PMG Audio Apx Review featured image

PMG Audio Apx Review

In today’s feature, Marcus reviews the PMG Audio Apx, which is a new flagship high-end hybrid planar and dynamic 11-driver universal IEM. It is priced at €6,000.

Disclaimer: This was sent to me as a sample in exchange for my honest opinion. Headfonics is an independent website with no affiliate links or services. I thank PMG Audio for its support.

You can click here to learn more about PMG Audio’s sister company, Custom Art, and the products we have previously assessed on Headfonics.

Note, that this post follows our current scoring guidelines which you can read in more detail here.

PMG Audio Apx Review featured image
PMG Audio Apx Review
The PMG Audio Apx to my ears is probably the most technically capable high-end in-ear monitor I have heard to date. It not only projects a huge soundstage but also a complex and resolving one reinforced by some incredible dynamic range if paired with an equally capable source.
Sound Quality
Comfort & Isolation
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World Class imaging & seperation
Gorgeous, open sounding midrange
Unique amber materials
Initially, a steely upper treble
Underwhelming packaging
Award Score

PMG Audio is a new name here at Headfonics but is fronted and supported by a more well-known brand and person, Piotr Granicki of Custom Art from Poland. 

The best way to summarize PMG Audio’s pitch is on the ‘premium product’ platform.

Or, perhaps laterally, a mix of technology that is on the bleeding edge of creativity and ambition with a range of audio gear that PMG feels best represents the summit of their technical know-how from a 12-year career in the portable audio industry.

The Apx (read Apex), is the debut product offering from PMG Audio priced at €6,000. This is a flagship ultra high-end universal IEM with a complex multi-driver mix of dynamic, BA, and planar.

It also comes stacked with a load of technology first seen in Custom Art’s portfolio and some newer acoustical features exclusive to the PMG Audio brand.

This is an ambitious offering, affordable only to a few but the Apx might well be a worthy showcase of just about everything Piotr has developed over the last decade. The Apx also sounds technically sublime offering some of the best soundstage properties I have heard in a universal IEM thus far. 

Read on to find out how I came to that conclusion including an outline of the pros and cons of the Apx and who it might appeal to when compared against some of the competition.

PMG Audio Apx front facing amber plates


Driver Configuration

The Apx’s driver mix is complex with no less than 11 drivers per shell including dynamic, balanced armature, and planar using a 7-way passive crossover. At a high level, Piotr has done this mix before with the FIBAE 5 under the Custom Art banner but the Apx takes it to an entirely different level.

You get two different types of custom planar, a rectangular Ultra version, (UPS), covering the sub-lows alongside a single 10mm PEEK diaphragm dynamic driver for the lows and lower-mids.

No less than 8 custom balanced armature drivers are used in 4 dual configs for the lower-mids, mids, mids/lower-highs, and highs. The grouping is completed with a smaller custom round Ultra planar tweeter for the highs above 10k.

The driver configuration is also supported by PGM’s POD technology or Pressure Optimizing Design which is acoustic filtering designed to help improve its response by reducing the pneumatic pressure in front of the driver.

The Apx has an impedance rating of 5Ω ±1Ω and a middling sensitivity level for an IEM at 107dB @1kHz 1mW. You should not find this monitor hard to drive from most portable sources.

Acoustical Enhancements

PMG has thrown in everything but the proverbial ‘kitchen sink’ in terms of innovative acoustical enhancements for the Apx alongside the new driver compliment.

For example, FIBAE is there. This is a long-established Custom Art patented flat impedance technology to help prevent the potential for impedance skew from output impedance mismatching.

In ‘3D’, we also have a massive evolution and expansion of the dedicated 3D-printed special waveguide concept first seen in the FIBAE 7 Unlimited.

This allows PMG to remove variable elements such as soft tubing and integrate the sound bores right into the shell to tighten up phase control of the various drivers. 

We have something new also called GSO or Geometrical Sound Outlet which is a parallel wall structure inside the nozzle. Besides keeping the Apx’s long nozzle rigid and robust it also allows PMG to finish the exit with a horn structure.

I am a fan of IEMs that use the horn principle. Allowing the bores to terminate first into a mini-chamber means the exiting soundwaves mix more naturally in the spout before they are introduced into your ear canal.

You get a superior high-frequency extension compared to the more traditional design that runs grouped frequencies via tubed bores right to the end of the canal with the mix happening inside your ear canal. 

PMG Audio Apx amber shells


Aside from the AAW Project 4+2 collaboration the Apx is the first universal design I have ever received for review from Piotr’s team.

There is currently no plan for a custom version but I can tell right away that a lot of the thinking here is plucked from their extensive customs design experience. 

The Apx aesthetics project a warm ambiance with a striking amber plate on top of a darker hand-made quasi-custom housing and lightly dusted with a complimentary warm speckled finish.

There is also a slimline venting port to the rear of the main housing to allow the dynamic driver to breathe with a carefully blended logo and name laser etched into the sides.

The overall look is more two-tone than singular so the similarly colored speckle helps give it more of a harmonious look which is a design approach I much prefer over plainer high-contrast plate and shell designs.

And yes, it is genuine amber and not some synthetic dye coloration made to look like amber. That means a much higher cost in terms of procurement. That also means no two Apx finishes will look the same. There are 25 of these in the wild, not a single one of them will mirror the other.

The Apx form factor is surprisingly small and elongated rather than fat and deep. It reminds me a little of Noble Audio’s design philosophy which also emphasizes the depth of the spout to get as close as possible to the second bend of the ear canal. Considering it has 2 planar drivers inside it’s not the heaviest monitor either. 

PMG Audio Apx speckled main shells

Comfort & Isolation

And this is where that long nozzle and narrow body come into their own. The Apx is very comfortable and secure in the ear with excellent penetration into the canal, particularly with the supplied silicone single flange tips.

The level of passive isolation for a dynamic driver-vented hybrid is also well above average though not quite to the level of an all-BA design with no venting. How much passive isolation will be determined by the type of tip you use and this also marks my first strong observational point in this review.

Ear Tips

You get two sets of tips with the Apx, foam, and single-flange wide-bore silicone alternatives. They come in three distinct sizes, small, medium, and large, and are neatly displayed in a translucent compact case.

For comfort, the silicone wins hands down for overall comfort with less friction and pressure on the ear canal walls. They also allow me to nudge the nozzle further down my ear canal compared to the thicker foam tips.

The foam tips do better for passive isolation blocking out more noise when compared to the silicone tips. I can live with both depending on my needs but the caveat is the distinct influence they have on the performance of the Apx.

The silicone tips are much more dynamic sounding compared to the laid-back and smoother presentation from the foam tips. They are also brighter sounding though the bass retains more impact and definition.

Go with the foams if you are sensitive to treble but I think you will miss out on the more immersive and articulate silicone tip performance.

PMG Audio Apx stock cable on blue leather

Stock Cable

PGM Audio has supplied the Apx with their own in-house design custom cable called the Omega which retails separately for €800.

This is a low-resistance 1.2m long 4-wire or 4-core silver copper alloy with a graphene core and terminated with an interchangeable plug system. The finishing isn’t too dissimilar to the core Apx warm aesthetic with a complimentary dark brown tone and some light silver speckling from its wiring under a transparent PVC jacket.

The cable is tightly braided, it does not feel like it will loosen up through repeated use. It also feels relatively light with its low-profile black aluminum splitter barrel and adjustable chin cinch made from the same materials. 

PMG Audio Apx three stock cable jacks

The branded plugs are made from the same aluminum finish as the splitter and connector barrels and come in 3 sizes including balanced 4.4mm, 2.5mm, and a single-ended 3.5mm TRS alternative.

The female port on the main cable is a simple 4-pin lock and load system making it very easy to connect and disconnect the plugs. For this review, I tried all three without issue and left the balanced one on for the sound impressions and comparisons.

PMG Audio Apx open display box

Packaging & Accessories

As you would expect for a premium product the Apx comes with a lot more grandeur than any Custom Art branded IEM, even the flagship variants. 

Everything comes packed inside a large branded wooden display box with two types of carry cases inside holding all of the accessories and neatly packed into a protective felt and foam layer. 

You will not see it in the pictures above but on the initial opening, both cases are sealed in plastic bags as is the wooden case itself to protect them from the elements. 

My one critique could be loosely described as subjective it just depends on your stance on what qualifies as luxury at this price point.  The whole ensemble feels a bit rough around the edges, both in terms of the finishing of the accessories and the box itself. 

I say this in the context of reviewing high-end packaging from the likes of Vision Ears or brands like Nostalgia Audio with their limited-edition Tesseract line and the beautiful cyberpunk imagery and story centered on Hong Kong skylines.

What it lacks is maybe a bit of ‘wow from the initial glance to the opening up. It’s a big step up from previous Custom Art packaging designs but I think there is another step yet to be done here at this level.

PMG Audio Apx inside of the leather carry case


Packaging and carrying around the Apx is more functional than visually exciting. I appreciate the supplied leather case’s size and the multiple pockets I can stuff the tips, cable, and jacks in without pressing down on the IEMs. Cases like these are rare these days.

Less so for the aluminum puck-style case which feels a bit dated and heavy. They can provide amazing protection when out and about but I would have preferred to have seen a Patina leather version with matching amber coloring to hammer home how unique it is to use amber in the Apx shells. 

Click on page 2 below for my sound impressions and recommended pairings.

Click on page 3 below for my selected comparisons.

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