alanca3
Member
Hey y'all. I recently completed a large set of measurements of the Bose sound system in the Porsche Macan. I'm a bit apprehensive of the results, and would love to hear your feedback.
This is a 14 speaker, 9 channel sound system. The picture below shows the layout and specifications of the drivers. Different car shown, but same system specifications.
Background
All measurements were taken with a Dayton UMM-6. Audio comes from the headphone out of a MacBook Pro.
I took a series of sine sweeps around the driver's head area. I was not in the car for these measurements.
I also took a moving average measurement. I was in the car for these measurements.
The audio settings in the car were left at their default positions. All sound processing disabled (SURROUND mode was set to OFF for all measurements).
All Channels Driven
14 measurement spatial average + two MMM measurements
With 45 dB scale
Front Left Channel Only
9 measurement spatial average + MMM average
With 45 dB scale
Front Left Channel: Near Field Driver Measurements
Keep in mind that near field measurements are only valid at lower frequencies and where the mic is nearly touching the radiator. For the tweeter measurement, the mic is sitting on top of the grill, perpendicular to the tweeter axis (Tweeter fires UP, mic pointing forward).
Subjective Evaluation
The Bose system is just OK. I prefer the sound of HARMAN automotive sound systems. On some tracks it really shines, while on others it falls apart. I remember Amir mentioning that this is a sign of a system that is spectrally unbalanced. It can get incredibly loud without distortion, and the limiter does a good job of protecting the drivers. The exaggerated bass response can be exciting sometimes, but it quickly gets tiring. The most glaring issue is the upper midrange/treble. It sounds like there is some weird resonance in that range. It makes some notes stand out, and really brings out the sibilance on vocals and cymbals. Also, the response of the front tweeters drastically changes above 6 kHz with listener height. Overall, it has a very "hi-fi curve" sound.
Adele, Mitski, and Florence + The Machine are fatiguing to listen to.
Hip-Hop/Rap stands out and sounds 'exciting' (smiley face response).
Bird On A Wire (Jennifer Warnes) sounds kind of muddy and fatiguing.
Fast Car (Tracy Chapman) sounds pleasing, but the cymbals and upper registers of her voice sound off.
Side note: Surround mode is horrible. It sounds like a poorly executed phase based matrix up mixer. It further screws up the tonality, and feels like you're in a vague soup of boomy sound.
Questions
What are your thoughts and experiences on measuring the response of car audio systems? I've seen some papers outline a system of measurement using KEMAR heads / HRTFs. Unfortunately I do not have access to such equipment.
I am wondering what causes the discrepancy between the moving mic averages and the averaged sine sweeps. Is it correct to assume that the MMM is more representative of the overall response that I hear?
If you were to measure the response of a car system, what would you do?
Thanks for reading!
Note: I have way too many raw measurements to post here. If you'd like the full REW file let me know.
This is a 14 speaker, 9 channel sound system. The picture below shows the layout and specifications of the drivers. Different car shown, but same system specifications.
Background
All measurements were taken with a Dayton UMM-6. Audio comes from the headphone out of a MacBook Pro.
I took a series of sine sweeps around the driver's head area. I was not in the car for these measurements.
I also took a moving average measurement. I was in the car for these measurements.
The audio settings in the car were left at their default positions. All sound processing disabled (SURROUND mode was set to OFF for all measurements).
All Channels Driven
14 measurement spatial average + two MMM measurements
With 45 dB scale
Front Left Channel Only
9 measurement spatial average + MMM average
With 45 dB scale
Front Left Channel: Near Field Driver Measurements
Keep in mind that near field measurements are only valid at lower frequencies and where the mic is nearly touching the radiator. For the tweeter measurement, the mic is sitting on top of the grill, perpendicular to the tweeter axis (Tweeter fires UP, mic pointing forward).
Subjective Evaluation
The Bose system is just OK. I prefer the sound of HARMAN automotive sound systems. On some tracks it really shines, while on others it falls apart. I remember Amir mentioning that this is a sign of a system that is spectrally unbalanced. It can get incredibly loud without distortion, and the limiter does a good job of protecting the drivers. The exaggerated bass response can be exciting sometimes, but it quickly gets tiring. The most glaring issue is the upper midrange/treble. It sounds like there is some weird resonance in that range. It makes some notes stand out, and really brings out the sibilance on vocals and cymbals. Also, the response of the front tweeters drastically changes above 6 kHz with listener height. Overall, it has a very "hi-fi curve" sound.
Adele, Mitski, and Florence + The Machine are fatiguing to listen to.
Hip-Hop/Rap stands out and sounds 'exciting' (smiley face response).
Bird On A Wire (Jennifer Warnes) sounds kind of muddy and fatiguing.
Fast Car (Tracy Chapman) sounds pleasing, but the cymbals and upper registers of her voice sound off.
Side note: Surround mode is horrible. It sounds like a poorly executed phase based matrix up mixer. It further screws up the tonality, and feels like you're in a vague soup of boomy sound.
Questions
What are your thoughts and experiences on measuring the response of car audio systems? I've seen some papers outline a system of measurement using KEMAR heads / HRTFs. Unfortunately I do not have access to such equipment.
I am wondering what causes the discrepancy between the moving mic averages and the averaged sine sweeps. Is it correct to assume that the MMM is more representative of the overall response that I hear?
If you were to measure the response of a car system, what would you do?
Thanks for reading!
Note: I have way too many raw measurements to post here. If you'd like the full REW file let me know.