The amount of ‘change’ created by TruePlay is dependent on the speaker placement, and the room the speaker is in. In some cases, it makes a difference, in others, not much. For years I have had rooms in which it really hasn’t made a significant, if any, difference, in others it’s been substantial. That’s the way TruePlay is supposed to work. 

@CycleSix,
You may notice it mentions at the end of the Trueplay tuning process this…

“You may hear subtle improvements at first, and increased clarity the more you listen"

Thanks for your replies!

The thing is that before the 14.12 update, TruePlay made a significant difference on my Arc. I know that for sure. After the update, I was prompted to perform the TruePlay again. I did it with three different Apple devices (just in case) and as I stated already, there is no difference whatsoever whilst toggling TruePlay. 

I’m trying to get in contact with the support, this must be a bug. If not, they ruined it completely. I returned a few other soundbars because they didn’t have such a powerful room correction software such TruePlay is (/was at least for Arc).  

Perhaps kindly feedback here what support have to say about your issue, that may prove helpful for any others who encounter the same/similar issue too  - thanks

Sure thing. Was on a chat support than got directed to the phone support. As per their instructions,after sending them diagnostic data, I did a factory resent the Sub and the Arc, performed a trueplay again, still not working. We run out of time and we’ll continue tomorrow during their working hours. 
 

It’s a really strange behavior. We’ll post the progress here again. 

I just had a second phone call with support. After sendig them more diagnostic data, I’ve been told that the issue I’m having with the TruePlay is related to the latest update. And, there is nothing that can be done at the momet. I simply have to wait for the next update which hopefully will fix this anoying issue. 

This is really disapointing and I can’t believe that a company like Sonos is, can do mistakes like this.

Even Apple, Google, Amazon and many other companies have software issues from time to time - it’s unfortunately what happens occasionally and no testing can cater for ‘real-world’ issues being discovered post-release to ‘production’. It is what it is.

I wouldn’t be disappointed as the issue is minor and Sonos are clearly working on a fix - which of course will need further testing. It’s just a case of waiting patiently.

Two thoughts in case they are helpful:

• Reading various forum discussions on 4.12 issues, including Sonos’s own public statement, it seems to me extremely likely that not all users are experiencing the same issues, and it isn’t just a case of whether you do or don’t have a sub, or surrounds, or whatever. So while what one user’s system might be impacted in a way they regard as minor, for another user their system might be impacted in a different way which they regard as terrible. Certainly I know the impact on my system has been huge, and switching trueplay off or on has not helped (not sure I can even tell the difference) contrary to the public statement I’ve read from Sonos’s about the issue.
• Having worked on large scale distributed software systems for most of my life (including software infrastructure components for the likes of Amazon and Google), in my opinion a company of the size of Sonos should have developed the ability to roll back software updates to previous versions. If they don’t have this then in my opinion it would be quite shocking and they probably would deserve a lot of end user anger. If they do have this then they have chosen not to use it in this case, perhaps because of marketing impact, or perhaps because of impact on users who are not experiencing issues, or perhaps because of the cost involved. 

Here’s the response I got about going back ..

It’s interesting that they claim they don’t have a way of reverting back to the old firmware. My guess is what they mean is they don’t have a way to allow individual users to revert back to old firmware, or don’t have a way of rolling everyone back to 4.10 without renumbering it to 4.13 for example. It would surprise me, for example,  if when 4.13 is rolled out it resulted in all devices being unable to produce any audio output, that they then couldn’t take 4.12, renumber it to 4.14 and roll it out. So my guess is they could do the same for 4.10 if they wanted to.

But perhaps they genuinely can’t and 4.12 firmware changes something that is incompatible with reverting to an older version. For example updating some stored state on each device to a new format that the old firmware would no longer understand. Any firmware version that has that kind of change in it is inherently very risky though, so in products I’ve worked on it has been avoided whenever it feasibly can.

Anyway, most of what I’m saying here is pure speculation. Just thinking out loud. Probably doesn’t help anyone. :-D

My own thoughts are, that there are many (many) dozens of programmers involved at Sonos and elsewhere, all working on their particular aspect of programming, whether that be software, hardware, user interface, voice control, music/partner services, cloud/api interaction etc; and each Sonos software release has onboard some work from each of them, as they move forward towards their intended goals - to roll back all that work and sort things with partners and change back cloud services etc; might seem an easy thing to mention, but I personally suspect it is actually quite a difficult and very costly thing to do. (Perhaps ?)

I suspect a lot of support documentation, both internally and externally, would need to be changed back too.

It’s likely much easier to move onward and upward.

What does this actually mean?

Like, we will begin to perceive more then before - as we ourselves adjust to the new profile?  Or does it mean that the profile will adjust slowly after tuning?

Could you elaborate?  One statement is kind of, “You’ll figure it out” , and the other is “Our software continues to refine on its data over time”

Rather than me elaborating here, it maybe easier if you have a read of this:

https://tech-blog.sonos.com/posts/trueplay-spectral-correction/