I have the same problem. I do not expect Sonia customer service to respond. Since going public CS is poor!

I agree. I just purchased the arc to replace my playbar. Don’t know why I spent the money, it sounds no better than my playbar!

Hi,

I have the same issue with my New arc, works fine since 2 weeks and now volume are very low in netflix or myCANAL and high in YouTube for example.

applications are in my Apple TV 4K.

the only things who change is my Arcana HD fury who receive the HDMI for the sound, I don’t use my Sony TV who have not eArc.

i can’t activate the pathrough mode.

I spoke with a Sonos rep and we discovered Comcast’s cable audio output (via “Settings” ) was set to PCM, not “auto”. I changed it to Auto and saw significant improvements for cable. I’m now able to hear at 25, not 50. I later played with some Samsung native apps like Netflix and saw improvement there by switching the audio on a show itself from “English Original” to “English Original 5.1”

Same issue here...sonos customer service was pretty good with looking at 4 diagnostics from my system...they didn’t see any faults on the diagnostics and one CS rep told me that this is unheard of and said it was a defective unit...so i get another ARC….no change….the technician said it probably has something to do with software up stream and has seen this issue with some other customers….thanks everyone in this forum as I have tried many different options here….I will keep an eye on this as I think Sonos should have fix here!!

Have an ARC for 2 years ….no issues….then one day it disappeared from my system...I go into the app and find it and reinstall...pretty easy to do….that’s when I discovered the low volume...sonos said it was a faulty ARC since the diagnostics did not show any problems...tried everything to get the low volume back to where I used to listen...about 23-25...now have to crank it to 55-60 to listen to music or TV...I’M ONLY 59 and hearing didn’t just go on me….So I swap out the ARC and get a new one…..NO CHANGE!!

I have Sony Oled..2 years old…..let us know if anyone gets a fix for this!!

This just happened to me too. I’ve had my ARC for about two years now and use it almost exclusively with my Apple TV, which I use for all my streaming and music. I rarely use the Sonos app, except when I want a readout of the audio format of whatever I’m watching. But I’ve always noticed the volume slider and it’s generally been in the 20-30 range for almost everything from stereo TV to Atmos movies. I was on vacation the past 10 days and came home and turned the TV on and noticed there wasn’t much volume. I discovered that the volume suddenly needed to be set to about 70 for TV and about 50 for Atmos to achieve the same actual volume as I had before. I tried everything from reseting the Sonos to unplugging to retuning. And it’s the same issue with the TV’s (LG CX) built-in apps. Ultimately, I’m not really sure it matters. It’s not like I ever want it crazy loud anyway. That is, I’m never going to set it to 100 volume or even 90, so it’s generally irrelevant what a somewhat arbitrary slider number reads. Still, it’s a really strange change and I can only assume Sonos did this intentionally to have a more realistic volume range. This is clearly an issue that a lot of people have -- a sudden and drastic change in volume reading -- and Sonos should offer an explanation. 

They have already explained the change to volume mapping here:

Fantastic, thank you! I’m surprised this didn’t make it into the thread earlier. Anyway, glad there’s a solid explanation and it makes sense. Appreciate that you pointed it out.

Sony A95L - Here’s what helped mine a little. It seems once the TV recognized you have an external audio system it uses the TV as the center speaker. This can be found under Audio System Settings.

Helped you with what, exactly?

If I understand your settings, you are using the TV’s speaker with a Sonos soundbar? That already provides a center speaker?

I’m unsure of how this is handled by CEC. 

I found out my daughter had been using her phone to cast a show (with amazon prime). She used the volume of her phone to turn down the volume (which I thought wasn't possible before). We solved the issue when we turned up the volume in the same way: cast a show from the phone to the chromecast and turn the volume back to maximum.