Meridian Unplugged - Powered by MrTechGuy.co.uk Forums Discussion Meridian - Systems HD621 Does it support 4K?

A bit hypothetical at the moment, but, will the HD621 pass upsampled 4K from an Oppo 103/105?

Maybe premature, but I wouldn't want to invest in a 4K capable screen and find that the HD621 is a bottleneck. I accept that the HDMI video feed could go straight to the display, but for elegance surely all HDMI feeds should go through the 'switchbox'? Particularly once Sky actually puts surround sound through the HDMI connection.

The HDMI spec for 4K is 1.4. The HD621 uses 1.3, so there's a fair chance it won't I would have thought.

However, given the lack of true 4K material, no true 4K players (or format for that matter), the cost of screens big enough for 4K to actually make a difference, etc., etc. I'm not sure I'd see a 4K screen as an "investment". Also I'd have thought that you're not going to see a lot of difference between up scaling in the Oppo and up scaling in the TV anyway, in which case is the HD621 really a bottleneck?

As the still happy owner of a PDP5000EX I'd recommend you just go ahead and get the sound top notch and not worry about increased visual clarity that your eyes couldn't resolve anyway.

Thanks dpstjp for the sensible response.
So would the 'upgrade' from HDMI 1.3 to 1.4 be handled by firmware in the HD621 or is it a 'nocando'?
Speculative yes, but I'm always worried that my Pioneer PDP will one day give up the ghost. Some of my blu-rays look great even at 1080i, but there's always 'upgradeitis' to consider!

Reading the spec for HDMI 1.4 I'd guess that it's a hardware issue, not software.

However, it might not actually matter. If you read the spec for 1.4 you'll see that there appears not to be any increase in bandwidth between it and 1.3. 1.4 adds an ARC (Audio Return Channel) which is possibly the last thing an HD621 needs, an Ethernet channel (see comment on ARC), an Automotive Connection System (again, if this is something to do with cars), 3D over HDMI (HD621 already transmits this), etc.

So it may well be that despite never being 1.4 compliant it doesn't actually matter as far as the HD621 is concerned. So long as it can strip off the audio and pass-through sufficient bandwidth of video it can happily stay 1.3 and still function. 1.3 requires 340MHz of bandwidth (same as 1.4). This is sufficient to pass 2160p30. Until you actually get a 4K signal into one it may be difficult to tell what limitations the unit has.

[edit my post merged into this thread]

With 4K material and displays starting to appear the HD621 is soon going to become a weak link in our video chains?
So when 4K sources arrive we will need to video bypass the HD621 but still somehow get HDMI audio to it, which could be very messy.

Anybody heard anything recently about HD621 and future 4K support?

I should be getting the Sony 4K projector in for a demo shortly so I may be able to test this out if Sony will also lend me some 4K source material.

Isn't that what people who put their Lumagen processors before their HD621's are doing already? 4K capable Lumagens won't be that long coming and anyone serious about 4k.

Good point. Right now I'm HD621->Lumagen, but I guess I could juggle if forced. 4K Radiance is in development.

Do you mean after Cliff?
I can imagine that you'd use the second HDMI output on a theoretical 4k Radiance to feed the HD621 at 1080p whilst the primary goes to your 4k capable display. You would lose the M comms switching (which is why I intend to stick a Mini3D after my 421) but would hopefully avoid any problems with 4K going through a 'legacy' device.

I've always run Radiance before HD621 in the HDMI chain...

I've tried both and they both work well. I'm currently using HD621 to LumagenXS because I need the extra 2 HDMI inputs the HD621 has compared to my XS

I'm trying to remember why I went HD621->Lumagen but I cannot remember... Most likely it was method that required the least reprogramming of the control systems...

Also I'd be concerned about passing video onward too quickly and not being able to correct lipsync issues that might arise from processing audio after the video is already at the projector...

HD621 has no problem passing 1920*1080@36bit so 4k should be no problem in regards to pure bandwidth IMHO.