We started out with very inexpensive HDMI cables between are Blu-Ray and Satellite box. Recently when I needed longer cables I decided to try much more expensive cables. The improvement in the sound was amazing. When my wife heard the system for the first time after changing the cables she also was stunned by the dramatic improvement.
Beovision 7-55 with Beolab 7-4, 9s and 4000s
Beovision 10-40 with Beolab 1s and 6000s
Beosound 1, 5, 2000, and 3000
Beotime, Beotalk, Beocoms