Take a look at the following BBC blog:-
BBC - Radio Labs
Gives an insight into their signal processing for 'Radio 3 FM, DAB, Freeview, Freesat & Online services' in respect of the 'BBC Proms'.
At the moment I am listening to Radio 2 via Freeview on my computers sound system (it does output via a USB DAC) and the sound is much preferable to my DAB radio.
For my DAB radio setup I use the DAB radio tuner optical output to feed a DAC which in turns connects to a Travagan Red headphone amplifier and a decent set of headphones.
The sound is passable but shows the shortcomings of the DAB transmission.
Harryo