Automotive Sound with miniDSP Products and REW

[John Mulcahy]

Philipp Paul Klose has produced a very comprehensive application note on measuring and tuning car audio systems. Although vehicle cabins are the focus, there is a lot of great information about measurement and tuning in general. Well worth a read.

Automotive Sound with miniDSP Products and REW

 

[pklose]

Thanks John, glad you liked it!

 

[jmorris644]

Wow, what perfect timing and thanks you @pklose .

I just purchased a new EV and through a number of discussions on the main forum for the car there seems to be a small number of us in the world that are experiencing very poor and troublesome audio performance yet at the same time others are raving about the sound quality. For those of us having issues it seems that we are missing midbass to low mids. We do not have much flexibility yet to improve the sound. There are 3 tonal adjustments, treble, bass, and subwoofer. There is also an EQ with 9 bands, each having the ability to adjust their frequency by +-3db (based on my REW measurements).

I took some measurements with a calibrated UMIK-1 and places the active part of the mic just in front of my nose. I did sit in the drivers seat for these measurements. I used a saved frequency sweep from REW with a time ref and played it through blue tooth from my iPhone.

Here is a web page talking about the HK audio system. https://www.polestar.com/us/polestar-2/plus-pack/harman-kardon-audio-system/

Below is a graph of the SPL with all tone and EQ settings set to neutral. I am brand new to reading REW graphs so please bear with me. What surprises me the most, if I am reading it correctly, is the out of phase frequencies. I would love to hear from anyone.

 

[pklose]

Thanks for reading, glad you liked it!

I havent heard a polestar yet. So I cannot judge it…

If you want to use the built-in equalizer to improve your system I recommend to take several measurements like you did it once already in slightly different locations around your head (4-8 measurements) and then average them (All SPL - average the responses in bottom left corner). Then you will see a real trend. Phase can be ignored in this case.

 

[jmorris644]

Thanks for reading, glad you liked it!

I havent heard a polestar yet. So I cannot judge it…

If you want to use the built-in equalizer to improve your system I recommend to take several measurements like you did it once already in slightly different locations around your head (4-8 measurements) and then average them (All SPL - average the responses in bottom left corner). Then you will see a real trend. Phase can be ignored in this case.

Thanks. I will take multiple measurements and average them. I am curious, why can I ignore phase?

 

[pklose]

Phase is simply not important, because I cannot draw any meaningful conclusions in this environment with this many speakers. But there are certain situations where it makes sense to look at it.