Has there been a resolution to this?

I have the same setup as the OP. I solved this issues by going into the AppleTV4k settings, video & audio, then turned ‘Reduce Loud Noises’ to ‘Off’. I never turned this on, maybe it happened in an update. Hope this helps. 

Just got the Arc along with the gen 3 sub and surrounds. I also had the same problem and was tempted to return until I played with my setup and figures out what the issue was. Basically I had two issues. Not sure which of the two was the issuer if both were the issue. 1 I was connecting the audio via AirPlay 2 on my Apple 4K tv. 2 I also had the Arc connected to optical input via the HDMI/optical connector that came with the arc. I have an older TV so I did not think I had an Earc port. I believe when connecting to airplay it compresses the sound too much. Air ply works on my sonos 5 just fine but when connecting my system via airplay I also had to have the volume at around 70% to hear movies…never a problem with music. I decided  to unplug all the system from the power and removed the connection from the optical drive. To my surprise one of the HDMI port on my TV was an ARC not Earc, so I just plugged the HDMI to the arc port on my TV and it worked! Obviously i don’t get the full benefit of atmos Dolby until I upgrade to a new TV, but the system still sounds fantastic! I hope this helps those who have an issue.

I’m extremely disappointed in the arc I don’t know if it’s only me but the Arc is not wowing me at all even in the Atmos mode specially at this price point.  
and when I’m watching a moving I have to turn the volume all the way up for me to hear talking so I bought 2 times the one SL didn’t get any better 

is someone experiencing this problem or is it just me ? 
 

Same problems here - output from the television using HDMI eArc needs to be turned up to 80% or more to be a usable volume.  This happens with anything from the television - AppleTV, over the air content, DVD, etc. The Arc playing music along with other speakers needs to be turned way down to normal volume levels.  This seems to have started after a previous update and persists to this day.  Nothing helps - powering everything off, swapping HDMI cables, etc.

I had similar problem. I use ARC plus 2x ONEs both as a TV (hdmi) and computer (optical) (unfortunately i have to switch manually cables due to only one hdmi input).
TV via eARC and optical runs fine, but computer sound was very low. I tried different soundcards, transmitting sound via bluetooth, different cables but nothing worked…. until I inceased the volume directly on soundbar using touch controls <facepalm>.

A remote or volume control option in app would be useful.

Just to maybe assist you a little here…There is a volume control for the Arc in the Sonos App?.. plus almost any infrared ‘remote’ can be setup and used to control the volume  of the Arc too, or it’s volume can be controlled using the connected TV remote over HDMI CEC and if you have an installed voice assistant (Alexa.Google) on the Arc, then something like ‘Alexa set the volume to 3’ (or any number between 1-10 inclusive)) will change its volume too. HTH.

Thanks so much for the suggestions but nothings seems to work and everything seems to point to the driver.  Manually manipulating the touch controls didn’t help as they directly drive the Sonos volume on the app.  I tried that with the HDMI cable connected and disconnected.  The volume on the TV itself is set to zero.  I’ve tried every sound setting on the set itself.  Nothing works.

I’m planning on a move in the Spring and will probably replace my Sonos gear solely based on this problem which is impossible to live with and not being addressed by Sonos.  I’ve been a Sonos customer for the life of the company.

Thanks. I’m familiar with voice control, but I just dont like it. And regarding the any infrated remote, this solution doesn’t work while my pc is connected. And yes, volumes on my pc are set to maximum volume.

An infrared ‘remote’ should work, whether your PC is connected, or nothing is connected, to the Sonos product - you just need to enable the IR sensor in the device room settings via the Sonos App.

facepalm… thank you :D

I just should follow good old RTFM rule . Im so embarrased :)

I am also experiencing the same issue with my arc. I have tried all the possible options multiple times. What I have observed is that sonos sounds loud for dolby Digital 2.0 format but becomes quite for any other DD+ format including Atmos. I need to to watch it at minimum 50% level to get reasonable listening volume level. I bought Sonos sub and 2 Ones SL to improve the overall sound quality of my system. I am happy with sub and sonos one SL but feel that arc is not doing Justice to over all system. Sometimes I feel my $2000+ system doesn’t sound as good as old $200 Vizio soundbar. I hope Sonos fixes this as soon as possible. 

As of February 3rd 2022 I am still experiencing this problem. I contacted a rep at Sonos and tried all of the suggested settings and resets and nothing seemed to help. My set up is LG CX TV and Sonos Arc via HDMI eARC and digital sound out set to Passthrough. I use the WebOS built in apps and If I’m using YouTube it displays that I am getting PCM and the volume is loud enough at 20/100. But when I switch to Disney Plus or Netflix and watch something in Dolby Atmos (DD+) it need to have the volume at 50/100 to be loud enough. At this point I’m not sure if it’s the sound bar, the TV or the sound output such as PCM, Dolby Atmos (DD+) etc. Very disappointed in the sound volume while watching Netflix or Disney plus which sucks because this is the only streaming services I use… Sonos please update if this is an issue on your end. 

It is absolutely asinine that this issue continues to exist. Along with the inconsistent LPCM audio issue and the 7.1 downmix fix seemingly MIA, Sonos has probably lost me as a customer. 

I have the exact same issue with my Sonos Arc, Sonos sub, Sony 77” A80J, and Monster Ultra High-Speed 8K Cobalt HDMI 2.1 Cable at 48 Gbps cable connected to the eARC port. Because I have Ruckus Wireless access points in my home I have to have the arc wired to my home network in order for the sub to link to it (Apparently a known bug according to Sonos support). 
 

Dolby 2.0 audio plays perfect and we range from 16-30 depending on the content we are watching and have zero issues. 
Dolby 5.1 or Atmos need fixing ASAP.
This weekend we watched Disney+ and Moana with our daughter and we had it up to 60-70 range in order to hear the dialogue comfortably. We watched West Side Story on HBO Max and we had it at 80 to hear the dialogue. 
I have not tried our older Apple TV. I also have a Mac mini with Plex that I have to do further testing with.

I have volume limit at 100%, Loudness and night mode turned off. Sonos is up to date. I tried using Trueplay but it didn’t help. Tried tuning trueplay with my iPad Pro (4th gen) vs. my iPhone Pro 13 but it made no difference. 

TV is set to use eARC and audio out set to pass through. Will review additional TV settings to confirm if I have things set correctly.  TV has latest March 1 update. 

Had the same problem- changed the digital audio output on the TV from the default - ‘PCM’ - to ‘bitstream’. Problem resolved. 

Been having the same issue on mine, Dolby digital 2.0 is loud even at 20  and ps4 set to Bitstream dolby 5.1 is normal at 35 (perfect level) but everything else is normal at 40-50 and even at 100 is feels capped.

Support has been disappointing so far, really feel let down by the brand here.

Device im running is a LG C9 fully updated, set to pass through and earc on.

might have to return the lot at this rate as it seems zero chance of a fix if this has been going on for a year.

Strange, only you mention in the link below that you recently bought a Beam to use with the C9 and you’ve only just joined the forum too - how come no complaints here before about your Arc?

Because I got my sonos product this month, since having these issues I’ve been looking for fixes and as I look find more and more people with the same issue with no fix or decent response.

No idea where you got the arc idea from but people here are mentioning the same issue with the beam, so it’s obviously a cross platform issue. 
 

In the Arc thread you posted “I've got the same problem on mine". Not being clear about the device you actually own and cross posting your problem can lead people to the conclusion you are  trolling.

It seaams you're not, so people can best help you in your own thread.

To me this looks like a cross product fault on the products, the fact that on TV normal view the sound peaks at 80db at 100% but on spotify app from the same tv at 50% I get 92db, that’s a huge difference.

Clearly the speakers themselves are capable but I suspect there is a software bug effecting all sonos products. When you read text from Reddit and this site people mention several brands of TV on both the beam and the arc. 
 

Until the community shout loudly enough there won’t be a fix, instead I imagine internally they are blaming TV manufacturers etc. Which I see a lot in electric cars - charger company blames the car while the one blame the charger. result is very little action until buybacks are used. then suddenly they work together to find both are partially at fault.

That is the sad truth of for profit companies they are hear to make money. that said I like sonos products the build quality is nice, I like the idea of building up a system over time, sound quality is good to my ears - it’s just this issue that’s ruined the experience, it feels like the systems been kneecapped because of it.

I can see there's a problem here. To me it seems you're a bit quick in pointing at the speakers, especially when your conclusion is that there's “a software bug effecting all sonos products". Only some people's systems seem to be affected and since Sonos is depending partly on your TV, there's another possible cause here.

My Beam and Samsung QE65Q90 are not affected.

maybe, but faults are really 100% hit rates, even major recalls 75% of people wont have experienced the issue. yeah it could be an issue with the TV but then again LG are just as likely to say that’s it’s not an issue with their TV because it works with other bars etc. Probably like the electric car issue - both parties have a part to play.

Only sonos knows but their customer service has no been helpful atm, I’ve got another call with them today to try an progress the issue but I’m quickly coming up to the end of the return period - ideally i like to keep the system so hoping that eventually they say something like they know what the issue is an working on a fix which I would happily take but atm it’s is night mode turned on, turn it on and off etc, send us a session number etc.  That’s why I’m frustrated.

I had a similar issue. Muted audio and unclear voice in songs on youtube music. . Airplaying the same song directly to Sonos played the expected clear and loud levels. So the issue was not in Sonos.

Setup was Roku Ultra → via HDMI → Samsung QN85DA → via HDMI eARC → Sonos ARC .

Solution:

1. Go to Roku → Audio → - Digital output Stream to “Passthrough” 
2. Go to Samsung or your TV and set digital Audio output to “Passthrough” as well

It’s not an Arc problem. The sources upstream are applying their logic/codecs to pass modified audio downstream. Let Arc do all the handling. 

Went to the local lab today and they told me that after checking with manufacturer setting - all is ok with the ARC. 
I told them I am playing music at 80-90% of the volume at my living room and they didn’t know what to tell me…