GRAND Maestro Custom IEM - FATFreq

GRAND Maestro Custom IEM

Sale price$3,999.00
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FATfreq's Flagship IEM 2023

Award-winning frequency response with exceptional bass feedback. Exchangable NOAH Modules customize bass response while providing sublime low-end tonality and rumble. Precisely tuned pressure valves prevent ear fatigue without any compromise on sound quality and isolation. Customize your hearing experience with the built-in vocal boost switch for a total of 4* expertly-tuned frequency curves. Grand Maestro is the ultimate end-game monitor for anyone looking to take their music experience to the highest level.

*with the purchase of Blue 'Control' Modules

Version updates:
- Recessed 2-pin sockets
- Recessed Vocal Switches

- Luxury Collector's Exhibition Box
- NOAH Modules in Metal

Express Shipping

All international orders will be shipped using DHL express.

Express Shipping

All international orders will be shipped using DHL express.


1 Year Limited Warranty included for IEMs.


1 Year Limited Warranty included for IEMs.

FATfreq Grand Maestro


A divine fusion of exceptional acoustics and cutting-edge design,
FATfreq Grand Maestro presents itself as FATfreq's TOTL monitor of 2023.

GRAND Maestro Universals - FATFreq

FF Custom-Designed

Bass Chamber

Meticulously engineered, the chamber utilizes cutting-edge acoustics to amplify low-frequency vibrations - Setting the benchmark for deep, captivating Bass response.


NOAH Modules

Detachable Bass Chamber Modules allow you to customize your Subwoofer Slam while retaining the breathability of our custom-built DD.

Black 'Power' Modules concentrates Sub-bass power for more Slam.
Blue 'Control' Modules controls the Sub-bass response for more Rumble.

GRAND Maestro Universals - FATFreq

FF Custom-Designed

Vox Boost Switch

Enhance the clarity of vocals in your audio content. Whether you're listening to music, podcasts, or watching videos, you'll hear every note and word with remarkable precision.


Quad EST Drivers

The Grand Maestro is powered by Quad precision-tuned Electrostatic drivers for unmatched detail retrieval and soundstage up to 40kHz and beyond.

Get the most out of your Grands

GPS Gold Cable

Upgrade your set with our Custom-made Gold-Plated Pure Silver Cable to enhance the Musicality and Headroom of your mixes. Package includes exchangeable 2.5/3.5/4.4 audio jacks for your choice of source.


Developed by FATfreq in Singapore

Bass Cannon™

(Patent Pending) Using proprietary dynamic woofers, bass chambers and acoustic filter networks, FATfreq was able to design the deepest bass ever recorded of over 20dB, concentrated below 200Hz with zero bleed. Not for the faint hearted.


A secure fit allows you to get the best out of your in-ear monitors. Using software and earmold retention principles, FATfreq digitizes your scans to shape important pressure points, ensuring your perfect 3D-fit. Models are then sent to our high-precision 3D printers for fabrication.

Linear Impedance

FATfreq uses proprietary circuits to correct the non-linear impedances of multi-driver systems. The different output impedances across all your devices cause frequency response to vary. Having this tech ensures consistency in frequency response for all our IEMs when plugged into any device - Be it your mic-pack, mixer board, phone or dedicated DAP.

Sonar La Trompa™

Inspired by the anatomy of the traditional french horn, FATfreq uses exponential horn curvature for gain control and to improve treble tonality via acoustics. Providing you with Smooth, natural sounding highs, grounded by a nice timbre in the mid and low frequencies.


The absence of a DSP in IEMs means that we have to match the phase of multi-way systems via Acoustic delay. Using proprietary structures, we were able to align the low, mid and high frequencies such that they reach your eardrum in a coherent manner. Giving you the sound accuracy and resolution demanded on stage and studio.

step by step guide:

how to order?

1. Start an Order

Go to our Custom-fit IEM page and click on the ‘Create Your Own’ button for your chosen IEM model.

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