Background Noise Simulation
A sequence that calibrates a 4.1 speaker array to conform with the ETSI ES 202 396-1 Standard.
This sequence calibrates a 4.1 speaker array in accordance to the ETSI ES 202 396-1 standard “Loudspeaker Setup for Background Noise Simulation”.
The standard is available for free download from the ETSI website here.
The sequence begins by measuring the front/rear balance of the left and right main speaker pairs. If they are within 2 dB of each other, the sequence will continue by measuring the combined sensitivity of each pair and, using pink noise, equalize the output of each pair. Once the left and right pairs are calibrated, the subwoofer level is manually adjusted to match the output level of the four main speakers.
Included with the sequence is a library of real world binaural recordings from the ETSI standard: cafeteria, pub, crossroad, vehicle, single voice distractor, and office noises. Custom or user-defined binaural recordings can also be used to create background noise tests directly applicable to your product. This sequence has many applications including evaluating ANC on headphones, noise suppression on communication devices, voice recognition testing of smart speakers / IoT, SNR optimization of microphones on telepresence devices and beamforming directionality studies of microphone arrays.
- Four (4) high quality monitor loudspeakers capable of flat response from 120 Hz to 20 kHz. The speakers may be powered or passive.
- Four channels of amplification (not needed if the main speakers are powered), e.g. Listen SCAmp or similar
- Powered subwoofer with a high frequency cutoff of 120 Hz and a line out to send the test signals on to the speaker array.
- Audio interface having at least 2 inputs and 2 outputs, e.g. Listen AudioConnect (Part # 4050) or similar
- Head and torso simulator (HATS) e.g. B&K Type 4128C or similar
- 2 channel microphone power supply, e.g. Listen SoundConnect 2 (Part # 4026) or similar
- 4 channel loudspeaker management system capable of creating precise delay values in the range of 0 to 30 ms.
- Splitter cables (Y adapters) to send the left and right output signals from the subwoofer line out to the two amplifier/powered speaker inputs. The termination configuration of these adapters will be determined by your specific subwoofer and amplifiers.
- SoundCheck Plus 16.0 or higher including the following modules
- 2004 – Post processing
- 2005 – RTA
- 2013 – EQ a WAV file
- 2014 – Signal Generator
- 2015 – Multimeter
- 2023 – 4 channel acquisition (8 channel optional)
Setup & Calibration
Hardware Setup & Calibration
- Observe the instructions in the standards document for recommended Test Room Requirements (section 6.1) and Loudspeaker Placement (section 6.2).
- Connect the hardware as shown in the System Diagram below
- Calibrate the HATS ears as described in the SoundCheck user manual
Software Setup & Calibration
Copy the folder containing the sequences and documentation to your SoundCheck PC. The sequences uses signal paths and calibrated device files that are unique to this sequence and not likely to be present on your current SoundCheck installation. To populate these paths and files into your calibration, please do the following.
- Launch SoundCheck and open the Calibration Editor (Setup > Calibration)
- Click the Import button, browse to the Calibration folder in the ES 202 396-1 sequence folder, select the file named system.cal and click OK. You will then encounter several dialog messages which you should respond to as follows:
Respond with: Yes to All
Respond with: No to All
At this point, your Calibration table will open automatically (open it manually if it does not) and you should assign Hardware Channels to the newly added Signal Paths.
Important: Note that the Calibrated Output device files referenced in the calibration sequence (Left and Right) are unique to this calibration sequence. The EQ, correction and sensitivity data created during the sequence run will only be written to the Left and Right Calibrated Output device files.
Also note that there are diffuse-field correction curves contained in the provided Ear Simulator calibrated device files. This correction is applied during analysis so it is critical that the default calibrated device files provided with this sequence package are used when running this calibration sequence.
You are ready to start the sequence.
This is a ‘for sale’ sequence. Please contact your sales engineer for pricing.