Skip to main content
Contributor III
October 14, 2020

Sound Quality Connect vs. Port

  • October 14, 2020
  • 34 replies
  • 2199 views

I need to replace one of my Connects that is Gen 1 and therefore not Sonos II compliant. I will be picking up a Port to replace it.

My question: if you are using the digital output to go into an outboard DAC, is the digital signal presumably a pure unprocessed bitstream?  I had assumed that this would be the case with both units, but have read that if you use the Port even for volume level, you are implementing a layer of signal processing that may/will affect sound quality.  I do not know if that was the same situation with the Connect.

When I get the Port I will have the choice of using it in one of my high res systems where volume is adjusted by another unit or in a secondary system where I do use the volume adjustment of the Sonos unit.

Does use of volume control with the Port affect sound quality?

Does use of volume control with the Connect affect sound quality?

FWIW, I have found the on board DA conversion on the Connect to be adequate for background music but deficient for serious listening and assume that the situation with the Port vis a vis it’s on board DAC is the same or (according to some reviews) worse.

This topic has been closed for further comments. You can use the search bar to find a similar topic, or create a new one by clicking Create Topic at the top of the page.

34 replies

October 15, 2020

Best try based on a listening test, people here claim to hear differences even using the digital out that is measured bit perfect. Which does not imply that they are right or wrong, people hear what they want to hear.

wspohnAuthor
Contributor III
October 15, 2020

Can you confirm that if the output is set for fixed volume there is no digital processing by either unit?

jgatie
October 15, 2020

Can you confirm that if the output is set for fixed volume there is no digital processing by either unit?

 

Fixed output is bit-perfect to the source. 

wspohnAuthor
Contributor III
October 15, 2020

Thanks

ratty
October 15, 2020

Use of Variable Volume on the digital output always involves some processing, whether on Connect or Port. Simple volume adjustment of course changes the samples from their original input values, never mind using EQ.

Along with most such devices, Connect had some dynamic range limiting on its digital output to avoid clipping. Port does too, but for some reason it’s evidently more aggressive.

Fixed Volume bypasses all such processing.

Reviewers have remarked that Port’s analog output is also a suitable way of avoiding the effects of Variable Volume on the digital out. Port’s DAC is based on the AK4490, which is a well regarded “premium” chip.

 

Lyricist III
November 18, 2020

Sorry to reopen this can of worms….

To clarify the use of Fixed Volume to obtain “bit perfect” output. Does this also require the volume limit to be set to 100%?

A quick test shows the volume limit reduces the analog and digital outputs together so i’d assume it’s doing some processing via DSP. If so, would expect that the limiter should be reset to 100% to avoid this.

If the volume variation is applied at the digital signal level (pre-DAC) I can’t see how the use of the analog outputs would bypass the problem (if there is actually a problem to bypass, i’m not sure there is anything audible) as some reviewers have suggested. Surely the only difference is that the signal is going via an internal rather external DAC.

I like the use of a fixed volume with a 66% limit to give a less sensitive dial on the external amp. However, analog attenuation might be “superior”, technically speaking.

:vulcan:

ratty
November 18, 2020

Although I’ve never analysed its effect, one would logically expect a volume limit below 100% to simply scale the digital samples down linearly. They would obviously no longer be bit-perfect to the source, but I can see no reason why the soft-knee protective limiter in the DSP would be engaged. It’s there to stop samples being scaled up over Full Scale and clipping on the output. That can’t happen if there’s no EQ. 

Avid Contributor I
November 22, 2020

I’m was in the same boat so I bought a Sonos amp to replace a zp90. Seems it is bit perfect to the source too. It sounded good even with my B&Ws from 1999. 
However, just got a new iPhone and casting via iPhone / AirPlay 2 sounds stellar; way better than the Amp as a source.
How is this possible? Is there a default setting messing up the sound from the Amp alone? 

ratty
November 22, 2020

I’m was in the same boat so I bought a Sonos amp to replace a zp90. Seems it is bit perfect to the source too. It sounded good even with my B&Ws from 1999. 

I’m not sure I understand. The Sonos Amp cannot be ‘bit perfect’ as such. It contains a DAC, and EQ, and drives analog passive speakers. 

 

However, just got a new iPhone and casting via iPhone / AirPlay 2 sounds stellar; way better than the Amp as a source.

Are you using AirPlay2 to stream from the iPhone to the Amp? If so, it’s clearly part of the chain, and is doing decode and DA conversion much as before. Perhaps the source you’re comparing with AirPlay2 was in some way compromised? 

Avid Contributor I
November 22, 2020

In bit perfect, I mean the bit before the digital stream hits the DAC in the amp.

Im using Airplay 2 to stream from the phone. So why in the name of all that is holy does it sound better? Not possible surely?