Many thanks for your replies. The rest of my system is DSP5000C for the centre and a pair of DSP5000s for the rears. The main speakers are Naim SBLs with a NA52 pre-amplifier and NAP300 power amp. The sub is a M&K MX-150.

The difference in sound between the DVD and Blu-ray of The Matrix is quite difficult to describe. Whilst the Blu-ray sound is definitely deeper and treble slightly brighter and more revealing, the sound from the DVD is more open with the Blu-ray sounding a little flatter (literally). When, for example, Neo dodges bullets as the whole sequence moves around the room, the DVD soundtrack is a lot more open and the steering far more accurate. However, when the sprinklers go off in an earlier scene, this sounds better on Blu-ray probably due to the more detailed treble.

Superior picture quality from one format and potentially better sound from another. I think that someone is trying to drive me a little crazy!