This is what you get

The short answer

Change the headphone, not the electronics. The HD 650 is a warm, intimate, closed-in-staging headphone by design, and no amp or DAC will turn it into a wide, airy one. Put the $400 into a HiFiMan Edition XS and keep the 650 for the nights you want that thick, comfortable sound.

Why this and not something else

Your weakest link for the thing you are asking about is the transducer, full stop. "Flat and closed in" is the HD 650's signature: gently rolled treble, modest air, a stage that sits between your ears rather than around them. People spend years chasing that out of it with amps and never get there.

Specifically, I am not recommending an amp upgrade. The Magni 3 has plenty of voltage swing for 300 ohms and is already transparent; moving to a Burson or a Woo would change the tonal flavor slightly and would not widen the stage. I am also not recommending a DAC step to a Qutest or Ares II. At $400 that money would buy you a difference you would strain to hear on a headphone that is the limiting factor.

One thing to be honest about: an open plan office has a noise floor, and low-level air and decay are the first casualties. Some of what you are calling "closed in" is the room eating the top two octaves of ambience. A quieter listening spot will do more for perceived space than any $400 purchase.

Now

HiFiMan Edition XS, roughly $400 to $500 depending on sales; it is discounted often, so wait for one. It is efficient enough that the Magni 3 will drive it properly, and it is the cheapest genuinely open, airy, large-staged headphone I would put in front of an HD 650 owner. Buy from somewhere with a return window: HiFiMan build and headband comfort are the real risk, not the sound.

Next

Nothing for at least six months. If, after living with the XS, you find it thin or a touch splashy on cymbals, that is the moment a warmer source starts to matter, and a Modi Multibit or Ares II would be the move, not an amp. That is a $200 to $800 decision to make later, with a specific complaint in hand.

Where it ends

For headphone listening, diminishing returns start hard right about here. HD 650 plus Edition XS covers warm-intimate and open-airy, and a clean transparent Modi/Magni stack does not hold either of them back in a room with a noise floor. A sensible stopping point is exactly this: two complementary headphones, one honest stack, and no third step. If you ever get a quiet dedicated room, revisit it then; until that changes, spend the money on records.

The short answer

Do not buy a component. Your boomy bass and recessed vocals are a desk and wall problem: the 3030i is rear ported and you have it jammed against a boundary, firing across a hard reflective desk into a small square-ish room. Fix the placement and the first reflections first, and you will hear more change than any $600 box would give you.

Why this and not something else

The weakest link is the room, and specifically the two surfaces closest to the drivers: the wall behind the port and the desktop in front of the tweeter. A rear port within a few inches of a wall reinforces everything from roughly 60 to 120 Hz, which is exactly the "boomy" you are describing. That same energy masks lower midrange and makes vocals sound like they stepped back a foot. The desk bounce adds a comb filter right through the presence region, which flattens vocal intelligibility further. An 11 x 12 room also has two nearly identical dimensions, so your room modes stack instead of spreading out.

I am specifically not recommending a DAC upgrade. The WiiM Pro's onboard DAC is not your problem, and swapping it for something like a Modi Multibit would change nothing you can hear under a 6 dB room-induced bass hump. I am also not recommending a new amp: the AXA35 is modest, but the 3030i is an easy 6 ohm load and you are in a small room at desk distance, so you are not running out of power. Amp coloration is not what is recessing your vocals.

Now

Roughly $250 to $350, in this order:

• Isolation and height: get the tweeters to ear level and decouple them from the desk. Isolation pads or small desktop stands, about $60 to $120. This alone kills a lot of the desktop smear.
• Pull them off the wall. Even 8 to 12 inches helps enormously. If the desk physically will not allow it, plug the ports with foam bungs; Q Acoustics ships some, or dense foam works. Free to $20.
• A rug with padding between you and the speakers, $80 to $150. Hardwood plus a small room is the other half of your problem.
• Toe them in so the axes cross just behind your head.

Then leave it a week and listen before spending anything else.

Next

Roughly $200 to $250 of the remaining budget, only if boominess persists after placement is settled: two panels of 2 inch to 4 inch absorption at the first sidewall reflection points, plus something at the wall behind your head if it is close and bare. Bass traps in the corners matter more than broadband panels in a room this size, but they are bulky and you may not have the space; check that before ordering.

What has to be true first: you have moved the speakers, added the rug, and the bass is still one-note on familiar tracks. If placement fixed it, bank the money.

Where it ends

For an 11 x 12 bedroom desk setup, this is essentially the finish line. Once the room is treated and the speakers are positioned, the 3030i and AXA35 are already past the point where more spending returns much. If you eventually want a step, it is a better speaker with a front port or a sealed design, something like a Buchardt S400, not a DAC and not cables. A sensible stopping point is: room fixed, speakers at ear level, and no third purchase. Most of what you are chasing costs under $300 and is not a component at all.

The short answer

Add a proper power amplifier and run the Uniti Atom as a preamp and streamer. The LS50 Meta at 85 dB sensitivity with an impedance dip below 4 ohms is asking for current the Atom cannot deliver at volume, and what you are hearing as "closed in" is the amp running out of headroom, not the speaker. Budget roughly $1,500 to $2,000 for the amp, and spend nothing on it until you have tried the free fix below.

Why this and not something else

The Qutest is not your weakest link. It is a more resolving DAC than this chain needs right now, and swapping it for anything, warmer R-2R included, will not give you one decibel more headroom. Same for cables and same for a streamer upgrade: you already have a good source feeding a strong preamp stage. Do not touch either.

The speakers are also not the problem. The LS50 Meta compresses when it is underdriven and it opens up dramatically with current behind it. Replacing them at this budget would be a lateral move.

Two things ahead of the amp, both free. First, check your sub crossover. If the KC62 is set at 50 or 60 Hz, raise it to 80 Hz. That takes the bottom two octaves off the Metas' woofers and buys you real dynamic headroom immediately, sometimes enough that you stop wanting an amp. Second, 2 ft off the wall in a 14 by 16 room with hardwood means you have a strong first reflection off the floor and side walls and likely a room mode in the 70 to 90 Hz region. The rug helps the floor. Try pulling the speakers to about 30 inches and toeing them so the axes cross just behind your head.

Now

Do the crossover and placement work this week. Cost: nothing. Live with it for two weeks.

If it still compresses, add a power amp into the Atom's preamp outputs. Look for something rated to roughly double its power into 4 ohms, which is the spec that matters here, not the 8 ohm number. In the $1,500 to $2,000 range, a Naim NAP 250 series unit used keeps the family voicing and is the safe pick; a used Hegel or a Benchmark AHB2 gets you more grip and a leaner tone. Confirm the exact preout behavior on your Atom firmware before buying, since Naim's preamp output configuration has varied.

Next

Once the amp has settled, spend $200 to $400 on first reflection absorption at the side walls and a panel behind the listening position. That is the only remaining thing in this system that will change what you hear meaningfully, and it will change it more than any component swap left on the table.

Where it ends

This is it. LS50 Meta plus KC62 plus a real power amp plus basic room treatment is a finished system, and your diminishing returns start the moment the amp is in. Anything past that is a speaker change, which means a different sound rather than a better one. Go listen to music.