Ok - I have tried to baseline things.

My old set-up was a 565z3v6.0 with an 18-bit centre and analogue speakers everywhere else. The Trifield "width" setting had a clear and noticable effect, especially on voice-oriented material where the BBC chestiness would lead me to a narrower setting so the image wasn't spread by the bass, while TV drama (e.g. Law and Order) would be better wider. Listening distance was about 14 feet.

The 565 is now in my second system. It is all DSP with 24-bit mains, centre and sub and 18-bit surrounds. Listening distance is about 8 feet. So the change is in the speakers, not the processor, though obviously the processor has been recalibrated. I have just experimented with Trifield on three source programmes; the snooker for the audience ambience, some MTV pap with lots of noise and some BBC drama/studio stuff.

There is absolutley no difference between any width setting that I can hear. I spent ten minutes at it and nothing that I could repeatably perceive.

Apart from the speakers, the only other possibly significant technical change is that the room aspect was 1.4 (deeper than wide) and is now 1.0 (squarish).

So my possible theorum for peer review (I am dancing on eggs here) is that we have all tended to upgrade to full DSP set-ups as we have upgraded our processors and it is the DSP change which has "disabled" Trifield through some obscure software bug/feature that was always there. Or even more remotely, there is a bug caused by the room aspect parameter.

There is a noticable bug/feature with the 565z3v6.0/all DSP set-up. I can't adjust bass or treble anywhere. I am sure I could with analogue speakers in the config. The processor manual says the speakers do it and vice-versa. This demonstrates (subject to ageing memory) that the analogue vs. DSP change can affect the procesor capabilities.

We need some-one with an analogue set-up fronted by a 565 to provide an alternative baseline.

Discuss!

In the spirit of Spinaltap, I would like to confirm that I am not involved in the corrupt theft of a global sport.