Here is the Speaker Layout for the 2019 ES PioneerView attachment 3150
I also have asked the dealership about this, and was told that "Lexus is aware there are complaints." "However, there is nothing in the works to change anything." So, rather than live with this substandard system until it's time to trade, I was wondering if anyone has tried an after market solution? My guess is that simply replacing the speakers isn't going to do it, that is likely the power going to the rear speakers.
I once had a Datsun B210 that had a better sounding system....