1. Transforming Sound into Knowledge
Sequence Note
EN50322-1 (Max SPL Standard)
Introduction
This sequence follows the test standard detailed in EN50322-1 for measuring the maximum sound pressure for
portable music players and the earphones/headphones they are bundled with. The test involves loading a
weighted pink noise stimulus file (as specified by IEC 268) onto the portable device and playing it through the
earphones at the player’s maximum volume. The earphones are positioned on a head and torso simulator
rd
(HATS). The signal from each ear is recorded, and a 1/3 octave curve is analyzed. An A weighting is applied to
the curves, as well as a free field correction for the HATS. The values between 20 Hz and 20 kHz are summed,
and the A weighted equivalent sound pressure level must be below 100 dBSPL.
Final Display for EN50322-1 sequence
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2. The sequence runs 5 separate trials. In between each trial the headphones must be removed and placed on the
HATS once again. This is done to average out any variability that may be due to the fit and sealing of the device
under test. The results from each trial are averaged to calculate the final LAeq values, which must be below 100
dBSPL to be in compliance with the standard.
This version of the sequence, updated for SoundCheck 11.1 makes use of the multiple virtual instrument feature
(records on two RTAs simultaneously) as well as the batch processing feature in post processing and limit steps.
Software Requirements
SoundCheck 11.1
2004 - Post Processing
2005 - RTA
2009 – Statistics
Hardware Requirements
Head and Torso Simulator (with Free Field correction curves)
Microphone Power Supplies (SoundConnect or equivalent)
4231 calibrator
Hardware Setup & Calibration
1. Load the file IEC 268_1 pink.mp3 or IEC 268_1 pink.wav onto your portable music player and set the
device to maximum volume.
2. Connect the HATS microphone outputs to the preamplifiers, and connect the preamplifier outputs to
inputs 1 and 2 on the soundcard.
3. Calibrate the HATS ears as per the instruction in the SoundCheck manual.
4. Open the free field correction curves for your HATS into the memory list. Save the two curves into the
single file HATS FF Correction Curves.dat located in the sequence folder. Overwrite the existing file.
5. Connect the earphones/headphones to the player, and fixture them on the HATS according to the
manufacturer’s fitment instructions.
You are ready to start the sequence.
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3. System diagram
Sequence Logic
Type Step Name # Out In
(Overall sequence)
Reference Standard All
Rec Curves 1 // Recalls weighting curves
Rec HATS Correction 2 // Recalls HATS FF correction curves
Mes Start Stimulus 3
display step
wait for confirmation
jump on pass to # 5: RTA
Mes Reposition 4
Acq RTA 5 Ear Sim L Ear Sim R
Pos Free field correction 6 // Applies HATS correction
// Calculates the power sum between
Pos LAEQ 7 20Hz-20kHz
Pos LAEQ 8
Sta Data Mean 9
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4. Lim Left Ear LAeq 10
Dis EN50322 display 11
display step
jump on pass to # 4: Reposition
jump on fail to # 4: Reposition
jump after 4 repetitions to # 12: EN50322 final display
overwrite curves
Dis EN50322 final display 12
Mes Test Complete - Max SPL 13
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