Connect no longer bit-perfect?

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.

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.

Indeed - very odd decision to change Bit Perfect "Fixed Volume" into something inferior.

Most of us who bought ZP90 or Connects generally did so to preserve our "High End" systems whilst being able to sync the rest of the house with Play X units.

Better fix it fast Sonos or your going to take a hammering once the Audio Press find out!

Adding functionality to our Sonos systems has always been a great plus point of ownership.

Removing audio quality is not going to win universal acclaim.

Interesting topic. I am new to the these forums, but does Sonos ever directly comment on these topics?

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 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.

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.

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?

"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.

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.