How exactly does one achieve room filling sound?

Example 1: super old school gramophone with one single large horn speaker. My audio memory is hazy but I distinctly recall one of those could really fill a room with its sound.

Example 2: the Sonos One is advertised as having “room filling sound”. I’ll admit to not having actually listened to one before but I’ll take Sonos at their word.

So the reason why I am wondering is - I’m in the process of furnishing a 25” by 9” (longish rectangular) room which will be roughly split in half, with one side a study (desk against one wall) and the other side a TV area with a sofa. My options are:

A: TV mounted onto one of the short walls, stand mount speakers which can, hopefully fill the entire room with sound. This would include me in the study area listening to music while I WFH. Based on how I will probably setup the study area though I would be perpendicular to the speakers, I.e the sound will come at me from my left (or right) side.

B: TV mounted on the longer walls, separate speaker setups for the TV area and the study area. Depending on where I am I would use different speakers in the room, setup for the optimal listening positions.

Apologies down the longabout introduction but this brings me to my problem - if one can achieve actual room filling sound, it should not matter where in the room the listener is in relation to the speakers? And where the listeners ears are actually facing? If this is actually achievable then I would of course have a preference for option A above, and be able to invest my budget in one great system instead of two good ones.

But what would a setup like that look like?

TLDR: how to setup a sound system in a long rectangular room such that there is great sound in the room no matter where the listener is sitting, and which direction the listener is facing?