1. Manuals
  2. Brands
  3. JBL Manuals
  4. Home Cinema speakers
  5. 300 Series
  6. Manual

JBL Cinema 300 Manual

Jbl cinema 300: user guide
Hide thumbs Also See for Cinema 300:
Table of Contents

Advertisement

Quick Links

See also: User Manual
CINEMA SOUND SYSTEM MANUAL

Advertisement

Table of Contents
loading

Related Manuals for JBL Cinema 300

Summary of Contents for JBL Cinema 300

  • Page 1 CINEMA SOUND SYSTEM MANUAL...

  • Page 2: Table Of Contents

    C. Surround Systems ... 34 Loudspeaker Signal Processing Settings for JBL DSC260A Digital System Controller ... 35 Cross-Reference of JBL Cinema Speakers to Crown Power Amplifiers ... 44 References and Additional Reading ... 44 Table of Contents: Loudspeaker Systems ... 19...

  • Page 3: Jbl 2003 Cinema Sound System Manual

    JBL has a strong commitment to the cinema market. We have become the acknowledged leader in the field, and our products are routinely specified for major studios and post-production houses throughout the world.
  • Page 4 Figure 1: Magnetic film formats. 70-mm (A); 35-mm (B) intended primarily for the left and right screen loudspeakers are fed to the left and right channels. Program material intended for the center screen loudspeaker, including most on-screen dialog, is fed to both stereo channels in phase.

  • Page 5: Digital Film Formats

    4B and 4C. The B-chain, including split surround channels and subwoofer channel, is shown at 4D. The B-chain is comprised of one-third-octave equalization, dividing networks (low- or high-level), power amplification, and loudspeakers. JBL Professional products are used extensively in the B-chain of the system.
  • Page 6 Figure 4: Analog A-chain (A); Digital A-chain, Dolby SR-D (B); Digital B-chain, DTS (C); Block diagram of B-chain with split surrounds (D); Dynamic range requirements for Dolby A, Dolby SR and and Dolby Digital formats (E)

  • Page 7: Evolving Dynamic Range Requirements In The Cinema

    200 Hz. The net result of this pattern narrowing in the horizontal and vertical planes is that they make a good match for the pattern control of the JBL 2360B horn at the normal crossover frequency of 500 Hz. Figure 5C shows the off-axis response ®...

  • Page 8: Coverage Requirements For Proper Stereo Reproduction

    Figure 6: Cinema equalization of power-flat systems. Unequalized system (A); JBL pioneered the concept of flat power response in the cinema (2, 3). It has become the guiding principle in much of JBL’s product design, and it has been adopted by the industry at large.
  • Page 9 This performance is seen in Figure 7. At 7A we show in plan view the direct field coverage given by the center channel JBL 5674 system aimed at the audience approximately two-thirds from front to back, with coverage at 2 kHz maintained within a range of ± 4 dB overall. A side section view of the theater is shown at 7B. Figure 7C shows similar coverage in a large stadium cinema with the center channel aimed at the audience approximately two-thirds from front to back.

  • Page 10: Acoustical Considerations

    The surround ensemble of loudspeakers, if properly specified, can easily produce a sound field that is uniform throughout the back two-thirds of the house, and level variations can often be held within a range of 2 to 3 dB. Details of surround system specification will be covered in a later section. When all of the above points are properly addressed, the sound in a cinema can approach that which we take for granted in a post-production screening facility —...

  • Page 11: Control Of Reverberation And Discrete Reflections

    The isolation task is certainly easier with new construction, since buffer areas can be designed between adjacent exhibition spaces. The most difficult problems occur when older spaces are to be subdivided to make multiplex cinemas, inasmuch as the chances of coupling through walls or through common air handling are compounded.

  • Page 12: The Role Of The Acoustical Consultant

    The 3000 Series is a lower cost line for use in small to medium cinemas. The series now includes the 3622N and 3632 ScreenArray systems. The 4000 Series includes JBL’s traditional line of cinema products, which have been the standard of the industry for fifteen years. The series now includes the 4622 and 4632 ScreenArray systems.
  • Page 13 Both 4670D and 4675C models can handle the largest spaces listed here with no problem at all. In fact, a single screen channel is capable of delivering 105 dB at the required distance in the 250-seat house. JBL recommends driving these models with amplifiers equal to their rated power, regardless of the application.

  • Page 14: Cinema Playback Level Calibration

    Figure 12 shows the horizontal off-axis response of the dual low frequency 4638 system, which incorporates two of the 2035 transducers. Figure 12: Horizontal-axis response of JBL 4638 LF system Maximum level )dB) at: (1W @ 1m) 1 m:...
  • Page 15 Figure 13: Drawings of 3000 Series screen systems. Front and side drawings of 3622N (A) and 3678 (B) Figure 14: 4000 Series screen systems. Perspective and side Figure 15: Drawings of 4000 Series screen systems. drawings of 4670D Front and side drawings of 4622N Figure 16: 4000 Series screen systems.
  • Page 16 Figure 18: 5672 screen system, front and side views. Figure 19: 5674 screen system, front and side views. Figure 20: Robinson-Dadson equal loudness contours.

  • Page 17: Mechanical Details Of Jbl Screen Channel Loudspeakers

    Because of the relative non-directionality of very low frequencies, the number of subwoofers specified for a given cinema must bear some relationship to the total volume in the space. JBL’s experience in specifying subwoofer units has led us to the following empirical recommendations: 1.

  • Page 18: Surround Requirements

    Several views of the surround models 8330A, 8340A are shown in Figure 25A and 3310 are shown in Figure 25B. Figure 25A: Front and side drawings of JBL surround loudspeakers. 8330A and 8340A (A); 3310 and 2502 bracket (B). Figure 24: Front and side drawings of the 3635 subwoofer.

  • Page 19: Screen Losses

    A driver must be specified that can handle this increased input — and at the same time be able to provide a good match with the low frequency system. All JBL cinema systems have been engineered with this requirement in mind.
  • Page 20 Figure 26: ScreenArray loudspeakers. Front (A) and side (B) views of model 4632; front (C) and side (D) views of model 3632.

  • Page 21: Mounting Requirements

    Figure 27: Performance of ScreenArray loudspeakers. Axial response (A), beamwidth (B) and directivity (C) of model 4632; axial response (D), beamwidth (E) and directivity (F) of model 3632. V. MOUNTING REQUIREMENTS A. General Comments: The following rules generally apply to screen loudspeakers: 1.

  • Page 22: Screen Loudspeaker Aiming

    The reason is simply that the surrounds should never be perceived as competing with the screen channels. Figure 31B shows a section view of the house looking toward the screen. JBL surround loudspeakers include an integral 20° downward tilt for ease in proper aiming. Generally, the surrounds should be placed 3 to 4.5 meters (10 to 15 ft) above the floor and aimed roughly at the wall/floor boundary on the far side of the space.

  • Page 23: Electrical Interface

    For reasons having to do with long-term product continuity and performance consistency in the field, many of JBL’s older transducer and systems groups have what is called “negative polarity convention,” that is, a positive-going voltage on the (+) or red terminal will result in an inward motion of the cone or driver diaphragm.

  • Page 24: Wiring Diagrams For 3000 Series Screen Systems

    EIA standard. When older products are modified with no change in the basic model number, or where new products will be required to interface with older ones, JBL usually maintains the negative convention to avoid confusion in the marketplace. In any event, all new positive convention products carry a legend to that effect next to their input terminals.

  • Page 25: Wiring Diagrams For 5000 Series Screen Systems

    5674, due to the quadruple set of LF units, makes use of four amplifier sections. All aspects of frequency division, time correction, power response equalization, and room equalization are carried out by the JBL model DSC260A digital controller. Pertinent wiring diagrams are shown in Figure 35A and B.

  • Page 26: Wiring Diagrams For Screenarray Systems

    Figure 35: Wiring diagram for 5000-series systems. 5671 and 5672 (A); 5674 (B) E. Wiring Diagrams for ScreenArray Systems: The model 3632 wired for biamped operation is shown in Figure 36A. The model 4632 is shown biamped in Figure 36B; triamped wiring of the 4632 is shown at 36C.

  • Page 27: Surround Wiring Diagrams

    A-chain technology. Since all of JBL’s surround models are nominally 8 ohms impedance, the parallel load of two of them will of course produce a 4-ohm load. Amplifiers should then be chosen that can deliver twice the loudspeaker rated power into 4 ohms, as compared with their 8-ohm ratings.
  • Page 28 Figure 37: Typical stereo surround hookup. Figure 38: Surround-EX hookup.

  • Page 29: Subwoofers

    G. Subwoofers: The general rule here is one amplifier section to one subwoofer driver, as in the case of the 4641 and 4645C models. The model 4642A contains two 2441H drivers connected in parallel resulting in a 4-ohm load. This system is intended for use in those installations that require multiple drivers to attain the necessary acoustical level.
  • Page 30 Figure 39: Level diagram for 5674 (LF section).

  • Page 31: Summary Of Recommendations For Selecting And Installing

    VII. SUMMARY OF RECOMMENDATIONS FOR SELECTING AND INSTALLING THEATER LOUDSPEAKER SYSTEMS A. Specifying and Installing Screen Channels: The following recommendations will give the reader a quick reference guide for specifying and installing loudspeakers in all cinema applications. These recommendations draw directly from the detailed information that has been presented before.

  • Page 32: Specifying And Installing Surround Channels

    B. Specifying and Installing Surround Channels: 1. Surround channel assumptions: • Moderate power surrounds (cone/dome): Sensitivity: 91 dB SPL, 1 W at 1 m, typical; power rating: 100 watts continuous. • High power surround (HF horn): Sensitivity 96 dB SPL, 1 W at 1 m, typical; power rating: 250 watts continuous.

  • Page 33: Specifying And Installing Subwoofers

    Figure 43: Surround channels, stereo wiring. 8. Selecting surround amplifiers: • Choose stereo amplifiers with a generous 4-ohm power rating equal to twice the individual surround loudspeaker power rating. • For example, using high power surrounds, select a stereo amplifier that can deliver 500 watts into four ohms.

  • Page 34: Listing Of Thx ® Certified Jbl Products

    • Watch out for rattles; use plenty of neoprene padding for isolation. (See Figure 45) Figure 45: Subwoofer placement, front and side section views. VIII. LISTING OF THX APPROVED JBL PROFESSIONAL PRODUCTS ® A. Screen systems: 3678 (3678-HF and 3678-LF)

  • Page 35: Loudspeaker Signal Processing Settings For Jbl Dsc260A

    XI. LOUDSPEAKER SIGNAL PROCESSING FOR JBL DSC260A The following loudspeaker signal processing settings are intended for the JBL DSC260A digital system controller. Different loudspeaker controllers may have channel-to-channel differences in delay settings. They may also have different definitions and implementations of parametric filter Q or bandwidth. As a result when alternative processors are used, field measurements, both electrically and acoustically, will ensure the maximum performance is retained.
  • Page 36 Recommended signal processing settings for DSC260A Digital System Controller. See www.jblpro.com for most current processor settings Speaker System: Parameter Input Delay Input EQ1 Type Input EQ1 Frequency Input EQ1 +/- Input EQ1 Bandwidth Input EQ2 Type Input EQ2 Frequency Input EQ2 +/- Input EQ2 Bandwidth Input EQ3 Type Input EQ3 Frequency...
  • Page 37 Recommended signal processing settings for DSC260A Digital System Controller. See www.jblpro.com for most current processor settings 4675C-8LF Speaker System: Parameter Input Delay Input EQ1 Type Input EQ1 Frequency Input EQ1 +/- Input EQ1 Bandwidth Input EQ2 Type Input EQ2 Frequency Input EQ2 +/- Input EQ2 Bandwidth Input EQ3 Type...
  • Page 38 Recommended signal processing settings for DSC260A Digital System Controller. See www.jblpro.com for most current processor settings Speaker System: Parameter Input Delay Input EQ1 Type Input EQ1 Frequency Input EQ1 +/- Input EQ1 Bandwidth Input EQ2 Type Input EQ2 Frequency Input EQ2 +/- Input EQ2 Bandwidth Input EQ3 Type Input EQ3 Frequency...
  • Page 39 Recommended signal processing settings for DSC260A Digital System Controller. See www.jblpro.com for most current processor settings ScreenArray Speaker System: Parameter Input Delay Input EQ1 Type Input EQ1 Frequency Input EQ1 +/- Input EQ1 Bandwidth Input EQ2 Type Input EQ2 Frequency Input EQ2 +/- Input EQ2 Bandwidth Input EQ3 Type...
  • Page 40 Recommended signal processing settings for DSC260A Digital System Controller. See www.jblpro.com for most current processor settings Speaker System: Parameter Input Delay Input EQ1 Type Input EQ1 Frequency Input EQ1 +/- Input EQ1 Bandwidth Input EQ2 Type Input EQ2 Frequency Input EQ2 +/- Input EQ2 Bandwidth Input EQ3 Type Input EQ3 Frequency...
  • Page 41 Recommended signal processing settings for DSC260A Digital System Controller. See www.jblpro.com for most current processor settings ScreenArray Speaker System: Parameter Input Delay Input EQ1 Type Input EQ1 Frequency Input EQ1 +/- Input EQ1 Bandwidth Input EQ2 Type Input EQ2 Frequency Input EQ2 +/- Input EQ2 Bandwidth Input EQ3 Type...
  • Page 42 Recommended signal processing settings for DSC260A Digital System Controller. See www.jblpro.com for most current processor settings Speaker System: Parameter Input Delay Input EQ1 Type Input EQ1 Frequency Input EQ1 +/- Input EQ1 Bandwidth Input EQ2 Type Input EQ2 Frequency Input EQ2 +/- Input EQ2 Bandwidth Input EQ3 Type Input EQ3 Frequency...
  • Page 43 DSC Recommended Settings Cinema 5000 March 23, 1999 System Output DELAY ms Subs Lows Mids Highs Polarity [+] unless noted A1 Frequency (Hz) Subs Bandwidth in Octaves A2 Frequency (Hz) Subs Bandwidth in Octaves B1 Frequency (Hz) Lows Bandwidth in Octaves B2 Frequency (Hz) Lows Bandwidth in Octaves...

  • Page 45: References And Additional Reading

    Way Loudspeaker System,” Journal SMPTE, vol. 106, no. 7 (July 1997). This document is available for download at: http://www.jblpro.com/pub/cinema/cinedsgn.pdf. Specification sheets and other support documentation for all JBL Professional Cinema Products can also be found on the JBL Professional web site.
  • Page 46 JBL Professional 8500 Balboa Boulevard Northridge, California 91329 USA ©Copyright 2003 JBL Professional Revised 6/11/03...

Table of Contents