Audio Systems — Testing and Evaluation
Visteon's audio testing laboratories are a key capability behind its success in premium audio systems. Located within Visteon's technical centers in Van Buren Township, Mich., U.S.; Dunton, England; São Paulo, Brazil; and Shanghai, China, these facilities provide the objective measurements and documentation that improve the subjective responses of in-vehicle audio listeners.
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| Established in 1981, Visteon's Dearborn facility is the industry's first car audio-lab on record. |
Speaker Testing
Visteon's audio laboratories feature hemi-anechoic chambers — sound-insulated rooms that eliminate echoes and reverberations during speaker testing. Through the elimination of echo and reverberation, engineers can measure the true acoustic performance of a speaker.
Visteon's speaker tests measure three parameters:
- Frequency Response – measuring how accurately a speaker reproduces each frequency within the range of human hearing.
- Total Harmonic and Inter-modulation Distortion – measuring non-linearity, Visteon engineers can prevent speaker distortion and add tones that are not part of the original recording.
- Cone Displacement and Offset Tracking – measuring speaker cone movement to diagnose and correct speaker design issues using a Visteon-developed test that includes laser-based measurements.
To isolate any potential issues, the speaker chambers allow the speaker's acoustic performance characteristics to be quantified before they are placed in the vehicle cabin for system-level measurements.
Objective Measurements
While Visteon audio engineers work toward the ultimate goal of constantly improving the subjective responses of listeners; the majority of testing efforts are based on objective criteria. Focusing upon scientific measurements and documentation, these engineers can deliver the best quality to a wide range of audio systems and vehicle types.
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Subjective Sound Qualities: Imaging — The positioning of separate sound elements. Often referred to as the "soundstage." Ambience — An aural sense of the space in which the recording was made. |
Assessing Listener Satisfaction
While having objective data can improve sound quality, necessary measurements of subjective characteristics, such as imaging and ambience, are more difficult to gauge. However, by using a subjective listening process based upon objectivity, Visteon can accurately compare the subjective parameters of different audio systems.
Conducted with trained listeners, these tests are referred to as "Blind A/B Tests." This test methodology uses unbranded audio systems, preventing the listener from knowing what system they are hearing. This approach eliminates the potential for bias, which typically makes such experiments difficult. With precise recordings that recreate audio system performance, including the imaging and ambience, listeners rate sound quality on a scale of 1 to 5, without knowing the type of vehicle or system being tested.
The data generated from this test is highly accurate. Visteon proprietary research indicates a 98-percent satisfaction correlation between customer response and test method measurements. Just another proof point that this valuable information can help vehicle manufacturer design teams understand how changes in packaging can positively or negatively affect audio system quality.
Additional Information
Interactive Module - Audio and Multimedia Systems
Product Specifications - Digital Signal Processing System
Capabilities - Audio Testing Laboratories
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