First Look Sunday – Effect Audio King Arthur

Effect Audio King Arthur



King Arthur breathes Luxury and it comes delivered in a huge and heavy box. To be more precise, the whole package weighs an impressive 6kg. Why? Because it comes in a huge aluminum box, with 3 layers, finished with the most luxurious leather. On the top level you’ll find the monitors, the second level displays the different face plates and the third level contains the Caliburn cable, the set of tips and the leather carrying case.

It’s huge, it’s impressive, it’s luxurious. It’s King Arthur.

Effect Audio King Arthur

Tech Specs

– 16 Precision Balanced Armature Drivers
– 2 Low, 7 Mid, 7 High
– 9-Way Crossover
– Sensitivity 117db @ 1kHz @1mw
– FR: 10Hz-40kHz
– Impedance: 10 Ω @ 1kHz
– Penta-Bores
– 5 Convertible Faceplates


I in general, apart from some special units such as the Rai Penta, Xelento, Etymotic ER-Series, Inear SD4 and iSines, am not the biggest fan universal monitors. I very much prefer custom ones but sometimes a specific universal IEM is so good, that you just can’t exclude it from your list of favorite IEMS.

The King Arthur for sure is one of those. With its 16 drivers it isn’t the smallest and it does stick out of your ears somewhat, but the comfort is quite good. Sure you might look silly on the go, but once you’ve heard how these IEMs perform, you really couldn’t care less. These simply are incredible. Let’s check out how they were tuned.

Effect Audio King Arthur

First Sound Impressions

Impressive, right from the start, that’s all I can say. I have listened to (way too) many IEMs over the last decade but the King Arthur immediately goes to my list of favorites.

Why? Cause it sounds incredibly good and not like your typical IEM or CIEM. It’s like you’re best possible place in the room, with a sound that’s all around you. And that’s not all, King Arthur does it with such ease as if it’s the most normal thing in the world. Listening to King Arthur is like listening to a great set of high end speakers being driven by tube mono blocks. You get everything you’ve ever wished for, and more. Lots more.

Effect Audio King Arthur

King Arthur is full bodied from top to bottom and the sound stage is the widest you can imagine. When some IEMs try to sound like this is sounds forced or unnatural, but here Effect Audio has tuned it perfectly with a realistic, natural sound as a result. The sound stage is both incredibly wide and deep, and it has extremely good layering. Timbre is unbelievable with mids to die for.

With this IEM you also get great dynamics and all the detail you ever wished for. Often this leads to an analytical sound, but here you get the perfect blend of precision and musicality. No matter what source you hook it up to and what music you throw at it, King Arthur sound engaging and out of this world. Separation, stereo image and instrument placing maybe is the very best I have ever heard from an IEM. It’s simply that impressive and good.

Effect Audio King Arthur

When I saw the specs upfront I was worried the dual bass drivers wouldn’t be able to get things done, but boy was I happy to hear I was wrong. This is really deep, impactful and yet tight bass with heeps of detail. It can go really deep, with gorgeous timbre, excellent layering and very impressive decay.

There’s absolutely nothing I can say King Arthur does wrong or too much. It’s like it was tuned specifically for my ears as it’s exactly what I want in a monitor, and then at the highest possible level. Now if only KA came in a custom set, that way I could retire my quest for the perfect IEM. All I have to do then is sell a kidney. My wife’s of course 😉

The full review will be published on Headfonia soon-ish.

2.6/5 - (140 votes)

Lieven is living in Europe and he's the leader of the gang. He's running Headfonia as a side project next to his full time day job in Digital Marketing & Consultancy. He's a big fan of tube amps and custom inear monitors and has published hundreds of product reviews over the years.


  • Reply May 5, 2020

    Tommy Lu

    Do you have any comment on how good this pair is in comparison to U18t? Thx!

  • Reply May 10, 2020


    Its the end game iem ????

    All other companies should just keep their products and close shop…

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