SPL Measuring Equipment
We use an industry standard SPL sensor as used by the worlds most popular SPL organisations.
Known as the Term Lab Sensor - It is currently the most accurate & reliable way of testing for SPL.
SPL Readings: Must be taken using a TermLab sensor. The Sensor must also be placed in roughly the same position for each car.
SPL Sensor Positions etc:
We are attempting to get an SPL reading which is as reasonably accurate as possible, as if you were listening to it. To that end we take the SPL readings from roughly where your head would be when sitting in the vehicle.
1: The sensor is positioned approx where the passengers or drivers head would normally be. This means that the Sensor is attached to a HEAD REST, which represents the person in a seated position.
1a: The sensor must always be facing towards the front windscreen and fitted in either the passenger or drivers Head Rest.
1b: Once the SPL Passenger or Drivers sensor position has been chosen it has to stay in that position for the whole SPL test.
1c:The only time the SPL sensor position can be changed is when the whole testing procedure has been completed and the participant wants it to be moved to the opposite position and another test carried out to see if any of their previous scores have increased.
This is allowed due to the design of some systems (Mainly walled systems)where the Port is to one side of the vehicle making certain frequencies louder at the driver and passenger positions.
2: Seat positioning is important as the drivers seat should remain in its normal daily driving position.
The passenger seat should mirror as much as possble, the drivers seat position.
2a:On no account should the seats be pushed all the way forwards or the seat backs be positioned in such a way to increase SPL.