Note that this is a discontinued product. You may want to visit the brand's page here to browse their newer products.
What reviewers think
Bloggers and YouTubers have tried this product—so we've summarized their strongest opinions below. Links to full reviews follow.
What are hifi reviews useful for? (1) Identifying products you should demo in person at a dealer. (2) Learning which products reviewers unanimously praise as the best they've heard (this means they probably are legitimately great). (3) Identifying a product's attributes that satisfy your idiosyncratic needs and tastes. Beyond that, we often discount what reviewers say because they heap praise on most products—and are often apprehensive about publishing strong criticism or comparisons between products. Further, they seldom have more than a few products on-hand, often relying on their memories to compare past products. Always listen for yourself.
All
Reference Plus Universals
reviews
Video Review
Manufacturer details
Features
Specifications
- Cable: 4-core Silver-Plated Copper (SPC) with 3.5 mm audio jack
- Case: FATfreq hard case
- Eartips: Silicone (sizes S / M / L)
- Tool: IEM cleaning tool
- Warranty: 1-year limited warranty
Description
A capable reference-grade dual-driver tuned dead flat with best-in-class treble extension that rivals IEMs more than 5x its price. The Reference Plus is a great tool for engineers and vocalists seeking neutral tuning, airiness, and transparency.
Release Timeline
Manufacturer Site
Brand highlights
Taking a step back to look at reviewers' thoughts of the brand's entire lineup—not just this product—what stands out most is the following:
- FATfreq is recognized for its distinct "basshead" sound signature, delivering powerful and impactful bass responses, particularly in the sub-bass region, without sacrificing clarity in the mids and highs.
- They offer customizable sound profiles through interchangeable NOAH modules and tuning switches, allowing users to tailor the IEM's sound to their preferences.
- FATfreq IEMs often feature high driver counts and tribrid configurations, combining dynamic drivers, balanced armatures, and electrostatic tweeters to achieve a detailed and balanced sound.
Select products
Select product comparisons
Reference Pro SE Universals
- Positioning: A compact, studio-grade IEM reimagined with enhanced vocal clarity.
- Description: Offers an extra tweeter designed to bring out vocal transparency and detailed transient response in a balanced tonal presentation. Compared to the Musician Pro and Quantum models, it emphasizes clean studio reproduction over extended bass or planar dynamics, making it ideal for users focused on vocal performance and moderate budgets.
Musician Pro SE Universals
- Positioning: A bass-optimized IEM tuned for energetic performance and low-end impact.
- Description: Offers a uniquely tuned three-way crossover with an extra low-frequency driver that deepens bass without bleeding into mid registers. In comparison to the Reference Pro SE, it prioritizes vigorous bass output, while Quantum and flagship models deliver additional precision and modular control.
FATfreq x Effect Audio: Quantum
- Positioning: A high-performance IEM featuring innovative planar driver and modular tuning technology.
- Description: Offers a planar magnetic driver paired with detachable Noah modules and a premium Ares S II cable to ensure speed, accuracy, and fatigue-free clarity. Unlike the Reference and Musician models that focus on one tonal aspect, it provides enhanced customizability and balanced resolution.
Hayabusa Universals
- Positioning: A versatile flagship IEM designed for both live and studio applications with dual tuning options.
- Description: Offers dual-mode tuning via an analog bass toggle and incorporates additional super tweeter modules to enhance vocal detail and instrumental separation. Compared to the entry-level Reference and Musician series, it bridges the gap with creative tuning flexibility, while remaining more accessible than the ultra-premium Grand Maestro.
GRAND Maestro Universals
- Positioning: The ultimate high-end monitor featuring state-of-the-art customization and advanced acoustic technology.
- Description: Offers customizable NOAH modules, precisely engineered bass chambers, and a built-in vocal boost switch to deliver exceptional detail and tailored frequency response. In contrast to all other models in the lineup, it delivers superior build quality, expansive soundstage, and cutting-edge technology.
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Avg. Product Price
$500
Used For Sale
0
Available (Scroll Down)
Brand Popularity
830
of 900+
Badges
Top 50 Brand
Top 250 Brand
Products Listed
31
Founding Year
2016
Our take on the brand
FATfreq is a hifi audio brand best known for headphones that using Basscannon technology that delivers extreme sub-bass levels (20-30 dB below 200-250 Hz) without midrange bleed, along with NOAH swappable bass-chamber modules that let users tune sub-bass power versus control while reducing ear fatigue.
Look inside the brand
Brand Page
Our interview with the brand
What are two key technological innovations or strong opinions that differ you from other brands?
What's your approach to customer support?
What are your favorite tracks for showcasing the strength of your products?
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From our interview with
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Brand Page
Used
FATfreq
All of the Brand's Used Products
What if you spend more?
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FATfreq
FATfreq x Effect Audio
785
785
/
7
Reviews
FATfreq is a hifi audio brand best known for headphones that using Basscannon technology that delivers extreme sub-bass levels (20-30 dB below 200-250 Hz) without midrange bleed, along with NOAH swappable bass-chamber modules that let users tune sub-bass power versus control while reducing ear fatigue.
Expand Details
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Product Strengths
- Bass is a highlight, with excellent detail, clarity, punch, depth, and a natural sound, and the sub-bass is often emphasized
- Offers the ability to customize the sound through the use of interchangeable NOAA modules
- Technical performance is considered excellent, with good instrument separation, imaging, and layering
- The 'Super Stage' module creates a wide and immersive soundstage that reviewers found exceptional, setting it apart from other planar IEMs
- Smooth and energetic treble that is controlled and not harsh or fatiguing for most listeners
Product Considerations:
- Some reviewers found the comfort to be an issue due to the IEM's shape, especially for those with smaller ears
- One reviewer noted that the treble can sometimes sound grainy, particularly in the air region
- The stock accessories, particularly the eartips, are considered adequate, but not exceptional for the price point
- The included Effect Audio Ares S2 cable, while high quality, exhibits some memory and stiffness
- The industrial design/aesthetics were considered 'bland' or 'not pretty' by some reviewers
Comparisons (according to reviewers)
- Vs Letshuoer S15: Quantum is a bassier version of the S15
- Vs FATfreq MP145: Quantum is better in many areas, including sub-bass, vocals, and treble smoothness
- Vs Letshuoer SO-8: Quantum has better sub-bass depth and texture, but less mid-bass punch than the SO-8
- Vs Jomo Nautilus: The Jomo Nautilus has a lusher mid-range and zingier treble, while the Quantum offers better bass detail and soundstage
- Vs Ice Lab Prismatica: The Prismatica has a stronger mid-range and clearer instrument separation, while the Quantum has better imaging and immersion
- Vs 7th Acoustics Supernova: The Quantum has a larger bass slam, while both have clear midranges and fantastic imaging
Takeaway: The FATfreq x Effect Audio Quantum is a planar IEM with a bass-focused sound signature and a highly customizable soundstage, thanks to its interchangeable modules. It is a good option for those who want a planar IEM with impactful bass and a unique listening experience.
Video review
Our take on the brand
FATfreq is a hifi audio brand best known for headphones that using Basscannon technology that delivers extreme sub-bass levels (20-30 dB below 200-250 Hz) without midrange bleed, along with NOAH swappable bass-chamber modules that let users tune sub-bass power versus control while reducing ear fatigue.
Product Page
Product Page
FATfreq
Musician Pro SE Custom IEM
667
667
/
2
Reviews
FATfreq is a hifi audio brand best known for headphones that using Basscannon technology that delivers extreme sub-bass levels (20-30 dB below 200-250 Hz) without midrange bleed, along with NOAH swappable bass-chamber modules that let users tune sub-bass power versus control while reducing ear fatigue.
Expand Details
Video review
Our take on the brand
FATfreq is a hifi audio brand best known for headphones that using Basscannon technology that delivers extreme sub-bass levels (20-30 dB below 200-250 Hz) without midrange bleed, along with NOAH swappable bass-chamber modules that let users tune sub-bass power versus control while reducing ear fatigue.
Product Page
Product Page
FATfreq
Scarlet Mini Universals
667
667
/
1
Reviews
FATfreq is a hifi audio brand best known for headphones that using Basscannon technology that delivers extreme sub-bass levels (20-30 dB below 200-250 Hz) without midrange bleed, along with NOAH swappable bass-chamber modules that let users tune sub-bass power versus control while reducing ear fatigue.
Expand Details
Our summary
Video review
Our take on the brand
FATfreq is a hifi audio brand best known for headphones that using Basscannon technology that delivers extreme sub-bass levels (20-30 dB below 200-250 Hz) without midrange bleed, along with NOAH swappable bass-chamber modules that let users tune sub-bass power versus control while reducing ear fatigue.
Product Page
Product Page
FATfreq
Reference Pro Custom IEM
584
584
/
1
Reviews
FATfreq is a hifi audio brand best known for headphones that using Basscannon technology that delivers extreme sub-bass levels (20-30 dB below 200-250 Hz) without midrange bleed, along with NOAH swappable bass-chamber modules that let users tune sub-bass power versus control while reducing ear fatigue.
Expand Details
Video review
Our take on the brand
FATfreq is a hifi audio brand best known for headphones that using Basscannon technology that delivers extreme sub-bass levels (20-30 dB below 200-250 Hz) without midrange bleed, along with NOAH swappable bass-chamber modules that let users tune sub-bass power versus control while reducing ear fatigue.
Product Page
Product Page
What competes at this price?
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FATfreq
FATfreq x HBB Deuce
250
/
Released
2024
Experience deep, focused power with the 2nd generation of FATfreq's Basscannon technology: 25dB sub-bass shelf, expertly controlled under 150Hz. FATfreq's proprietary tubeless system provides a phase-accurate three-dimensional audio experience, placing instruments and vocals precisely within a spacious environment. The Deuce excels in dynamics, capturing both subtle and powerful moments with ease.
FATfreq is a hifi audio brand best known for headphones that using Basscannon technology that delivers extreme sub-bass levels (20-30 dB below 200-250 Hz) without midrange bleed, along with NOAH swappable bass-chamber modules that let users tune sub-bass power versus control while reducing ear fatigue.
Expand Details
Our Summary
Product Strengths
- Excellent bass response that is 'bold,' 'monstrous,' and 'addictive,' especially for bass heads
- Vocals are well-captured and separated from other elements in the mix, preventing them from getting lost in the bass
- Smooth and digestible treble that is detailed and consistent, separating it from other IEMs with potentially odd or peaky treble responses
- Comfortable fit due to its design
- Good soundstage and imaging
Product Considerations
- Some reviewers experienced issues with FATfreq order fulfillment and customer service
- The included cable can be microphonic
- The looks (black and red) aren't for everyone
Comparisons (according to reviewers)
- Vs. Moondrop Variations: The Deuce draws inspiration from the Variations' treble and upper mids but with a more impactful bass
- Vs. Sennheiser IE 300: The Deuce is a better execution of a bassy dynamic driver sound, with more contrast and less muddiness
- Vs. Letshuoer E20: E20 is technically better, but the Deuce's low end feels heavier and goes deeper, with more rumble in the sub-bass
Takeaway: The FATfreq x HBB Deuce is a fun IEM that's great if you love bass, but it also has good vocals and smooth treble. Experiencing that bass and enjoying the music could be worth the purchase.
Video review
Our take on the brand
FATfreq is a hifi audio brand best known for headphones that using Basscannon technology that delivers extreme sub-bass levels (20-30 dB below 200-250 Hz) without midrange bleed, along with NOAH swappable bass-chamber modules that let users tune sub-bass power versus control while reducing ear fatigue.
Product Page
Product Page
FATfreq
Maestro Mini Universals
500
/
Released
2023
The sub-bass IEM that all audiophile Basshead IEMs are measured against. The Maestro Mini's unique design ensures a concentrated bass response in the sub-bass region, without any undesirable bleed into mid-frequencies. As a result, it has earned its place as the benchmark for audiophiles and bass heads seeking uncompromised sub-bass performance.
FATfreq is a hifi audio brand best known for headphones that using Basscannon technology that delivers extreme sub-bass levels (20-30 dB below 200-250 Hz) without midrange bleed, along with NOAH swappable bass-chamber modules that let users tune sub-bass power versus control while reducing ear fatigue.
Expand Details
Our Summary
Product Strengths
- Small and ergonomic design allows for comfortable wear, even while sleeping.
- A-tier or A+ tier mid-range that is clean and clear, but not lean; female vocals sound phenomenal.
- Good treble extension with energy around 8k and extension from 10k-14k, resulting in a natural timbre.
- Bass is textured and defined, with clear sub-bass rumble.
- Impressive imaging and instrument separation for its price point.
Product Considerations
- The stock cable is of poor quality and may need to be replaced.
- Exposed nozzles with no guard.
- Slight driver flex may occur, leading to ear pressurization after extended listening.
- Sub-bass can sometimes feel out of place or overwhelming, depending on the music genre/mastering.
Comparisons (according to reviewers)
- Vs Empire Ears Legend Evo: The Maestro Mini has better treble extension.
- Vs Thieaudio Monarch MK1/MK2/Clairvoyance: The Maestro Mini has better tonality and timbre.
- Vs Moondrop Variations: The Maestro Mini has better technical performance and more natural timbre.
Takeaway: The Maestro Mini Universals are comfortable and have impressive technical performance and a natural timbre. They are worth trying if you like bass and want to listen to music on the go or while you sleep.
Video review
Our take on the brand
FATfreq is a hifi audio brand best known for headphones that using Basscannon technology that delivers extreme sub-bass levels (20-30 dB below 200-250 Hz) without midrange bleed, along with NOAH swappable bass-chamber modules that let users tune sub-bass power versus control while reducing ear fatigue.
Product Page
Product Page
FATfreq
Reference Pro Universals
417
/
Released
2023
Reference Pro offers textbook, reference-grade detail, and separation via three precision-tuned balanced armature drivers for the accuracy demanded while monitoring and mixing. The perfect tool for producers and singer-instrumentalists seeking to bring their mixes to the next level.
FATfreq is a hifi audio brand best known for headphones that using Basscannon technology that delivers extreme sub-bass levels (20-30 dB below 200-250 Hz) without midrange bleed, along with NOAH swappable bass-chamber modules that let users tune sub-bass power versus control while reducing ear fatigue.
Expand Details
Our Summary
Video review
Our take on the brand
FATfreq is a hifi audio brand best known for headphones that using Basscannon technology that delivers extreme sub-bass levels (20-30 dB below 200-250 Hz) without midrange bleed, along with NOAH swappable bass-chamber modules that let users tune sub-bass power versus control while reducing ear fatigue.
Product Page
Product Page
FATfreq
Musician Plus Custom IEM
417
/
Released
2021
The classic 'V' shape response with best-in-class bass control. The Musician Plus is ideal for emerging performers seeking a lush, full-bodied monitor at an affordable price. Having a dedicated woofer and tweeter combination allows for the separation of the high and low frequencies.
FATfreq is a hifi audio brand best known for headphones that using Basscannon technology that delivers extreme sub-bass levels (20-30 dB below 200-250 Hz) without midrange bleed, along with NOAH swappable bass-chamber modules that let users tune sub-bass power versus control while reducing ear fatigue.
Expand Details
Our Summary
Video review
Our take on the brand
FATfreq is a hifi audio brand best known for headphones that using Basscannon technology that delivers extreme sub-bass levels (20-30 dB below 200-250 Hz) without midrange bleed, along with NOAH swappable bass-chamber modules that let users tune sub-bass power versus control while reducing ear fatigue.
Product Page
Product Page
FATfreq
Musician Plus Universals
250
/
Released
2023
The Musician Plus is ideal for emerging performers seeking a lush, full-bodied monitor at an affordable price. Having a dedicated woofer and tweeter combination allows for the separation of the high and low frequencies.
FATfreq is a hifi audio brand best known for headphones that using Basscannon technology that delivers extreme sub-bass levels (20-30 dB below 200-250 Hz) without midrange bleed, along with NOAH swappable bass-chamber modules that let users tune sub-bass power versus control while reducing ear fatigue.
Expand Details
Our Summary
Video review
Our take on the brand
FATfreq is a hifi audio brand best known for headphones that using Basscannon technology that delivers extreme sub-bass levels (20-30 dB below 200-250 Hz) without midrange bleed, along with NOAH swappable bass-chamber modules that let users tune sub-bass power versus control while reducing ear fatigue.
Product Page
Product Page
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