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OWNER’S MANUAL
APM /
1. APM DESCRIPTION
THE PROJECT
Audison APM is the result of years of research and development into a complex topic, the evaluation of in-car sound
quality. It has always been a challenge for the automotive industry to provide a measurement system dedicated
to the objective evaluation of the sound quality, intended to support and not replace the subjective evaluation that
remains one of the most amazing human qualities.
Thanks to APM’s technology, sound quality evaluation is no longer influenced by the listener’s preferred music
genre. APM technology is able to replicate the auditory perception of humans and therefore to measure the system
performance with a high level of precision.
The bit Tune hardware platform implements APM functions, providing the market as well as industry specialists with
a complete tool. This enables two innovative types of analysis, which objectively evaluate customized and OEM car
audio systems.
APM MEASUREMENTS
The APM software is composed by two measurement tools: the
FSA (Front Stage Analysis) and TMD (Total Music Distortion)
.
The asymmetric listening position affects the quality of in-car sound reproduction. Placing the front soundstage
at the center of a car hi-fi system is the most critical and challenging element. The FSA tool provides the ability to
automatically determine the location of the virtual sound image generated by a stereophonic configuration.
This technology was made possible thanks to the dummy head, which allows to recreate the HRTF (Head Related
Transfer Function) and an innovative approach, based on binaural and monaural cue which was studied to
simulate the human auditory perception of the sound image.
Thanks to the FSA, the front sound emission can be analysed as if your dashboard were the soundstage of a
concert to determine, with high level of accuracy, the centre stage on the two axis, providing the FSA score as result.
TMD (Total Music Distortion) is a tool able to measure the linear and non-linear distortions of the system’s
frequency response using a real musical track unlike conventional methods of measurement.This analysis can be
performed at different sound pressure levels, which is very significant to identify the system’s performance when
we push the system close to or over its distortion point, giving different TMD scores for different SPL categories.
MASTER SOUND QUALITY RACE
The Master Sound Quality Race is a new contest format where the evaluation of the sound quality is determined
partly by a traditional listening test, made by qualified judges, and partly by the APM system.
Our goal is not to replace human presence with APM technology. We rather see an opportunity to add further value
to the judge’s critical listening and create an online worldwide network to allow the participants to compare and
share the APM results.
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