of the BET ACOUSTICS MASS1015 system is simple owing to the 4

transport handles.

 All of the units can be stacked together, forming easily handled, stored and transported clusters.

 The reduced weight and compact size of each unit facilitates their handling.

 The configurations can be kept assembled after events, both for transport as well as storage.

 The flying system between enclosures contains only one type of connecting rod for easy

disassembly of units.

 All fastenings are made with pins with magnetic heads for rapid handling.

 The elevation mechanism is easily disassembled.

 One single pin is used for all necessary functions as regards interconnection of units.

 The STACK OUT output of each enclosure allows parallel connection of up to four acoustic

enclosures.

TRANSPORT, STORAGE

The most practical and usual way of transporting the BET ACOUSTICS MASS1015 system is in

configured clusters of 3 or 2x3 units. In this way the configuration of the vertical coverage of the system

can be maintained in addition to enabling transport of the iron elevation fittings installed in the same

cluster.

CALIBRATION OF VERTICAL COVERAGE

The calibration of vertical coverage of the system is easily carried out prior to being flown. The

positions of the pins are altered as indicated on the silk-screen print on the lateral, frontal iron fitting, the

intervals of the positions being 1º.

The positions of the pins of the rear laterals are not changed as the rear mechanism is only

intended to serve as a hinge.

DESCRIPTIVE DIAGRAMS

The following diagrams describe each of the acoustic enclosures of the BET ACOUSTICS

MASS1015 system as well as its various flying parts.

1- The system includes four handles, two on each side, both strategically placed for maintaining

equilibrium during individual transport. The orifices of the two handles on the right side of the system act

as bass resonators.

2- There are four rabbets at the top of each unit which serve to accommodate the skids of the unit

stacked on top.

3- At the bottom of each unit there are four skids that are inserted in the unit stacked below.

4- The lateral iron fittings together with the "strut" connecting rods serve as hinges.

5- The lateral, front iron fittings calibrated degree for degree determine the vertical angle between each

of the units.

6- Connecting rod that serves as a strut.

7- 9.8 mm diameter pin with magnetic head.

FRONT

LATERAL

5º-

4º-

3º-

2º-

1º-

0º-

REAR

ASSEMBLY

1- MASS1015 units.

2- Elevation system.

3– Wheel transport system.

4– Lateral elevation system plate.

5– Central elevation system plate.

6– Beam for connecting the elevation cord.

7– Union beam for the lateral and central plates.

8– Rivet for fastening lateral plates to the beam.

9– Drill holes for lateral plates.

5º-

4º-

3º-

2º-

1º-

0º-

5º-

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3º-

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1– Rear, bottom fastening pin of a unit for the connecting rod that functions as a strut between it and the

next unit below.

2– Top, rear pin to the connecting rod to avoid swaying of the system.

3– Fastening pin of the top rear of a unit that serves as a strut between it and the next unit above.

4– Fastening pin of the bottom front of a unit to the connecting rod that functions as a strut between it

and the next unit below.

5– Fastening pin of the top front of a unit that functions as a strut between it and the next unit above.

The position of pin no. 5 determines the angle of the opening between units (lower and upper) as

indicated by the silk print inscribed in the lateral, front iron fittings.

The maximum angular opening between two contiguous units is five degrees. It is possible to

calibrate this opening in intervals of one degree.

5º-

4º-

3º-

2º-

1º-

0º-

REAR

FRONT

1– Cluster assembly of 3 units.

2– Cluster assembly of 3 units, with the “Bumper”.

3– The cluster is elevated and the wheel transport unit removed.

4– After elevating cluster no. 1, cluster no. 2 is positioned below it (cluster without “Bumper”).

5– After the skids of the lower unit cluster no. 2 have been inserted in the accommodations of the upper

unit cluster no. 1, the two are fastened with the connecting rods by inserting the magnetic pins.

6– After all of the units have been connected the system is elevated and removed from the wheel

transport system.

5º-

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5. CONFIGURATIONS

BET ACOUSTICS offers the following possible configurations for efficiently combining 6 or 12

acoustic enclosures, using the same power and processing rack.

Each of these configurations offers the possibility of adapting the equipment to the requirements

of the application, minimising the number of elements and providing MASS1015 with a flexibility that

makes it the optimum solution for a large number of needs…

In any case, BET ACOUSTICS places at your disposal the simulation program EASE FOCUS

with the corresponding MASS1015 system library for dimensioning the equipment rapidly and effectively

whatever the application might be.

EASE FOCUS can be downloaded free from www.betacoustics.com

6. TECHNICAL CHARACTERISTICS

Frequency response ±3dB 45Hz÷18kHz

Maximum SPL continuous LF 133dB

Maximum SPL continuous MF 128dB

Maximum SPL continuous HF 130dB

Maximum SPL peak LF 139dB

Maximum SPL peak MF 134dB

Maximum SPL peak HF 136dB

POWER

Power AES LF 1200W

Power AES MF 400W

Power AES HF 120W

Power peak LF 4800W

Power peak MF 1600W

Power peak HF 640W

SENSITIVITY

Sensitivity LF 102dB

Sensitivity MF 102dB

Sensitivity HF 109dB

DIMENSIONS WEIGHT

Dimensions mm. (W) 1050

Dimensions mm. (H) 316

Dimensions mm. (D) 719

Weight (kg.) 53

DESCRIPTION

Drivers LF 1 x 15"

Drivers MF 1 x 10"

Drivers HF 2 x 1 in.

Nominal impedance (ohms) LF 8

Nominal impedance (ohms) MF 16

Nominal impedance (ohms) HF 16

Finish (textured paint) Black

Protective grille Steel

Connectors 2 x NL8

ECLER Laboratorio de electro-acústica S.A.

Motors 166-168, 08038 Barcelona, Spain

INTERNET http://www.ecler.com e-mail: [email protected]

50.0150.01.00

BET ACOUSTICS MASS1015 User manual

Brand: BET ACOUSTICS

Model: MASS1015

Type: User manual

This manual is also suitable for

MASS1015FL3

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BET ACOUSTICS MASS1015 User manual

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BET ACOUSTICS MASS1015 User manual

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