Streaming: WiFi or wired??

If you are going to stream hard wire using CAT6.  Otherwise you will get signal breakup.

I'll second larry's notion on CAT6. I have a new Node2i that I started with wifi. The setup was a challenge.  For networking reasons, I moved my router from another floor to the stereo cabinet in my lair. When I hooked up the provided ethernet cable, I was impressed with a lower noise floor, etc. And there was no setup.
Upgraded to AQ Pearl and am like a pig in mud.

Anyone believing they're getting "better" or "clearer" SQ from wired vs wireless ethernet (or vice versa) has fallen into one of those confirmation bias traps we humans are prone to falling into.

Empirically and physically THERE IS NO DIFFERENCE in the final correct and intended data received by an ethernet network endpoint, whether wired or wireless. IT's IDENTICAL if the associated networks are performant. Read @cakyol's replies above then read up on tcp/ip, application protocols and the OSI network stack model.

ps: and all those snake-oil peddlers of "audiophile" network gear? Best-case is they don't understand ethernet network science, and are running their businesses for the usual reasons. Worst-case is they do understand ethernet network science - and are running their businesses for the usual reasons + engaging it with less-than-honest intent.

Yes.  Don't believe your lyin' ears!

There are so many ways to slice and dice streaming. Wired is best, but a solid wifi mesh is excellent. Orbi works well. I run ethernet Cat7 out of the Orbi.Streamer is Ultrarendu from Small Green Computer. Uses Roon/Tidal/Qobuz and my ripped CDs. I run ethernet from Orbi into an EtherRegen custom ethernet switch. It really improves the sound. Then connect Ultrarendu to switch. UpTone audio sells the custom switch and great power supplies. 

Good routers let you prioritize service to specific devices.  I was having weird dropouts until my daughter found a "Max Connections" settings deep down in the LinkSys router configuration that was set by default  to 12.  Upped it to 50 and everything is solid.

+1 to the posts by @darkstar and @electroslacker 

You can also specify priority length of time for when you want to switch between say your audio to the TV etc. Depending on which gear you are using, those settings may be available via a phone based App.

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.

@classdstreamer what low noise power supply did you add to your modem/router?

@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. 

I’m late to the discussion here. However, I thought it was important enough to bring up something obvious regarding the Orbi system.

I am using the Orbi system with a Cat 8 ethernet cable connection to my Gold Note DS-10/ PSU-10 Evo combo.

I was quite satisfied with what I was getting and then it struck me that what I was hearing was only as good as what was being transmitted from the Orbi router to the Orbi satellite.
I was still using the cheap Cat 5 cable that was included between the cable modem and Orbi router!

I swapped to Cat 8 cable between the modem and Orbi router.

The result was a jaw dropping change in sound quality in every respect. 

The lack of basic understanding of networking, hell, even basic physics is somewhere between amusing and appalling. 

Digital SQ begins with sample rate and bit depth. For a CD that's 44.1 KHz and 16 bits. 16 bits isn't adequate to avoid detail loss of low level signals, that requires 24 bit depth.

As for Ethernet, as long as the network is cable of sustaining ~1.5 Mbits/sec it is adequate for CD quality Bitstream, 5 Mbits/sec for 'Hi-Res' Bitstream, 100Mbit/sec enables multiple devices to share the network successfully, but nothing more. Wi-Fi or wired makes no difference, nor can it. If external sources cause enough interference to cause buffering or dropouts, that is no more Ethernets fault than blaming your speakers for not playing louder than the jackhammer down the street. 

Spend a little time with the 7-Layer OSI model and a basic TCP/IP primer and it will shortly equip you to understand what is real and what is hype.