FATfreq X HBB - Deuce

After spending 4 solid months with the Deuce, I can confidently say it’s been nothing short of spectacular. For those hunting for a basshead IEM that punches well above its price bracket and challenges sets twice its cost, the Deuce demands attention. It’s only fair I give it the in-depth review it deserves for anyone on the fence or simply curious -

1. Noise Cancellation
The passive noise isolation is surprisingly good, thanks to the stock tips. But this might vary depending on how they fit your ears. For me, I prefer the smallest tips for a snug fit.

2. Tips
The stock tips are comfortable, but I find foam tips more suitable for long sessions. I currently use the Symbio W (Silicone + Memory Foam) and Galaxy Buds Pro foam tips. I recently ordered the Sony EP-TC 50 (fingers crossed they fit, as they’re wide-bore).

With the stock tips, I managed 6–8 hours of use with 5 hours of ideal listening and 2-3 hours of listening while working out. They tend to get uncomfortable while working out especially during cardio sessions.

Foam tips lock in better for me and feel significantly more comfortable during extended use (though this is subjective).

3. Build Quality
Here’s where the Deuce really shines:

The blood-red cables? Gorgeous. They’re a bit on the heavy side, but damn, they look good.

The shell design is sleek, with a black finish and marble-like grey accents. Super smooth, smudge-proof, and just classy.

Universal fit feels comfortable and doesn’t stick out as much as I thought it would.

The cables are a pain to remove, though. I’m thinking of grabbing the Yongse Venom cables, but honestly, the stock red ones are sick!

The casing that comes with the Deuce is super fine, but it’s hella small. They fit, sure, but I really wish it were bigger...

4. Sound Quality
Now for the main event:

Soundstage: Just wide enough to hit that sweet spot—not too narrow, not too wide. Just wide enough to catch those subtle front-left, front-right as well as the center details.

Treble: Silky smooth warm analogue goodness. You can still hear every bit of raspiness, even in hip-hop tracks

Bass/Sub-bass: Classic FATFreq signature. It’s deep, thumpy, and perfectly balanced with the treble. No mids bleed, which is a huge plus. These need power to shine. Plugging straight into your phone or desktop won’t do them justice, even with the bass adapter. Pair them with a good DAC/Amp, and you’ll feel that spine-tingling “thrrr” rumble.

Pro tip: The bass adapter is fun, but sometimes it’s too much. Even with it, the treble holds its own (shoutout to HBB’s tuning).

5. Tuning/EQ
Now generally the Deuce, really doesnt require Eq-ing atleast for the purpose I have purchased it for:

For indie pop and rock, I made minor adjustments to the mids especially the upper

For genres like drum and bass, EDM, and hip-hop, the Deuce doesn’t need any EQ tweaking.

I personally like the PEQ tuning by Ducbloke, which improved high frequencies and midrange.

I used the Deuce with BTR15, and wow, it makes a huge difference in sound quality delivering the power that it needs. For EQ, I use Nahimic, SteelSeries Sonar, and APO Equalizer….each one is great for specific use cases.

Nahimic and Sonar: Perfect for gaming/calls/discord.

APO: Unbeatable for music.

I also tested Wavelet on my OnePlus 7T Pro. Wish iPhone had a proper EQ which is why I’m seriously considering getting the Qudelix 5K.

Conclusion:

I’m so glad I picked these up based on HBB’s recommendation and looking forward to more of his collabs and already considering the Punch. All-in-all, The Deuce has been an absolute banger!!

I was genuinely excited about these IEMs, mainly for their reputation of delivering deep, powerful bass and in that department, they absolutely lived up to the hype. Paired with my iBasso Jr. and PowerDAC V2.1, the bass is thick, immersive, and incredibly satisfying. If you're someone who craves low-end punch, these are a solid choice. That said, if you're chasing a balanced or neutral sound signature, you might want to look elsewhere.

However, my initial experience wasn’t smooth. Within a week of using them, I started facing a frustrating issue, the right earphone would cut out with even the slightest head movement. At first, I ignored it, since I was using them in short bursts. But in a noisy workspace, where I depended on them for hours, it became unbearable. I found myself sitting absolutely still just to keep the sound going. For a pair of ₹25,000 IEMs, that kind of problem is a dealbreaker.

Thankfully, the customer service from Headphone Zone was outstanding. They promptly responded, asking me to send the faulty unit back. I kept delaying the return, but they patiently followed up with polite reminders. Eventually, I sent them in. A week after confirming they received the IEMs, they diagnosed the issue, acknowledged the defect, and shipped me a replacement, which reached me within three days. So, within 12 days from my first response, I had a brand-new pair.

I've now been using the replacement set for over a week, and I can confidently say the issue was a one-off. These IEMs are truly fantastic. The bass has body and presence, though let me set realistic expectations: no IEM or headphone can replicate the full-body bass you feel at a live show or in a car with a subwoofer. If you're expecting that, you'll be disappointed. But if you understand the limits of portable audio, this is easily one of the best you can get under ₹30K–₹50K.

Lastly, big shoutout to Headphone Zone for their customer service—they made the whole process smooth and stress-free. If it weren’t for their reminders, I might’ve completely forgotten to return the faulty pair.

Final Verdict:
Sound: 9/10 (especially for bass lovers)
Build Quality: 7/10 (considering the first unit had issues)
Customer Service: 10/10
Value for Money: 8.5/10

For me, it's not a bass head IEM instead it is more to enjoy a neutral music and sub-bass like theater effect. Almost perfect IEM to listen to it.

The sub-bass is good and gets even better with the additional amp boost included in the package. For the price its good although a little on the high side, got it during the sale so cant complain. It lacks mid-bass, if you use an EQ and push the mid-bass, you will get some amount but since they are not made for mid-bass, after certain level of increase which comes very early it just sounds boomy and muddles into the vocals.
Treble if good and does not need any EQ tuning, sometimes for certain songs and genres you might need to EQ the treble down if you listen on high volumes.
Finally, thanks to HZ team for making this available during the sale.

I was so skeptical about prebooking it. But i am really glad i made the right decision. Its light on the ears and it looks just sick. 4 stars for the product,But the package could have been way better considering the money you spent on it.

Earlier this year, I noticed a lot of hype surrounding the FatFreq x HBB Deuce. Initially, I wasn’t keen on it, as I’m not a basshead, and my music library and genre preferences are quite different from those of its chief promoter, HBB. I didn’t feel any regret about missing the pre-booking window.
However, just before the IEMs started shipping, they suddenly became available again on Headphone Zone. It felt like a godsend opportunity to try this overhyped IEM, so I took a leap of faith.
Thanks to the excellent service from Headphone Zone, I received the IEM within just a couple of days.
After trying this IEM for a few months now, here’s my take:
Reiterating upfront: I’m not a basshead.
Pros:
1. Build:
Wonderfully crafted and extremely beautiful. While it’s slightly gaudy, it’s not an issue if used at home or outdoors.
2. Cable:
No complaints, but nothing extraordinary either. It complements the aesthetics well.
3. Tips:
A pleasant surprise. The IEM came with TRI Clarion tips, which I hadn’t experienced before since they’re not widely available online in India. With my extensive eartip collection, these wide-bore tips stood out due to their unique shape and excellent seal.
4. Impedance Adapter:
Another great inclusion. I had never used one before, and its ability to boost bass is useful not only with the Deuce but also with my other IEMs. It has significantly improved the performance of many planar IEMs in my collection.
5. Bass:
Yes, it delivers bass—and cleanly at that. It doesn’t interfere with the mids and offers a glimpse into basshead sound.
Cons:
1. Bass:
While it’s abundant, the bass feels “pillowy.” It’s focused entirely in the sub-bass region, with a noticeable lack of mid-bass slam, leaving a sense that something is missing.
2. Treble:
There isn’t much treble presence, and what’s there is of poor quality with limited technicality.
Conclusion:
The conclusion is obvious: if there’s more to write about the build and accessories than the sound, it’s not a good sign. Perhaps this IEM is simply too niche for my preferences. Sound-wise, despite supporting it with best of DACs and ample power, even AirPods (even with BT with ACC codec) feel a few notches more balanced and better.

The Deuce reminds me of the Bose Triport In-Ear (discontinued over a decade ago), which had everything except good tuning and technical prowess. Collector's item, but of not much use.

My only consolation is that I now own a so-called basshead IEM in my collection.

I was excited about these IEMs, especially for their deep, powerful bass, and they delivered exceptionally well with my iBasso Jr. and PowerDAC V2.1. If you love bass, this is a solid choice. But if you prefer a balanced sound, you might want to skip these.

However, after a week, I noticed a major issue—the right earphone stops working with even slight head movements. I first ignored it since I used them for short sessions, but in a noisy workspace, where I relied on them for longer durations, it became unbearable. I had to keep my head in the same position to hear properly, which is simply unacceptable.

For a ₹2,000 IEM, I’d let it slide, but at ₹25,000, this is a dealbreaker.

2/5 – Amazing bass, but unreliable and frustrating to use.