Page 1
Instruction Manual GRAS 45BB KEMAR Head and Torso GRAS 45BC KEMAR Head and Torso with Mouth Simulator...
Page 2
Any technical documentation that is made available by GRAS is the copyrighted work of GRAS and is owned by GRAS. The content in this document is subject to change without notice. GRAS Sound & Vibration is not liable or responsible for any errors or inaccuracies that may appear in this document.
Contents Introduction ..............................5 The Concept ................................5 Standards ................................5 General Description ............................6 45BB KEMAR and 45BC KEMAR – Common Description ................6 45BC KEMAR Head and Torso with Mouth Simulator – 45BC only ............15 45BB KEMAR – Delivered Items ....................... 18 45BB KEMAR Head &...
Page 4
Test Setups ..............................36 45BB KEMAR Test Setups ..........................37 Hearing Aid Test ..............................37 Sound Quality Recording ...........................38 Ear and Headphone Test ...........................39 Test of Binaural Hearing Aids ..........................40 Low-noise Test of Ear- and Headphones .......................41 45BC KEMAR Test Setups ..........................42 Headset Test .................................42 Telephone Test ..............................45 Low-noise Testing of Headsets ........................46...
• ITU-T Rec. P.57 Type 3.3 Artificial Ears and based on • ITU-T Rec. P.58 Head and Torso Simulator for Telemetry See also the KEMAR Book (KB0000). Can also be downloaded from www.gras.dk. Instruction Manual 45BB/45BC Kemar Head and Torso | 5...
Mouth Simulator – 45BC only” on page 15. The GRAS 45BB KEMAR Head and Torso and the GRAS 45BC KEMAR Head and Torso with Mouth Simulator simulate the way an average human being influences a sound field. They are modern- ized versions of the original KEMAR and made according to the same dimensions and speci- fications as the original KEMAR.
Page 7
G.R.A.S. Serial No. XXXXXX Head and Torso Type 45BB Left Ear Right Ear Power G.R.A.S. 200V 200V Supply Serial No. XXXXXX Head and Torso Type 45BB Left Ear Right Ear Power Supply 200V 200V Fig. 3. Side view of KEMAR shown with pinnae. Fig.
Page 8
KEMAR Pinna Standard Pinna Six different pairs of pinnae are available from GRAS for the KEMAR Head and Torso. They are designed for an easy push-fit in the ear recesses on the sides of the KEMAR Head. A pair of KEMAR pinnae is included in all pre-configured KEMARs, selected according to the con- figuration in question.
Page 9
The hardness is 35 Shore 00. Ear Canal Extensions All standard GRAS ear canal extension are made of steel and will not deform when testing devices in the concha or devices that are pressed against the pinnae, for example telephone handsets and earphones.
Page 10
45BB-7 and 45BB-8 KEMAR. The IEC 60318-4 (formerly 60711) Ear Simulator The GRAS 60318-4 Ear Simulator is an ear simulator with an input impedance that closely resem- bles that of the human ear when it is combined with ear canal extension and pinna.
Page 11
Note: The RA0045 / RA0045-S1 can be mounted for both left and right ear. The Externally Polarized Ear Simulator RA0045 It is based on the GRAS 40AG ½” Ext. Polarized Pressure Microphone and is supplied with an indi- vidual calibration chart for the coupler-microphone combination.
Page 12
The 43BB Low-noise Ear Simulator/43BB Low-noise Ear Simulator System The GRAS 43BB is a low-noise, high-sensitive version of the well known IEC 60318-4 ear simu- lator. It consists of the standardized IEC 60318-4 ear simulator and the GRAS 40HT low-noise microphone system.
Page 13
For further information about RA0401/RA0402, visit gras.dk. A whitepaper discussing the High- Frequency Ear Simulator in detail can be downloaded from the RA0401 product page at gras.dk. Typical response Upper tolerance Lower tolerance 1000 10000 Frequency [Hz] Fig. 12. Typical coupler frequency response re. 500 Hz.
Page 14
3D Simulation Model For simulation of KEMAR’s influence on the sound field, a simulation model of KEMAR can be ordered separately. This product contains a USB flash drive with a CAD file. The CAD file is in STEP file format and is made as a solid part file and is compatible with almost any 3D CAD software.
45BC KEMAR Head and Torso with Mouth Simulator – 45BC only The 45BC KEMAR Head and Torso is similar to the 45BB except that it also has a built-in mouth simulator and a power amplifier for the mouth simulator. The power amplifier is located in the KEMAR’s base.
Page 16
For feeding an external signal to the mouth simulator, two options exist: • Feed a line signal via the built-in power amplifier. • Feed the signal directly from an external power amplifier. In this case, do not connect the included power supply to the KEMAR (the internal power amplifier is automatically bypassed). Fig.
Page 17
Instruction Manual 45BB/45BC Kemar Head and Torso | 1 7...
45BB KEMAR – Delivered Items 45BB KEMAR Head & Torso, non-configured The GRAS 45BB KEMAR Head & Torso, non-configured is a basic head and torso assembly without configuration specific accessories. The parts shown in Fig. 16 are included. 45BB KEMAR Assembly...
Page 19
The components listed below are delivered if you order a non-configured version of the 45BB KEMAR without the additional application specific components. If you order a pre-configured 45BB KEMAR, the components that comprise the 45BB KEMAR Head & Torso, non-configured are delivered as part of the pre-configured assemblies.
45BB-5 KEMAR for Ear and Headphone Test, 2-Ch LEMO 45BB-6 KEMAR for Ear and Headphone Test, 2-Ch CCP Basic Delivery KEMAR Head and Torso, non-configured 45BB Common Accessories Large Left Large Right Straight Pinna Straight Pinna 26AS GR1440B 45EA GR0917 (55 Shore 00) (55 Shore 00) KB0066...
45BB-7 KEMAR for Test of Binaural Hearing Aid, 2-Ch LEMO 45BB-8 KEMAR for Test of Binaural Hearing Aid 2-Ch CCP Basic Delivery KEMAR Head and Torso, non-configured 45BB Delivery as a standard 45BB except that the assemblies for holding the Pinnae and Ear Canal Extensions are made from POM to enable RF communication.
45BB-9 KEMAR w. Anthropometric Pinna for Ear and Headphone Test, 2-Ch LEMO 45BB-10 KEMAR w. Anthropometric Pinna for Ear and Headphone Test, 2-Ch CCP Basic Delivery KEMAR Head and Torso, non-configured 45BB Common Accessories Large Left Large Right GR1440B 26AS 45EA GR0917 G.R.A.S.
45BB-11 KEMAR for Low-noise Ear and Headphone Test, 1-Ch 45BB-12 KEMAR for Low-noise Ear and Headphone Test, 2-Ch Basic Delivery KEMAR Head and Torso, non-configured 45BB 45EA Common Accessories GR1440B 26AS GR1440B GR0917 GR0917 Large Left Large Right G.R.A.S. G.R.A.S. G.R.A.S.
45BB-13 High-Frequency Test of Ear and Headphones, 2-Ch LEMO 45BB-14 High-Frequency Test of Ear and Headphones, 2-Ch CCP Basic Delivery KEMAR Head and Torso, non-configured 45BB Common Accessories Large Left Large Right GR1440B 26AS 45EA GR0917 G.R.A.S. G.R.A.S. G.R.A.S. G.R.A.S. Anthropometric Pinna Anthropometric Pinna (35 Shore 00)
45BB-15 KEMAR, Test of Ear & Headphones w. Hi-Res Ear Simulator, 2-Ch LEMO 45BB-16 KEMAR, Test of Ear & Headphones w. Hi-Res Ear Simulator, 2-Ch CCP Basic Delivery KEMAR Head and Torso, non-configured 45BB Common Accessories Large Left Large Right GR1440B 26AS GR0917...
45BC KEMAR – Delivered Items 45BC KEMAR Head & Torso with Mouth Simulator, non-configured The GRAS 45BC KEMAR Head & Torso with Mouth Simulator, non-configured is a basic head and torso assembly with mouth simulator, but without application-specific accessories. The parts shown in Fig.
Page 29
45BC KEMAR Head & Torso with Mouth Simulator, non-configured – Delivered Items The components listed are delivered if you order the GRAS 45BC KEMAR Head & Torso with Mouth Simulator, non-configured. If you order a 45BC KEMAR for a specific application, the components that comprise the non-configured 45BC KEMAR are delivered in addition to the application-spe- cific accessories.
45BC-1 KEMAR for Headset Test, 2-Ch LEMO 45BC-2 KEMAR for Headset Test, 2-Ch CCP Basic Delivery KEMAR Head and Torso with Mouth Simulator, non-configured 45BC Common Accessories 26AS GR1440B GR0917 Large Left Straight Large Right Straight 45EA Pinna Pinna (55 Shore 00) (55 Shore 00) KB0066 KB0065...
45BC-9 KEMAR w. Anthropometric Pinna for Headset Test, 2-Ch LEMO 45BC-10 KEMAR w. Anthropometric Pinna for Headset Test, 2-Ch CCP Basic Delivery KEMAR Head and Torso with Mouth Simulator, non-configured 45BC GR1440B 26AS GR0917 Common Accessories 45EA Large Left Large Right G.R.A.S.
45BC-13 KEMAR for High-Frequency Headset Test, 2-Ch LEMO 45BC-14 KEMAR for High-Frequency Headset Test, 2-Ch CCP Basic Delivery KEMAR Head and Torso with Mouth Simulator, non-configured 45BC GR1440B 26AS GR0917 Common Accessories 45EA Large Left Large Right G.R.A.S. G.R.A.S. G.R.A.S. G.R.A.S.
45BC-15 KEMAR, Test of Headsets w. Hi-Res Ear Simulator, 2-Ch LEMO 45BC-16 KEMAR, Test of Headsets w. Hi-Res Ear Simulator, 2-Ch CCP Basic Delivery KEMAR Head and Torso with Mouth Simulator, non-configured 45BC GR1440B 26AS GR0917 Common Accessories Large Left Large Right G.R.A.S.
Test Setups The 45BB KEMAR Head and Torso and the 45BC KEMAR Head and Torso with Mouth Simulator are delivered fully pre-configured and tested for a number of standard test setups. Where applicable, two versions are available: • A LEMO version with externally polarized ear simulators/microphones •...
KEMAR’s ear. The externally-polarized microphone of the RA0045 Ear Simulator fitted to KEMAR picks up the hearing aid’s audio signal and sends it to the analyzer via for example the GRAS 12AK Power Module.
Sound Quality Recording The GRAS 45BB-3 KEMAR Head & Torso for sound quality recording, 2-Ch LEMO and the 45BB-4 KEMAR Head & Torso for sound quality recording, 2-Ch CCP are used for evaluation of the quality of sound. Fig. 19 shows a binaural setup for recording sound using a 45BB-3 KEMAR configured with two 40AG ½”...
Ear and Headphone Test The GRAS 45BB-5 Head & Torso for ear- and headphone test, 2-Ch LEMO and the GRAS 45BB-6 Head & Torso for ear- and headphone test, 2-Ch CCP are used for testing earphones and head- phones. Fig. 20 shows a binaural setup for testing earphones. The test signal is passed via an adjustable power amplifier to the earphones attached to KEMAR’s ears.
Test of Binaural Hearing Aids The 45BB-7 KEMAR for Test of Binaural Hearing Aid, 2-Ch LEMO and the 45BB-8 KEMAR for Test of Binaural Hearing Aid 2-Ch CCP can be used for testing of binaural hearing-aids using RF com- munication. Normally, a 45BB or 45BC KEMAR is fitted with ear-holder plates made of aluminium.
Low-noise Test of Ear- and Headphones The GRAS 45BB-11 KEMAR and 45BB-12 KEMAR are used for low-noise testing of earphones and headphones. Fig. 21 shows a monaural setup for testing earphones. The test signal is passed via an adjustable power amplifier to the earphones attached to KEMAR’s ears.
45BC KEMAR Test Setups Headset Test The GRAS 45BC-1 KEMAR Head & Torso with Mouth Simulator for headset test, 2-Ch LEMO and the 45BC-2 KEMAR Head & Torso with Mouth Simulator for headset test, 2-Ch CCP are used for testing of all types of headsets: •...
Page 43
Boom Microphone of Headsets Fig. 23 shows a monaural setup for testing a headset’s boom microphone. The test signal is passed to the mouth simulator via the built-in power amplifier. The headset’s microphone receives the signal and sends it to the analyzer via some appropriate signal condi- tioning.
Page 44
Bluetooth Headsets KEMAR Type 45BC fitted with the Artificial Ear assembly described in the previous section can also be used for Testing the Receiver of Bluetooth Headsets Fig. 24 shows a monaural setup for testing the earphones of a headset. Receiving: The KEMAR artificial ear receives the RF-to-audio converted signal from the Bluetooth headset’s receiver.
The GRAS 45BC-3 KEMAR Head & Torso with Mouth Simulator for telephone test, 1-Ch LEMO and the GRAS 45BC-4 KEMAR Head & Torso with Mouth Simulator for telephone test, 1-Ch CCP is typically used together with the 45EA Handset Positioning System for telephone tests – as shown in Fig.
Low-noise Testing of Headsets Fig. 26 shows a binaural setup for low-noise testing of the headphones of a headset. A binaural setup requires the use of two 43BB low-noise ear simulator systems. It is important that the 26HT Gain and Filter units are connected to the correct ear simulator as each pair of ear simulator and gain and filter unit are calibrated together.
Cabling and Connections External and Internal Sockets Fig. 27 shows the location of KEMAR’s sockets. Remove the head to access the sockets in the bottom of the neck. Auxilary (mouth) Left Right 200V pol 200V pol G.R.A.S. Serial No. XXXXXX Head and Torso Type 45BB Left Ear Right Ear...
Setup with Power Modules and Externally Polarized Microphones LEMO cables to ear simu- lator/microphone inside the head Auxilary u xilary xilary ilar (mouth) m outh) outh Left Left Right Right 200V pol 200V pol G.R.A.S. Serial No. XXXXXX Head and Torso Type 45BB Left Ear Right Ear Power...
Setup with CCP Preamplifiers and Prepolarized Microphones BNC cables to ear simulator/microphone inside the head Auxilary u xilary xilary (mouth) m outh) mouth) Left Right 200V pol 200V pol G.R.A.S. Serial No. XXXXXX Head and Torso Type 45BB Left Ear Right Ear Power 200V...
Setup with Low-noise Ear-Simulator LEMO cables to ear simu- lator/microphone inside the head Auxilary u xilary xilary ilar (mouth) m outh) outh Auxilary u xilary xilary ilar Left Left Right Right (mouth) m outh) outh 200V pol 200V pol Left Left Right Right...
Connections for the Mouth Simulator [45BC ONLY] To KEMAR’s mouth simulator Auxilary Auxilary (mouth) (mouth) Left Right 200V pol 200V pol G.R.A.S. Serial No. XXXXXX Head and Torso Type 45BC Left Ear Right Ear Power 200V Mouth 200V Supply Input from Power supply for external signal mouth simulator...
Disassembly and Maintenance Removing and Installing the Top of the KEMAR Head The transducers – the ear simulator(s) and/or the mouth simulator – are built into the KEMAR at delivery. To get access to the interior of the head, you must remove the top of the head as shown in Fig.
Page 53
Mounting the Top of the Head The top of the head is attached to the head by a tap at the front, two springs and a metal plate at the back. To install the top of the head: 1. Slide the pin at the front of the top into the slit at the top front of the (fore)head. 2.
Removing and Mounting Transducers The Snap Lock Mechanism Ear simulators and microphones are mounted in KEMAR’s head with a snap lock mechanism. Four spring-loaded balls in KEMAR’s ear holder plates locks the flange of the ear canal extension or microphone holder and keeps them locked in position. An O-ring on the front of the flange of the ear canal extension/microphone holder ensures a tight fit.
Page 55
Assembling with Ear Canal Extension,Microphone Holder or Ear Simulator Holder Before mounting in KEMAR, ear simulator/microphone must be assembled with preamplifier and ear canal extension, microphone holder or ear simulator holder, as shown in . When assembling, take care to not overtighten the threads. Ear Simulator with Ear Canal Extension Ear Simulator with Ear Simulator Holder Microphone with Microphone Holder...
Page 56
Removal Loosen the Allen locking screw and push on the ear simulator/microphone holder from the out- side. Mounting Guide the front of the ear canal extension/the holder through the ear holder plate and push on the back until it clicks into position. Secure the assembly with the M3 Allen screw. The flange of the ear canal extension/holder is locked to the head by four spring-loaded balls...
Removing and Mounting the Standard Pinna The standard pinna are mounted as shown in Fig. 37. The standard KEMAR pinnae all have eight holes corresponding to the KEMAR’s eight studs. A pinna is removed by gently prying and pulling it outwards. Do NOT pull at the ear lobe. To mount the pinna: 1.
Removing and Mounting the Anthropometric Pinna As shown in Fig. 38, the anthropo- metric pinna is secured to the KEMAR head with two M3 finger screws from the inside of the head. These screws ensure that the pinna seals correctly against the KEMAR head and the arti- ficial ear.
Locking the Head at an Angle Recesses for neck screw Scale and straight lined screw for locking the head at any angle Auxilary (mouth) Left Right 200V pol 200V pol 0° 45° -45° G.R.A.S. Serial No. XXXXXX Head and Torso Type 45BB Left Ear Right Ear Power...
Retrofitting KEMAR for Test of Binaural Hearing Aid KEMAR Retrofit Kit for Test of Binaural Hearing Aid Order number KEMAR Retrofit Kit for Test of Binaural Hearing Aid RA0251 Delivered items Part number Plastic Ear Holder Plates GR1676 Teflon Screw for Ear Holder Plate, M3 x 14 GR1677 Teflon Screw for Ear Holder Plate, M3 x 7 GR1678...
Page 61
Mounting the Plastic Ear Holder Plates The ear holder plates are secured by 8 screws. Use a suitable screwdriver to fasten the 8 Teflon screws. Note that one screw is shorter than the others. This one must be used in the upper middle position as shown in Fig.
Retrofitting KEMAR with Anthropometric Pinna KEMAR Retrofit Kit for Anthropometric Pinna Order number KEMAR Retrofit Kit for Anthropometric Pinna RA0311 Delivered items Part number Ear Simulator Holder for Anthropometric Pinna GR1874 Finger Screws SK6012 Allen key, 3 mm YY0028 External Ear Canal* GR0408 Union Nut* GR0409...
Page 63
Fig. 47. Ear Simulator without Ear Canal Exten- Fig. 48. Ear Simulator with the new Ear Simulator sion. Holder. 3. Remove the Ear Canal Extension by unscrewing it counterclockwise. (Fig. 47) 4. Mount the Ear Simulator Holder onto the Ear Simulator by turning it clockwise. (Fig. 48) 5.
Assembly for the Mouth Simulator [45BC ONLY] One end of the BNC-BNC Cable AA0033 is connected to the mouth simulator’s BNC socket as shown in Fig. 51, the other end is led through the neck opening and connected to the Aux socket located at the top of the torso.
Equalizing the Mouth Simulator [45BC ONLY] To equalize the mouth simulator, you will need: • The ¼” pressure microphone set delivered for this purpose with the pre-configured KEMAR. (LEMO: 46BP, CCP: 46BD). • An analyzer that is capable of equalizing the mouth simulator signal. The tube holds the microphone and preamplifier at 90 °...
Page 66
1. Using the 2 mm Allen key and the 2 x M3 screws (all supplied), mount the microphone holder onto the black collar ring (Fig. 53). The collar rings for extending the neck are not used. 2. Mount the assembly onto KEMAR. 2-mm M3x12mm Allen key...
4. Slide down the microphone set into the tube until the grid rests on the tube. The grid’s diam- eter is slightly larger than that of the tube and ensures that the microphone set is correctly positioned in the tube. 5.
If the response of the specific ear simulator at 1 kHz is + 1.45 dB (re 500 Hz), the final correction value will be -0.2 + 1.45 = 1.25 dB. GRAS recommends calibrating at 250 Hz whenever possible. 6 8 | 45BB/45BC Kemar Head and Torso...
Calibration of a KEMAR Configured with the 60318-4 Artificial Ear To calibrate the ear simulator, you will need the following (available from GRAS): • A pistonphone with a ½” coupler, e.g. GRAS 42AP Intelligent Pistonphone (recommended) or GRAS 42AA Pistonphone.
Page 70
Fig. 56. In-situ calibration of ear simulator. The low-noise ear simulator cannot be calibrated in-situ. 5. Set the analyzer to either wide band or to the 1/3-octave band (center frequency: 250 Hz). 6. When conditions are stable, adjust the analyzer so that it correctly gauges the pistonphone signal (nominally 114.00 –...
Calibration Done Outside the Head, after Clicking out the Ear Simulators Calibrating a KEMAR Configured with a Low-noise Ear Simulator For calibrating the low-noise ear simulator, the 42AG Multifunction Calibrator must be used because it calibrates at 94 dB, a level that will not overload the ear simulator. Because of size constraints, the ear simulator must be removed from the KEMAR head for calibra- tion.
Calibrating a KEMAR Configured for Sound Quality Recording Calibration of the 1/2” microphones of a KEMAR configured for Sound Quality Recording (45BB-3 and 45BB-4) cannot be done in-situ. Therefore, you must remove the microphone assemblies (holder + microphone sets) from the ear holder plates. There is no need for further disassembly, you need not remove the microphone from the microphone holder.
Technical Specifications Head-related Transfer Function Measurements The following pages feature Head-related Transfer Function (HRTF) measurements in 0º azi- muth, performed with a sound source at a distance of 1.4 m from the KEMAR. Effects of Pinna (Concha) Size and Shore Hardness Fig.
Page 74
360° HRTF Measurements on Large Left Pinna 55 Shore OO KB0066 Fig. 60 shows 360° measurements on a large 55 Shore OO pinna at seven frequencies from 250 Hz to 20 kHz. 180º 165º 195º Sound source 150º 210º 1.4 m 180º...
Page 75
Effects of Clothing and Hair A small pinna KB0060 55 Shore OO hardness against a range of manikin attire. KEMAR KEMAR with jumper KEMAR with wig KEMAR with wig and jumper 1000 10000 Frequency, Hz Fig. 61. Sound pressure level measured in the frequency range 100 Hz - 10 kHz for four different combina- tions of manikin attire.
Page 76
Effects of Neck Length A small pinna KB0060 55 Shore OO hardness against a varying neck length (0, 1, and 2 collar rings). 0 Neck rings 1 Neck ring 2 Neck rings 1000 10000 Frequency, Hz Fig. 62. Sound pressure level measured in the frequency range 100 Hz - 10 kHz for three different neck lengths.
Standards, Dimensions and other Specifications Standards ANSI S3.36/ASA58-2012 Specification for a Manikin for Simulated in situ Airborne Acoustic Measurements ANSI S3.25/ASA-2009 American National Standard for an Occluded Ear Simulator IEC 60318-7:2011 Head and Torso Simulator for the Measurement of Hearing Aids Ear Simulator, Occluded-ear simulator for the measurement of earphones coupled to IEC 60318-4 the ear by means of ear inserts...
Page 78
KEMAR External Connectors 2 × 7-pin LEMO For externally polarized microphones 3 × BNC 2 for prepolarized microphones (CCP), 1 for signal to mouth simulator DC-socket For mouth simulator amplifier, 24 V DC, max 1A Head Related Transfer Function Head and Torso Simulator for the Measurement of Hearing Aids Standard IEC 60318-7:2011 1000...
Page 79
RA0045 Ear Simulator Standards IEC 60318-4 Occluded-ear simulators for the measurement of earphones coupled to the ear by ear inserts Series P: Telephone transmission quality, Objective measuring apparatus: Artificial ITU-T Recommendation P.57 ears ANSI S3.25/ASA-2009 American National Standard For an Occluded Ear Simulator Frequency Response Typical transfer impedance RA0045 Typical Response...
Page 80
RA0401/RA0402 High-Frequency Ear Simulator Standards, based on: IEC 60318-4 Occluded-ear simulators for the measurement of earphones coupled to the ear by ear inserts ITU-T Recommendation P.57 Series P: Telephone transmission quality, Objective measuring apparatus: Artificial ears ANSI S3.25/ASA-2009 American National Standard For an Occluded Ear Simulator Frequency Response Typical transfer impedance re 500 Hz...
Page 81
Series P: Telephone transmission quality, Objective measuring apparatus: Artificial ears ANSI S3.25/ASA-2009 American National Standard For an Occluded Ear Simulator Frequency Response Typical transfer impedance re 500 Hz Typical response RA0403 GRAS RA0403 Tolerance IEC Tolerance 1000 10000 100000 Frequency [Hz] Resonance frequency 13.5 kHz ±...
Page 82
43BB Low-noise Ear Simulator Frequency Response Typical frequency response Typical Frequency Response for 43BB re 500 Hz Typical frequency response (solid blue) versus the IEC tolerances (dashed black) and the ideal IEC 60318-4 frequency response (red curve) 1000 10000 Frequency [Hz] Noise floor Typical Linear Noise Floor of the 43BB Typical linear noise floor (solid...
Page 83
Mouth Simulator Frequency Response Frequency response before 120,0 and after equalization 110,0 100,0 90,0 80,0 70,0 60,0 50,0 40,0 30,0 20,0 10,0 100,0 1000,0 10000,0 Frequency [Hz] Typical Mouth Response Typical Equalized Mouth Response Maximum Continuous Output Level at MRP 200 Hz –...
Page 84
The warranty for cables is 6 months. Service and Repair All repairs are made at GRAS International Support Center located in Denmark. Our Support Center is equipped with the newest test equipment and staffed with dedicated and highly skilled engineers. Upon request, we make cost estimates based on fixed repair categories.
Need help?
Do you have a question about the KEMAR 45BB and is the answer not in the manual?
Questions and answers