Thanks, Shancopp. I picked Blackberry Crush. I had to order the 5-sp man. with no options except the alarm and it took 2 weeks.
Frostwolf, I already checked the setting before posting here. It was already set at xB. I played around with the different car-model settings. It didn't make a difference as far as front speakers/rear speakers sound quality.
I made some recordings with
Olympus DS-30 to illustrate the condition.
Front is front speakers only with recorder held at the height of the head unit between the two front speakers.
Rear is rear speakers only with recorder held at the height of the head unit between the two rear speakers.
Front Right is recorder held at about 12 inches in front of front right speaker.
Rear Right is recorder held at about 12 inches in front of rear right speaker.
Volume level (35), Bass level (0), Treble level (5), and SSP (Feel) settings are all the same during the four conditions. Fade is all the way front during front speaker recordings and all the way rear during rear speaker recordings.
From listening to and comparing these recordings, I think the rear speakers lack the bass and the 'boom' feeling and a bit too much mid-range compared to front right speaker. And I think the rear speakers are positioned too low. The sound quality sitting at the middle of rear seat is nowhere near the sound quality sitting at either the front seat.
I don't know why Scion makes front speakers sound so much better than the rear speakers. That was why I posted the question in the first place, wondering if there was something wrong with my rear speakers.
Make sure you turn down your treble level when you listen to these recordings, treble is very sharp. I have also included a clip of the actual mp3 music file for reference.
Front Speakers
Rear Speakers
Front Right Speaker
Rear Right Speaker
The actual mp3