I don't know what type of speaker setup you have, placement, specs, etc. they are so I cannot/will not pass judgement nor comment on them...
However, I will say this...
After having using P-N-P desktop speakers, in all formats (2.0, 2.1, 5.1) from various manufacturers such as JBL, Altec-Lansing, Logitech, Bose, Midiland and Corsair up until 2014... They simply cannot AND will never compete with true monitor and/or passive bookshelf speakers (powered w/AVR, integrated, amp, etc.) for power, detailed sound, sound-stage (as you mentioned) and overall presence of the sound.
I am not bragging I am simply stating my PC sound system as it is and for music (and gaming), I am simply stunned especially for what it is and for the price-point of everything:
- Klipsch RB-81 II Ref. Series Bookshelf; 2 each placed on my desktop, facing forward, either side of my 27" monitor
- Klipsch RW-12D Subwoofer; placed on left-hand side of PC desk due to space in a 10" x 12" room
- Onkyo TX-NR809 AVR; set to "stereo" w/Music Optimizer set to "On" as the only sound mod
- Speaker wires are 10 ga/oxy-free w/gold-plate banana-plug connecters; bi-wired to the AVR
- Monster Cable subwoofer cable used from sub to AVR
- Creative SoundBlaster ZxR PCI-e internal soundcard w/2 Monster RCA cables connected to the AVR; one of if not the best card for
EMI shielding and just overall for any format use
I'll admit that I have different sound profiles within the SB Pro Studio... But, One is for Gaming, one is for listening to Sirius XM (has a rather anemic sound transmission) and one set for FLAT, so that nothing is boosted or equalized when listening to my iTunes and LP's.
Again, for music this setup is amazing for what it is and for gaming... Forget it, it's the perfect marriage!
I will admit though, that I am curious about looking into an integrated-amp for even better sound BUT would require a sub-out or require some ingenuity on my part and compare side-by-side at my desk.
Headphones are great for music (and gaming) but having your sitting position filled with sound, it's full-presence and then feeling it too, simply cannot be replicated by any headphone at any price-point.