Streaming: WiFi or wired??

I have a silly question: would using LNPS's on a modem and main router in a mesh system make a difference if the stereo system is connected to a satellite router via Ethernet? I think the answer is likely 99% to be no. But I feel like the obvious no's change every 10-20 years in this hobby.

I have been playing with home networking over the last year. Wifi 6 and mesh are the emerging standards. However, systems deploying both wifi 6 and mesh are only starting to hit the market. 

I picked up a Netgear wifi 6 router a year ago, but traded it out for a Google mesh WiFi system earlier this year. Mesh is the way to go for sure, as every room in my relatively small house has a similar connection. And I also love how simple Google software is compared to traditional router software. 

I run the stereo system from the main router, but the home theater is connected to a satellite router. So I won't test my question anytime soon. 

I only stream, and I've been testing wifi and Ethernet connections at various stages of my stereo build. 

The last components I upgraded were the power supplies for my streamer, modem and router, and the Ethernet cables connecting them. I used the iFi power components because they are the most affordable low noise power supplies I know of ($50 or $100 depending on the amperage requirement of the component).

I added the LNPS's over time, and can say that the sound went from raw to refined when I replaced the streamer PSU. Next I replaced the modem PSU. The difference there was slight, but the sound had added resolution and body. Then replacing the router PSU changed the sound from edgy/fatiguing to relaxed.

So much of this hobby seems to revolve around prioritizing upgrades correctly. Sometimes an upgrade has no affect because of another bottleneck in the system. And only after I resolve the other bottleneck does the first upgrade become meaningful. 

What's your experience, OP?

I expected more votes for wired. To you wireless proponents, consider this:

I too didn't hear a difference between wifi and Ethernet until I connected low noise power supplies to the modem and router. It's possible the WiFi card in your streamer is about as electrically noisy as the power bricks for your modem and router. You won't know for certain until you try. 

@erik_squires if you'd like to go wired, try running mesh router system. And throw a low noise power supply on the satelite router you connect to your stereo. It's worth a shot, and cheaper than a lot of other audiophile purchases. Worse case scenario, you end up upgrading your home network.

@snowbuffalo I used iFi power supplies on my modem and router. I recommend them. If you do try a low noise PS for you modem/router, I'm Interested to hear whether they make a difference for you. 

Hans and Darko are two audiophile YouTubers who both prioritize digital audio. They both agree that what comes before the DAC makes a difference. 

In this video Hans mentions that galvonic isolation and reclocking, although helpful, are insufficient to fix all noise. https://youtu.be/d9RSLHOFOTc

Another commenter posted a relevant Darko video earlier, so I won't repeat that one here. 

In my experience, treating a modem and router as part of the source has been useful, and I can say that adding low noise power supplies to my modem and router made an obvious improvement for me. This, in my view, the convenience of wifi comes at a cost. 

I wonder how many different philosophies underlie the various views expressed in this thread in answering the question wifi vs wired for SQ. Here's my attempt to articulate them:
1. Nothing upstream from a quality DAC matters for SQ.
2. Nothing upstream from a quality streamer (or reclocker) matters for SQ.
3. WiFi can sound identical to wired when the WiFi card is well implemented. 
4. Noise is introduced in all sorts of ways upstream, and the tools we have to remove noise can be used farther upstream than a streamer with clear improvements to SQ.

@rsf507 
I used iFi power supplies. They have two different models to match most various voltage and amperage requirements for streamers, DACs, modems and routers. iFi is relatively affordable, which makes it a perfect to start to see if you hear a difference compared to your streamer's wifi card. If you do try a low noise power supply with your modem and router, I'd be interested whether the difference was obvious (or worth the cost) in your system. 

Just as a side note, I suspect that a reclocker and power supply / power cable upgrade should be prioritized over power supplies for the modem and router. iFi also makes a few reclockers in case you haven't tried one. I suspect that a Node 2i, for example, would benefit from a reclocker; but I also suspect that most Node owners don't run a reclocker.