I would suspect a poor speaker/amp match just because all the Dynaudios I know like lots of juice. From what I've heard or been told, SimAudio amps like them, so do KT88-based tube amps.
That said, positioning and the room make a great difference in how speakers sound. More hard than soft surfaces tend to make the music sound, well, hard. Positioning near the wall or too close to a corner can make boom.
If you suspect your DVD player is the weak link, cheap tweaks include a power cord, an isolation transformer (eBay) and antivibration footers like the ones from Herbie's Audio Labs. The PC source can be helped with a quality USB cable like the one from Acreyes here.
Also, is your digital interconnect 1.5 meters long?
That said, positioning and the room make a great difference in how speakers sound. More hard than soft surfaces tend to make the music sound, well, hard. Positioning near the wall or too close to a corner can make boom.
If you suspect your DVD player is the weak link, cheap tweaks include a power cord, an isolation transformer (eBay) and antivibration footers like the ones from Herbie's Audio Labs. The PC source can be helped with a quality USB cable like the one from Acreyes here.
Also, is your digital interconnect 1.5 meters long?