What could have been! I keep pondering this as I collect my thoughts on the HarmonicDyne P.D.1. I was expecting to begin my coverage of the brand with the Zeus headphones, which might well be a whole other story. But between waiting for the new headphone testing setup and sample availability, the P.D.1 ended up taking the spot. The P.D.1 is not only HarmonicDyne's latest product, but also its most expensive, and thus the brand's de-facto flagship. It is also the first set of IEMs from the brand, which is so new it currently only has two active products, one accessory set of ear pads, and an EOL set of headphones. In this regard, I do understand that there will be stumbling blocks when setting up a new brand no one knows of.

Linsoul, on the other hand, does not get that luxury. HarmonicDyne has a direct relationship with the Chifi giant, whose in-house brand ThieAudio is quickly becoming a powerhouse in the IEM market thanks to its truly fantastic tuning team and audio engineers. Why not help HarmonicDyne instead of putting out a product that you know has some tuning issues? Why not get help from your own team, however separate the official title may seem, to help with the currently immature tuning of HarmonicDyne? It's amazing that this is even a thing, and I fail to understand what factors could be so important even in a different culture to where something so promising ended up being a letdown where it matters the most.

In many ways, the HarmonicDyne P.D.1 is an opposite case of the Audeze Euclid, the only other planar magnetic set of IEMs I have tested to date. The Euclids are far more expensive, have a lackluster unboxing experience with a meh cable in terms of aesthetics and feel, and then go in with function over form when it comes to the accessories with a hard Pelican case, good set of silicone and foam tips, and, frankly, astonishingly good tuning in comparison to the P.D.1 with the flashy but mediocre case, excellent unboxing, amazing cables, and then the tuning coming back to be a debbie downer.

It's just that when you are paying $380 for IEMs, you expect to get something better than most IEMs, and I unfortunately have to say that many less expensive IEMs sound better and are certainly more competently tuned technically, too. Based on my testing and listening, it does seem like the planar driver and its tuning is to blame here. The lows are really good by comparison, with enough energy and punch to make your head rock along to house music even as you notice plenty of detail here. The custom dynamic driver thus is not the issue here, and the added warmth lends favorably to the lower mids and male vocals, too. It is in the mids proper where things get wonky and then go bad in the highs to where a single BA IEM with better tuning will perform better for nearly half the price, as with the Campfire Audio Satsuma, and this is even before we get into hybrids such as the ThieAudio Legacy 5 and XENNS/Mangird Tea that I would take any day of the week over this, and it costs significantly less.

I think the P.D.1 has hurt the HarmonicDyne brand more than it has helped it, which hopefully does not spell the end of IEMs from the brand. There are clear positives here, and I would recommend Linsoul do some repair with a better tuning job or even by releasing an EQ profile soon. Go ahead and also sell those cables separately under the HarmonicDyne brand so there are some good-looking and working products in addition to the headphones set currently. I do look forward to seeing what is next, especially with the promise shown here, but the P.D.1 in its current state gets a nope from me.