I just replaced my trusty RS45 JVC projector with a new RS520... which has rendered my current 50 ft HDMI active cable (which uses Redmere) useless. I did a ton of reading on the subject and found that info on the net is somewhat hard to follow, largely because new technologies are constantly popping up, and coming along quickly. The short end is that you can't push 4K/HDR over a quality cable that's much longer than 25 feet, which is problematic for folks, such as myself, that need significantly more length. It looks like monoprice is offering a new 4K cable with Redmyre-esque technology in it... but user reviews confirming its 4K/HDR compatibility aren't good. There's a very cheap monoprice signal repeater option called "Blackbird" that appears to work...and there's a very expensive non-booster powered devices called the GA1 made by Metra (which has been confirmed to work for cable runs up to 50'). After lots of back and forth (and a few purchases that I'm opting to return), I'm going to try my luck with a RUIPRO fiberoptic cable available on amazon. It's not as expensive as the Metra option, but doesn't introduce a break in the line that the Blackbird product does... I should be be receiving it in a few days and will report back. Until then, curious to hear what kinds of solutions members have dug up!