Originally Posted by BokitoNL
about downgrading back from v2.5b firmware to v2.12 is like you say with risks?
I do found some other topics here on this forum, about users got some problems with DSP modes not working anymore after downgrading, or so it seems to me.

Anyway we dont use Trifield DSP, so perhaps V2.5B will be the best firmware for us to use I think, what do you thin?
Hi

I think there has been almost unanimous agreement that the 2.5b firmware sounds better than the 2.12. There's even better clarity and openness with 2.5b whilst still retaining the Meridian house sound of fluid, organic and natural musicality. I found 2.12 to be warmer and a touch less open, and that was with DSPs, so I can't comment on analogue system use.

One user recently posted his frustration that the 2.5b firmware sounds different with old Dolby ProLogic content, it seems that aspect was changed after 2.12. He reported that swapping back to 2.12 left the newer 2.5b processing in place for Prologic, so he couldn't get back to the sound he preferred. I think the 2.5b handles this content with Dolby ProLogic II processing, but I haven't needed that since VHS days and the occasional rare DVD that only had a stereo soundtrack. He had quite a specific use case, due to a large archive of Prologic material. I haven't read of any other user having an issue with the upgrade.

If you don't use Trifield, then no problem. The bug was that Trifield width was locked at a value of around 1.2 (my estimate) and it wouldn't change when you adjusted that parameter. IIRC, historically it could be adjusted from 0 (effectively mono, everything in the centre) to 1.5, a very wide sound stage wrapped around the rears to some extent. It was quite evident then that adjusting the width setting was having no effect. Later firmware across the processor range offered more subtle adjustment, from ~normal stereo to very wide and you could no longer shrink the image down to mono. It may be that the "locked" width setting actually suits your ears and room layout should you ever try it out.

Hope that's a help.

Cheers
George