Question

Connect no longer bit-perfect?



Show first post
This topic has been closed for further comments. You can use the search bar to find a similar topic, or create a new one by clicking Create Topic at the top of the page.

453 replies

Hi Kumar

Sonos DOES respond to volume normalization information contained in the metadata of individual songs. However, this CANNOT be turned off, so songs that follow on from each other on an album can have a volume jump.

In your audiophile days, if an amplifier was advertised as modifying all inputs by applying a 1dB compression, would you buy this in preference to one that was advertised as being a "straight wire with gain"? The Connect applies such a compression without the option to disable it.

Cheers, Peter.
Userlevel 5
Badge +4
There is only one person here showing a degree of intolerance that rises to a level of calling for people to shut up and stop posting their opinion.

Leave Chicks out of this, I think he/she has some issues. 😉




All I was saying, is if you don't see why someone would want a player that offers say Hires or MQA or bit perfect, then why bother entering the thread of those that do want that to tell them they are wrong and it is not needed?
There are so many threads that I don't agree with, but I don't feel the need to go in there and say to those posting "You're wrong!!".

Try and bite your tongue, let those that want these options ask for them?

So yeah, if I am asking Sonos for an audiophile connect, and you jump in to say it is not needed I have the right to say "Shut up, just because you don't want it doesn't none of us can have it.".

Moderation edit: Please watch the language. - Ryan S.
Peter, in my old audiophile days, I would not touch even wireless with a barge pole, let alone what you refer to. Straight enough to not be heard as bent is good enough now.

I am wiser today and I don't care now about anything that I can't hear. Even more so, if it means added convenience and music access.

More importantly, if as you say Sonos responds to normalization information, why do I get volume changes from one album to another, both ripped or bought in iTunes? Or from ripped CDs to Apple Music streams?
Userlevel 5
Badge +4

I think the problem maybe that Bigot has been used so much in the last few months with what has been happening with Brexit and Trump that many maybe only know it from hearing it in a derogatory way.

I disagree; accusing someone of bigotry has been a serious thing for a long time now and I am saying this with confidence even as someone whose mother tongue isn't English. A lot more people may be throwing the word around these days, but an undeserved/unproved accusation of bigotry would be derogatory in my book for decades now.


Really?

I think I am a bigot when it comes to many things.

I can't stand those left wing snowflakes that mouth off so much at the moment, you know, the ones that tend to be offended on behalf of others. I think their views should be ignored completely, that is me being a bigot.
"Straight enough to not be heard as bent..." - what a great phrase and philosophy - I love it!

The background to my concerns is this: I bought a new amp recently - a Peachtree Nova 125SE to replace a Cambridge Audio Azur 640a. I believe amps are all much the same, but the Cambridge was cutting out randomly, and the Peachtree has digital inputs that allow me to ditch an external DAC and clear up some cables. Surprisingly, the Peachtree sounds much better through my speakers (an old pair of Duntech Marquis). Two friends commented on this independently - it is a very clear difference. This was using the analog outputs of the Connect. When I tried the digital outputs of the Connect into the Peachtree DAC input, the bass on my favourite test song was substantially worse. It had lost a lot of punch. I tried a number of other songs, and the same difference was clear. So I decided to test the difference between the two setups. The first step in this test was to ensure the Connect passed the digital signal through unchanged. It doesn't. So now I'm left wondering whether the Connect is the cause of the problem.

The Connect should be "a straight wire with gain" so it cannot be suspected of being a source of audio problems.

To your other point. Coincidentally, my partner just complained that there was a substantial difference in volume between tracks she was listening to (not a single album - a Deezer "best of"). I think volume normalization can help somewhat, but it's not perfect. It is an amplitude correction that cannot fully correct for RMS differences caused by compression. Different albums with different mastering engineers use different degrees of compression. Almost all modern songs peak at very close to 0dB, but can have very different loudness as judged by RMS. No amount of amplitude correction can fully compensate.

Cheers, Peter.
the Peachtree sounds much better through my speakers (an old pair of Duntech Marquis). Two friends commented on this independently - it is a very clear difference. This was using the analog outputs of the Connect. When I tried the digital outputs of the Connect into the Peachtree DAC input, the bass on my favourite test song was substantially worse. It had lost a lot of punch.

I think volume normalization can help somewhat, but it's not perfect. It is an amplitude correction that cannot fully correct for RMS differences caused by compression


To the first part; I am sure you know that if you are comparing two bits of kit/sources that have one ending up sounding as little as 0.2dB lower than the other, the one with the lower level will yield sound that is perceived by humans to be thin and lacking body - what you describe as lacking punch may well be that. Now I am not saying that what you heard must be on account of the same reason and there was no other reason for lack of sound quality present, but to say the opposite needs sound levels to be matched to within 0.2dB, something that can only be achieved by instruments. After this is done, if you can still reliably pick out the two sources in a blind test, only then can you conclude that there is something different between the two sources and that the sound from the Connect is bent enough to be heard as such. Note that I am not saying whether it is, or it isn't; I am just saying what needs to be in place first to say so in a way that will be replicable and conclusive of something that is both measurably AND audibly out of whack.

Obtaining the same, measured to be within 0.2dB, sound levels from the Peachtree with digital outputs of the Connect may need the Peachtree volume control to be at a higher setting than when using the analog outputs of the Connect. If thereafter the sound cannot be audibly distinguished, the Connect is still audibly enough of a straight wire, even if it doesn't measure to be so on an instrument. If it can audibly be distinguished after the precise level matching, it isn't. And to avoid expectation bias, you should not know what outputs are in use. Admittedly, not an easy test to set up, but the only reliable and replicable one found thus far, AFAIK. As Hydrogen Audio also continues to say.

As to the part about volume normalisation, if I was to generalise, I'd say with the HighNote label for jazz, I find that I always have to intervene to reduce the volume a little in a mixed playlist. And for Apple music, I have to have the volume control at a higher setting than for ripped/downloaded from iTunes music from a NAS, so a mixed source shuffled playlist from NAS+Apple delivers constantly varying levels of sound and is therefore inconvenient. Should Sonos not be able to fix something like this? I have asked the questions elsewhere, but I am not optimistic of a response.
Userlevel 5
Badge +4
I think that sums up your attitude a treat.

At least we all know where we stand.
I agree that comparison of minor differences requires careful technique. The bass punch I'm referring to is not minor. You are right that the digital and analog cases require different volume settings. I have tried subjective matching as I switch. Sometimes I get it too loud, sometimes too soft. The conclusion is always the same - analog output sounds punchier. So, I think this is a case where the difference is sufficiently large that small volume mismatches will not confound the comparison. But as a scientist I remained somewhat skeptical. I was hoping to record the digital and analog signals into my recording software to do a more rigorous comparison. This was when I discovered that the digital signal was not bit-perfect. So I am stuck on this issue for the moment.

If you play the same track ripped via itunes, and streamed from Apple, do you notice a difference?

I just recorded part of a song while auditioning within itunes and compared to my ripped CD version. All this was in the digital domain on a PC. If I left soundcheck on in itunes preferences, the peak was about 3dB quieter than the CD version but the RMS was the same. If I turned soundcheck off, the peak was about the same but the RMS was about 3dB larger. What this means is that itunes is different to the CD version - I suspect itunes applies compression. The itunes version is also out of phase with my CD version - this isn't the case when I use Sonos rather than itunes.

As you can see, there are some interesting issues with streaming music. It's why I prefer ripped CDs from a NAS. If only the Connect would have an option to play them back as intended!

One final point - this is not reducing my enjoyment of music at all. I have listened to so much good music lately and enjoyed it all thoroughly. Some of it comes from podcasts at 128kbps, so I can't be all that fussy! If you get a moment, listen to a track called All Day All Night by the group River Whyless from their latest album We All The Light.

Cheers, Peter.
I never called anyone a liar.

Mr. Reiss is lying in his PR statement.

I stand by my accusation. Dr. Reiss is lying in his PR statement.

...in reality a lie, attributed directly to you.


And not once did I say Mr. Reiss is a liar. Only that his statement (if in fact, it was his statement) with regards to the PR release for his study was a lie.

I stand by that assessment.


@jgatie

OK, I've done some more reading and thinking about lying (not really what I expected to get out of this forum, but what the heck, always ready to learn). I had thought that accusing a person of lying must mean you are also accusing them of being a liar. However, it seems common usage of the word liar means someone who habitually and deliberately tells lies. A lie is a deliberate mistruth, told in the knowledge it is false.

The other distinction to be made here is between a deliberate mistruth (a lie) and an error (statement is wrong without deliberate intent). Without solid evidence, I don't think it can be claimed that Dr Reiss is lying. In fact, the evidence from the primary source (his paper) indicates otherwise.

So here is what I propose if you agree with my analysis:
I will agree that you did not call Dr Reiss a liar, but that you accused him of lying; and
You will agree that the statement attributed to Dr Reiss is wrong but not deliberately, so it is not a lie.
If you still believe his statement to be a lie, you will provide evidence of deliberate intent.

Do we agree?

@PeterMc
When itunes rips to a format that allows metadata (I use Apple lossless - ALAC), itunes computes and stores the volume normalization in the track metadata and Sonos then responds to this.

This is where I discovered the 1dB compression.


My CD rips are all in ALAC, while iTunes purchases are in AAC, so the volume normalisation information is available to Sonos, I should think. I just don't think that Sonos is using this effectively in playback.

I hear what you are saying about bass frequency effects that you are seeing and how volume increases don't/won't work selectively. And if using Music Eq is what is needed to restore things - even if that is possible here - then the Connect has stopped being the straight wire, I agree.

A question though: do you think that the measured compression of 1dB that you are seeing will cause this selective frequency effect? Or is there something more that is happening here?
Userlevel 7
Badge +21
I also notice that Sonos still hasn't replied to my normalisation question posed elsewhere for a second time.

And is noticeably silent here. Either their engineers don't know what is happening or they are choosing silence.


I get the feeling that they're choosing silence. I still don't know why they would remove the ability of a component with a digital output to provide the bit-perfect digital output that it used to be capable of, and was well lauded for. They should at least provide some kind of setting to allow bit-perfect digital output again, whether it's tied to the already existing "Fixed Volume" setting or a separate setting that can be enabled only when Fixed Volume is enabled.

Do I personally care about it? Not anymore... my Connect now serves as an input-only. But obviously there are others that do.
Userlevel 7
Badge +26
I also notice that Sonos still hasn't replied to my normalisation question posed elsewhere for a second time.

And is noticeably silent here. Either their engineers don't know what is happening or they are choosing silence.


I just replied to that thread. We just hadn't read it yet.

When I read the thread over I found nothing definitive about why Sonos "degraded" the Connect. It can't have been for volume normalisation because that, as far as I can see, still doesn't work.

Normalization for tracks does work, but we'd be happy to help take a look with you to make sure it's working right with your system.

So why degrade the digital output at all?

We are talking about a minor change to the audio when applying normalization.

And does this have any effect on sound quality where Connect is the first player in a group that is wirelessly broadcasting a digital stream to other players in the group? Is that stream not bit perfect any more? If so, this is a bigger problem than of being one only for such people that are using the Connect wired to the digital inputs of an external DAC? Based on my experience of the Connect used in that mode, I'd say that I haven't noticed any sound quality loss, but I don't have a reference baseline anymore, so I can't be certain!

Short answer, no. When players are grouped together the audio that's sent across the system is the original digital file of the track, retrieved from the source by the group coordinator and then distributed untouched to the others. Each player uses its own DAC and settings on that original file once they receive it.

We are talking about a minor change to the audio when applying normalization.


Normalization is ALWAYS applied, therefore the minor change (compression) is also ALWAYS applied. I can defeat normalization by either removing the tags or using wav files. I CANNOT defeat the compression. It applies to everything I play through a Connect, and presumably every other component of Sonos.

Surely any hi-fi gear that forcibly altered the signal in this way would be reviewed poorly and eventually fail in the hi-fi marketplace. The best audio gear tries to reproduce the signal without adding its own coloration. Surely the Connect should be capable of passing through the digital signal faithfully and unaltered.

Please consider adding a switch so we can choose to disable the coloration, or at least return to the old setting where fixed volume output bypassed it.

Cheers, Peter.

Normalization for tracks does work, but we'd be happy to help take a look with you to make sure it's working right with your system.

When players are grouped together the audio that's sent across the system is the original digital file of the track, retrieved from the source by the group coordinator and then distributed untouched to the others. Each player uses its own DAC and settings on that original file once they receive it.

Ryan, very good, thank you. How do we proceed with seeing if things are ok with my system? It will be easy enough for me to set up a playlist with just two ripped tracks, one of which plays louder than the other. Do you need to know which tracks I will be using in advance?

Peter, to the second paragraph in the quote, this should mean that in grouped mode, your weakened bass problem ought to disappear when the Connect to digital input on Peachtree set up is in use and reappear when the Connect is not in grouped mode? Although Ryan confuses me by saying each player uses its own DAC. In your set up, the Connect obviously will not. Or does it mean that you will still see the bass issue via the Connect fed zone, but the other zones won't see it even if the Connect is the group coordinator? And in a later post you refer to this being a minor change - going by your description of how it affects bass quality, it is a MAJOR issue even if the compression may be minor?
Userlevel 7
Badge +26

Normalization for tracks does work, but we'd be happy to help take a look with you to make sure it's working right with your system.

When players are grouped together the audio that's sent across the system is the original digital file of the track, retrieved from the source by the group coordinator and then distributed untouched to the others. Each player uses its own DAC and settings on that original file once they receive it.

Ryan, very good, thank you. How do we proceed with seeing if things are ok with my system? It will be easy enough for me to set up a playlist with just two ripped tracks, one of which plays louder than the other. Do you need to know which tracks I will be using in advance?


I just opened up an incident for you with the support team to take a closer look into this. They'll want to see a couple tracks where you've noticed trouble like you described above and will likely want to remote in to take a look at the metadata of the tracks themselves. The reference number is: 160913-001584. I'll see if a technician can reach out to you directly, but feel free to give us a call on our support line with that number too.

Peter, to the second paragraph in the quote, this should mean that in grouped mode, your weakened bass problem ought to disappear when the Connect to digital input on Peachtree set up is in use and reappear when the Connect is not in grouped mode? Although Ryan confuses me by saying each player uses its own DAC. In your set up, the Connect obviously will not. Or does it mean that you will still see the bass issue via the Connect fed zone, but the other zones won't see it even if the Connect is the group coordinator? And in a later post you refer to this being a minor change - going by your description of how it affects bass quality, it is a MAJOR issue even if the compression may be minor?
My comment in regards to the DAC was if you were grouping the CONNECT with a PLAY:5 for example, the PLAY:5 would do it's own conversion. In short, when you group players they each get the same starting digital stream from the original source without any alteration done. Once the player gets it they will take it from there as if you'd played the audio right to the unit. tl;dr Grouping doesn't affect audio quality of a stream.
Hey Ryan - Thanks for the clarification. Please note that I think it unlikely the Connect DSP is responsible for the bass issues I hear, but I can't rule it out because I can't turn the DSP off.

How do we make progress on this issue? Should I open a support ticket?

Cheers, Peter.
Userlevel 7
Badge +26
Hey Ryan - Thanks for the clarification. Please note that I think it unlikely the Connect DSP is responsible for the bass issues I hear, but I can't rule it out because I can't turn the DSP off.

How do we make progress on this issue? Should I open a support ticket?

Cheers, Peter.


We're looking into it on our end here right now. We may want to get a ticket started up for you as well, but I'll let you know on that.
Userlevel 2
Badge
I just managed to get hold of a pre-2011 Connect (ZD90) in perfect working order. Happy camper here! If Sonos doesn't solve this, I guess those connect units might become more expensive on the second hand market as the issue becomes more widely known (so far I've yet to read about it on any of the audiophile websites). So I'm happy I got one now. Will install it in my system in a few days.

Btw, I've done some more listening tests, where I compare the sound from my connect-fed monitors+sub to the sound from my Sennheisers. It seems to me that the biggest audible change is about volume normalization between tracks. The compression of peaks CAN be audible on some tracks, but it's still relatively subtle. What is not subtle, however, is what happens when I play full orchestral pieces where some of the tracks/movements are much more loud and explosive than the rest. Much of this between-tracks dynamics gets lost with the volume normalization applied. And according to the information from Ryan from Sonos here in the forum, this volume normalization is not applied to the pre-2011 Connects.

I do realize that I'm in the clear minority here - as a person who listens critically to very dynamic classical music, and who possesses a system that is actually able to do justice to such dynamics. What I perceive as a problem, will not be a problem for 99 percent of sonos users. It might even be that this volume normalization makes life easier for most people out there. I don't know. Still, I would have liked Sonos to cater to people like me as well, and I'll watch over this new/old connect as if my life depended on it 😉
Userlevel 2
Badge
Functionality wise I don't think there is any difference. But ZD90s and Connects from before 2011 ran on a slightly different hardware. My understanding is that because of this, Sonos can't implement the same DSP and volume normalization in the older connects as in the new ones. So no, you can't modify the new ones. The only solution for the new ones is if Sonos makes a change in the software.
Userlevel 1
I just noticed this thread and I can concur that there is something wrong
with the Connect. I have been streaming AIFF rips via itunes (from a NAS)
to an airport express, to an emotiva DAC via the optical output on the air
express. I've bee doing this for years.

I purchased a Sonos Connect a few weeks ago, with the idea that I would get
the improved user experience that Sonos advertises, but with the same audio
quality by streaming the same AIFF files to the Sonos then to the Emotiva
Dac via the optical output on the Sonos. Note that I have fixed volume
turned on, no EQ or cross fade.

The Emotiva Dac has two optical inputs, so it is easy to do an A/B
comparison.

The bottom line is that going through the air express is sounds far better
to me. The Sonos is less detailed, almost muddy. Not very pleasing at all.
It seems to me that the Sonos is transcoding along the path, which is quite
unexpected given what I have read.

Oh well, convenience matters and when I am in the mood to listen at more
then background volume, I can use the air express path.
Userlevel 1
Badge
So much for my letter to the CEO, he quit. Followed the 100 laid off employees out the door, I guess.
Userlevel 7
Badge +21
So much for my letter to the CEO, he quit. Followed the 100 laid off employees out the door, I guess.

No, he's remaining an employee

Give it a couple of weeks and send another mail to the new man
Userlevel 1
Badge
Two letters and an email to Sonos about the issue that started this thread have gone unanswered. Four months ago, Sonos staff member, Ryan S. suggested that an option to allow a bit perfect stream was being considered. It's overdue and I'm tired of waiting.

It wasn't this thread that started me wondering why my music started sounding worse. I moved during October and November of 2015 and was remodeling for months. When I could finally listen to music, I thought maybe it was the smaller room or wallboard walls instead of the log ones in my house. I hung a quilt behind the sofa, moved things around and finally gave up and didn't listen to much music. Then I stumbled upon this thread.

I used the word "audiophile" in my first post and one member assumed I must be one of those that will spend $500 on a gold-plated wall socket and other such things. No, I mean audiophile in the ancient 1960s sense of wanting something better than a Zenith console to play my records. I have Peachtree Nova SE65, used Dynaudio Contour 1.8 MKII speakers and a used Oppo DV-981DH DVD/CD player. I sit myself in the sweet spot on my sofa, turn down the lights and do nothing but listen to the music. That's audiophile to me.

I used to rip my CDs with iTunes to Apple Lossless. Now I use dbPoweramp and clean up the tags with MP3TAG. I highly recommend both, not so much of a difference in quality, if any (the bit streams compare identical), but to better organize and maintain a collection.

I started searching around for a replacement that will do what the Sonos Connect was sold to me to do when I bought it in early 2015. I won't go into a sales pitch for what I found, but it is very important to say that the high-end audio store (Hanson Audio Video in Kettering, Ohio) where I bought the Connect was unaware of the change made in the November 2015 release. They, and all of the salespersons at the dealers I spoke with (Crutchfield, for example) were unaware and, concerned. To quote one, "We sell a lot of Sonos Connects as bit-perfect streamers."

A good friend recently bought a Connect based on my recommending it well over a year ago. He returned it and it trying a Yamaha WXC-50. I have decided to go with an Auralic Aeries Mini and a 240GB internal SSD drive I installed. I was no longer using the drive with my PC. No network except to tell the Aeries what to play. So far, so good. It is night and day better than the Sonos. Simply stunning. Clarity and bass bowled me over. I'll stop there, no audiophile terms.

I have a Sonos PlayBar for my TV in the great room (living, dining and kitchen combined) and will still use it for that and casual music listening (mostly Pandora) like house cleaning, cooking or parties. It’s plenty good enough for that. Sonos makes quality products, but it's obvious their priorities are not my priorities.

Your needs might be different, but I refer back to the post that started this thread. It is about users of the Connect that bought it to deliver a bit perfect stream. Most of us who bought it for that purpose don't care that it has a DAC and analog output. It that's not you, please don't flame me for agreeing with the first post, expecting a resolution and running out of patience.
Userlevel 2
Badge

Lol. I prefer the short route these days; if it sounds good to me and if I enjoy the music/experience, I don't bother about objective measurements to confirm or in any way validate my experience! Perhaps this is the result of a decade of equipment obsession that I am happy to have left behind.


I have never been that kind of an audiophile, perhaps that's why I'm still interested in getting as good sound as I can get, as I've not been dogged down too much by audiohilia nevrosa... After getting my first stereo system it took me exactly two weeks to get over the subjectivist tinkering thing. A salesman convinced me to get some very expensive cables. I took them home, and heard exactly zero difference... So I started to read up on what cables actually did, and realized that I had been scammed. I became so angry that I went back and demanded to get my money back. At first they refused, but when I threatened to sue them for misleading me as a customer, they gave in.

As for now, this new connect unit is the first audio thing I've bought in three years. Prior to that I also had the same system for 8 years, without a single change. When I buy audio stuff, I try to buy durable and sturdy stuff that measure as good as possible, and which fit aesthetically. That's basically it.

Btw, I agree that two play:1s plus sub, equalized with trueplay, is almost laughably good. I have that setup in my kitchen. I do prefer the other setup I have in the salon by some degree, but the sonos setup really is superb.

As to the Connect DAC - before I boxed my legacy audiophile kit after buying Sonos, I did a lot of testing, admittedly imperfect, but good enough for my decision making. I compared the sound quality from analog output of the Connect with that from my SACD player, both into high end amplification and Kind of Blue was one of the test albums. I found no difference in quality and decided that I did not need the SACD player. Nor have I heard of anyone that has been able to pick out the Connect DAC in a well constructed level matched listening test against any other DAC - not even ones with five digit price tags. I therefore believe that the Connect DAC is audibly straight enough. As are many others - indeed I strongly suspect that a modern DAC is no longer a factor, having become a reliable commodity at a low price point.

Ironically, going by your findings, it would appear that those that don't think so, and want to use the Connect into another fancier looking external DAC may be ill served by Sonos while doing this, with audibly poorer sound quality than they would obtain via the analog outputs on the Connect!

Quoting myself here, in response to what may be happening with the Connect, because I doubt that any changes have occurred to the sound signature from the analog output of my Connect.
As another audiophile in the sense that I often listen to just music late at night, I have noticed no change in my sound since the time of the quoted tests. The last quoted sentence is a guess, no experience to back it up.
PS: And to highlight a word in the quote that may be skipped over - " level matched". If the signal voltage from the external DAC is higher than that from the Connect analog outputs by even a very small amount, it will be enough to have the amplifier set at the same volume control position to deliver sound levels that will be higher than more than 0.2 dB in comparison to when the analog outputs of the Connect are in use. Once that happens, all bets are off; a 0.2db level difference is all it takes for louder to sound better, including all the jargon that is used to describe better. There is a simple solution to this of course - the volume control on the amp needs to be set a little higher when using the analog outputs of the Connect to restore sound quality levels to that delivered by a DAC with a higher signal output voltage.