I changed my small home office last year, best ever: it was the layout, listening triangle that made all the difference.
I ended up with a perfect 6’ listening triangle, the imaging is terrific.
Bookshelves opposite my desk, a 3 foot aisle between the front of the bookshelves and the front of my desk. Chair and 27" monitor dead center of the speakers. (3 foot aisle is snug, a larger room would allow a wider aisle)
True bookshelf speakers (fit 11-1/2" deep shelf, no ports). Horizontal at seated ear level.
Single sub at the end of the 3’ aisle, firing sideways, just a mono extension of the bass.. Volume: not aware of it unless I turn it off.
Center is phantom, so the monitor is not an issue. I stream a lot of video, the imaging is right on the center of the monitor.
I used 3 shelf high bookcase so I could put a vertical TT and Vertical R2R on top. Also, I use a Carver Cube Amp and other equipment that easily fit on a shallow shelf.
Also, if you go preamp to the sub first, sub strips the low bass out, send only upper bass, mids, highs to your amp and then to the bookshelf speakers, your amp needs less power, and the speakers don’t try to make low bass. Less needed power helps with cost, size, placement options, and the ability to use tubes with far less heat.