Your ears simply acclimatise to the less coloured sound. 

 … maybe it’s just in my environment where Trueplay has a detrimental effect … simply put as an example listening to a particular track where the cymbals were clearly audible without trueplay and clearly missing with trueplay ..

I would maybe quickly grab a couple of diagnostic reports from your A/B test and make an audio recording aswell.

From your description, that sounds a fairly drastic difference, rather than a subtle change, almost like something is moving ‘out of phase’. What music track is it? (The approx. time on the track too, might actually prove helpful).

If I get chance tomorrow (it’s late here now) I’ll A/B play the track here too (environment differences accepted, of course) that’s if I have access to the track …and just see what I am able to hear on a stereo pair of Era-300s/Sub Mini in my Home and see if I hear the sort of difference mentioned. 

As stated, it may also be worth recording these things and perhaps posting a link to a .wav file when you have a chance, then go onto Trueplay-tune the room again afterwards. Also just ensure the case/cover is removed from the mobile device and maybe even try a different mobile device to use for the TP tuning (if available). 

Any data you can gather along the way, may actually prove helpful to Sonos, perhaps? You can always pass the information onto them by contacting them later via this Customer Support Link.

https://support.sonos.com/s/contact

Thanks for your feedback Ken_Griffith . Yes I’ll see what useful feedback I can bring further to this discussion.
 

Just for infor the speakers are located with placement positions and height to maximise stereo presentation and also lightened the severity of the Trueplay correction. 

But for now if you  are able to listen to Arny Margret - Album title “They only talk about the weather “ 

The track “cold aired breeze”is a simple mix of vocals , guitar and drums.. For me the  sound of the vocals and drums highlight the damping of the high frequencies throughout the track with a simple A/B with trueplay on/off.. 

By invoking the tone controls there is some restoration of the high frequency edges but am wondering if that is actually needed if Trueplay corrects as needed . 
 

In the case of the diagnostics , is it a case of just running it with trueplay on and off ?

Yes - a diagnostic report with/without TP enabled after track playback, note their references, then at least you have those if you need to go onto report the issue to Sonos Support.

Also, what is the timestamp within that track where you mention that the symbols are clearly missing with Trueplay enabled, but are present when it’s off?

If the track is being streamed, what music service are you using? I’ll give it a try tomorrow, if you can let me know the detail.

I use Qobuz and it’s a high Rez stream.  
 

on the suggested track about 43sec into the track the drums come in ; combined with the vocals the A/B comparison is clear to me …

Also there was a review of the stereo era 300 with a sub on  the TechHive website where the reviewer alluded to problems with Trueplay in 2.1 settings …

https://www.techhive.com/article/2024512/sonos-era-300-stereo-pair-and-sonos-sub-review-value-times-3.html

He indicated that  Sonos tech had mentioned the ongoing work to improve Trueplay under this arrangement ..

I don’t have Qobuz, but I will go onto play the track from other sources I have here and report back - as the issue as been highlighted, I would definitely gather your evidence and pass it to Sonos, as I’m sure these things can only help them to improve tuning.

For my test here I used Amazon Music Ultra HD, presumably the quality is 24bit/48kHz .flac audio (UltraHD badge displayed on ‘Now Playing’ screen) from that streaming service, to play ‘Cold Aired `Breezed’ - I used a Flat EQ/All default room settings. I tried both Advanced Trueplay tuning and Quick Trueplay (using iPhone XR) and repeatedly toggled the Trueplay setting on/off and repeated the track (and parts of the track) lots of times. I let any TP setting settle for one minute. 

Anyhow, in my Home listening environment I’m not personally hearing any significant differences and certainly not noticing anything missing from the audio when either ‘Advanced’ or ‘Quick’ Trueplay setting is enabled. The changes in each case were quite subtle, to an extent I could have perhaps left Trueplay either enabled, or disabled, in this listening room. (The two speakers were set at head height, approx. 6 feet from ‘sweet-spot’ - The Sub-Mini positioned in corner of room to right hand side).

So my initial thoughts @Audiosymbol are it’s ‘perhaps’ just your listening environment, or maybe go onto try a different mobile device for advanced tuning in the room in case your mobile device mic/aperture has any issues, or easier still, perhaps just try Quick Trueplay tuning, if not tried already, as that seemed to also work well for me. 

So all seemed fine in my few tests. I took a few screenshots to support the fact I tested things here. And here’s a couple of diagnostics too.

1206790419 - TruePlay disabled

1834187965 - TruePlay enabled

I must say, whilst it was not my preferred type of music to listen to, I really do like the tone/sound of the Era 300 stereo pair both with and without the Sub Mini - it’s a great sounding stereo setup for my listening environment and it certainly suits how I like to hear my music.

I’m just posting this additional screenshot attached just to show the track tested is UltraHD quality - it was shown as HD in my posted collage, but clearly the badge had not updated - that’s a known issue with Sonos, but just wanted to clarify the point here that the audio played appeared to be 24-bit/48kHz and HiRes quality.

Many thanks Ken_Griffiths for taking the time to provide a detailed response . Much appreciated..

Yes music flavours are personal and I do enjoy a wide range of of styles . This particular track just happens to,show up the issue for me !

I’m beginning to come to the conclusion that it’s either an iPhone issue, room anomalies or Trueplay showing some artefacts that is peculiar to a select few including me and the reviewer from TechHive!

I’ve got a iPhone 12 Pro Max but I’ll try using my IPad to recalibrate Trueplay to see if it makes a difference .
 

Your era300 stereo pair with a subs mini is distanced not that far off from what I’ve got here and great you are enjoying the system . 
 

Just to expand further the origination of my query ; I have a dedicated AV/ music room which has a traditional ( non Sonos ) Hi-Fi/av setup with subs etc. I’ve also got a streamer which decodes original resolution streams from Qobuz . The AV/ music decoder like most processors these days has its own room correction software (Dirac) and it required a detailed mapping of the room with microphones etc .  Listening to the track through this room compensated  traditional system showed the high frequency attenuation displayed by the era300 stereo pair with sub mini (2.1) with advanced Trueplay enabled . 
 

Also I do have the 2.1 Sonos setup also in the AV room so I am able to do a quick comparison of the track with the non Sonos system and with Trueplay enabled or switched off. The same setup in another room and it also shows the same issue. 

Incidentally I’m intrigued that you are able to choose between the quick and advanced Trueplay option in your 2.1 system as I’m only able to get the advanced option. The quick option is available if it’s just a singular ERA 300 on its own .  Have I missed something ? 
 

I have contacted Sonos tech support and provided them with diagnostics for trueplay enabled and disabled ( ref 200294059 and 1559546002). The former is with Trueplay enabled .
 

They couldn’t see a difference between the two but they did notice that the sub mini was Ethernet enabled for both systems and said that was a no-no with possible implications for sound quality . Perhaps the diagnostics don’t display Trueplay info unless it’s broken.
 

In any case , I can’t see how having a more secure Ethernet connection would be detrimental to sound quality but followed  their advise and disconnected the wired network connection and redid Trueplay but unfortunately no changes to the perceived high freq attenuation effects to my ears.  
 

So I will now try to  recalibrate with  the quick Trueplay if you can let me know how you accessed the quick Trueplay option.

As a side issue , on the subject of high Rez music streams ,Qobuz at least details the sampling rates …see below 

You may be aware of this .. Sonos only decodes hi Rez if it’s exactly 24/48kHz ; anything else is down sampled to CD standard . My request for full decoding at full native streaming has been taken as a product enhancement request now . 

For some reason Ken_Griffiths my two detailed responses to your reply appear to have have got lost or moderator barred !   If so I didn’t think there was anything contentious in it …

Anyway .. won’t attempt another long reply other than to ask you how your were able to get both Trueplay options to show up as choices  if you have a 2.1 system .  I’m only  getting the detailed version available to choose. Thanks . 

Dunno - but there should be an option to do either a ‘quick’ or ‘advanced’ Trueplay tuning of your Era-300s on an iPhone. See this support link:

https://support.sonos.com/en-us/article/tune-your-era-100-or-era-300-with-trueplay

Are you using an Android controller?

Thx . It is a bit weird . I can get both options if tuning is just for a singular unit but that choice is limited to the detailed option only once paired up as stereo units .  I suppose I could quick tune  each separately before joining up and see how that sounds assuming that the Trueplay setting for each  do not  get reset once joined up. 

Sorry .. no only the iPhone version ..

I can only assume it’s perhaps down to different availability on the various iOS devices - but that said, have you definitely got the microphone rear switch and top button/Mic-LED enabled on both your speakers?

Trueplay will get reset if you pair/unpair the speakers.

@Audiosymbol 
Just to also mention, it’s the advanced Trueplay tuning you really need to use in any case here, as covering your whole ‘listening’ room with the mobile device is the best way to tune the devices to your room. I would maybe consider trying the tuning too a few times, or even trying a different mobile device (out its case/cover) to see if that makes any difference. If not, then go onto report your issue to Sonos Support, if you think it may help them to improve things, or you think something maybe not working as it should be.

I also wonder what happened to your earlier reports/posts too? Probably auto-moderated out for review by Staff and the Staff are yet to review them before returning them to the thread. It happens sometimes. 

What is even stranger, I’ve just gone back to the App and now only seeing the Advanced Trueplay option too with the 2.1 setup, so perhaps something went awry when I did that tuning earlier (gremlins)? But Advanced TP Tuning is still working okay here.

I’ve checked and both mics are on .  Tried to re perform Trueplay  and only the advanced option comes up .  The iPhone is a 12pro max .. not the latest .. 

the anomalies to you say  could be done to room issues or something or peculiar in my setup .  I’m heading the same in two separate locations which has the same 2.1 setup . Also I do have a Hi-Fi  separates system room adjusted ( via Dirac ) in a dedicated room which also houses one of the 2.1 system . The same track for me shows the impact of Trueplay with a quick swap between systems . 

Maybe Sonos are working on the Quick TP tuning, perhaps? Anyhow, App-gremlins aside, as you’re still seeing/hearing the mentioned issues in your listening environment, I’m sure it certainly will be useful to Sonos if you give their Customer Support Staff the data you have collected, as it can only help them to improve things for you. Here is their link, as mentioned earlier, but probably best to contact them after the Holiday/Weekend period.

https://support.sonos.com/s/contact

Hope it gets sorted for you.

Thank you and many thanks for the time you have spent going through the checks at your end . I’m glad you are getting good sounds . Sonos is generally good .. I have other Sonos speakers dotted around elsewhere in the house .  They provide other functions not available on the specialist stuff ..

yrs I did contact support . Provided diagnostics for with and without Trueplay . They can’t see anything . They did ask for  me to remove Ethernet cabling from both subs mini .. but no change .. 

guess maybe live with this for  now and hope next updates resolves issues for me ..