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Peter Mc
August 23, 2016
Question

Connect no longer bit-perfect?

  • August 23, 2016
  • 450 replies
  • 29769 views
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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    450 replies

    jgatie
    March 11, 2017
    7


    If you weren't such an opinionated bigot I would bother, but what's the point?

    I know for a fact I'm not the only one who thinks this because of the PMs I have had from other members telling me they have just learnt to ignore you or don't post in the threads you post in, although pretty hard with such a post count as you do seem to be in almost every thread.

    Find a large following? Is that what you think people want? Is that why you have nearly 13000 posts on here? To get a following.
    Oh dear.


    The funny thing about this is I've not called you any names, fool or otherwise. Yet you feel the need to accuse me of name calling and attack me personally with an extremely loaded term such as "bigot". I suggest you reread your exchanges with me in this thread and you may begin to understand why you feel the anger you do. When one has to resort to calling another names like "idiot", "old man know it all" or "bigot" without any evidence of them being true, it's more than likely they are losing the factual argument.
    Enthusiast II
    March 11, 2017
    Wow. Do you even know the meaning of the word you're so casually using? Highly offensive, and far from true in this case.

    Which word would that be?

    I have read through my post a few times and I can't see what is highly offensive and certainly can't see what is 'far from the truth'?

    The only word I have used to describe him is 'bigot'.
    Is that the word?

    bigot

    noun
    a person who is intolerant towards those holding different opinions.


    I think that sums him up perfectly.
    In every thread he comes across as someone whose opinion is fact, and anyone who has a different opinion is wrong. The constant tosh he spouts about 'ABX testing' and 'prove you prefer it' is just.......never mind.

    I am saying as someone joining the Sonos forum there are a handful of people on here that make it pretty painful to those who might want to get involved with discussion. You can chose what you want to do with that info, I can pretty much guess what will be done with it.


    Enjoy the weekend.
    Enthusiast II
    March 11, 2017
    7


    If you weren't such an opinionated bigot I would bother, but what's the point?

    I know for a fact I'm not the only one who thinks this because of the PMs I have had from other members telling me they have just learnt to ignore you or don't post in the threads you post in, although pretty hard with such a post count as you do seem to be in almost every thread.

    Find a large following? Is that what you think people want? Is that why you have nearly 13000 posts on here? To get a following.
    Oh dear.


    The funny thing about this is I've not called you any names, fool or otherwise. Yet you feel the need to accuse me of name calling and attack me personally with an extremely loaded term such as "bigot". I suggest you reread your exchanges with me in this thread and you may begin to understand why you feel the anger you do. When one has to resort to calling another names like "idiot", "old man know it all" or "bigot" without any evidence of them being true, it's more than likely they are losing the factual argument.



    Your constant droning on is very bigoted.
    Those that call people who hear differences in different kit "audiofools" are idiots, those that preach that sort of thing as fact do come across as 'know it all old men'.
    It is boring, it is rude, so if those doing it don't want to be pulled up on it, don't do it.
    That is not aimed just at you, there are so many threads with the same nonsense posted from the same few people that in the end you just think 'sod it' and want people to shut the hell up. We get you don't agree with differences in DACs etc. We get you don't think having a bit perfect player matters, and if it doesn't matter to you fine, but why tell everyone it does matter to that they are wrong?!

    As I said before, we shall agree to disagree. You think I talk shite, I think you talk shite. Ho hum, that's life. So what? :D


    Have fun, it's the weekend after all, and in 2 minutes I am off for 2 days!
    jgatie
    March 11, 2017
    If someone joining the forum starts off calling people "idiots", and then proceeds to call someone who happens to disagree with them an "old man know it all", I believe it is highly hypocritical for them to then complain about other's decorum or how it is "painful" to get involved in the discussion. I've merely disagreed with you and explained why. You've called people names and then claimed the victim.

    Physician, heal thyself.
    jgatie
    March 11, 2017

    Your constant droning on is very bigoted.
    Those that call people who hear differences in different kit "audiofools" are idiots, those that preach that sort of thing as fact do come across as 'know it all old men'.
    It is boring, it is rude, so if those doing it don't want to be pulled up on it, don't do it.
    That is not aimed just at you, there are so many threads with the same nonsense posted from the same few people that in the end you just think 'sod it' and want people to shut the hell up. We get you don't agree with differences in DACs etc. We get you don't think having a bit perfect player matters, and if it doesn't matter to you fine, but why tell everyone it does matter to that they are wrong?!

    As I said before, we shall agree to disagree. You think I talk shite, I think you talk shite. Ho hum, that's life. So what? :D


    Have fun, it's the weekend after all, and in 2 minutes I am off for 2 days!


    Show me where I called you an audiophool, or any other similar term. You won't find it. Unlike you, I don't need to resort to juvenile personal attacks.

    As to the other stuff, I happen to think there can be differences between DACs, and my very first post in this thread was to call it a bad move for Sonos to make the Connect no longer bit-perfect. Do you even read my posts? For someone so judgmental, you get a lot of things about me wrong.
    chicks
    March 11, 2017
    Wow. Do you even know the meaning of the word you're so casually using? Highly offensive, and far from true in this case.

    Which word would that be?

    I have read through my post a few times and I can't see what is highly offensive and certainly can't see what is 'far from the truth'?

    The only word I have used to describe him is 'bigot'.
    Is that the word?

    bigot

    noun
    a person who is intolerant towards those holding different opinions.


    I think that sums him up perfectly.
    In every thread he comes across as someone whose opinion is fact, and anyone who has a different opinion is wrong. The constant tosh he spouts about 'ABX testing' and 'prove you prefer it' is just.......never mind.

    I am saying as someone joining the Sonos forum there are a handful of people on here that make it pretty painful to those who might want to get involved with discussion. You can chose what you want to do with that info, I can pretty much guess what will be done with it.


    Enjoy the weekend.


    Big difference between opinions of the uninformed and those grounded solidly in facts. Yours, I fear, have a basis about as scientific as those of the current administration...
    Lyricist III
    March 11, 2017
    Actually, this mostly reminds me of why I rarely come to community forums ... I seem to remember a long time ago this thread was about a very specific issue; that the Sonos Connect no longer streams the original bits to its optical output, but is transcoding them.
    jgatie
    March 11, 2017
    This actually was a pretty good thread until off-topic posts about MQA and "idiots" who dont believe in it started. There does seem to be a pattern of many threads that have nothing to do with Hi-res audio being steered that way by newer posters.
    Enthusiast II
    March 11, 2017
    I started my post saying I liked my Sonos gear, but after trying other sources into my DAC realised it was seriously behind in terms if fidelity, I logged into the forum and saw this thread, hence why I posted in here asking if something that was higher end that could also possibly handle MQA etc was on the roadmap.

    The first reply was...


    A "Hi Rez" Connect might sell in the thousands, or perhaps tens of thousands. The Play:1 sells in the millions. I doubt Sonos will produce something that only self-deluded audiophiles can "hear" a difference with.


    So, first reply is being called a 'self-deluded audiophile.

    I then asked Chicks if he/she had heard MQA?

    I don't deal with "beliefs". That's for the audiophools. I stick to facts. Real facts, not alternative ones.


    By that point I should have just stopped discussing it, lesson learnt.


    I then said that a DAC is not designed to sound 'pure' to you jgatie, and I don't believe they should, there should be filters to tailor the sonic signature.

    Your reply...

    What's wrong with that is you can do the exact same thing with a DSP and/or equalizer, in an almost infinite amount of configurations, and not pay thousands of dollars for it. A DAC shouldn't be purposefully coloring the output, if it does, it is not a "pure" DAC, it's nothing but DSP snake oil easily achieved in much less deceptive (and less expensive) ways.

    Snake oil is a term used to belittle nonsense in the hifi world, which I agree there is plenty of, nonsense I mean. So how am I meant to take that?

    At the end of the day, there are differences of opinion, I was not the one who started with the name calling, but if someone talks crap and spouts nonsense as if it were fact I will call them an idiot.

    Reading back through it seems it is mainly Chicks who keeps starting with the crap, and just talks in riddles.

    What the hell is the following meant to mean?


    Big difference between opinions of the uninformed and those grounded solidly in facts. Yours, I fear, have a basis about as scientific as those of the current administration...


    That was in reply to using the word Bigot and people talking about ABX testing of files like MQA that they haven't even heard yet. Not a clue what you're babbling about to be honest. Current administration?
    Maybe English is not your first language Chicks? Bigot is not a 'highly offensive' word, I am a bigot about a lot of things, human nature, I am also ignorant to a lot of things, any one who says they are not ignorant about anything, is, well............look up ignorant. Kind of ironic.


    I look forward to the grilling lying ahead for me.
    jgatie
    March 11, 2017
    So the way I see it, the guy accusing me of name calling and intolerance for different opinions is the one calling me names and telling me I should shut the hell up and stop posting my opinion. The same guy who says you shouldn't judge people on their beliefs judges me on two beliefs about DACs and whether the Connect should be bit-perfect that I never said, and don't even hold to be true.

    As to how you should "take" my comment on DACs? Why should I care how you take it? If I say I think deliberately coloring the sonic signature on a DAC is snake oil, it's an attack on the DAC manufacturer, not you. The fact you take it personally is your problem, not mine. No wonder you escalate to personal attacks when someone disagrees with you, it seems it really is personal to you. Maybe you should take your own advice and just let people disagree with you?

    Still waiting for the post where I called you an audiophool or an apology for accusing me without evidence. Got a feeling I'll be waiting quite awhile for either.