King Arthur
Headfonics 2019

Effect Audio King Arthur Review

The Effect Audio King Arthur is a collaborative TOTL 16-driver monitor complete with a unique high-end 24AWG hybrid “Caliburn” cable. It retails for $6999.

Disclaimer: The Effect Audio King Arthur sent to us is a loan sample and will be returned after this review. Many thanks to Effect Audio for giving us this opportunity.

To read more about Effect Audio products reviewed on Headfonics click here.

Note, this 2-page review follows our new scoring guidelines for 2020 which you can read up on here.

King Arthur
King Arthur
King Arthur is not an Asian sound that is stereotypically mids to treble and very clean. This is much more relaxed and smoother. The timbre is also richer with a low-end to lower-mids weighting wand excellent width.
Slide here to add your score on the gear!125 Votes
Reader's Score

So the King Arthur just arrived and I could tell it was special before I even got out of the box because the DHL guy was stooped over on his way up the office staircase.

This box is incredibly heavy for what amounts to an in-ear monitor. There is a good reason for that as it shares a box that is every bit as extravagant as the Vision Ears Elysium offering but with far more expensive raw materials.

The price for this TOTL monitor is $6999 and hilariously, it is not the most expensive IEM we have seen in the office. In fact, it is about 31% cheaper than the oBravo Ra we reviewed last year.

I chuckle to myself because even at the ‘much lower’ price it is still well beyond my budgetary capability. This is a true ‘luxury offering’ pitched squarely at a niche clientele and more comfortable front row Harrods than top-shelf Best Buy.

An Enhanced Arthur

Now to clear up some confusion, this is not the same King Arthur that was doing the rounds a few months ago. Yes, it is still a collaborative effort with Empire Ears but the original one was priced much lower but with a 14 driver count and a simpler set of accessories and associated add-ons.

The new Arthur has an upgraded very high-end cable from Effect Audio called the Caliburn, a higher-driver count at 16 (so we presume a different tuning also), and an out-of-this-world luxury packaging and accessory line-up.

Tech Inside

King Arthur is a complex massive multi-driver beast of a universal monitor. This is a 16 balanced armature driver, that’s actually 2 more than the original Arthur doing the rounds during the summer so clearly an “upgrade of sorts”.

The precise configuration is 2 for the lows, a massive 7 for the mids, 7 more for the highs, and all pieced together with a huge 9-way crossover. Phasing seems to be via 5 tubes hence a Penta-bore design. No acronyms for their drivers or crossover so I cannot tell you anything more than that at this stage.


Technical specifications also indicate, (and tested to be quite true), a very efficient monitor. King Arthur is rated at just 10Ω and 117dB SPL. We did some light testing already on the Hifiman R2R2000 and you can barely get it past the first step volume setting and it is already very loud.

Considering the tia Trio from 64 Audio needs about 10-13 steps that is quite some difference so we will be keen to see how sensitive this is compared to the efficiency kings, the Campfire Audio Solaris, and Andromeda.

King Arthur

Caliburn Cable

The package is a 2 part in terms of tech because we can’t have an EA IEM without an EA cable. In this case, this is called the Caliburn which is a spin on the original Excalibur that came with the EE Arthur a while ago.

This is a 24AWG Rare UPOCC gold plated silver & gold-silver alloy mixed with pure silver. The geometry is a multi-bundled Litz wire with a 7-core build using individually enameled stranding techniques. The slightly larger than normal wire is wrapped in EA’s usual and excellent UltraFlexi translucent jacket.

The overtone is a hue of silver and a gold-infused tightly braided overlap. It has a certain shimmer to it and complimented by a rose-gold KA Designer aluminum splitter. I can tell right away this is a pitch to the Asian audience. Rose Gold is so very popular in many Asian regions.

Termination options are for the jack end only as the cable is exclusive to the King Arthur’s 2-pin connection system. All connectors are PSquared and come in 3.5mm, 2.5mm, and 4.4mm with an additional leather branded organizer clip.

As always, the 1.2m cable is beautifully deadened against physical noise and virtually memory retention free. I have never had any complaints about the latest EA range of cables with regards to handling, they are one of the best out there.


King Arthur


Quite possibly the mother of all IEM retail packages, (thus far). More ambitious and heavier than the oBravo Ra environmentally friendly white box and decidedly more sturdy than the zany but cool Vision Ears Elysium articulated presentation set. And when I say heavy I mean “Lex Luthor sitting on it and warning you not to touch that” level of encasing.

King Arthur

This is a huge space grey and leather finished aluminum box with a lift lid and 3 additional aluminum layers underneath. Each layer is just as weighty as you think it might be but each with a specific purpose.

The top layer holds the actual driver units in a small shaped opening right in the middle. They are kept in place by a small foam cutout at the base so they do not knock and damage against the aluminum. Effect Audio has also placed a small vinyl sheet above to prevent them from falling out.

King Arthur

Convertible Faceplate

The second layer holds 4 pairs of faceplates which means, yes, King Arthur has an interchangeable faceplate mechanism, called a Convertible Clutch Mechanism. The faceplates are not just run of the mill different color plates either. The materials here are high-end and I am told it is very difficult to work with for faceplate cutting, especially leather hide.

The five individual faceplates are as follows:

  1. Vivid Acrylic (on the driver shells by default)
  2. Elegant Rosewood
  3. Classic carbon fiber
  4. Textured leather (my favorite)
  5. Metallics

It pretty much covers the bases with all five designs but I have to pay special mention to the textured leather faceplate. I have seen this styling starting to creep into customs designs and they cost a fortune. I am not surprised to see one here and it is indeed soft and smells of yummy genuine leather.

Is this all overkill? Absolutely, but then that is the whole point of luxury.

King Arthur


Aside from the Caliburn cable, the interchangeable 5 faceplates, and the mammoth aluminum case you also get a genuine stitched black leather soft carry case and a selection of Final E Series tips in XS, S, M, and L.

The case is real leather also and smells equally as good. It has a soft but sturdy build, not unlike the Leonidas II patina leather style case we received earlier in the year.

If I have one criticism it is the selection of tips being a bit limited. I like Final’s tips for King Arthur but it would be great to see a much wider range of options for this price point. SpinFits, foams, balanced, vocal, etc would be nice to have been included.

King Arthur


This is a big monitor and honestly, I am not surprised given the driver count. It is bigger than the 18-driver custom A18 I have from 64 Audio a few years ago but I suspect EA are using large subwoofer drivers for the lows than what is in the A18.

The shell and base plate is an all-black shiny finish with some custom contouring and a relatively short actual nozzle. It does not need to be that long because the general thrust of the design is already narrowing towards the nozzle.

There is an additional mm or 2 on the faceplate side to allow for the changeable plates to slide on and off with a small grooved clasp on the underside. I actually find the sliding clasp a shade on the loose side. Whilst it is very easy to use my concern is that they can fall out easily when adjusting the drivers in your ear.

King Arthur

Comfort & Isolation

They are big but seem light and fit very comfortably in the ear. They do stick out a bit but they have zero upward or downward pressure so the balance is spot on. The seal is also excellent.

The King Arthur shells have no venting because it is an all-BA design so you can get above average seal with the Final E tips that do a good job of block out low Hz hum from air cons and similar background noise.

King Arthur

Sound Impressions

Now, I have not heard the original Arthur that was circulating a few months back. However, from the descriptions, online the new Arthur seems quite different. I have no point of reference so those who have heard both can chime in below in the comments section.

What I am hearing is a full-bodied mid-bass to lower-mids solidity with a bit of 1-4k boosting for vocal presence, particularly female vocals. The low-end has some good weight for a BA driver with a slightly longish decay fairly common for these bigger vented drivers.

It reaches quite deep with fairly impressive sub-bass performance and quantity. It would say the sub-bass is in line to about 50Hz but nothing considerably elevated above its mid-bass warmth.

Mids seem the star of the show here and for those who like a rich creamy texture and plenty of note thickness then the King Arthur seems to fit the bill. Staging is plenty wide though so it is not congested or veiled.

The separation and detail are actually excellent despite the bias to the lower-mids. Higher pitched vocals are allowed plenty of space to deliver a fairly natural to organic tone with no edginess or sibilance.

Treble seems rolled-off a little and not that extended though I can detect some minor bumps that prevent everything sounded overly soft or rounded.

Interestingly, King Arthur does respond very well indeed to PMEQ and DSP, and just pumping that 5-8k region by a few dB can make a palatable difference. You can extract a lot more sparkle from the top-end than the stock tuning might suggest.


Using the PMEQ rock preset on the Lotoo PAW Gold Touch was a night and day difference and really stretched the soundstage as well as inject a much cleaner timbre. I suspect there is a lot of matching to try here with the King Arthur, both in terms of source, DSP and I suspect tips also. This is a very flexible or chameleon-like presentation from King Arthur.

King Arthur

Our Verdict

I am intrigued with King Arthur because my time with it seems to suggest it is much like the oBravo Ra in that it requires a bit of a studied matching process for both source, genre, and possibly some DSP and EQ to get the balance just right for personal tastes.

This is not an Asian sound that is stereotypically mids to treble and very clean. This is much more relaxed and smoother. The timbre is also richer with a low-end to lower-mids weighting wand excellent width.

And wow, physical presentation is just spectacular and every bit the luxury offering. I wish I could compare this to the Vision Ears Erlkönig which I think is perhaps the obvious close contender here both in terms of price and application.

I will be sad to see this go after because it is so intriguing to play around with but back it must go!

King Arthur Specifications

Monitor Specifications

  • 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

Caliburn Cable Specifications

  • 24AWG
  • Rare UPOCC |Gold Plated Silver & Gold Silver Alloy| +|Gold Plated Silver & Pure Silver|
  • Individually Enamelled Strands
  • Septuple Core, Multi-Bundled Litz
  • EA UltraFlexi Insulation
  • KA Designer Y-Split
  • EA Patented Convertible Clutch Mechanism // Convertible Faceplate


Sharing is caring!