Pretty much any HDMI cable, it is trivial to pass a DD 5.1 signal over any HDMI cable. Is there something wrong with the one that comes with the Beam for you?

Yeah I need a 15m long one and every cable I have testet in this length didn’t worked or had strange fractured sound.

so the last one was also glassfiber and should have been pretty good, but same effect.

Hi @chasper,

Most manufacturers don’t recommend using HDMI cables over 20ft (~6m) without some form of signal booster, such as an “active” HDMI cable. You’re likely to experience strange artifacting and dropouts by using a passive HDMI cable of this length, and this problem isn’t exclusive to Sonos products. I’ve found this article that explains it in a bit more detail, as well as alternatives to work around this issue.

Many thanks for your response.

I dont think this is also appliable to a ethernet hdmi with glassfiber which is build for up to 100m distance.
It is also mentioned in the article, that therefore the max distance is much higher (up to 300m)

The fiber cable must support HDMI-ARC.

Yeah It supported HDMI-ARC. Are there any other requirements?

Propably HDMI Version 2.1 or something?

In this application bandwidth is not much of a consideration. As long as there is an explicit statement that the cable supports HDMI-ARC the cable should be OK.

How does the cable get it’s power? There could be a power issue. As a quick test, can the fiber cable support another HDMI path -- such as the cable box, ROKU, AppleTV, etc. connection to the TV?

yeah I will try this one, thanks for the hint :)

So, the cable worked on a PC setup.
I therefore also assume that it is a power issue.

Does anyone know how to work around the problem without great cost?
Could a cheap HDMI repeater be enough?
Due to the required Sonos optical adapter I do not know if a pure repeater will suffice....

There are these kind of extenders on Amazon, but it’s not a cheap option (sorry ‍♂️) …and I personally couldn’t say how well they may work for your chosen setup, but maybe worth considering perhaps, keeping in mind the distance you’re trying to achieve. The setup caters for S/PDIF connections too.

https://www.amazon.co.uk/HDMI-Extender-ARC-60Hz-Bi-Directional/dp/B08QTQYK6S

The alternative is to extend the S/PDIF from the beamer. 15 metres could be a bit of a stretch without amplification. Optical may not work, but coax might.

I’ve used 45 foot Blue Jeans TOSLINK cables between PLAYBAR and a projector. 

I have no experience with this set, but it’s another approach.