Question

Connect no longer bit-perfect?


It looks like the Connect is no longer bit-perfect. Here's my evidence: let's discuss this.

First, I constructed a wav file of pink noise with amplitude ramping up from zero to digital max and back to zero.
I play this through my Connect and record the SPDIF output from the coax output into my PC.
The recording uses a Scarlett 8i6 audio interface set to use the Connect as master clock.
I record into a DAW (Sonar) multiple times - all instances are identical.
However, this recorded signal is not quite the same as the original wav file - it can be up to -21dB different.
See https://www.dropbox.com/s/t8od479xo9hi5el/connect_diff.PNG?dl=1
Note the expanded scale on the difference (third) track.

It looks like the difference gets larger when the signal is larger. To confirm this, I import the
original and difference files into Matlab and plot the raw data (difference vs original). There is clearly audio compression
happening here. See https://www.dropbox.com/s/p1yq6wcqafvnhaj/diff_vs_orig.png?dl=1
The scale is such that digital maximum is 1.

There also appears to be a slight bias when the waveform is negative and the signal is below the
compression threshold. See an expanded version of the previous plot
https://www.dropbox.com/s/9001tl9mkle4wly/diff_vs_orig_zoom.png?dl=1

Happy to answer questions about the method and conclusions.

Cheers, Peter.

p.s. Volume is set to fixed - I haven't tried variable.
In a loopback test (8i6 out from DAW to 8i6 in, no Sonos gear involved), I get bit-perfect cancellation.

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Therefore, I didn't notice this when the change came. The ear adapts. I only became aware of it when by accident I came to compare directly how some tracks with high dynamic content sounded on my headphones (the Sennheiser 650) and my active monitors when fed by the connect. The difference seemed quite substantial to me. After that, I started to read up, and became aware that the Connect was no longer bit perfect. By now it has biased my listening, and I tend to be aware of it all the time when listening to classical music, which I wasn't before.


These words beg two questions:
1. Why is not possible that the same difference would have been heard - between the headphones and the active speakers - before the change? I realise that this isn't a question that can be easily answered, but it remains a valid one even so. And as I am sure you know, it is very difficult to obtain the same sound quality that a good headphone can deliver, from speakers that have to overcome all the challenges of room responses and ambient noise levels even in a very quiet room. The closest comparison can only come from a speaker set up that is optimised for near field listening, but even that is disadvantaged compared to quality headphones. Comparing sound quality between headphones and speakers is apples v oranges.
2. And to complete your own line of thinking in the second part - why can't it be said that what you are now aware of is just the result of Expectation Bias and not any change in the Connect?


Good questions. I'll try to brief:
1) My monitors of choice are quite excellent, and I listen to them in the near-field together with a subwoofer. It's the DM10s from the small English manufacturer AVI. Outstanding value for money. They are more revealing than the Sennheiser 650s, probably on a par with the Sennheiser 800s. But the room can obviously mess things up. That's why I listen to them in the near-field. EDIT/clarification: So ordinarily, my near-field setup with speakers provides better clarity and better dynamics than my headphones. But you are completely right that headphones usually outplay speakers in those regards.

2) You are obviously right. I don't see my own listening impressions to be the final word on anything. I'm as prone to expectation bias as everybody else. That's why I try to find out whether there are measurements and objective facts which back up my listening impressions. In this case, I believe that there is.
But the JBL 305/308s, for example, are superior. When I say that, it is not only based on my own listening. After all, your listening experiences may be different from mine. When I say that, it is based on objective parameters that have been shown to correlate with listener satisfaction in psychoacoustic studies: Frequency response, dispersion pattern, polar response, response in the time domain, the ability to play loud without distortion, etc. On all of these parameters, the JBL 305s/308s perform better than a pair of Sonos play:1 with sub.

Digressing from the thread, but this is a very interesting point.
I would argue that not all measured differences will result in audible differences, and of those that do, not all will be preferred.
For something like a speaker, all that matters is which one I prefer to listen to. Not what you do, or not what has been "shown" to correlate with listener satisfaction in studies, although I grant that the odds in that case are skewed to that speaker ending up to be preferred more often than not. And some things that aren't measured, like looks, will also influence the preference.
Which is why it is never a good idea to buy a speaker only based on its reported measurements. For instance, I may prefer the way the 1 pair + hidden Sub looks, compared to the industrial looks of the JBL, and that may drive my preference for the Sonos set up. Or not.
So for speakers, the only use of measurements is to make a short list; ideally before buying, they should be heard at home, sighted, with preferred music, from the usual source, and the ones that then sound best for the budget should be the ones to buy.
And although this is a digression, it does underline the irrelevance of the bit perfect thing, except to meet psychological needs. That said, I get that those that are influenced by these needs will not be happy with the Connect as it is stated to be these days.
By the way - when you say the 305/308 perform better than the 1 pair + Sub, you also need to say whether this is the case with today's Connect, or the one before the change was made, and also based on what kind of inputs are given to the JBL pair...:) Which makes things complicated and just an example of why a listening test at home of the kind I described trumps all measurements for electro mechanical devices like speakers.
Does Sonos care about this state of affairs for the Connect? For them to say, so let's see if any response is forthcoming.
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Digressing from the thread, but this is a very interesting point.
I would argue that not all measured differences will result in audible differences, and of those that do, not all will be preferred.
For something like a speaker, all that matters is which one I prefer to listen to. Not what you do, or not what has been "shown" to correlate with listener satisfaction in studies, although I grant that the odds in that case are skewed to that speaker ending up to be preferred more often than not. And some things that aren't measured, like looks, will also influence the preference.
Which is why it is never a good idea to buy a speaker only based on its reported measurements. For instance, I may prefer the way the 1 pair + hidden Sub looks, compared to the industrial looks of the JBL, and that may drive my preference for the Sonos set up. Or not.
So for speakers, the only use of measurements is to make a short list; ideally before buying, they should be heard at home, sighted, with preferred music, from the usual source, and the ones that then sound best for the budget should be the ones to buy.
And although this is a digression, it does underline the irrelevance of the bit perfect thing, except to meet psychological needs. That said, I get that those that are influenced by these needs will not be happy with the Connect as it is stated to be these days.
By the way - when you say the 305/308 perform better than the 1 pair + Sub, you also need to say whether this is the case with today's Connect, or the one before the change was made, and also based on what kind of inputs are given to the JBL pair...:) Which makes things complicated and just an example of why a listening test at home of the kind I described trumps all measurements for electro mechanical devices like speakers.
Does Sonos care about this state of affairs for the Connect? For them to say, so let's see if any response is forthcoming.


Good points. Agreed.

1) My monitors of choice are quite excellent, and I listen to them in the near-field together with a subwoofer. It's the DM10s from the small English manufacturer AVI. Outstanding value for money.

Excellent speakers those; I also know that ratty, who is one of the true wise heads here, has a Connect driven AVI active set up, so maybe he will find his way here some time soon and shed some light on any thing different he finds with the sound quality he now obtains.
I also know that ratty, who is one of the true wise heads here, has a Connect driven AVI active set up
Not any more. That room has a pair of PLAY:5 Gen2 plus a SUB. Trueplay tuned of course, smoothing out what would otherwise be a very lumpy room response starting with a major peak at 30Hz.

In any case, it wasn't a CONNECT it was a 2007 ZP80. Now doing service driving a combo DAC/headphone amp into Sennheiser HD599s for late night listening.

Not any more. That room has a pair of PLAY:5 Gen2 plus a SUB. Trueplay tuned of course, smoothing out what would otherwise be a very lumpy room response starting with a major peak at 30Hz.
.

Oh, ok.
Would I be right in thinking that this sounds better to you than the bit perfect ZP80 into the AVI actives - even if the Sonos Sub was to be removed for an apples to apples comparison?
Would I be right in thinking that this sounds better to you than the bit perfect ZP80 into the AVI actives - even if the Sonos Sub was to be removed for an apples to apples comparison?
I now longer have the AVIs (which had a subwoofer too) -- so can't make a side-by-side comparison -- and they were early ADM9s in any case, so several generations back. My recollection was that the P:5s sounded more natural in the midrange (piano, voice), and of course with Trueplay the bass response at the sweet spot is much smoother.
Seems to me from conversation here that there are the following five categories of people for whom Connect has/had some relevance:
1. Those that don't care about bit perfect, and have moved on to play units/Sub for even serious listening
2. Those that don't care about bit perfect, but use the Connect for its other features on the input side
3. Those that don't care about bit perfect, realising that all that the lack of it does is the fuelling of Expectation Bias driven perceptions of sound quality degradation
4. Those with high end legacy tech kit who won't touch even a bit perfect Connect because they don't believe that Sonos kit is worthy of a place on their component racks, because it is cheap in price and looks
5. Those that are affected by this bit perfect thing.
The odds that Sonos will act to address the needs of just the last category don't seem very good, also because the change would have been made for valid reasons that may then have to be addressed in a different way.
....also because the change would have been made for valid reasons that may then have to be addressed in a different way.

You have no idea why the change was made - this is pure speculation.

The thing that I find most ironic is that for years the fanboys have been yelling 'bit-perfect, bit perfect' (because it says so in a very old test of a ZP80) and shouting down people who claim that other dacs and conversions sound better. We now find out that, since 2011, people who care about sound quality could have been right all along...


You have no idea why the change was made - this is pure speculation.

The thing that I find most ironic is that for years the fanboys have been yelling 'bit-perfect, bit perfect' (because it says so in a very old test of a ZP80) and shouting down people who claim that other dacs and conversions sound better. We now find out that, since 2011, people who care about sound quality could have been right all along...


You won't find anybody who "yelled" bit-perfect before defending Sonos on this issue. At least I won't be. Sonos, for whatever reason, screwed with what should be bit-perfect output, and that is not good. So can it with the "fanboy" nonsense, it's a weak and cowardly tactic to attack the messenger and not the message. Either you can defeat the argument, or you can't.
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You won't find anybody who "yelled" bit-perfect before defending Sonos on this issue. At least I won't be. Sonos, for whatever reason, screwed with what should be bit-perfect output, and that is not good. So can it with the "fanboy" nonsense, it's a weak and cowardly tactic to attack the messenger and not the message. Either you can defeat the argument, or you can't.


Agreed, this is about being able to stream the original bits to my DAC. If they are transcoded before they get there, there is not much point, why bother to have two digital outputs, they could save the money and not confuse people.
[quote=jgatieSo can it with the "fanboy" nonsense, it's a weak and cowardly tactic to attack the messenger and not the message.[/quote]

You do realise that you're not a mod, don't you?

You do realise that you're not a mod, don't you?


So I'm not allowed to call you out on weak and cowardly arguments unless I'm a mod? Who makes these rules?
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You do realise that you're not a mod, don't you?


So I'm not allowed to call you out on weak and cowardly arguments unless I'm a mod? Who makes these rules?


How about both of you move on so we can get back to the discussion.
....also because the change would have been made for valid reasons that may then have to be addressed in a different way.

You have no idea why the change was made - this is pure speculation.

The thing that I find most ironic is that for years the fanboys have been yelling 'bit-perfect, bit perfect' (because it says so in a very old test of a ZP80) and shouting down people who claim that other dacs and conversions sound better. We now find out that, since 2011, people who care about sound quality could have been right all along...


Of course I do not know why the change was made, but I'd say it is more reasonable to assume that Sonos made the change for valid reasons, than to say that they did not have a valid reason to do so...or are you challenging this statement as well?:-)

And those that were saying "bit perfect" were doing so - AFAIK - to explain that the Connect was equivalent to any digital transport out there, and was therefore just as capable as any CD player for example, to supply bits to any external DAC for conversion. That - as I am convinced - the Connect DAC is audibly just as good as any other DAC was not being claimed by those saying "bit perfect".
I also take your last statement to imply that "people who care about sound quality could have been right all along", could also have been wrong; and if so, I agree with that statement:)

I agree with LeighB that if the digital output isn't bit perfect anymore, why have it there at all - except perhaps that it would mean a cost to even change the hardware to remove it such that may not be worth the corresponding saving.

Thunderous silence continues from Sonos on this thread...
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The silence represents Sonos's arrogance IMO. Does Sonos have a great products yes. Is there room for improvement on on both the hardware and software -Yes. I think the secrecy surrounding new product refreshes(if any are even coming) is getting a little frustrating for us loyal Sonos supporters. Lets look at the outdated Connect. Aesthetically it ugly. I personally hide my three behind all my other gear. Not bit perfect, does not have a 12v trigger output, does not support high res files (even over a hard wired connection) wont be able to support MQA even if MQA is successful. Compeditors like the Bluesound and their Node 2 hardware has surpassed offering from Sonos. They have listed to their customers and critics and responded with upgraded equipment. Why can't Sonos do the same for their customers. If Sonos is working on a Connect replacement what would be wrong with a small press release from Sonos to stating exciting times ahead for you Sonos Connect users. Give us loyal customers a bone. if they are not working on a replacement connect then let us know here in this thread. If Sonos does not feel a replacement Connect is where they want to spend their resourses at this time please let the rest of us know. Maybe they dont sell enough connects to warrant an upgrade in their opinion. I dont think there are many users here who are heavily invested in the Sonos ecosystem want to change from Sonos. This is of course provided the Sonos offereing are up to date and current. I personally do not what to change. I only what an upgraded connect that will compete with the majortiy of other streamers in the market today addressing todays requirements. Sure Sonos is going through some overdue changes in management. Hopefully the new president will have vision of the future and wont be scared to talk about it. If new connect hardware is not in the future then let us know so we can move on to other offerings in the market place. We all want Sonos to succeed. Sonos not answering valid customer questions makes me feel slighted and unappreciated by Sonos.
Lol @ MQA. 😃
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I agree on the MQA front, but it still does not address the silence from Sonos. I just spent the last hour reading over at the the Bluesound forums. I must admit it was refreshing. Bluesound employees answering questions and concerns.

If the Node2 bit perfect. Answer yes. Employees addressing issues and acknowledging customer requests for future software upgrades. It is just a different culture over there. I think Sonos could learn a little from visiting their compeditotrs forums. Like I said i dont want to change from Sonos but the Node2 is looking more interesting everyday. In the mean time we the Sonos supporters are left with well, nothing to look forward too on the connect front.
Bluesound caters to a tiny niche market, audiophiles who often believe things which have no basis in fact. They really aren't much of a threat. Sonos has moved well beyond that niche to become the premier provider of high quality connected speakers for the fast growing music streaming market. So long as they don't lose their focus on sound quality, ala Bose, I'll be a happy customer.
I find it amazing that people will put up with a crap interface like Bluesound just because they "answer" questions in a forum. Apparently for some, tickling egos with promises of future enhancements is far more important than actually following through with those promises. Personally, I'm not interested in being stroked.
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Jgaitie

Like I said a completely different culture over there. I hope to in the next few days write to the new Sonos President and use your reply as an example of how the Sonos community is moving forward with a positive attitude and direction. Let's hope he does not take your lead or Sonos will be destined to fail.

Let's hope he appreciates the customers he does have.

Enjoy the rest of your day.
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Chicks

I can appreciate your response if all you may be looking forward for is good sounding wireless speakers. I agree and I enjoy the Sonos speaker lineup. I personally would like to see enhancements to products other that their speaker lineup. I would like a 12v trigger in a connect to be able to turn on a separate amp to drive a better set of speakers than what Sonos is the offering. The Sonos connect amp does not have enough power for my use.
Use a Sonos Connect with an amp that can turn itself on when it senses audio. These amps also usually provide 12V out in case you need to activate other devices as well.
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UpstateMike

Thanks for your reply.

I have tried that with inconsistent results. Parasound A23 amp set to turn on when it senses audio worked inconsistent. Low volumes it would shut down. Better audio equipment use 12v trigger as a standard. I would hope Sonos would consider my suggestion in future upgrades to the connect.
Jgaitie

Like I said a completely different culture over there. I hope to in the next few days write to the new Sonos President and use your reply as an example of how the Sonos community is moving forward with a positive attitude and direction. Let's hope he does not take your lead or Sonos will be destined to fail.

Let's hope he appreciates the customers he does have.

Enjoy the rest of your day.


Use my reply all you wish. I hope he actually does follow my lead. I'd much rather Sonos keep doing as it is doing than follow companies like Denon or Bluesound who promise the world to their customers and never follow through. I also don't want Sonos chasing nonsense like MQA. I couldn't care less about the culture of a company if their product doesn't match up. As I said, I don't need my ego stroked in a forum and I don't need audio snake oil.