Linsoul Audio/HarmonicDyne Poseidon Review: These Handsome Headphones Know How To Get Down!

Linsoul Audio/HarmonicDyne Poseidon

Linsoul Audio/HarmonicDyne Poseidon







What We Dig

  • Engaging Sound
  • Excellent Build Quality
  • Sleek Beautiful Design

What To Think About

  • Midrange Can Be A Little Edgy
  • A Little Too Much Upper Bass Energy


The Linsoul Audio/HarmonicDyne Poseidon ($439.00) is third in the line of wood cup HarmonicDyne headphones, each named after a Greek god. The first one was Helios, followed by Zeus. The Zeus headphones featured drivers with a Beryllium coating, which reduced distortion and added clarity.

The Poseidon picks up where Zeus left off, including the same slick briefcase storage box, wood/metal construction (this time maple instead of dark walnut), and plush velvet earpads.

However, this time around, a nickel-coated diaphragm is used, which is supposed to provide even more transparency than achieved in Zeus. While I haven’t heard those headphones, I’ve heard many good things about them, so I’m excited to dig in on this “new and improved” model.

I’m pretty curious to know how they match up with my current favorite headphone under $500, the Hifiman Sundara, and find out what kind of value proposition they offer! If you’re wondering this as well, then read on, and I’ll give you my total impressions!

Disclaimer: This unit was sent to us by Linsoul in exchange for our review. No outside input was given or promises made regarding the content contained therein.


Driver: 50mm Nickel Coated diaphragm Dynamic Driver

Impedance: 64 Ohm

THD: <0.2 % (1000 Hz , 1mw

Sensitivity: 103± 2dB @ 1000Hz

Cable: 2m XLR- 4 Balanced cable (Additional XLR to 6.35mm cable adapter)

Weight: 380g w/o Cable


If it weren’t for the lighter color of the wood or black metal in place of silver-painted hardware, it would be hard to tell Zeus and Poseidon apart. The overall construction is basically the same.

That said, this is not a bad thing since the build seems to be pretty solid. The yokes that hold the earcups are made of metal, plus the wood cups and inlay seem to be of good quality. The overall design looks good to me, even though I’ve heard that some feel different.

If I have any complaint, it would be about how the yolks slide down. They stick out at a funny angle, and there’s not much room for adjustment, especially for big heads like mine. As a result, the cups barely make it over my ears, and the clamp is a little tighter than I would like.

Nevertheless, I still find the Poseidon pretty comfortable due to the comfy velvet earpads and full swivel of the earcups. The fact that these headphones are lightweight also helps. I can wear them for long periods without them bothering me, and I even fell asleep a couple of times with them on.

I also have a little apprehension regarding the plastic used to connect the headband to the yolks that hold the earcups. While it seems sturdy out of the box, I’m just a touch uncertain about the long-term durability. However, I haven’t heard of any issues with the previous model, so there shouldn’t be any problems with this one.

As stated earlier, the Poseidon comes with a heavy-duty storage box that’s more like a briefcase. It’s nice as far as carrying cases go, and you even get keys to lock it. You also get a velvet carrying bag for your cables.

Speaking of cables, there’s a detachable XLR to 3.5mm balanced cable for the headphones, which is nice and thick. That means it won’t tangle too easily, which is good, but it’s also stiff and may twist around in strange ways from time to time. I found myself unplugging the cable from my amp every once in a while to untwist it.

You also get an adapter that goes from XLR to a 1/4” plug for single-ended amplifiers. It’s pretty clunky, but at least they don’t make you hunt around on your own for a forty-something dollar adapter.


For my sound tests, I connected the Poseidon’s XLR cable to the balanced output on the SMSL HO200 Headphone Amp, which in turn was connected to the SMSL DO200 MQA DAC. Finally, the DAC was connected via USB to my HP Envy X360 laptop.

I played a wide variety of music on the TIDAL desktop app, and first of all, I found the Poseidon relatively easy to drive. Even though the included cable almost requires you to use a headphone amp of some sort, you don’t need a very powerful one to do the job.

Tonal Balance

When it comes to Poseidon’s tonal balance, it’s pretty apparent these headphones are tuned for excitement. They have a V-shaped sound with a definite lift in the bass, upper mids, and lower treble regions. This gives them a lot of presence up top and weight on the bottom end, but I also found them shouty at times.

For example, listening to the new “Dawn FM” album from The Weeknd, I found the bass to be deep, tight, and fast with a good punch. The mids were pretty clean as well, albeit a little more little recessed than I’d like. However, I also found the upper mids to be somewhat edgy, making the Weeknd’s high-pitched vocals a little too intense for my taste. On the other hand, the upper treble was handled well, as there was some nice air and no sibilance.


As far as detail goes, I found these headphones to have decent resolution but not quite class-leading. Listening to Diana Krall’s “Someone In Love,” the Piano, Bass, and Guitar were full-bodied with lovely texture, and the trailing edges of notes were well represented.

Even though it was a little recessed in the mix, Diana’s vocal sounded somewhat natural, but there was also a little bit of “cuppiness” from midrange bloom. I didn’t quite hear the transparency I’m used to hearing from my go-to headphones at this price point, the Hifiman Sundara, but there was still some good clarity there.


Dynamics (esp. Macrodynamics) maybe the Poseidon’s strong suit, as they can really rock. Listening to Carey Bell’s “Sweet Little Woman,” these headphones put the pedal down. Drums hit with power, the verses are fast and sharp, and the choruses hit hard, propelling the song forward with ferocity.

Soundstage and Imaging

Poseidon’s soundstage is much deeper than it is wide; to be honest, it isn’t that wide at all. Even so, I like the depth and separation of these headphones. In addition, the imaging is top-notch, as instruments are nicely focused and placed precisely around the soundstage. As a result, you don’t get a lot of the “three-blob effect” you get from lesser headphones.

Vs. Hifiman Sundara

When I compared the Poseidon to the $349 Hifiman Sundara, I found the Sundara cleaner than the Posideon with more resolution, especially through the mids. The mids on the HarmonicDyne are a little more colored. The Hifiman is also a more neutral and open headphone with a broader soundstage.

That said, the Poseidon had a lot more punch down low and better dynamics than the Hifiman headphone, and they rocked out a lot harder, especially with Blues and Classic Rock. The Poseidon also had a bit better imaging and separation than the Sundara.

The Wrap Up

To sum things up, I think the Linsoul Audio/HarmonicDyne Poseidon is a nicely built, good-looking, and comfortable headphone. It also comes with a great accessory package, providing both balanced and single-ended cables along with a luxurious case.

As far as sound goes, while there could be a bit more micro-detail, macro-detail is good, plus depth and separation are excellent. I also liked the dynamics, speed, and slam, making me feel the music. That said, on songs with really heavy bass, the boosted low end can be a little too much of a good thing. The lift in the upper mids can also make these headphones shouty.

If you like lively headphones with a lot of presence and sparkle, you will probably love these. However, if you like your headphones more on the neutral side, you may want to listen first before you buy these.

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