Related Manuals for BRUEL & KJAER 4720
Summary of Contents for BRUEL & KJAER 4720
- Page 1 Technical Documentation Echo Speech Source Type 4720 User Manual English BE 1866– 11...
- Page 3 Echo Speech Source Type 4720 User Manual December 2013 BE 186611...
- Page 4 Safety Considerations This apparatus has been designed and tested in accordance with IEC/EN 61010 – 1 and ANSI/UL 61010 – 1 Safety Requirements for Electrical Equipment for Measurement, Control and Laboratory Use. This manual contains information and warnings which must be followed to ensure safe operation and to retain the apparatus in safe condition.
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Page 5: Table Of Contents
Table of Contents CHAPTER 1 Introduction......................1 Before First Use ....................1 CHAPTER 2 Overview......................3 Control Panel and Loudspeaker ................3 Battery Compartment................... 5 Tripod Mounting Plate..................5 CHAPTER 3 Installation......................7 Installing the Echo Speech Source Software............7 Batteries....................... -
Page 7: Introduction
Chapter 1 Introduction Thank you for purchasing Brüel & Kjær’s Echo Speech Source Type 4720. This manual contains important information for correctly and safely operating Echo Speech Source. Please take the time to read this manual and familiarise yourself with the advanced features. - Page 8 Echo Speech Source Type 4270 – User Manual • Refer all servicing to qualified service personnel. Servicing is required when the apparatus has been damaged in any way, such as: – Liquid has been spilled into the unit – The unit has been exposed to rain or moisture –...
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Page 9: Overview
Chapter 2 Overview Echo Speech Source Type 4720 is a small active loudspeaker box that provides calibrated acoustic signals for speech intelligibility measurements for use with DIRAC Room Acoustics Software Type 7841. Echo Speech Source is typically placed at a human speaker position. The received signal at a... - Page 10 Echo Speech Source Type 4270 – User Manual 2) Reference Level Speaker button (yellow LED): Plays the internal signal through the loudspeaker (13) at an A-weighted output level of 60 dB, at a distance of 1 m in front of the loudspeaker.
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Page 11: Battery Compartment
(17). 17) Battery orientation diagram. 18) Serial number label: Your Speech Source’s unique serial number. Tripod Mounting Plate Echo Speech Source Type 4720 has a 1/4-20 UNC screw thread on the bottom, which is compatible with many standard camera tripods. - Page 12 Echo Speech Source Type 4270 – User Manual Fig.2.3 Tripod mounting plate Made in the Netherlands 130733...
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Page 13: Installation
ECHO SETUP.MSI file from the stick. Batteries Echo Speech Source Type 4720 can be battery operated, using four AA batteries – 1.5 V alkaline or 1.2 V rechargeable, such as NiMH batteries. To remove the battery cover, push the centre of the locking strip (17) towards the cover center. -
Page 14: Mains Power Supply
Echo Speech Source Type 4270 – User Manual Fig.3.1 Battery removal tool and battery removal 130734 When the batteries are get low (Power Low condition), the green Power On LED (13) starts to flash and the loudspeaker is muted. The Power Low condition may disappear due to temporary battery recovery but will resume and remain (longer) as the batteries are increasingly depleted. -
Page 15: Operation
This section contains instructions for a typical auditorium speech intelligibility measurement using the Echo Speech Source and DIRAC. 1) Place Echo Speech Source Type 4720 on a camera tripod at the speaker position in an auditorium. 2) Place a hand-held analyzer at a listener position. -
Page 16: High Background Noise
This can be improved by pressing the Raised Level Speaker button (1) on Echo Speech Source Type 4720 or by increasing the Pre-Average value in DIRAC. On the other hand, if the SNR exceeds 15 dB, raising the level may not in all cases lead to a further reduction of the noise in the impulse response because the inherently higher distortion at the raised level will also add some noise that might dominate a low background noise level. -
Page 17: Voice Versus Noise
Voice versus Noise Echo Speech Source Type 4720 contains a test voice signal. This signal is based on a standard male spectrum according to IEC 60268–16 and also has a known spectral relation to the measurement stimuli (the intermittent and continuous noise signals). -
Page 18: Using An External Signal
Echo Speech Source Type 4270 – User Manual 2) Select the Test Voice (Test Voice button (6)) and, if the Echo Speech Source is placed in front of a microphone, also select Reference Speaker Level (Reference Level Speaker button (2)). NOTE: With the test voice signal selected, the Raised Speaker Level is disabled. -
Page 19: Calibration, Certification And Troubleshooting
Fig.2.1 and their descriptions in the text. Calibration After installing the included software, Echo Speech Source Type 4720, in conjunction with DIRAC Room Acoustics Software Type 7841 version 6, provides a calibrated system to measure speech intelligibility in compliance with IEC 60268–16. The nominal A-weighted sound level at a distance of 1 m in front of the loudspeaker equals 60 dB at the Reference Speaker Level and 72 dB at the Raised Speaker Level. -
Page 20: Certification
Echo Speech Source Type 4270 – User Manual NOTE 1: The check values are nominal values, based on the third octave band levels used for the calibration during production or certification. Deviations may arise due to measurement system errors or parasitic reflections if the calibration check is not carried out in an anechoic room or free field. - Page 21 CHAPTER 5 Calibration, Certification and Troubleshooting If no solution is found after checking each of the above possibilities, or if another serious fault occurs: Secure Echo Speech Source against unintended operation and Contact your local Brüel & Kjær representative and give details of any errors found. Under no circumstances should repair be attempted by persons not qualified in the service of electronic instrumentation.
- Page 22 Echo Speech Source Type 4270 – User Manual...
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Page 23: Specifications
Chapter 6 Specifications Specifications – Echo Speech Source Type 4720 STIMULI CONNECTORS Frequency range: 125 – 8000 Hz octave bands Input and output socket: BNC Maximum acoustical third-octave spectral error Max cable length: 30 m (100 – 10000 Hz bands): ± 1 dB CONTROLS Period time: 10.9 s... - Page 24 2000 Hz 8000 Hz –120º 120º 150º –150º 180º 130875 Ordering Information Type 4720 Echo Speech Source QZ-2104 Battery removal tool ZG-0864 Mains Power Supply COMPONENTS INCLUDED WITH THE ECHO Input: 100 – 240 V ~ 0.4 A SPEECH SOURCE 50 –...
- Page 25 CHAPTER 6 Specifications Compliance with Standards The CE marking is the manufacturer's declaration that the product meets the requirements of the applicable EU directives RCM mark indicates compliance with applicable ACMA technical standards – that is, for telecommunications, radio communications, EMC and EME China RoHS mark indicates compliance with administrative measures on the control of pollution caused by electronic information products according to the Ministry of Information Industries of the People’s Republic of China...
- Page 26 Echo Speech Source Type 4270 – User Manual...
- Page 27 Numerics 4231................9 IEC 60268–16............ 11, 13 4720.......1, 3, 5, 7, 9, 10, 11, 13, 17, 18 Impulse response ............. 11 7841..............9, 13 Impulse response-to-Noise Ratio......10 Input ................4 LED ............... 4 Attenuator cable ............12 Signal ..............4 A-weighted............
- Page 28 Test voice..........4, 11, 12, 17 Voice ................ 11 third-octave ............13, 17 Voice versus noise............ 11 Tripod mounting plate..........5, 6 Troubleshooting ............14 Warnings ..............1 USB Audio Interface............ 9 Using an external signal ..........12 ZE-0948..............9...
- Page 32 HEADQUARTERS: Brüel & Kjær Sound & Vibration Measurement A/S · DK-2850 Nærum · Denmark Telephone: +45 7741 2000 · Fax: +45 4580 1405 · www.bksv.com · info@bksv.com Local representatives and service organisations worldwide...