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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I never called anyone a liar. I stated the quote that was printed was a lie, i.e. the opposite of the truth. Big difference, especially when the person later claimed he was misquoted.
As to the other, I've repeatedly stated that MQA probably does sound better. So fact or opinion, I've got no problem with either. Hi-resolution audio often sounds much better than CD.
As to the other, I've repeatedly stated that MQA probably does sound better. So fact or opinion, I've got no problem with either. Hi-resolution audio often sounds much better than CD.
It seems that there IS something going on under the hood, and for those of us that can't understand much of it:
1. What is the audible effect, if any, of this behaviour?
2. What is the way to deal with it where music listening is concerned?
And the same questions for where the Connect is used in Variable mode.
1. What is the audible effect, if any, of this behaviour?
2. What is the way to deal with it where music listening is concerned?
And the same questions for where the Connect is used in Variable mode.
Because of the conversation around this post (before and after). It seems people who claim hi-res sounds better cop a beating on this forum for not providing suitable evidence of what is taken to be a statement of fact, whereas a claim that someone is a liar is to be inferred as opinion and therefore need not be backed up with evidence. How do your "people that know better" tell the difference between these two scenarios?
Hi Kumar - here's my take. Others may like to chime in.
1. There is 1dB of soft-knee compression applied. 1dB is an audible change in total volume (3dB is a doubling in power). A 1dB compression will be less audible as it only decreases the loud bits.
2. There is a 1-bit bias on the negative part of the waveform. I really don't know whether this is audible. It will, however, apply a slight DC signal to the speakers.
3. Volume normalization will alter the overall volume of all tracks to be more similar across tracks. For sequential tracks from an album that flow into each other this can cause an audible volume change.
4. There is reputational danger for Sonos and the Connect because it can no longer be considered audiophile-quality gear. The original stereophile review of the Connect would have been scathing if these issues were happening back then.
What can you/we do? Put pressure on Sonos to go back to disabling all signal processing when in fixed volume mode.
The volume normalization problem can be overcome by removing the ITUNNORM tags from files. This is a hassle, and removes the option to use these tags when playing individual songs for a party etc.
I think by far the best solution would be for Sonos to disable DSP for fixed volume, or add a switch so users can decide.
As far as variable mode is concerned, I speculate that the same answers apply, but I haven't made any measurements in this mode.
Cheers, Peter.
1. There is 1dB of soft-knee compression applied. 1dB is an audible change in total volume (3dB is a doubling in power). A 1dB compression will be less audible as it only decreases the loud bits.
2. There is a 1-bit bias on the negative part of the waveform. I really don't know whether this is audible. It will, however, apply a slight DC signal to the speakers.
3. Volume normalization will alter the overall volume of all tracks to be more similar across tracks. For sequential tracks from an album that flow into each other this can cause an audible volume change.
4. There is reputational danger for Sonos and the Connect because it can no longer be considered audiophile-quality gear. The original stereophile review of the Connect would have been scathing if these issues were happening back then.
What can you/we do? Put pressure on Sonos to go back to disabling all signal processing when in fixed volume mode.
The volume normalization problem can be overcome by removing the ITUNNORM tags from files. This is a hassle, and removes the option to use these tags when playing individual songs for a party etc.
I think by far the best solution would be for Sonos to disable DSP for fixed volume, or add a switch so users can decide.
As far as variable mode is concerned, I speculate that the same answers apply, but I haven't made any measurements in this mode.
Cheers, Peter.
Both.
Fixed Volume should return to being guaranteed bit-perfect for players with a digital out.
There should also be a normalisation defeat switch in room settings for all players. If loudness can be turned on and off I don't see why normalisation shouldn't too. (Objections from Sonos along the lines of "in the absence of normalisation tags a confused user wouldn't hear any difference" can surely be addressed.)
Does all this apply to REPLAYGAIN TRACK?
Does removing this Tag return us back to Bit Perfect on the Connect?
Does removing this Tag return us back to Bit Perfect on the Connect?
This post. It's the shill statement, not the lying one, that I should have used as an example. I challenged jgatie to provide evidence of his statement that "This study was a carefully crafted shill for the Hi-res audio industry". He claimed that everyone else would have already inferred that his statement was an opinion, and therefore he provided no evidence to back it up. As jgatie also said, " It's once someone starts making definitive claims that they need to start giving proof." How very convenient that he considers that his statement should be inferred to be an opinion, perhaps by your "people that know better". Do you start to understand now the double standard being applied here?
Yes, at present that can't be defeated at all on later models of CONNECT. See this thread: https://en.community.sonos.com/setting-up-sonos-228990/volume-normalization-processed-fixed-volume-output-6738413
Does removing this Tag return us back to Bit Perfect on the Connect?
Apparently not, to judge by Peter Mc's findings, at least on the later CONNECTs. It could be all bound up with the undefeatable volume normalisation issue.
It would be interesting is someone could make comparable tests on ZP80 and ZP90.
. Do you start to understand now the double standard being applied here?
I see what you mean, and I am doing something that isn't usually wise - jumping into a conversation between two people - but this may just as likely be cross talk and not double standards.
Here is what would probably have yielded better results:
Statement: "This study was a carefully crafted shill for the Hi-res audio industry"
Response: "Why do you think so?" or another form of the same question, asking for a justification of the statement. And it doesn't matter if the statement is an opinion or a fact - or whether it was prefaced with the " In my opinion". In any of these case, the response is legitimate.
Somehow I doubt that the response to the response above would then have been on these lines:
" I just think so, it is my subjective opinion and I don't have to say why I hold it".
Couldn't agree more...
Agreed here too.
There needs to be a way where Connect users can guarantee bit-perfect signal from the digital outputs.
As ratty suggests, I also think having the option to turn on/off volume normalisation is something that is long overdue. This way external DAC users can chose whether they want bit-perfect, or normalised. And, yes, this should be configurable per player.
I also think that the "Album" type of volume normalisation should be the standard, instead of the "track" type if no user-selectable option is available.
Cheers,
Keith
There needs to be a way where Connect users can guarantee bit-perfect signal from the digital outputs.
As ratty suggests, I also think having the option to turn on/off volume normalisation is something that is long overdue. This way external DAC users can chose whether they want bit-perfect, or normalised. And, yes, this should be configurable per player.
I also think that the "Album" type of volume normalisation should be the standard, instead of the "track" type if no user-selectable option is available.
Cheers,
Keith
I'm not even sure he "allowed himself to be directly quoted". I have seen so many examples of journalists misquoting scientists. Mostly we try and approve the final copy, but this is not always possible. There is no evidence that the inaccuracy was found and allowed through. When you say "cleverly done", this implies a deliberate act, and there is no evidence of this. Also, the wrong quote can only be admitted when it is observed. Finally, the primary source is the paper. No such statement appears in the paper. So I would say, on appeal, Not Out!
I must be lucky - Hardware Version 1.1.16.4-2
That's a ZP80 isn't it? Or just maybe a ZP90? Not a CONNECT surely.
If all that bought into the benefits of Hi res audio and then proclaimed its benefits in audiophile circles and internet forums had the bent of mind to do the kind of diligence you refer to, and to exert efforts to read and understand primary papers, would they exist even in the small numbers they do today?!:D
At the end of the day, people will believe what they want to believe. Fortunately in this case, not enough believe in Hi Res to the extent that Sonos see them as a market of interest. Long may that market dynamic not change!
That's a ZP80 isn't it? Or just maybe a ZP90? Not a CONNECT surely.
Yes ZP90 - but wasn't Connect just a rename rather than different device?
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.
Well, certainly it was initially a cosmetic change -- or so we thought -- but from recent posts it's clear that from 2011 it was a somewhat different hardware platform.
Digressing completely, the American meaning of the word bigot, from the Webster dictionary:
"a person who is obstinately or intolerantly devoted to his or her own opinions and prejudices; especially : one who regards or treats the members of a group (as a racial or ethnic group) with hatred and intolerance"
and the English one, from the Oxford English dictionary:
"A person who is intolerant towards those holding different opinions"
Presumably which side of the Atlantic one is from would decide what meaning gets conveyed by the word.
I would not be comfortable being called either kind of a person, but it seems that the word would sit a little more easily in the UK.
Bit perfect means the same on both sides.;)
"a person who is obstinately or intolerantly devoted to his or her own opinions and prejudices; especially : one who regards or treats the members of a group (as a racial or ethnic group) with hatred and intolerance"
and the English one, from the Oxford English dictionary:
"A person who is intolerant towards those holding different opinions"
Presumably which side of the Atlantic one is from would decide what meaning gets conveyed by the word.
I would not be comfortable being called either kind of a person, but it seems that the word would sit a little more easily in the UK.
Bit perfect means the same on both sides.;)
Interesting topic. I am new to the these forums, but does Sonos ever directly comment on these topics?
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.
Removing audio quality is not going to win universal acclaim.
I asked this here a couple of times, how has audio quality been audibly affected? Anyone picked that up in a level matched blind test?
I get that level matching has been affected by this in some way, but I am still not sure exactly how this is even an inconvenience.
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.
I also have another unanswered question that I think is related to this subject. Because Sonos gives me the facility to easily make playlists from my favourite albums, it is very easy for one that is recorded loud or hot - to mess up the sound level from a playlist where it is included and even more of an inconvenience in a shuffled one. These aren't poor recordings by any other measure, they just happen to need the volume levels set noticeably lower for the same sound level delivery as from most others.
The rips are from iTunes and presumably have the necessary information in a tag, so why can't Sonos react to this information and have the playlist not need volume control interventions whenever the songs are played, for the sound levels to not noticeably vary? I don't see this missing feature as a quality thing, but as a feature that would be very welcome.
I also find that Apple Music is always a little less loud for a volume control setting than ripped CDs, so using mixed source playlists becomes an issue; isn't this something that Sonos can solve?
Once sound levels are equalised across, I doubt that any little bit loss, if needed to achieve this, is going to be audible. After all, much of sound quality issues arise from audibly heard sound level differences as low as 0.2dB, so this seems an obvious fix to me. What stops Sonos from doing this effectively and automatically across tracks/albums/playlists/music sources?
PS: Question now posted in a new dedicated to the question thread.
The rips are from iTunes and presumably have the necessary information in a tag, so why can't Sonos react to this information and have the playlist not need volume control interventions whenever the songs are played, for the sound levels to not noticeably vary? I don't see this missing feature as a quality thing, but as a feature that would be very welcome.
I also find that Apple Music is always a little less loud for a volume control setting than ripped CDs, so using mixed source playlists becomes an issue; isn't this something that Sonos can solve?
Once sound levels are equalised across, I doubt that any little bit loss, if needed to achieve this, is going to be audible. After all, much of sound quality issues arise from audibly heard sound level differences as low as 0.2dB, so this seems an obvious fix to me. What stops Sonos from doing this effectively and automatically across tracks/albums/playlists/music sources?
PS: Question now posted in a new dedicated to the question thread.
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