Meridian Unplugged - Powered by MrTechGuy.co.uk Forums Discussion Meridian - Systems Meridian 568 upgrade to 568.2mm

I just remember Chris Coaster saying when he was trying to put together some .2mm upgrade kits, that the transformer used in the .2mm version was larger and he was trying to source replacements.

Having worked on a couple of 568's, I've not noticed any differences in transformer size, although there is a mention of a transformer swap in the upgrade notes.

With regards to firmware - 2.5b9 is very close in sound to the 861, and if you don't use Trifield, is probably the best bet.

Cheers,

Steve

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

Thanks for your message, and everyone else here !

I recently had some time to upgrade to 2.5b9 firmware, and it sounds great, and much beter than the original 2.0 or 2.12.

Big thanks to everyone who helped and gave his input !!

We are very happy with our 568.2MM compared to the 568, the bass management is now finally working great

and bonus the display problems where also solved on our 568.2MM when upgrading to new firmware..

Wasn't there some way of rolling back just the centre DSP file in the 568 to restore Trifield width in the latest FW?

I thought so too, I think the answer is perhaps within the DSPC influence on highres/apodizing sources topic, I'm not sure.

I've not read it thoroughly, but I think DSPC0044 file can also be used with 2.5b9, and gives another sound and perhaps also fixes the center width.
I don't know yet, but I will have to dive deeper into this..

Yes, that's what I was recalling, I think, good find!

Worth a try if you need Trifield Width working...?