It is impossible for me to enjoy listening to the radio when the speakers are mounted down by my feet 🦶. Reasons our Creator did not put ears on our feet. I own Mazda Miata also and I having large speakers in the door panel .
When I was having my car assembled I listen to the speakers in the show room and yes they sounded fantastic because the engine was in running.
I believe that the reason that the speakers are under the dash is because it’s very easy for the manufacture to put them there so you don’t have to deal with wiring into the door
Your feelings about this, because I’m having of radio disconnect and returning it. The name of the radio is called Retrosound. Expensive radio with so many options that I don’t use and I’m very disappointed that I bought the radio with the car because face plate match the paint on the dashboard. I put a different muffler on it and my dB her reading about 96 to 100.
My best enjoyment of radio is having head buds in and in when I’m in traffic , I only have one in.