Hi Jae,
You can try manually optimizing your settings by selecting the Surround or Standard buttons to change the sound mode. Additionally, Press the BASS + or BASS - buttons to adjust the level of the woofer (bass) between -6 to +6.
With the latest firmware version installed (ver. 1014), press and hold the STANDARD button on the remote control for about 6 seconds then use the Bass Up/Down buttons to adjust the level of the rear speakers between -6 to +6.
^Andrew