Multiroom using Optical Input

[dwood]

I have the same issue using Optical In as the source on the master. I have three WiiM Pros, all set for SPDIF/Out at max 96 kHz/16 bit. When linked, I am able to hear music in all three when the master receives music from Qobuz (WiFi source) or Line In on the master. As soon as I change the source to Optical (USB - Optical converter on my Mac), I can only hear music through the master WiiM Pro. The other two outputs from the slave WiiM Pros are silent. When I unlink them, I can hear test output when I test the SPDIF/Out.

I trust my WiFi set up. It is working fine when input to the Master WiiM Pro is Qobuz or Line In. I did also try setting them all to 44 kHz/16 bit just in case the WiiM Pro was not passing the input rates to the slave WiiM Pros. I got the same result (silence with Optical in for the Master for the slaved WiiM Pros). Because Qobuz is working, I believe that the WiiM Pros send out information about the data rate for the music.

I have sent feedback from the WiiM app.

 

[WiiM Support]

Hi Team,

Known Issue Alert: Multiroom audio doesn't function when the optical input resolution exceeds 48kHz/16-bit. Our team is on it and aims to roll out a fix by the end of next week.

As a temporary fix, you can cap your source device's optical output resolution at 48k/16-bit. Thanks for your patience!

 

[dwood]

I am concerned that the multiroom audio solution in the previous message does not capture the problem I am having. The multi-room audio works fine with line-in and WiFi input (like TuneIn and Qobuz). It only plays locally when I select optical in (which, in my case, is an optical out from my laptop playing audio files at 16 bits/44.1 kHz). I tried setting all the optical output resolutions at 48 kHz/16 bit and Optical In is not distributed.

My problem is that Optical In does not seem to distribute in multi-room mode, it plays locally only. As stated above, I have three WiiM Pro's attached to Modi 3 plus DACs. They all work locally (plays the test audio) and work in linked-mode with the input being WiFi (various sources) and line in, but not with Optical In on the master WiiM Pro. This is different from the issue of optical output resolution of the source WiiM Pro (as stated, I tested that and it still doesn't work).

 

[Brantome]

What’s your ticket number?

 

[dwood]

Hmmm, I have a forum account. I clicked on the support email and I am told that I don't have an account or my password is wrong. It is apparent that faq.wiimhome.com/helpdesk URL has a different account from forum.wiimhome.com. If it helps, the email link telling me about the ticket ends with 490089 (https://faq.wiimhome.com/helpdesk/tickets/490089. It might be the ticket number, it might just be a URL with the ticket number on the web page (I dunno).

 

[Brantome]

Hmmm, I have a forum account. I clicked on the support email and I am told that I don't have an account or my password is wrong. It is apparent that faq.wiimhome.com/helpdesk URL has a different account from forum.wiimhome.com. If it helps, the email link telling me about the ticket ends with 490089 (https://faq.wiimhome.com/helpdesk/tickets/490089. It might be the ticket number, it might just be a URL with the ticket number on the web page (I dunno).

Looks like a ticket number. I’ll flag it up to Wiim.

 

[WiiM Support]

I am concerned that the multiroom audio solution in the previous message does not capture the problem I am having. The multi-room audio works fine with line-in and WiFi input (like TuneIn and Qobuz). It only plays locally when I select optical in (which, in my case, is an optical out from my laptop playing audio files at 16 bits/44.1 kHz). I tried setting all the optical output resolutions at 48 kHz/16 bit and Optical In is not distributed.

My problem is that Optical In does not seem to distribute in multi-room mode, it plays locally only. As stated above, I have three WiiM Pro's attached to Modi 3 plus DACs. They all work locally (plays the test audio) and work in linked-mode with the input being WiFi (various sources) and line in, but not with Optical In on the master WiiM Pro. This is different from the issue of optical output resolution of the source WiiM Pro (as stated, I tested that and it still doesn't work).

Hi dwood,

We're aware that the optical input exceeding 48kHz/16-bit isn't currently supported in multi-room mode. Good news: a fix is coming early next week! Stay tuned and thanks for helping us make our products better!

 

[Brantome]

Hi dwood,

We're aware that the optical input exceeding 48kHz/16-bit isn't currently supported in multi-room mode. Good news: a fix is coming early next week! Stay tuned and thanks for helping us make our products better!

Isn’t @dwood saying they’re not exceeding that and only trying 16/44.1?

 

[dwood]

Here is additional detail given that the response to my post is the same as before. Maybe I made an assumption. I connected my Mac to a Douk Audio U2 Pro, USB - Optical out. I assumed that it would replicate the USB source to the optical out (44.1 kHz,16 bit audio file being played). I do not have anything that displays the output format from the Douk Audio U2 Pro.

I am hoping it doesn't interpolate to a multiple of 48 kHz, (like 48/96/192 kHz) since 44.1 kHz does not have a rational fraction with a multiple of 48 kHz. On the other hand, it does sound good to me, so maybe I can't hear the artifacts if it is doing interpolation. I just was hoping it was not doing that.

My Google skills isn't up to finding out the technical details of the Douk Audio U2 Pro, there is a lot of noise on the Internet when it comes to details like clocks in audio equipment.

 

[dwood]

I set the output resolution to 16/44.1 and 16/48 on all WiiM Pros, no luck. The response has been about input resolution and to set the output resolution on the master WiiM Pro. I set the output resolution since setting it on the master didn't seem to change the problem.

I will point out that I can hear the music on the master WiiM Pro, it just does not seem to be distributing the audio stream to the linked WiiM Pros. To me, that implies that whatever my input is, the master can play the music. If the master is linking the slaves to a higher resolution than what I can play, that still seems like a bug since I have all the WiiM Pro's are set to be able to play through the Modi 3 Plus DACs and they are playing WiFi sources fine. As for Line In, as far as I know, I can't control the effective input A/D rates except if it is trying to match the output rate. I do not like the sound of Line In at all, much prefer digital inputs to the WiiM Pro.

 

[WiiM Support]

Here is additional detail given that the response to my post is the same as before. Maybe I made an assumption. I connected my Mac to a Douk Audio U2 Pro, USB - Optical out. I assumed that it would replicate the USB source to the optical out (44.1 kHz,16 bit audio file being played). I do not have anything that displays the output format from the Douk Audio U2 Pro.

I am hoping it doesn't interpolate to a multiple of 48 kHz, (like 48/96/192 kHz) since 44.1 kHz does not have a rational fraction with a multiple of 48 kHz. On the other hand, it does sound good to me, so maybe I can't hear the artifacts if it is doing interpolation. I just was hoping it was not doing that.

My Google skills isn't up to finding out the technical details of the Douk Audio U2 Pro, there is a lot of noise on the Internet when it comes to details like clocks in audio equipment.

Hi dwood,

If your Mac's audio output exceeds 48k/16-bit, it's likely that the Douk audio's optical output will also surpass 48k/16-bit. I don't think there will be any resampling during the USB-to-optical conversion. If you prefer, our team can whitelist your device soon, allowing you to test if this setup works for you. Stay tuned!

 

[WiiM Support]

I set the output resolution to 16/44.1 and 16/48 on all WiiM Pros, no luck. The response has been about input resolution and to set the output resolution on the master WiiM Pro. I set the output resolution since setting it on the master didn't seem to change the problem.

I will point out that I can hear the music on the master WiiM Pro, it just does not seem to be distributing the audio stream to the linked WiiM Pros. To me, that implies that whatever my input is, the master can play the music. If the master is linking the slaves to a higher resolution than what I can play, that still seems like a bug since I have all the WiiM Pro's are set to be able to play through the Modi 3 Plus DACs and they are playing WiFi sources fine. As for Line In, as far as I know, I can't control the effective input A/D rates except if it is trying to match the output rate. I do not like the sound of Line In at all, much prefer digital inputs to the WiiM Pro.

Hi dwood,

As noted in my previous message, the issue pertains to the optical input resolution we receive, not the maximum output resolution of the WiiM Pros. If your downstream device can handle it, please set your output to either 192k/24-bit or 96k/24-bit. Thank you!

 

[Mr Ee]

since 44.1 kHz does not have a rational fraction with a multiple of 48 kHz.

The ratio is 147:160
Seems rational enough to me.

 

[dwood]

Okay, thanks, it is rational. But, the anchors of the interpolation has lots of samples in between meaning that the vast majority of samples played will be interpolated, unlike small integer fractions like 48 kHz to 96 kHz, etc. I am not sure what interpolation algorithms are used that ensures that frequency content is not harmed by the interpolation, so the math I would do would not accurately represent how any device would do with the interpolation.

This reminds me of a synthesizer back in the 1980's, name escapes me. They had obviously done something like linear interpolation for the intervening samples, put in horrible triangle wave artifacts in the outputs. It was horrible. This is why I know that the interpolation algorithm is quite important in the characteristics of the affect of sound. Not knowing the algorithms means that one has to use ears and listening to judge how good the interpolation is - or have expensive equipment to measure the frequency outputs using specific frequencies as the source. I do not have the time to do such measurements. Cheap approaches like using apps in iPads do not cut it unless somebody has a suggestion for a really good spectrum analyzer app, though I worry about the microphone in the iPad (Yeah, I know, I should be real mics, again, time and expense means I don't have time to do this properly)

It is an assumption of mine that small integer ratio makes interpolation errors less important.

 

[dwood]

I am happy to report that the firmware update fixed my multiroom distribution problem using optical input on the WiiM Pro. I am able to set all the WiiM Pro's to 96 kHz/24 bit depth. My remaining problem is why I can't connect to the Schiit Modi Plus DACs at 192 kHz at any bit depth, but that is not so important. I cannot blame WiiM Pro for that problem. It could be that I have to get better optical fibers.

The sound is so much better with optical input vice connecting via Line In from my DAP.