Powering WiiM Pro Plus with a power bank

[slartibartfast]

Some of you folks think your opinion is "education." While fascinating, it does reveal the human condition as it is.
The measurements are not as you offer "completely irrelevant" just as the Alpha Audio blind switch test results in the link are also not irrelevant.

That people have found improvement in their audio setups using rather inexpensive options with batteries and switches isn't going to end because it upsets some. You're certainly not going to convince people with quality systems they are not hearing significant improvements. You're conclusions are not based on science. They are based on your personal expectations. Mine were low but that's proven incorrect, so, I'm pleased with the benefit.

Alpha Audio's analysis on the Cisco Meraki is useful and as I've experienced in my setup.

https://www.alpha-audio.net/review/a-very-deep-dive-into-network-switches-listening-and-measuring/3/

If the significant improvement was heard in a blind test fair enough. If not then the brain hears what it wants to hear.

 

[Horsey]

If the significant improvement was heard in a blind test fair enough. If not then the brain hears what it wants to hear.

Four hours plus of blind tests with a sample group of switches. You must watch the complete four hours straight otherwise you've failed the test.
Please do not fail. Enjoy!

 

[HansD-NL]

Four hours plus of blind tests with a sample group of switches. You must watch the complete four hours straight otherwise you've failed the test.
Please do not fail. Enjoy!

You are such a strange guy. I'm out of words really.

 

[Horsey]

You are such a strange guy. I'm out of words really.

Hans, that's cheating. Expected better of you considering the Alpha Audio guys are in the Netherlands too.
You did not complete their four hour switch test. This is unacceptable and unfortunately I must issue you a failing grade.

You are definitely among that special audio debunking crowd without a sense of humor?

 

[Fletcher Munson]

Four hours plus of blind tests with a sample group of switches. You must watch the complete four hours straight otherwise you've failed the test.
Please do not fail. Enjoy!

Thats not a real test

 

[HansD-NL]

Hans, that's cheating. Expected better of you considering the Alpha Audio guys are in the Netherlands too.
You did not complete their four hour switch test. This is unacceptable and unfortunately I must issue you a failing grade.

You are definitely among that special audio debunking crowd without a sense of humor?

What does that mean "Expected better of you considering the Alpha Audio guys are in the Netherlands too." Don't understand the correlation you try to point out.
So now the problem is my sense of humor or lack thereof? Got it, that's funny..
Calling education in science not science was also a good one, forgot to mention that earlier.

 

[dominikz]

While I truly have no desire to get involved in this back-and-forth, I've still decided to post for the potential benefit of people who might genuinely be interested in listening test protocols.

The issue with this specific listening test is that the protocol lacks the basic mechanisms to ensure that the listener can actually tell the difference between any of the network switches at all. It is just assumed the perceived differences are related to the network switches being exchanged, and some pretty severe biasing factors are completely disregarded.

While the listener in this test doesn't know which network switch is connected, he knows exactly when a change is made as well as that each time a different device would be connected - so there's still a very real chance of cognitive bias influencing the results.
Not to even mention the fact that the person making the device exchanges was really quite suggestive in his comments and mannerism during the test (e.g. see how he behaves between 44min to 48min in while discussing switch 2) - this is a very strong biasing factor as well.

Imagine this: what if a few times they didn't actually exchange the network switch model when they said they did, but did so at other times?
Would the listener notice this every time?
If the listener noticed this (and did so often enough that the results were statistically significant) then that would be a good indication that he can indeed tell the network switches apart just by listening. Then the qualitative impressions of the sound might have some weight.

Nothing like this was attempted in this video, however.

To compare with a common test protocol, this is why in e.g. the ABX protocol we have the "X", and we need to say whether "X" is the same as "A" or "B". If the listener is able to do this consistently (and under strict blind conditions), then that is good evidence that the listener can actually tell "A" and "B" apart.
I.e. just having a preference for "A" or "B" (without establishing audibility first) doesn't necessarily mean that the perceived difference between "A" and "B" is real. Blind ABX may not the only protocol that can be used to determine this, but it is a fairly common one.

To summarize, doing the test blind is for sure important (and absolutely a step in the right direction), but that alone is not enough to make the test robust in a scientific sense. So while I absolutely appreciate whenever people put in effort to make their testing more reliable, the test in that YT video definitely can't be used as evidence that there are audible differences between different makes and models of network switches used for streaming.

EDIT: For those interested to learn more about listening test protocols, I can recommend this nice article from Linear Audio Volume 2 by Stuart Yaniger.

 

[slartibartfast]

Four hours plus of blind tests with a sample group of switches. You must watch the complete four hours straight otherwise you've failed the test.
Please do not fail. Enjoy!

So if this is all about noise in the cables does WiFi sound even better?

 

[taube Taube]

WiFi sound even better?

If the signal is stable and there's no data packs loss, then it's an ideal interface with 100% isolation from the source. But no one will believe it, because you need a special, battery-powered router that costs a lot of money.

 

[Mr Ee]

So if this is all about noise in the cables does WiFi sound even better?

I do recall a certain prestige brand recommending wifi over ethernet for at least one of their streamers.
But I can't recall which brand / streamer!

 

[Horsey]

What does that mean "Expected better of you considering the Alpha Audio guys are in the Netherlands too." Don't understand the correlation you try to point out.
So now the problem is my sense of humor or lack thereof? Got it, that's funny..
Calling education in science not science was also a good one, forgot to mention that earlier.

You offered nothing by way of education, Hans. You offered speculative opinion not hearing any impact of a test with Cisco Meraki routers and a battery powered WiiM.

Yes, you also missed the recent humor.

Feel free to let us know of any testing, scientific or otherwise you wish to share.

 

[Horsey]

If the signal is stable and there's no data packs loss, then it's an ideal interface with 100% isolation from the source. But no one will believe it, because you need a special, battery-powered router that costs a lot of money.

Absolutely not as there’s plenty of inexpensive options for a battery powered WiiM.
Ian Canada has some cool ones but they are widespread and cost little.

 

[Horsey]

So if this is all about noise in the cables does WiFi sound even better?

Ethernet cable is subject to EMI impact. Wifi I has its own set of issues in implementation and some prominent streaming manufacturers don’t offer it in their products.

Those manufacturers limit their streamers to Ethernet only.

 

[taube Taube]

Absolutely not as there’s plenty of inexpensive options for a battery powered WiiM.
Ian Canada has some cool ones but they are widespread and cost little.

In fact, I won't be buying anything from Jan. If you can hear a difference in network equipment, that's good. I can't.

 

[Horsey]

While I truly have no desire to get involved in this back-and-forth, I've still decided to post for the potential benefit of people who might genuinely be interested in listening test protocols.

The issue with this specific listening test is that the protocol lacks the basic mechanisms to ensure that the listener can actually tell the difference between any of the network switches at all. It is just assumed the perceived differences are related to the network switches being exchanged, and some pretty severe biasing factors are completely disregarded.

While the listener in this test doesn't know which network switch is connected, he knows exactly when a change is made as well as that each time a different device would be connected - so there's still a very real chance of cognitive bias influencing the results.
Not to even mention the fact that the person making the device exchanges was really quite suggestive in his comments and mannerism during the test (e.g. see how he behaves between 44min to 48min in while discussing switch 2) - this is a very strong biasing factor as well.

Imagine this: what if a few times they didn't actually exchange the network switch model when they said they did, but did so at other times?
Would the listener notice this every time?
If the listener noticed this (and did so often enough that the results were statistically significant) then that would be a good indication that he can indeed tell the network switches apart just by listening. Then the qualitative impressions of the sound might have some weight.

Nothing like this was attempted in this video, however.

To compare with a common test protocol, this is why in e.g. the ABX protocol we have the "X", and we need to say whether "X" is the same as "A" or "B". If the listener is able to do this consistently (and under strict blind conditions), then that is good evidence that the listener can actually tell "A" and "B" apart.
I.e. just having a preference for "A" or "B" (without establishing audibility first) doesn't necessarily mean that the perceived difference between "A" and "B" is real. Blind ABX may not the only protocol that can be used to determine this, but it is a fairly common one.

To summarize, doing the test blind is for sure important (and absolutely a step in the right direction), but that alone is not enough to make the test robust in a scientific sense. So while I absolutely appreciate whenever people put in effort to make their testing more reliable, the test in that YT video definitely can't be used as evidence that there are audible differences between different makes and models of network switches used for streaming.

EDIT: For those interested to learn more about listening test protocols, I can recommend this nice article from Linear Audio Volume 2 by Stuart Yaniger.

It certainly can be viewed as a test even lacking a single variable cited. Adding that in also makes it difficult if not impossible for the blind tested participant to make note of their listening impressions.

If there is a potential unknown alteration made by the test conductor change every few seconds, the blind test participant can’t record anything at all other than they believe a change occurred at the three second mark, the nine second mark, etc.

Alpha Audio recorded and did publish measurements as noted earlier in the thread.

 

[slartibartfast]

It certainly can be viewed as a test even lacking a single variable cited. Adding that in also makes it difficult if not impossible for the blind tested participant to make note of their listening impressions.

If there is a potential unknown alteration made by the test conductor change every few seconds, the blind test participant can’t record anything at all other than they believe a change occurred at the three second mark, the nine second mark, etc.

Alpha Audio recorded and did publish measurements as noted earlier in the thread.

It wouldn't need to be changed every few seconds. Just tell them a change was made exactly as in the listening test but leave the same switch in circuit. They can then make listening notes as usual. Then compare the sets of listening notes for the same switch.

 

[Fletcher Munson]

This explains how little noise on the ethernet gets through to the audio output of the dac or streamer:

Power supplies have a similar level of effect if the DAC or streamer is designed adequately well

 

[jfbuk]

Ethernet cable is subject to EMI impact.

You have a a basic ignorance of how TCP/IP networking ensures data integrity and this is why that statement is meaningless. Your Cisco switches have nothing to do with the rendering of digital data into the analogue sound you hear.

 

[taube Taube]

Ethernet cable is subject to EMI impact. Wifi I has its own set of issues in implementation

So what? The data is delivered losslessly, and the same in both cases. Just don't tell me about how interference penetrates directly into the analog signal. That's a fairy tale.

 

[Horsey]

In fact, I won't be buying anything from Jan. If you can hear a difference in network equipment, that's good. I can't.

I’ve heard a difference in an internet provider’s fiber optic router service, Cisco models as noted earlier and a LPS- battery powered WiiM streamer in my full range tube amp monoblock system. Wasn’t subtle. YMMV.

This explains how little noise on the ethernet gets through to the audio output of the dac or streamer:

Power supplies have a similar level of effect if the DAC or streamer is designed adequately well

There’s potential interference with the Ethernet cable. Did see this video before.

Was pretty surprised when I heard improvement with a Blue Jeans Ethernet cable. Didn’t expect that.