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Sound stutters with 30 meter AOC HDMI eArc cable on ARC

  • August 17, 2026
  • 8 replies
  • 58 views
S

XGIMI Horizon Ultra + Sonos Arc Ultra: Dolby Atmos stuttering with 30 m AOC HDMI cable

The idea was to create a home cinema with a decent projector and decent sound, including Dolby Atmos.

The projector is an XGIMI Horizon Ultra, and for the sound system I have two Sonos Era 100s and a Sonos Arc Ultra.

The difficulty with this setup is connecting the projector and the Arc without having a visible cable running across the room. The projector is on the back wall, while the Arc is on the opposite side of the room. The only way to hide the cable is to run it through a lowered ceiling and the technical room.

I estimated the required cable length to be around 19 meters. To be safe, I decided to order a 30-meter HDMI AOC (Active Optical Cable) that is eARC-certified. Since the cable is optical, I assumed the additional 10 meters wouldn't be an issue.

However, before installing the cable behind the wall/ceiling, I tested it in my living room. To my surprise, the sound constantly stutters.

Things I have tried:

  • Fully unwound the cable.

  • Connected the source end to the projector (HDMI 2/eARC) and the display end to the Sonos Arc Ultra (the Arc only has one HDMI port).

  • Switched the ends of the cable around, but this made no difference.

  • Bought an HDMI power injector and tried it on both ends of the cable.

  • Set the projector's HDMI/eARC settings to eARC and Passthrough.

  • Bought an identical second cable and tested that one as well.

  • Tested different sources, including Prime with a movie that supports Dolby Atmos.

  • I reset the handshake multiple times

To make sure I wasn't going crazy, I then put the projector and Arc on the floor and connected them using the HDMI cable supplied by Sonos. Everything worked perfectly.

I also checked the Sonos app, which confirmed that the audio signal was Dolby Atmos.

So I know that the projector can successfully send a Dolby Atmos signal to the Arc Ultra. It works perfectly with the short copper HDMI cable, but not with the 30-meter AOC HDMI cable.

Has anyone encountered a similar problem with a long active optical HDMI cable and eARC/Dolby Atmos? If so, how did you solve it?

I'm particularly wondering whether this could be related to the 30-meter cable length, eARC bandwidth/handshake, power delivery, or some compatibility issue between the XGIMI and Sonos.

Best answer by Stanley_4

Thanks, that translated nicely.

The specs certainly look good.

You tried a power injector to eliminate the weak power supply issue.

Using the short cable for testing eliminates projector compatibility issues.

Unless you can get Sonos support to look at a diagnostic I can't think of an option other than trying different cables. If the support contact seems to not understand the issue you can request escalation.

I, years ago, needed long HDMI cables for sharing my satellite TV and I ended up trying several cables here. The one that worked was not the one with the best specifications or the thickest wires, it also wasn't the most expensive.

8 replies

controlav
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  • controlav
  • Lead Maestro
  • August 17, 2026

The long cable is the problem, HDMI is a real challenge at 30m, you might be able to solve that problem at some expense using baluns over CAT6 or fiber but even then its hard to get a working system (based on what I have seen on the Sonos Installers FB group).

Sonos is not ideal for PJ use, and this is one of the reasons.

Author of the leading independent Sonos apps for Android, MacOS, iOS, Windows and Xbox.
    buzz
    • buzz
    • August 17, 2026

    What are your sources? Where are they connected?

    Stanley_4
    • Stanley_4
    • Grand Maestro
    • August 17, 2026

    Which cable?  Do you nave a link to it?

    Is the cable end sensitive?

    Does it offer an external power supply or just use the HDMI power?

    S
    • SurrealSound
    • Author
    • Contributor I
    • August 23, 2026

    What are your sources? Where are they connected?

    The cable is connecter in HDMI port2 which is eARC compatible and the sonos only has a single HDMI port.  The cable end with source written on it is connected to the projector (XGIMI Horizon Ultra). The other end with “Display” written on it is inserted in the Sonos.

    S
    • SurrealSound
    • Author
    • Contributor I
    • August 23, 2026

    Which cable?  Do you nave a link to it?

    Is the cable end sensitive?

    Does it offer an external power supply or just use the HDMI power?

    Hi i have added the link of the webshop i ordered it from:
    https://www.onlinekabelshop.nl/hdmi-active-optical-cable-aoc-hdmi21-8k-60hz-hdr-3.html?_gl=1*8j5tng*_up*MQ..*_gs*MQ..&gclid=CjwKCAjwpqHTBhAcEiwAj2Afurzr1PHTh_7uK-rlw_IKRSv8LPLAty_fGYww83RIgB0B5WRhZ6AonBoCGycQAvD_BwE&gbraid=0AAAAAD1yb3GvRHE1CUuFPYxwXeJnCxJ_T

    I assume your browser can translate the website otherwise I can translate it for you.

    S
    • SurrealSound
    • Author
    • Contributor I
    • August 23, 2026

    The long cable is the problem, HDMI is a real challenge at 30m, you might be able to solve that problem at some expense using baluns over CAT6 or fiber but even then its hard to get a working system (based on what I have seen on the Sonos Installers FB group).

    Sonos is not ideal for PJ use, and this is one of the reasons.

    Sorry can you explain this a bit more?  

    Just to avoid confusion the HDMI cable is not a copper cable but an active optical cable. I chose this because  I understood that these cables overcome the length problem that regular copper cables encounter (that the resistance of the cable becomes greater with each meter/foot/inch). 

    I also read somewhere you can create a very long connection with a CAT6 cable but can Dolby Atmos still be transmitted via UTP? If this is possible a CAT6 cable is a perfect alternative.

    Stanley_4
    • Stanley_4
    • Grand Maestro
    • Answer
    • August 23, 2026

    Thanks, that translated nicely.

    The specs certainly look good.

    You tried a power injector to eliminate the weak power supply issue.

    Using the short cable for testing eliminates projector compatibility issues.

    Unless you can get Sonos support to look at a diagnostic I can't think of an option other than trying different cables. If the support contact seems to not understand the issue you can request escalation.

    I, years ago, needed long HDMI cables for sharing my satellite TV and I ended up trying several cables here. The one that worked was not the one with the best specifications or the thickest wires, it also wasn't the most expensive.

      K
      • kdowling
      • August 23, 2026

      What are your sources? Where are they connected?

      The cable is connecter in HDMI port2 which is eARC compatible and the sonos only has a single HDMI port.  The cable end with source written on it is connected to the projector (XGIMI Horizon Ultra). The other end with “Display” written on it is inserted in the Sonos.

      The eARC connection is the same as the other HDMI connectors in regards to input. The display end is the projector and the source end is the Sonos. The Audio Return Channel means the eARC audio is sent in reverse back to the soundbar/av equipment. But all the HDMI connectors on the projector are considered inputs (display end). 

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