On my Xbox 360, I have both Guitar Hero World Tour and Guitar Hero 5. The Xbox is connected to an Onkyo TX-SR606 receiver via HDMI. I have a high-end (SV Sound) 5.1 surround sound system that is precisely calibrated in both frequency and time domains, and the TV is a Pioneer Elite PRO-111FD connected via HDMI to the receiver.
The audio in GH:WT is crystal clear - all frequencies are balanced and even, including bass coming out of the subwoofer - sounds amazing to listen to, and my Dolby Digital option in the game is enabled. However, when I play Guitar Hero 5, using the exact same hardware configuration, the audio is muddy, and the bass coming from the subwoofer is not deep and is rather weak. In GH5, I've tried both Dolby on and off - neither make a difference in clearing up the audio.
In both GH:WT and GH5, I have all the sliders set to Reset (all even and in the middle), so all instruments are balanced to dead center in both games.
Why does the audio suck so bad in GH5 and is there any way to fix it?