Our Bose system behaves the same way. Most of the sound comes from the front. I don’t believe Mazda in conjunction with Bose really care about rear passengers. The sound quality for the front passengers on the Bose upgrade is only “good”. The rear passenger audio is adequate and the third row is outright terrible and not comfortable to listen to because of the 3d effect coming from the third row speakers and the unrefined subwoofer in the rear. The speaker drivers for the second and third row for the Cx-9 are not as powerful and not designed to be driven loudly like the front.
Have you tried with centerpoint turned off ? I find centerpoint brings the sound forward in front of you. I have not compared 2nd and 3rd row seating with it on or off. But from the front seat i can say with it on the sounds is definitely pushed more from the front, where as with it off it seems to be more equally distributed in the cabin.
Really, I'm not being a nag, but the sound system's front speakers are almost too loud when they are turned up, but it's very noticeable in the rear seats, it's almost like Mazda didn't "tune" the amp. I feel there is something wrong with it or a pot on the board inside that's not turned up enough. Just thinking outside the box..
UPDATE: Replaced all door speakers (wanted to anyway). NO CHANGE in the sound volume on the rear door speakers, when faded to the rear only. In fact, all 4 door speakers are the same descent quality and not too bad.
It just boggles my mind why the volume is so much softer on the rear speakers than the fronts. Yes, i understand this car/stereo is different than the past cars I have owned, but it's just a bit strange that the rear speakers alone are hardly loud as the fronts.
I just picked up a 2022 CX-9 Touring (no Bose Upgrade) this week. I found out the the rear speakers (2nd row door speakers) were pushing out virtually no volume. I adjusted the fade control entirely to the back, and the rear speakers are only about 15 percent of what the front speakers are. I can even adjust balance and the sound does move left to right, just with virtually no volume. When I fade it back to the front, I get full volume out of the front again. I figured this out when my tween daughter kept asking for the stereo to be turned up. Any ideas. Since the speakers are making sound, I doubt if they are the issue. Also, wiring very unlikely to be the cause.
I'm assuming this is just the way it is.. I originally noticed this when Apple Maps directions kick in, it cuts the two front speakers for the voice, but leaves the rear ones on slightly.
After reading this thread I realized that its not turning down the rears, but that's just the normal volume all the time. I wonder if it was some type of programming glitch that will get addressed in a future update.