The King, Retuned and Refined

More than one and half years after its initial release, the most popular and praised Thieaudio Signature series IEM is ready to make a comeback! The Monarch has been completely redefined with driver overhauls and an enhanced tuning. The Monarch was a monumental milestone for both Thieaudio and the global audio community, hallmarking not only one of the first IEM’s to properly integrate the EST driver technology, but also firmly establishing Thieaudio’s place in the world of Hi-Fi audio. Our R&D team has been following up with the reviews and comments from the audiophile community to refine that which was already one of the most revered monitors of its class and present the ultimate form of the Monarch: Monarch Mark II.

A New Engine to Set New Limits

Our goal for the Monarch MKII was to enhance its technical performance and introduce a more balanced tuning, while staying true to the original spirit of this monitor. We took this opportunity to update all of the internal drivers, swapping them out for their latest counterparts and rearranging their configurations to achieve an even more optimal performance.

The 10mm dynamic driver has been upgraded to a brand new composite diaphragm driver. With a tremendous increase in membrane tension and magnet strength, the new driver allows extreme responsiveness. And when engineered to specifically reproduce only the sub-bass frequencies, this dynamic driver becomes a subwoofer, producing even tighter and more impactful kick drum and bass line punches. Additionally, two dedicated subwoofer balanced armature drivers were paired with the dynamic driver, bringing about an immaculate coherency between the lows and the rest of the frequency spectrum.

Driver Configuration

The heart of the Monarch has always been its extremely precise and neutral mids that make it such a capable studio monitor. To emphasize this trait, we reconfigured the balanced armature drivers, reinforcing this core range with four mid-frequency drivers.

Doubling the midrange drivers from the original Monarch presented incredible advances in technical performance. Distortion was reduced, while the resolution, clarity, and articulation of the mid and treble sections were significantly enhanced. This single change was enough to make the Monarch MKII feel like a completely new beast compared to its predecessor, all the while still maintaining the characteristic studio-neutral midrange.

Latest Technology

The latest electrostatic drivers are incorporated into the Monarch MKII, and rearrangement of driver location has minimized unwanted tubing resonance and extended its high frequency rolloff compared to the original Monarch. This means that the treble range is more even and detailed, and our innovative incorporation of the EST drivers into the setup allows for a greater sense of sparkly, airy, and high-resolution atmosphere in your music. The Monarch MKII continues the Thieaudio legacy of being one of the few in-ear monitors in the world to properly utilize the EST technology.

Retuned for a Balanced Perfection

One of the controversial sound aspects of the original Monarch was its super defined and emphasized sub-bass. While some enjoyed the clean separation between the sub-bass and the low-mid frequencies, others voiced concern of the sheer quantity of sub-bass. To bring about a resolution, we have slightly decreased the volume of the sub-bass to more appropriate levels, while pushing the low-pass crossover from 150Hz to 200Hz. This change still maintains the clean and punchy subwoofer-like characteristic of the lows that doesn’t muddy the mids, but introduces an ever-slightly warm texture to fundamental low-frequency instruments such as the bass guitar.

The mid-frequencies between 200Hz and 1kHz are still kept at a ruler-flat neutral that makes the Monarch MKII an impeccable professional monitoring device. The mid-treble transition between 1 and 2kHz has been pushed back to 3kHz, which reduces any nasal or harsh vocal textures, while still emphasizing the bite and crispness of instruments. Every aspect of the tuning process has been scrutinized, being meticulously tested by ear and measurement equipment, and we are proud to present the perfect vision that is the Monarch MKII.

Premium Cable System

With our new release, we have also upgraded its previous EST cable. Beloved for both its feel and high resolution sonic properties, our EST cable has been one of our top selling products. We have improved the physical texture of the cable by using a soft braided paracord material.

The Monarch MKII's stock cable still maintains the ultra-pure silver plated 26AWG OCC copper litz wires, but the additional strand incorporation gives it a slightly meatier feel and a richer sound. Most significantly, this new stock cable features the proprietary "Smart Switch", a new modular plug design, allowing you to choose between 4.4mm balanced, 2.5mm balanced and 3.5mm unbalanced terminations, simply by swapping out the plug ends. This reduces the need for bulky adaptors, giving your setup a more complete look and feel. The 2-pin connectors on the stock cable are also updated to provide a more secure fit with your IEMs.

About Thieaudio

Thieaudio was launched in 2019 as a creative endeavor of Linsoul Audio. The goal of Thieaudio was to serve as a creative platform for gathering the best teams of engineers to inspire revolutionary audio products for audiophiles and professionals alike. For each project, we hand select the most innovative and renowned engineers in his or her field to oversee the design, engineering, and manufacturing of the products.

Gathering the momentum from the success of the Thieaudio Phantom planar magnetic headphones, as well as the Voyager, Legacy, and Signature series In-Ear Monitors (IEM’s), we are committed to the continual expansion on the limits of high-fidelity audio. We welcome you to join us and experience excellence in musical performance.

HIGH END VIENNA 2026