My OEM setup is the JBL 12 spks system. On FM and CD modes I get a descent high and low frequency output (though I'd need to crank up the bass setting to 4; 5 being the highest). Depending on the radio station (difference in broadcasting) and CD (difference in recording) I may need to lower the setting from setting no. 4.
However, when connecting my ipod, the "apparent" sound fidelity is HUGE. Even at bass setting "0", there is more than enough low frequency output. In my opinion, listenind through the Auxiliary jack input (for connecting ipods, etc.) the sound system is at its best, and I mean HUGE, AWESOME. By the way, the bitrate at which I burn songs on the ipod is 320 kbps; not the standard 128 kbps.