Empire Ears ESR MKII vs FATfreq x Effect Audio: Quantum
Introduction
The Empire Ears ESR MKII and FATfreq x Effect Audio: Quantum 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 FATfreq.
ESR MKII vs Quantum Price Comparison
The ESR MKII and Quantum sit at slightly different price points.
The ESR MKII comes in at $1,099.00.
The Quantum comes in at $779.00.
The ESR MKII costs slightly more than the Quantum. 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:
- 5-driver hybrid system with 3 BA + 2 electrostatic drivers
- 4-way synX crossover with EIVEC for electrostatic integration
- A.R.C. technology to reduce resonance for cleaner sound
- Brushed Silver aluminum faceplate with ergonomic resin shell
- Includes Alpha IV UPOCC Copper Litz cable
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 FATfreq x Effect Audio: Quantum
The Quantum is a high-end IEM made in collaboration with premium cable manufacturer Effect Audio. The FATfreq x Effect Audio Quantum features a large planar driver with Bass Cannon technology, ResoFlow Acoustic System, and a premium Ares S II cable from Effect Audio.
Quantum Features:
- 14.2 mm planar driver with ResoFlow™ acoustic system
- Modular Noah system (SuperStage, Blue, Black options)
- Premium Effect Audio Ares S II cable included
- Reverse exponential horn for taming planar bite
Quantum Specs:
Driver: 14.2mm ultra-fast planar magnetic driver
Frequency Response: 20Hz-45kHz
Impedance: 38Ω
Cable: Effect Audio Ares S II (UP-OCC copper with a central solid core, 26 AWG with 8 wires)
Termination: 4.4mm balanced, ConX 2-pin
Technologies: Dual vent technology, Noah Technology, Basscannon Technology, ResoFlow Acoustic System
Design and Build Quality
The ESR MKII and Quantum are premium IEMs inside and out, boasting exceptional build quality, design, and ergonomics.
The ESR MKII keeps things professional yet simple. Its medical-grade resin shell is ergonomic and lightweight, ensuring long-term comfort, while the brushed aluminum faceplate adds a subtle touch of refinement. With A.R.C. applied inside the housing, internal resonances are minimized, making the sound cleaner and more accurate.
The Effect Audio x Quantum is FATfreq's most premium IEM in terms of build quality and materials. It features a composite shell mated to stainless steel faceplates. To complete the look, the Quantum comes with an ultra-premium ConX 2-pin Ares S II cable from Effect Audio.
The composite parts of the shells are painted black and feature a scratch-resistant design. They also feature nifty blue and red markings for the Left and Right channels. At the front, you'll find brushed stainless steel faceplates with round vent holes in the middle. At the bottom are the interchangeable Noah modules.
The Quantum is a departure from FATfreq's typical resin-based IEMs. The combination of stainless steel and composite materials gives the Quantum a solid yet lightweight feel. These IEMs are compact enough to feel comfortable in the ear during extended listening sessions.
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.
Quantum Sound Signature
The Effect Audio x Quantum is a departure from typical FATfreq bass-heavy tuning. It features a neutral, energetic, and detailed sound signature for a more exciting sound experience.
The Quantum delivers deep-reaching sub-bass with lightning-quick mid-bass response. This translates into a superbly textured bass rumble and punchy bass kicks - perfect for EDM, R&B, Pop, and more. The midrange and treble are precise and very accurate. Vocals sound clear and natural, while cymbals and strings are rendered with excellent clarity free from harshness. The soundstage is where the Quantum shines, offering a spacious and immersive soundstage with excellent instrument separation and accurate positioning.
Price and Value
At $1,099, the ESR MKII offers impressive 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, delivering studio-grade performance without the premium price tag. For those who want precision sound and build, the ESR MKII delivers exactly that.
The $779 Effect Audio x Quantum delivers superb sound quality that's both accurate and exciting. It features a 14.2mm planar magnetic driver housed in a high-quality composite/stainless steel shell. The Quantum comes with a premium 2-pin ConX Ares S II cable in 4.4mm termination, alongside Black, Blue, and SuperStage NOAH Modules. The Quantum also comes with a compact Black Metal Case.
Our Thoughts
Get the ESR MKII IEM if you're looking for a flat, accurate, and detailed sound for music production or mixing. The ESR MKII's reference-grade sound will help reveal subtle details in music making it a joy to use for mixing and mastering at home or in the studio.
Get the Quantum if you want more excitement from your listening sessions. While the Quantum doesn't have the raw bass power of its siblings like the Maestro Mini, it still delivers incredibly textured rumbles and an impactful punch in your favorite tunes. Vocals sound life-like, and its soundstage presentation is some of the best you'll experience in any IEM sub-$1000. Swappable Noah Modules let you fine-tune sound signatures, and the included Ares S II cable is nothing short of exceptional in both aesthetics and performance.
Elevate Your Listening Experience With These Related Articles
Enjoyed this article? Check out our other product comparisons!