In this article, I review the EPZ P40 IEMs. The P40 is a hybrid quad-driver IEM with a 2DD+1Planar+1PZT configuration and a 4-way electronic crossover in a classy resin housing. It’s priced at $149 USD.

Disclaimer: This sample was provided by EPZ for an honest review. All observations and opinions here are my own, based on my experience with the product.

EPZ P40

Inside the Box

• EPZ P40 IEMs
• Detachable 0.78mm 2-pin cable
• 3.5mm and 4.4mm plugs
• 6x pairs of silicone eartips
• Carrying case

Design

The P40 has dense, 3D-printed resin shells that feel solid in hand, giving them a more robust and premium feel (but also making them slightly heavier). The faceplates have a laser-textured metallic panel under a clear resin coating that refracts a rainbow of colours as the light shifts.

There’s only a single vent near the base of the aluminium nozzles but despite that, I didn’t feel any uncomfortable pressure build-up while using the IEMs. In fact, I find the P40 shells extremely comfortable to wear for hours at a time. Furthermore, the solidity of the resin housings creates above-average passive noise isolation, meaning you can enjoy your music without distractions.

Included with the IEMs is a 4-strand Furukawa silver-plated OFC cable. It’s a lovely, albeit slightly thick cable that feels sturdy and handles nicely. It’s modular too, so you can easily switch between the included L-shaped 3.5mm and 4.4mm plugs.

Sound

Sources used for testing include the D&A Alpha, iBasso DX180 and FiiO KA17. The EPZ P40 is efficient when it comes to power requirements, so you can plug it into pretty much any source and get good results.

The P40 follows the Harman 2019 in-ear target quite closely, with a moderate bass lift, a well-balanced midrange, and a smooth, lightly elevated treble. It comes across as clean and engaging, with vocals maintaining good clarity without being pushed unnaturally forward.

Bass

Compared to the Harman target, the P40 trades a hint of sub-bass for more mid-bass body. This is essential to bolster the lower mids, which might otherwise sound hollow due to their neutral tone. Still, there is more than enough sub-bass presence, and the 9mm dynamic driver handling the lows has good depth and texture. The mid-bass is punchy without being bloated, delivering plenty of impact and rhythm.

Midrange

The P40 has a neutral midrange that avoids being recessed or overly intimate. While this lean character might imply an analytical sound, that isn’t quite the case. The P40 manages to avoid a bright or clinical tone despite its lack of lower-midrange weight. This is due to a subtle mid-bass presence that provides just enough body to bolster it.

Treble

The treble notes have a satisfying sense of thickness and weight. This region rolls off evenly and is free of any dissonant peaks that might cause fatigue. It provides a high level of clarity without becoming overly bright or clinical. Furthermore, the P40 offers better extension than a strict Harman tuning, which aids in a highly resolving presentation that uncovers plenty of fine detail.

Soundstage & Presentation

This is where the P40 really stands out for me. While the stage isn’t exactly expansive, it never feels cramped or restricting. It has a rounded shape with excellent depth and height alongside moderate width. This creates a three-dimensional environment with plenty of air between instruments and pinpoint imaging. Furthermore, the overall resolution is better than average for IEMs in this price range.

Comparisons

Kefine Quatio

Starting with the bass, the Quatio reaches deeper into the sub-bass and gives you more rumble down low. Its mid-bass is cleaner and more defined, but it doesn’t hit as hard. The P40, on the other hand, has more punch and a stronger sense of impact, even if it’s not quite as tidy. So it’s basically a choice between weight and control here.

Through the mids, the Quatio comes across a bit leaner. Notes are thinner and a bit more separated, which can sound cleaner, but also less full. The P40 sounds thicker and more solid in comparison, which gives it a more natural feel on a lot of tracks. The Quatio is also the brighter of the two, even if that’s not what you’d expect from the graph. It has more bite up top, while the P40 sounds a bit more even and settled.

In terms of staging, they’re pretty similar in size. The difference is in imaging. The P40 is more precise and places sounds more accurately, while the Quatio is slightly less pinpoint in that regard, even if it still separates things well.

Kiwi Ears KE4 ($129 USD)

Starting with the bass, the Kiwi Ears KE4 sits somewhere between the Quatio and the EPZ P40 in terms of quantity. It has more presence and weight than the P40, but doesn’t quite reach the same level of sub-bass emphasis as the Quatio. Compared to the P40, it comes across fuller and more authoritative down low, while still keeping things relatively controlled. The P40, in contrast, sounds a bit lighter and punchier, trading some of that weight for a cleaner, more nimble presentation.

Through the mids, the KE4 is slightly fuller and more grounded, which gives instruments a bit more body. The P40 sounds a touch leaner but also a bit cleaner in how it separates notes. It’s not a huge difference, but the KE4 leans more towards richness, while the P40 keeps things a bit more neutral and open.

Up top is where the difference becomes more about tuning preference. The KE4 has a bit more extension and reach, which brings out some extra air, but the P40’s treble is more even and better integrated. It sounds smoother and more controlled, without drawing attention to itself, whereas the KE4 can come across slightly more forward by comparison.

In terms of staging, they’re fairly close in size. The P40 still has the edge when it comes to imaging precision, placing sounds more accurately within the stage, while the KE4 is slightly softer in that regard.

Verdict

The EPZ P40 is one of those IEMs that just gets the fundamentals right. The shells look and feel great in the hand, and the included cable is actually worth using, which isn’t always a given at this price. It comes across as a well put-together package from the start, without any obvious weak points.

The tuning is equally well judged. It leans towards a U-shape, close to a Harman-style balance, but with a bit more mid-bass to fill things out and a smoother treble response. The result is a clean, engaging sound with strong vocal clarity, punchy bass, and treble that has enough presence to bring out detail without sharpness.

All things considered, the P40 offers a lot of performance for the money. Between the design, the cable, and a tuning that’s easy to get along with, it’s an easy recommendation if you’re after something balanced and capable without obvious trade-offs.

Specifications

Drivers: 2DD+1PLANAR+1PZ
Frequency response: 20Hz – 20kHz
Sensitivity: 100dB
Impedance: 14Ω