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Review, Measurements, and Questions: Porsche Macan Bose Audio

alanca3

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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.
Bose-Porsche-Panamera-Sound-System-Overview.jpg


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

MMM vs Spatial Average (All Channels Linear ON Surround OFF).png


With 45 dB scale
MMM Vs Spatial Average 45 DB scale.png


Front Left Channel Only
9 measurement spatial average + MMM average

MMM vs Spatial Average Left Channel .png


With 45 dB scale

MMM vs Spatial Average Left 45 Db Scale .png



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).
Front Speaker Alignment.png


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.
 

pozz

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Nice work! First review of its kind that I've seen

Maybe the surround mode would sound better? Does it include upmixing? Car systems have to deal with a lot of crosstalk and comb filtering.

Not sure what accounts for the MMM results other than your sweep pattern.

@hardisj Do you have an opinion?
 
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alanca3

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Nice work! First review of its kind that I've seen

Maybe the surround mode would sound better? Does it include upmixing? Car systems have to deal with a lot of crosstalk and comb filtering.

Not sure what accounts for the MMM results other than your sweep pattern.

@hardisj Do you have an opinion?

Thanks!

Bose is very vague and lists two DSPs, "Centerpoint" and "SurroundStage." Centerpoint is an up mixer, and this is how they describe SurroundStage:
SurroundStage signal processing puts every listener in the center of the music, no matter where they’re sitting. It uses every speaker optimally to ensure a rich and immersive audio experience within the confines of your car.
Hmm...

Sometimes it's nice sometimes it's annoying, so I typically leave it off.
 

GD Fan

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Really interesting stuff.

The Bose system in my 2013 Boxster S has a default setting that's essentially bass boost (can't recall the exact name at the moment). For years the exaggerated bass was alternatingly pleasing and (mostly) annoying until I turned it off. The sound is now far more in balance, though still definitely Bose. Not sure why such a thing would be on by default. Anyway, does yours have a similar default?

Thanks for posting.
 

andreasmaaan

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Yeh, well done with this :)

Is there a simple old EQ in the settings? I would just knock back that vicious peak at 40Hz by about 10dB and see how it sounded.

What signal did you use for the MM measurements?
 

hardisj

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Car audio is my birthplace. And, I'll just say this out loud, regardless of what others will think...

Car audio is waaaaaaaaaaaay harder than home audio. Way. Harder. I'll die on this hill. ;)



See if this video helps you. I made this a while back and focus on the differences between MMM and spatial averaging. Pointedly, there are two methods of a MMM. 1) Sit in the car and hold the mic up in front of your face. 2) Sit behind the MLP and move the mic around. The body makes a lot of difference. And if you are trying to achieve a 'target curve' then odds are that curve never once considered the effect of the body in the seat (#1) and assuredly was built off #2.

Keep in mind, this was created using a little bluetooth speaker in my living room. It's not intended to represent the response in the car. It is simply to illustrate the different measurement methods and the issues/differences between them.

 

GD Fan

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The body makes a lot of difference. And if you are trying to achieve a 'target curve' then odds are that curve never once considered the effect of the body in the seat (#1) and assuredly was built off #2.

Keep in mind, this was created using a little bluetooth speaker in my living room. It's not intended to represent the response in the car. It is simply to illustrate the different measurement methods and the issues/differences between them.

This reminds me of once reading that concert soundboard pros have been known to refer to the audience as "meat baffles." Not an easy phrase to forget, that.
 
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alanca3

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thanks y'all : )

Really interesting stuff.

The Bose system in my 2013 Boxster S has a default setting that's essentially bass boost (can't recall the exact name at the moment). For years the exaggerated bass was alternatingly pleasing and (mostly) annoying until I turned it off. The sound is now far more in balance, though still definitely Bose. Not sure why such a thing would be on by default. Anyway, does yours have a similar default?

Thanks for posting.


Yes, Linear mode! It takes a good bit of bass away.

Yeh, well done with this :)

Is there a simple old EQ in the settings? I would just knock back that vicious peak at 40Hz by about 10dB and see how it sounded.

What signal did you use for the MM measurements?


Unfortunately no EQ except "bass/treble"
Mono 64k Pink Periodic

Car audio is my birthplace. And, I'll just say this out loud, regardless of what others will think...

Car audio is waaaaaaaaaaaay harder than home audio. Way. Harder. I'll die on this hill. ;)


Thats what I've been looking for, I'll have to check it out.
I agree with you, car audio is way more frustrating than in-room stuff.
 

CDMC

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Car audio is my birthplace. And, I'll just say this out loud, regardless of what others will think...

Car audio is waaaaaaaaaaaay harder than home audio. Way. Harder. I'll die on this hill. ;)



See if this video helps you. I made this a while back and focus on the differences between MMM and spatial averaging. Pointedly, there are two methods of a MMM. 1) Sit in the car and hold the mic up in front of your face. 2) Sit behind the MLP and move the mic around. The body makes a lot of difference. And if you are trying to achieve a 'target curve' then odds are that curve never once considered the effect of the body in the seat (#1) and assuredly was built off #2.

Keep in mind, this was created using a little bluetooth speaker in my living room. It's not intended to represent the response in the car. It is simply to illustrate the different measurement methods and the issues/differences between them.


I have played with car audio a fair amount. The biggest problem I have had is the noise floor of 70db. Too much bass at stops and low speeds, too much at higher, fatigue from higher listening levels to drown out the background.
 

amirm

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The smaller the space, the higher the transition frequency, and the larger the modal response. In other words, the car seriously impacts the frequency response of the speaker well into hundreds of kilohertz. If you talk to Harman folks, they always remind you that getting good sound in a car is a lot harder than home.
 

restorer-john

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In other words, the car seriously impacts the frequency response of the speaker well into hundreds of kilohertz.

Hundreds of Kilohertz. They be some amazing tweeters you got in that vehicle. ;)
 

Blumlein 88

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I would have guessed Schroeder was higher than it is. Apparently an average sized sedan is 400 hz or so.

Oh well one of my vehicles I can drop the top.

I've one car with an early Bose system. It isn't very good by my subjective judgement. Not terrible, just not all that special. Have an Infinity system in another and it is pretty nice for in car stuff OEM. It isn't the finest I've heard in a car, but it is truly better than the normal level of clarity and musical satisfaction in most OEM audio gear.
 

thewas

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Very nice review, I used to do MMM RTA in my cars to adjust the EQs long before it became fashionable in home hifi, using back then a software called Praxis from Liberty Instruments.
Find also your MMM discrepancy weird though as it usually matched the averages of individual sweeps much better, could you maybe post a screenshot of your REW RTA settings?
 

Chromatischism

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Car audio is my birthplace. And, I'll just say this out loud, regardless of what others will think...

Car audio is waaaaaaaaaaaay harder than home audio. Way. Harder. I'll die on this hill. ;)



See if this video helps you. I made this a while back and focus on the differences between MMM and spatial averaging. Pointedly, there are two methods of a MMM. 1) Sit in the car and hold the mic up in front of your face. 2) Sit behind the MLP and move the mic around. The body makes a lot of difference. And if you are trying to achieve a 'target curve' then odds are that curve never once considered the effect of the body in the seat (#1) and assuredly was built off #2.

Keep in mind, this was created using a little bluetooth speaker in my living room. It's not intended to represent the response in the car. It is simply to illustrate the different measurement methods and the issues/differences between them.

Do you do Dirac measurements with a body in the seat? In your theater?
 

hyperplanar

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Nice review! I had a Macan S with the Bose system a few weeks ago as a loaner and your impressions match mine exactly. Exaggerated peaky bass with rolled off subbass, weirdly harsh, glaring, and unnatural lower treble, and a generally scooped sound. I’m curious as to whether you have any measurements with linear mode being on? Would be nice to quantify exactly what it does to the frequency response.
IMO Porsche’s sound systems are pretty underwhelming in general, and one of the brand’s biggest sore spots. Overall, I would describe the sound system in the Macan as acceptable but not particularly high fidelity. It was better than the Bose system in my 911 though. Additionally, I rented a Cayman before and the base system in that was absolutely unacceptable.
On the other hand I find BMW does a pretty good job with both the base US (this is called the Hi-Fi option outside of US) and Harman Kardon options.
 

ernestcarl

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Never measured inside of a car before, but I think this will be very interesting to try out next time around -- maybe in the summer as it already snowing and quite cold ~ -8 degrees celsius here now outside.
 

ernestcarl

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Very nice review, I used to do MMM RTA in my cars to adjust the EQs long before it became fashionable in home hifi, using back then a software called Praxis from Liberty Instruments.
Find also your MMM discrepancy weird though as it usually matched the averages of individual sweeps much better, could you maybe post a screenshot of your REW RTA settings?

Yeah, there is something definitely odd with the MMM measurements.
 

hardisj

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Also, I see you guys focusing on the FR of a car audio system being hard. Tonality is easy with enough EQ bands.

The hard part; the part that will never be close to home audio is the other stuff. Imaging, focus, width, depth. Even with time alignment (I have a video on that as well). In a car, the width is practically defined by the physical placement. You don't have the benefit of a side wall 3 feet away from the speakers like you do in the home. So, there is no apparent source width (ASW) other than the side windows as new pointsources but they are still extremely close to the physical location, so the image might increase in width by a couple inches, but not by feet.

And, FWIW, when I say I am in to car audio, it's not as a general hobbyist. I actually have been "competing" (side topic) in car audio at the highest level for years. Helping tune the world's best cars (literally). I am drawing from immense experience on this topic.
 
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