Is there a router on the market with sound out?

There are other options but without the router.. you can get chrome cast type units that will provide sound to speakers and amplifiers.. just do a search on eBay for airplay.

There are not a few posts here about alternatives. e.g.

https://discussions.apple.com/thread/8374924

https://discussions.apple.com/thread/250748932

https://discussions.apple.com/thread/250753208

An Apple TV would also work to hdmi but of course you likely need a converter and that is expensive.

I think we are talking about different things.

Since I can browse fine on my neighbor's network I don't understand how separating browsing and backup's a problem - two networks seem to operate independently of each other. If one of them's "main," i.e. connected to the modem via Ethernet - so be it - but they don't seem to interfere with one another.

It is not a problem.. per se..

When you browse on the Neighbour's network.. you are using a totally different network. You cannot backup at the same time.. let me spell this out.

On a desktop Mac computer you have a wireless and ethernet connection. Apple laptops only have wifi built in now but you can have ethernet dongle. You cannot use both at once.. (without having two networks) only one connection is active even if both are live.. i.e. all packets will go down the wireless connection if wireless is at the top of list.

Nor can you have two wireless networks operating at the same time.. i.e. the TC is standalone and setup as a wireless router.. as well as mesh router. The wireless on the computer can only connect to one router at a time.. and must use only one band.. so either 2.4ghz or 5ghz. The router can use both at the same time.

So here is my setup.

A Time Capsule is plugged into a switch.. and in bridge mode.

But you will notice no wireless connection.. this would show up as wireless client if connected.

My main router is Asus.

All packets go out the wireless through the Asus.. those that go to internet.. go out the WAN port..

Those that go to the TC for backup go out through LAN port to switch and thence to the TC. The Asus as any router sees what address is required and if it is local will route to local device.. via LAN and if internet will route out to the internet via WAN.

Now I could plug the TC by ethernet directly to the computer.. this will not work.. although I can make it work by setting it up as a totally separate network with different IP subnet. I have done this on occasion to achieve much higher speeds ethernet offers. It is only for the brave (or foolish). This is to make both ports active.. and to do that it has to have two different networks.

If you plug the TC into the network (must be ethernet for non-apple) and set the TC to bridge mode.. i.e. no routing.. then the computer can both browse and backup.. they use bandwidth over the same wifi.. so during backup the internet is likely to go slower (assuming your internet is very fast). All packets must go via the same wifi network..

BTW, the two generations of Airport Express are incompatible - at least on my Time Cap network, i.e. devices connected thru one just don't play together, even worse - activating one causes AirPlay to inactivate. It's ok if both show up as available speakers on the TV screen but I dare not use both at the same time.

I would say this is wireless issue.. but I haven't got a lot of experience with multiple express.

Can't one have the best of both worlds by using a mesh system for connectivity

and retain Time Capsule for Time Machine HD backup - distributing audio from

TV (set on the admittedly better mesh network) to sound-ported AEX's?

What think ye?

Surely can.. but as with all things of mixed origin.. how one device works with another is often mysterious to say nothing of voodoo and black arts.

I would carefully check before you buy any mesh system.. assuming you don't already have one or placed an order.. a quick google search for brand xyz airplay issues, another search for bonjour issues, another search for apple wireless issues.

You will find complaints about every brand out there.. but look carefully at volume of complaints.. and if companies are taking it seriously. Apple still depends on bonjour but not all brands test seriously how their routers and systems handle it. Much the same with backup to a Time Capsule plugged into the network.. it can be difficult to get it working right. We can give some hints.. but in your future there is going to be some changes.. a NAS perhaps as media centre and backup target for example.

I'd connect ethernet between modem and mesh router.

That is required anyway.

TM backs up my disk which is all important while network connectivity allows browsing -

aren't the two entirely separate?

The two operate through the same network. One is to a local LAN device and not using internet.. the other is using internet.

But both depend on the network operating as fast as possible and reliably as possible. And the main router still controls both.. so it must be compatible with bonjour, airplay and any other special apple protocols going on.

Meanwhile, TV can tune to any available network - which in this case w/b mesh.

The Apple TV will work fine connecting to the network. How much issue it might have with airplay is another question. It still goes back to how the mesh system is designed to handle Bonjour packets. Even some of the better brands can have failures.. although they are at least responsive to fixing them.

As a general comment.. you might keep your eye on the second hand market for suitable Express.. even Gen 1 A1264 will still work with a bit of care.. I have bought dead ones with blown supplies and simply replace the supply with external DC.

The case is ruined but it is easy enough to figure out a suitable case.. since it is now entirely safe running 3.3v. And the size dramatically reduced. This is not for the Apple purist though.. I have made suggestions about how to fix different things and the response was death before a black non-Apple power cord. This will lead you to airpods. good luck with them.

https://sites.google.com/site/lapastenague/airport-express-repair

AFAIK, there are still no direct replacements for the AirPort Express base stations out there.