MCS 3500 Modular Ceiling Loudspeaker System
Architect’s and Engineer’s Specifications
Executive summary
The Bosch Security Systems MCS 3500 is a modular ceiling loudspeaker system for indoor public address applications. It is the first ceiling loudspeaker to use wave guide technology to provide constant sound directivity over a wide range of frequency octaves, thus improving the quality of both speech and music reproduction. The wide opening angle of MCS 3500 loudspeakers fitted with a wave guide means that fewer units are required to cover a given area compared to similar ceiling loudspeakers without a wave guide.
Introduction
The MCS 3500 range comprises three loudspeaker units, wave guide grille, surface mounting box, a fire dome and back box. The system elements are combined to assemble high-quality ceiling loudspeakers for a wide range of applications and situations.
The loudspeakers are designed for both speech and music reproduction, and incorporate a number of special features that enhance sound quality. These include a tri-cone loudspeaker, a bass reflex port, an optional wave guide and an optional back box. The rigid frame construction reduces unwanted vibration.
The fire dome, which is mounted directly to the ceiling panels and not the loudspeaker frame, provides additional protection in the event of fire. The fire-resistant thermosetting material used for the loudspeaker frame does not deform when heated, contributing further to fire safety. The MCS 3500 is certified to F30 according to DIN4102.
The loudspeaker units incorporate many features for assisting installation, including a switch for power setting, screw terminal blocks (for loop-through wiring), built-in screw clamps and a safety cord.
Scope of this specification
This architect’s and engineer’s specification contains detailed functional and descriptive information about the MCS 3500. The text is intended to help prepare a tender or quotation for public address installations. For these purposes, all or part of the specification may be copied and/or reproduces as required. On request the text file is available from Bosch Security Systems.
System summary
The MCS 3500 modular ceiling loudspeaker units are available with 6, 12 and 24 W rated power handling capacities. The wave guide grille is secured to the front of the loudspeakers frame using integral bayonet fittings. The wave guide is secured to the loudspeaker frame using two crews (supplied). The optional back box (standard on the 24 W loudspeaker unit) is secured to the rear of the loudspeaker frame to improve low-frequency (bass) performance. The back box also prevents sound traveling to adjacent areas via the ceiling cavity, and fully protects the loudspeaker from dust and makes the unit vermin proof.
The loudspeaker units are secured in a cut-out in the ceiling panel using the three integral screw clamps, or using three screws (not supplied). The surface-mounting box is for mounting the loudspeaker unit onto hard walls or ceilings. A back box cannot be used in combination with the surface-mounting box.
The fire dome is secured to the ceiling panel. It completely encloses the rear of the loudspeaker frame and makes a good seal with the ceiling panel. A back box cannot be used in combination with the fire dome. MCS 3500 loudspeakers with fire domes are certified as F30 according to DIN 4102. All plastic parts on the MCS 3500 are self-extinguishing acc. To UL94VO. The loudspeakers comply with the relevant safety and installation regulations of EN 60065 and are BS5839 part 8 compliant.
Loudspeaker units
The ceiling loudspeaker unit shall have a tri-cone loudspeaker and a 100V line matching transformer with power tapping for full-power, half power and quarter-power radiation. It shall have a switch to enable the power tapping to be selected from a compartment that is accessible from the front of the unit. This compartment shall also have a ceramic screw terminal block to facilitate loop-through wiring. Cables entering the loudspeaker frame from the rear side shall be accessible from the front, and shall have strain relief facilities to inhibit the cable being pulled out.
The frame shall be made from glass-reinforced thermosetting polyester material. The colour shall be black. It shall have three integral screw clamps for mounting the unit in a cut-out in a ceiling panel up to 50 mm (2 in) thick. A cutting template is supplied for the ceiling cut-out. For ceiling panels thicker than 50 mm (2 in), it shall be possible to mount the frame using three screws (not supplied).
The frame shall have provision for mounting a back box, a wave guide and a grille.
A dust cover shall be secured to the rear of the loudspeaker. The frame shall have provision for securing a safety cord (supplied) to facilitate hanging the loudspeaker unit on any convenient point during installation and thereafter. The safety cord shall support the weight of the loudspeaker. The frame shall include a bass reflex port to enhance low-frequency performance when used in combination with the LBC 3665/00 back box. Provision for mounting a loudspeaker surveillance board shall be provided.
LBC 3510/40 6 W loudspeaker unit
The LBC 3510/40 shall deliver 6 W rated power (9 W maximum power), and have a sound pressure level at its rated power of 98 dB at 1 kHz octave. The rated impedance shall be 1666 Ω. The frequency range shall be 60 Hz to 20 kHz. The opening angle shall be 150º/120º at 1kHz/4kHz (-6dB) respectively with the wave guide fitted. The loudspeaker unit shall weigh 1.2 kg. (2.64 lb), have a diameter of 292 mm (11.5 in) and be 98 mm deep (3.9 in).
LBC 3520/40 12 W loudspeaker unit
The LBC 3520/40 shall deliver 12 W rated power (18 W maximum power), and have a sound pressure lever at its rated power of 101 dB at 1kHz octave. The rated impedance shall be 833 Ω. The frequency range shall be 60 Hz to 20 kHz. The opening angle shall be 150º/120º at 1kHz/4kHz (-6dB) respectively with the wave guide fitted. The loudspeaker unit shall weigh 1.6 kg (3.52 lb), have a diameter of 292 mm (11.5 in) and be 98 mm deep (3.9 in).
LBC 3530/40 24 W loudspeaker unit
The LBC 3530/40 shall deliver 24 W rated power (36 W maximum power), and have a sound pressure level at its rated power of 105 dB at 1 kHz octave. The rated impedance shall be 416 Ω. The frequency range shall be 60 Hz to 20 kHz. The opening angle shall be 145º/130º at 1kHz/4kHz (-6dB) respectively with the wave guide fitted. The loudspeaker unit shall weigh 2.6 kg. (5.73 lb), have a diameter of 292 mm (11.5 in) and be 98 mm deep (3.9 in). The unit shall be supplied with the LBC 3665/00 back box to enhance low-frequency performance in combination with the bass reflex port.
Grille
LBC 3601/01 circular wave guide grille (including wave guide)
The LBC 3603/01 grille shall have a three-point bayonet fixing for securing it to the MCS 3500 loudspeaker unit. It shall be fabricated from metal, and it shall be painted in RAL 9010 white. The wave guide shall be moulded in black self extinguishing (acc. To UL94V0) ABS material. Two fixing screws shall be provided. The wave guide grille and wave guide shall weigh 440 g (0.96 lb), have a total diameter of 300 mm (11.8 in) and be 50 mm deep (2.0 in). The grille shall have a perforated hole pattern.
Fire dome
LBC 3650/00 metal fire dome
The LBC 3650/00 fire dome shall be made from steel. It shall include push-out apertures in the top and side surfaces for two cable glands (PG 13) to allow cables to be fed to the loudspeakers unit. The fire dome shall be certified as F30 acc. To DIN 4102. The fire dome shall weigh 1.9 kg. (4.18 lb), have a maximum diameter of 330 mm (15.0 in) and be 120 mm deep (7.1 in).
Back box
LBC 3665/00 Back box
The LBC 3665/00 back box shall be made from black self-extinguishing (acc. To UL94V0) glass-reinforced thermosetting polyester material. Provision for mounting a loudspeaker surveillance board shall be provided. Three screws shall be supplied to mount the back box to the loudspeaker unit. The back box shall weigh 550 g (1.21 lb), have a maximum diameter of 251 mm (9.9 in) and be 116 mm deep (4.5 in).