Empire Ears ESR MKII vs 64Audio Solo
Introduction
The Empire Ears ESR MKII and Solo are premium IEMs designed to deliver studio-accurate, high-resolution sound. Let's compare both models so you can find the best in-ear monitors for your listening preferences.
Not the right fit? Browse other In-Ear Monitors from Empire Ears and 64Audio.
Empire Ears ESR MKII vs 64Audio Solo Price Comparison
The ESR MKII and Solo sit at two very different price points.
The ESR MKII comes in at $1,099.00.
The Solo comes in at $1,399.00.
The ESR MKII costs slightly less than the Solo. Let's dive deep into the specs, design, sound signatures, and features of both so you can get a better idea of what each IEM brings to the table.
The Empire Ears ESR MKII
The ESR MKII is Empire Ears' studio-reference IEM. It features a five-driver hybrid setup with three BA and two Electrostatic drivers. In terms of features, the ESR MKII packs SynX, EIVEC, and A.R.C technology for enhanced sound and reliability.
Empire Ears ESR MKII Features:
- Anti-Resonance Compound (A.R.C.)
- SynX Crossover Technology
- Proprietary Drivers
- UPOCC Cable
- EIVEC Module
Empire Ears ESR MKII Specs:
Driver Configuration: 3x Balanced Armature Drivers + 2x Electrostatic Drivers
Frequency Response: 10Hz - 100kHz
Sensitivity: 111dB @ 1kHz, 1mW
Crossover: 4-Way synX Crossover Network
Impedance: 3.9 Ohms @ 1kHz
The 64Audio Solo
The 64Audio Solo is a premium single-driver IEM built around a custom 14.2 mm planar magnetic driver, designed to deliver fast transients, textured bass, and extended treble in a clean, coherent package. With proprietary 64Audio technologies like tia, Apex Core, LID, and dual Helmholtz resonators, the Solo offers a highly engineered take on the single-driver concept. Crafted from T6061 aluminum with copper mesh faceplates, it combines durability, comfort, and a modern aesthetic while shipping with a generous set of accessories.
64Audio Solo Features:
- 14.2 mm Planar Magnetic Driver: Impactful yet controlled bass, and smooth treble without crossover distortion.
- Apex Core: Vented acoustic design that relieves air pressure, reducing fatigue while maintaining staging and openness.
- LID (Linear Impedance Design): Ensures consistent sound across a wide range of audio sources.
- Dual Helmholtz Resonators: Precisely tuned acoustic chambers that balance low frequencies and improve overall clarity.
64Audio Solo Specs:
Driver Configuration: 14.2 mm planar magnetic driver
Frequency Response: 20Hz – 20kHz
Sensitivity: 100 dB/mW @1kHz
Impedance: 16 Ω @1kHz
Isolation: ~–12 dB (vented Apex Core design)
Shell Material: T6061 aluminum with copper mesh faceplate
Cable: OCC copper 8-braid (25 AWG + 23 AWG), ~0.26 Ω, 3.5 mm + 4.4 mm terminations
Design and Build Quality
The ESR MKII and Solo are unmistakably premium IEMs, boasting exceptional build quality, design, and ergonomics.
The ESR MKII carries Empire Ears’ more understated design language, featuring a sleek resin shell with smooth contours that sit flush in the ear. Its lightweight build makes it easy to wear for hours, and the snug fit ensures excellent isolation. The understated faceplate design complements its role as a “tool-first” IEM rather than a flashy showpiece.
The 64Audio Solo is built from T6061 aluminum for optimal weight and durability. Up front, the Solo features a copper mesh faceplate that adds both ventilation and a premium aesthetic.
Despite housing a large 14.2 mm planar driver, the shells are ergonomically shaped for comfort. The build quality reflects 64Audio’s high standards, with hand-assembled components and tight tolerances that give the Solo a solid, professional feel.
The included OCC copper eight-braid cable is equally premium, offering low impedance and both 3.5 mm single-ended and 4.4 mm balanced terminations out of the box.
Altogether, the Solo’s design strikes a balance between rugged durability, modern styling, and practical usability, consistent with its premium pricing.
Sound Signature
You're probably looking to see how these IEMs stack up on sound. We'll share our thoughts here, although keep in mind this information tends to be anecdotal and subjective.
ESR MKII Sound Signature
The ESR MKII is built around accuracy and balance, making it ideal for professionals or listeners who want to hear music exactly as it’s recorded.
Its bass is tight and controlled, never overpowering the mix. The midrange is clean and transparent, bringing out vocals and instruments with lifelike clarity - perfect for mixing or critical listening. The treble is extended yet smooth, revealing subtle details without harshness, ensuring long listening sessions stay fatigue-free. This combination gives you the confidence to make precise judgments on recordings while still enjoying natural musicality.
Solo Sound Signature
The 64Audio Solo offers a neutral-reference tuning shaped by its planar magnetic driver and proprietary acoustic tech.
Bass is tight and articulate, with the Helmholtz resonators adding weight and depth without muddiness. The midrange is clean and transparent, giving vocals and instruments a natural presence. Treble is extended and detailed thanks to tia’s open design, offering air and sparkle without harshness.
Combined with the Apex Core venting, the Solo presents an open, spacious soundstage with excellent resolution and speed, making it a standout for those who value clarity, detail, and accuracy in their music.
Price and Value
At $1,099, the ESR MKII offers tremendous value for professionals, studio engineers, or anyone who wants a reliable reference tool. Its neutral, accurate tuning gives you confidence in what you’re hearing, making it a cost-effective investment for critical work. The lightweight design and excellent isolation further enhance its practicality, proving that you don’t need to spend flagship-level prices to get studio-grade performance. For those who want precision without excess, the ESR MKII delivers exactly that.
At $1,399 USD, the Solo comes with a custom 14.2 mm planar magnetic driver, premium T6061 aluminum housings with copper mesh faceplates, and 64Audio’s proprietary technologies including tia, Apex Core, LID, and dual Helmholtz resonators. The package also includes a premium OCC copper eight-braid cable with both 3.5 mm and 4.4 mm terminations, multiple tip options, and a protective carry case.
Our Thoughts
If you're looking for the most accurate sound from an IEM, the ESR MKII is the one to get. With the ESR MKII, your music will sound pure, clean, and immaculate - just like it would in the studio. Its balanced bass, midrange, and treble frequencies make it easy to pick out every note and detail in music, while its realistic soundstage lets you enjoy your favorite music with satisfying immersion.
The 64Audio Solo is for audiophiles who want a flagship single-driver IEM that emphasizes speed, coherence, and resolution over sheer driver count. It’s an excellent match for listeners who value clarity, accuracy, and natural staging in a durable, premium build. The Solo’s combination of planar dynamics and 64Audio’s proprietary tech makes it versatile enough for both casual listening and studio reference use.
If you like tight and textured bass, clean mids, airy treble, and a design that blends innovation with minimalism, the Solo is the IEM for you.
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