Effect of Internet Service Quality on Streaming?

It’s probably some external change since internal changes (audio chain components) do not happen according to the 24 hour clock - worse dinner time then problems ends at the latest midnight.  Therefore the obvious eternal influences are power and internet connection, or somehow EMF/RFI spikes periodically in his living zone.  

Seems the only external influences come from RFI, EMI, power line, internet connection.  If not within the home, then it’s the power line or the internet connection.  Both peak times coincide when people use both more power and personal internet resources, dwindling as people go to bed.  It can also be some business using more resources, like a restaurant, illegal manufacturing lab, Internet cafe.

If it’s the internet connection, then maybe change carriers or change carrier line if possible.

If it’s electrical, then maybe get your power quality tested. For crappy power, Stromtank or solar panels + battery storage system to at least get your system off the grid.  Maybe balanced power conditioner like Equitech o EquiCore might help.  Or a power generator like PS Audio.  Good luck. 
 

Unless you are hearing dropouts, it's definitely not your Internet connection.

I suggest building a dome around your house so you can control light, air pressure, and humidity.  Then your only remaining variable is your mood.  There may be ways to control that too!

Seriously, none of the gear- or connection-based variables being discussed here should have such a dramatic impact on sound.  That's why, while I joke above, I gotta think it's some other external thing - mood, weather, something. 

And I have experienced the phenomena - many people have commented that music sounds best when it is dark out.  I have experienced that too, albeit that also mostly correlates to how much THC I've consumed. 

Occam’s razor time.

@nyev you’ve appear to have spent a lot of money and time on everything but a new router and good Ethernet cable. Dump the router from your ISP as they are worthless. Also, change out whatever Ethernet cable you’re using to Cat-8. As cheap as Cat-6e but super shielded. Check Amazon.

You’ve also mentioned that your problem occurs in the late afternoon, after your kids get home and hit the internet. Sounds like the crappy ISP router can’t take the load and is dropping out (high chance one of your internal connections is bad and causing excessive packet retries which drag down a cheap router). Also the cheap routers don’t have any sizable ring buffers so they can’t queue things up well.

Remember that 4k video requires 34Mb of bandwidth.  Add on whatever else you’ve got streaming (phones (cellular using WiFi and VoIP), internet streamers/radios, television, etc. and you’re probably using 50-74Mb bandwidth easy. Bet the router you have came from when you had 100Mb or less internet. 

I recently attended a demo of Shunyata Altaira $3k. This works to correct

noise caused by poor grounding. No idea what your issue is but I will

say that demo provided the best sound I have ever heard. Go Shunyata!!

Thanks All - New Router, CAT-8 Cables, Grounding Boxes, and THC - Got It!

These are all great ideas that will likely improve sound quality (esp THC - what is that, “Total Harmonic Control” or something?  Sounds promising.

But none of these will fix the dips in quality, which in case you haven’t read my post above, I agree with everyone that has said it’s not my network.  Because, playing an equivalent local file is also bad when quality is bad.

That leaves noisy AC power and RF as likely culprits, but probably AC.  And as above I’ve tried many conditioners and isolation transformers.  It may be that my only solution is a Stromtank, one day down the road.