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      04-01-2021, 08:52 PM   #56
jv92red
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Drives: F22 M240i (SOLD) E92M3 (SOLD)
Join Date: Jul 2016
Location: SoCal

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The problem with how BMW implemented the center signal in this car (no experience with BMW cars with Logic 7) is that the audio signal fed to the center channel is a summed signal AKA Mono. This is terrible for stereo separation as it will only pull the stereo signal to the center because it contains both the left and right signals along with any common signal present in the music. This is why unplugging the center channel in this car improves the sound so much. With it unplugged you go back to having left and right channels played out from their respective positions in the car. With just left and right channels playing, I would argue that the center image is actually BETTER this way than before as now it's a phantom center image. The common music between both left and right channels will be presented by your brain as in the middle of the car.

And no, replacing the center channel drivers with high-quality drivers is not a solution to fix this issue. Sure the quality of sound coming out of the drivers will be vastly improved but now you'll have very good sound reproduction of the same mono signal it's still being fed, and still pulling the stereo signal to the middle.

To implement a proper center channel will require separate processing via a DSP. If you look at for example the Audiotec Fisher DSP (Match UP 7BMW or any of the Helix units), this DSP will create a new processed center channel signal that emphasizes that "common" music that is present in BOTH the left and right channels. So with music, if there is only a right image playing and nothing else then with a proper DSP the sound will ONLY come from the right speaker. So with their proprietary algorithms of handling the left and right signals along with some level attenuation of the signal and some time alignment, THEN is a proper center channel signal fed to the center channel speaker(s)
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