(Preferably under $500.) I saw suggested elsewhere - a much better way is a cheap passive sound bar connected to an AVR with Audyssey software.?
But that would cost $$$.?

A pair of decent second hand bookshelf speakers for about $200 and a Topping Tripath amp ($100). If you want to be really flash add a second hand car 'underseat' sub (mine cost $25).

Great.. Thanks.. Its for my mums tv - a 5 yo Samsung LED which sits on a 2-draw wide entertainment type cabinet the one with the shelf 1-down for your dvd / VHS players so space is quite limited at least on top.
The Topping is very small though isn't it.
I think unfortunately bookshelf size speakers would be too big. Unless they were computer speakers. I did hear some great Sony micro-size speakers once. But with the way some of these sound bars advertise the way they spread the sound (even non-atmos) I might be missing out on something choosing a computer speaker.

I use the famous 1970s Realistic Minimus speakers`which I bought for $100 (very small but much better than 'computer' speakers) which was widely copied. The Topping is the size of a couple of cigarette packages.

Sony SRS-X50 I think were the ones I'd heard. I think so-called computer speakers are getting better and better now.

www.techgoondu.com/2021/01/29/sonys-srs-ra-5000-srs-ra-3000-360-reality-audio-speakers-out-in-singapore/