The HEAD Measurement Systems used in combination with the HEAD Playback Systems offer an unmatched level of realism and clarity in the recording and reproduction of product noise events. The use of artificial heads allows all the attributes of a sound to be preserved including three dimensional cues and room effects. When the recordings are played through the calibrated Playback System and Electrostatic HEADphones, the listener can hear the sound precisely as it occurred during the live event. Use of artificial head recordings is important for design teams because it enables accurate comparison of different products' sounds or uncovering subtle annoyances in the sound. The recordings become an effective communication tool for setting targets, approving designs, or providing direction to engineers as to which attributes of the sound need to be measured and controlled.
HEAD Measurement Systems
HMS III.0
The HMS III.0 is a digital HEAD Measurement System that uses state-of-the-art 24 bit technology to provide a dynamic range comparable to that of human hearing. Digital equalizations (ID, FF, DF, USER) are selectable for measurement compatibility and to ensure a high level of repeatability between different heads. The HMS III.0 has a built-in system check to ensure error-free function of all elements in the signal chain.
Inputs include up to two tach signals and AES/EBU to connect a second HMS III or BEQ II to create 4 channel measurements. Outputs include USB, AES/EBU, and analog. Set-up and control of the HMS III.0 is either by RS232 (PC and RC V) or by the USB interface. Analog outputs of equalized head data are available for sending signals to analog data acquisition systems.
All set-ups of range, equalizations, sampling rates, etc., can be either accomplished via the connected PC or via the handheld remote control unit RC V. Set-up information may be embedded on the least significant bit (LSB) on one of the data channels to fully self document measurements. All the electronics are housed inside the head and shoulder unit and can be powered by an internal battery or external DC source.
Using the USB interface, all that is needed for a complete recording and analysis system is the HMS III.0 and a Notebook PC.
Following is an overview of the possible connections to the HMS III.0:
For a data sheet, please select the "downloads" area from the HEAD acoustics GmbH site www.head-acoustics.de
HMS III.L
The HMS III.L is a lower cost 16 bit alternative to the HMS III.0 HEAD Measurement System. It has all the features of the HMS III.0 with the following exceptions: Only 16 bit operation, no USB interface, no automatic system check, and no sound level meter. It is a nice option when budgets are restricted and recordings are being made to analog data acquisition systems or to 16 bit digital measurement systems. The HMS III.L can be upgraded to the HMS III.0.
For a data sheet, please select the "downloads" area from the HEAD acoustics GmbH site www.head-acoustics.de
HEAD and Shoulder Unit
HSU III
The HSU III is a simple analog artificial head that includes only microphones and preamplifiers. Thus it can be used with any device that supports measurement microphones. Proper use requires the application of the appropriate equalizations (ID, FF, DF) prior to measurement of data. Equalization may be performed with the BEQ II.1 frontend.
For a data sheet, please select the "downloads" area from the HEAD acoustics GmbH site www.head-acoustics.de
Artificial Head Microphone for high sound pressure levels
HSU III.1
HSU III.1 is an artificial head measurement system for high sound pressures, such as those occurring during the inflation of an airbag. HSU III.1 reproduces the acoustically relevant components of the human outer ear, thus allowing binaural, aurally-accurate recordings of sound events to be made. HSU III.1 complies with the requirements of the ITU-T P.58 standard in the receiving direction. The microphones in the ears of HSU III.1 also comply with the requirements of the IEC 1094 standard.
The HSU III.1 artificial head is to be used in combination with the BEQ II.1 frontend, which features the necessary signal conditioning and provides custom equalization options.
For a data sheet, please select the "downloads" area from the HEAD acoustics GmbH site www.head-acoustics.de
Binaural HEAD Microphone
BHM III.2, BHM III.3
The Binaural HEAD Microphone BHM III is designed for measurement situations in which the artificial head cannot take the place of the human listener, e.g. behind the steering wheel of a vehicle.
The Binaural HEAD Microphone BHM III is worn like standard headphones and the user takes over the acoustic function normally performed by the artificial head in the sound field. The sound is conducted via small tubes to two measurement microphones which are housed in special capsules located externally to the ears. An adjustable headband ensures optimum comfort for wearer. The BHM III.2 can be used with any device that supports measurement microphones, while the BHM III.3 utilizes ICP preamplifiers and can be used with any device providing ICP power. Proper use requires the application of the appropriate equalizations (ID, FF, DF) prior to measurement of data. Equalization may be performed with the BEQ II.1 or other available frontends in combination with HEAD acoustics acquisition software.
For a data sheet, please select the "downloads" area from the HEAD acoustics GmbH site www.head-acoustics.de
HEADphone Playback Systems
Programmable Equalizer with Electrostatic Headphones and Power Amplifier
PEQ IV, PVA IV.3, and HA III
The digital 24 bit HEADphone Playback System is complementary to the Head Measuring System HMS III. Conditioning of audio data for aurally-accurate playback is via equalization of the acoustic signal in the programmable Equalizer PEQ IV, with subsequent amplification via the Power Amplifier PVA IV.3. Two individually calibrated electrostatic headphones HA III can be connected to the Power Amplifier system. Additional sets of amplifiers and headphones may be connected in series to add an unlimited amount of listeners.
The HEADphone Playback System ensures true-to-the-original playback of both 24 bit recordings of Artificial Head of the new HMS III generation, and 16 bit Artificial Head recordings, thus achieving optimum spatial imaging with aurally-accurate reproduction of recorded acoustic situations.
For a data sheet, please select the "downloads" area from the HEAD acoustics GmbH site www.head-acoustics.de
Programmable Equalizer with Electrodynamic Headphones and Distribution Amplifier
PEQ V, HD IV.1, and HDA IV
A very suitable low cost alternative to the electrostatic HA III HEADphones for calibrated playback is the HD IV.1 Dynamic Headphones, which can be plugged directly into the PEQ V for up to two listeners and do not require the power amplifier for operation. To extend the number of listeners, the HDA IV.1 and HDA IV.2 (shown above) Headphone Distribution Amplifiers can be used in combination with the PEQ IV to supply signals for up to four and eight pairs of HD IV.1 headphones respectively.
For a data sheet, please select the "downloads" area from the HEAD acoustics GmbH site www.head-acoustics.de
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