Question

Connect no longer bit-perfect?

Forum|Forum|10 years ago
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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jgatie

Accent on the SONOS products. It really seems that passive-aggressive pimping of other products is the goal of some, a goal far better served at a place like AVS, rather than a forum dedicated to one manufacturer.

G

gizze

Enthusiast II

Sorry, I totally disagree with you.

Sonos is a system that works with other kit, it is designed to work with other marques and does that well, so being able to discuss what it works with well and where the kit could be improved to keep existing customers and bring in new customers is what forums like this should be about.

One of the main reasons I mentioned moving away from the connects to the Raspberry Pi units is because they allow me to do what I do now with Sonos but also allow me to send files via Airplay too, which is one thing I really wish Sonos would add at some point in the future.

The Meridian forum I am on are always suggesting other peoples kit to people if it will do what they want better, I found most of the info on Bel Canto last week from the Cyrus forum and I bought my E Class estate after loads of guys on the BMW forum I used suggested it would be the best for my needs.

Complete refusal to acknowledge other peoples way of thinking and shooting down their discussions is not good for the forum or for Sonos.

I'm not passive aggressive pimping other products at all, I'm just not saying 'there is only Sonos'.

It feels a bit like being on a Playstation or Xbox forum on here!
We get you are well and truly "Sonos" but maybe not everyone is quite so blinkered in how you have to use Sonos to enjoy it, it isn't an all or nothing, you can have Sonos and other kit too you know? 😃

K

Kumar

I have just ordered a Raspberry Pi which will allow me to have my Meridian Explorer 2 DAC attached to it as a Roon endpoint.
It will also allow airplay, soundcloud, spotify etc. which are the bits missing from Roon.

I borrowed a mates the other day and it is on a very different level to my Connect sound wise. Plus total cost is £160.
That will replace the Connect, but I think I am going to get another one, sell the Connect Amp and buy a power amp for my little Quad S2 ribbon speakers.

Three speaker that I have in my house that sound considerably better than a pair of Play 5s are Meridian DSP5200s, Martin Logan Electromotion and the little Quad Ribbons, which I just paid £480 for, but the Quad 11L's they replaced were better too. They replaced a pair of Play 5s, I put the Quads in there with the ZP100, so similar price point.

I'm not knocking the Play 5, I think it is an amazing bit of kit, and a pair can really boogie, but they are extremely coloured (in a good way) compared to even a pair of decent bookshelf speakers.

A lot of the guys on another forum are swapping their Play units for these.....

https://www.whathifi.com/q-acoustics/q-bt3/review

They seem well pleased with them.

Where in the above is any reference to Sonos kit other than your plans to replace it? Of course, Sonos is quite comfortable letting you pontificate here because you have no ability to hurt sales, so go ahead and do so. Pimping other kit sounds a good description for the quoted post though.
Ahh..I just noticed your plans to keep a zp100:) I am sure we are all grateful for that.

jgatie

I'm not passive aggressive pimping other products at all, I'm just not saying 'there is only Sonos'.

I'm pretty sure if Websters had a definition for passive-aggressive pimping of other products it would be this! 😃

chicks

My QUAD ESL-63 'stats are from 1983, so I'm not pimping them, lol. The Connect:Amp drives them nicely, and has done so for years. Perfection, imo. Maybe when I retire and downsize, I'll go 100% Sonos.

K

Kumar

My QUAD ESL-63 'stats are from 1983.

If I could get a pair of Quad ESLs for a price that won't need me to sell my car, that is the one change I would consider even now:). Driven by a Connect Amp, that would be one HiFi flavour worth having; replacing play units with conventionally constructed speakers from any other make isn't worth the effort, money, or the cabling mess. One problem with ESL though is the space they need left behind them for best results. No Trueplay solutions for that!

L

Luc45

Trending Lyricist I

Are there any news about whether the issue has been fixed with recent updates?

Airgetlam

I don't believe that Sonos considers this an issue, so I would doubt there would be any updates.

Bruce

J

John B

I don't believe that Sonos considers this an issue, so I would doubt there would be any updates.I suspect you are right. Nobody would notice anything had changed if Sonos did 'fix' it. Just like nobody noticed for five years that it had become (strictly speaking) non-bit-perfect.

Y

Yiannis74

I also think that the changes in the Connect's digital output are the result of a decision by Sonos. Who knows, maybe they decided they wanted to 'voice' the output in a certain way. I am not so sure that the results are not audible though. I cannot back it up with hard science / blind testings etc. I think the OP (Peter Mc) reported he could actually hear the difference so I would not rule out audible differences so quickly.

I used Connects for many years and I became unhappy with the sound (digital out) a few years ago without being able to figure out why. This does not prove anything of course so I have decided to purchase an old ZP90 (reported as remaining bit-perfect) and once I get my hands on it I will try a blind test against my recent Connect to see what I find 🙂. It will be a few weeks before I do this but I will report back.

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