Left One SL surround speaker plays lower volume


Recently bought home theatre set: Arc + Sub (Gen 3) + One SL (pair), with hd fury Arcana to go with single source Apple tv 4K 2021. Tuned the Sonos system using Trueplay (using iPhone 12 mini). It sounded really well after tuning. All equipment connected to mesh wifi network with 100mbps bandwidth. Everything worked great for first couple of days.

I’m based in Mumbai, India. After looking on forum, activated Alexa voice services on Arc by changing location to US via weblogin for the account.

Need help with each of the part issues below.


Part A: Noticed that the Sub, LS and RS started dropping (?+?+?) in any combination. Tried keeping them powered off for a while and used only Arc for listening to music. Powering them back on brought back same issue.

Removed surrounds and Sub from room config and added back. Did a full reboot. The issue stopped thereafter. However, it takes anywhere between 40sec to 80sec for Sub and surrounds to get connected online (solid white LED) every time, whereas Arc comes online (solid white LED) in under 10 seconds. Should it be taking this much time to get online every time.

Note: Arc & Sub are within 0.5m of the wifi router & ATV, LS & RS are nearly equidistant from Arc & wifi router - 15-18feet.


Part B: After couple of days, left surround started sounding very feeble as compared to right one.

Tried full system reboot.

After retuning using Trueplay, it plays well immediately; however, once powered off and powered back on at a later time, issue with LS persists. Tried toggling OFF Trueplay and toggled back ON; everything sounds great again. Now every time i have to switch ON the system, i have to toggle Trueplay OFF and back ON.


Part C: With HDFury Arcana in the mix with Apple tv 4K, the Sonos home theatre setup does not output sound. Have to fiddle with TV settings every time. Its really frustrating that the product was marketed for seamless integration with ATV & Sonos Arc. Is there a known solution to this and is there a specific start / boot sequence for these products?

11 replies

I would perhaps try wiring your Arc direct to your primary mesh hub/router and if it’s possible set your SonosNet channel in "Settings/System/Network" in the S2 App to one that is not being used by your mesh system. Do not disable the wireless on any of your Sonos devices.

Also whilst in the network Settings remove your WiFi credentials from the App as these are not required when running your devices on SonosNet with one device cabled to the main router.

You should not have to fiddle with your TV Settings at all when playing your Apple TV, because you are completely by-passing the TV for audio purposes when using the Arcana, so I’m wondering if you have it setup correctly - see this diagram below, which is slightly more complex, as a HDMI switch is also in the mix, but the principles are the same:


Hello Ken,

Thanks for your response.

My setup is as per single source as shown on hdfury Arcana’s website.

The Hdfury Arcana user manual says there is a particular start sequence that one needs to figure out based on their TV device.

As for SonosNet, did not do it thus far as I want to avoid any additional wires. But even that would be to avoid the (?+?+?) in any combination, which seems fo be recurring intermittently at start of the system. Will give it a try though.

As for LS being low volume, I haven’t found a solution; seems like a bug as several users have reported it. The workaround I mentioned works only while listening to music, not movies / TV.

Also, with network credentials removed from the App, how would the devices update whenever the new updates are released?

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Sonos surrounds are connected wirelessly to the soundbar via a direct 5Ghz connection. The surounds will be connected to your network through the soundbar - they will have an ip-address on your router. So they wil be updated through this connection.

Since there’s no change in the connection between soundbar and surround when switching to Sonosnet, I doubt if this would help with your problems, where the surrounds are dropping. Maybe @Ken_Griffiths can explain his reasoning behind this proposal for a solution?

Sonos surrounds are connected wirelessly to the soundbar via a direct 5Ghz connection. The surounds will be connected to your network through the soundbar - they will have an ip-address on your router. So they wil be updated through this connection.

Since there’s no change in the connection between soundbar and surround when switching to Sonosnet, I doubt if this would help with your problems, where the surrounds are dropping. Maybe @Ken_Griffiths can explain his reasoning behind this proposal for a solution?

My thoughts were that the soundbar is perhaps experiencing wireless Interference and wiring it to the primary hub would improve its own connection and in-turn the ad-hoc 5Ghz connection to the surrounds. I was hopeful that the switch would also likely cause the main player to renegotiate the 5Ghz connection between it and the surrounds. Removing the WiFi credentials in the Sonos App and setting the SonosNet signal to a ‘unique’ channel would also reduce the potential interference nearby. That was my thinking. 

If that resolved the surround speakers connection issues, then my follow-up suggestion was going to be to retune the room after that, to see if that then resolved the imbalance issue with the left speaker.

If the left SL speaker remains problematic after that by the way, I would then maybe try unbonding its  surrounds, perhaps swap the left/right speaker and see what the outcome is when they are rebonded back to the Arc.

As the Arc is close by the router, run an Ethernet cable between the two. Wait 5 minutes to allow the system to flip to SonosNet mode, then remove the WiFi credentials from the system. Do not “disable WiFi” in any devices; it disables SonosNet.

The problem is likely to be due to:

  • the router objecting to proxied IP requests for the satellites in WiFi mode (which the above would fix), or
  • the satellites connecting to different WiFi mesh nodes from the Arc (which the above would fix), or
  • interference on the Arc/satellite connections, which should resolve itself as the Arc dynamically changes channel

Thanks for that helpful information here too @ratty - much appreciated.👍 

Thanks Ken, Rallye & Ratty for detailing things out. More importantly, much appreciate the timely responses.


Here is my Quick response: Part A & C have been resolved. Part B, as mentioned before, seems to be a common bug.

Detailed response: Beneficial for newbies.

Part A:  I finally chose to wire down Arc via (old) CAT6 Ethernet cable. Arc(+Sub+LS+RS) is rock solid stable now. Also, boot up time has reduced a bit for the setup.

I did try few things like assigning static IP addresses to all wifi devices in the house. Once SonosNet was active, assigned static IP addresses to Arc, Sub & surrounds. Removed wifi password from Sonos App under Network settings. Tested this setup with at least 2 power cycles, one after each test to see whether connectivity dropped / was delayed. 
Reboot / Power cycled entire setup again. This time, Removed the Ethernet cable, included each component on wifi network again (this time with static IPs assigned earlier). Components dropping issue resurfaced. It was now kind of clear that most likely it’s my cordless phone base unit & router (both within 0.5m from Arc center) interfering with Arc to components connection.

Switched back everything to SonosNet by connecting CAT6 to Arc & including Sub, LS & RS on the SonosNet. Switched to dynamic IP assignment on router.


Part C: Finally discovered boot sequence to avoid

a. Sonos not getting discovered on TV CEC

b. Apple TV 4K 2021 remote unable to control volume on Arc

Boot sequence: Assuming CEC is configured on TV for Sonos & ATV setup (Arcana included on chain) & also enabled on ATV. And that correct settings have been maintained on Arcana as per user manual / official YouTube tutorials.

1. Power ON Sonos Arc (10 sec to stable LED), followed by Sonos Sub (approx 40 sec to stable LED), next Surrounds (approx 40sec for stable LED), next step

2. Power ON TV; once it displays source input label on screen, next step

3. Power ON Apple TV 4K; once it’s power LED blinks for 3-4 times, next step

4. Power ON Hdfury Arcana. Ensure IN, T0 & T1 values are displayed correct on its OLED.

5. Once ATV welcome message comes up in top right corner, wait for it to go; 5-10sec later press ‘TV’ button on ATV remote.

6. After ‘Remote connected’ message vanished from screen, wait 5-10sec and then start operating ATV as usual. You will now be able to control Sonos Arc setup volume with ATV remote.


Part B: Issue persists despite all of above. Did Trueplay couple of times more. Inclined towards thinking it’s a bug since lot many folks have reported the same by trying physical as well as logical reversing left right labeling of surround One SLs. Only toggling between Trueplay OFF/ON or Surround music setting to Ambient/Full solves it, while listening to music.

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Hi @VishalB 

Welcome to the Sonos Community!

I’m glad to hear the help you’ve received so far has solved two of the problems!

The issue with the one surround going quiet is likely an issue in software, but not necessarily a bug. As @Ken_Griffiths suggested, please un-bind the surrounds from the Arc and physically swap the surrounds over and re-bind them to the Arc again (if they’re wall-mounted, don’t physically swap them but do lie to the app about which is which).

  • If the problem follows the unit (so it’s now the right-hand speaker that goes quiet), please un-bind the surrounds again, then factory reset the problem speaker. Add it back to the system, bind both back to the Arc, and test once more.
  • If the problem remains with the left-hand speaker, regardless of which speaker that is, then we need to look to the Arc. In this case, please un-bind the surrounds and the Sub, but this time factory reset the Arc. Once done, set it back up and bind the Sub and Surrounds back to it.

Hopefully, one of these resets will help. If not, I recommend you get in touch with our technical support team and relay the results of these tests/steps to them. As you’re not in a supported location, however, organising a replacement may be troublesome (but not impossible).

I hope this helps.

Hello Corry,


Thanks for your response. Appreciate it. The community definitely is a boon.

Not sure on the support availability comment, as Sonos is now officially available in India through distribution channels and there is a support helpline for the region. Have tried reaching out them as well (call and email), but on sharing diagnostics, the latest response was that HDMI-CEC interference was observed. Responded them back with revised use-case details, yet to hear back.

BTW, without Trueplay, both, LS & RS sound equal.


Taking your advice, proceeded with options; noticed that Arc Factory reset use-case was applicable.

However, since it was hardwired to the router, after its reset, other devices could not be found and therefore had to reset them all.

This still did not solve the issue.

Note, the HDMI-CEC connectivity (ATV, Arcana, TV) wasn’t active at the time.


Not sure whether orientation and line of sight for the LS & RS with respect to the Arc plays any role in Trueplay here. Our living room does not have an ideal shape to go with HT setup. Posting some pics here for clarity (pardon the mess). Arc, LS & RS are all approx. same distance from ground - about 2 feet.