Hear your music come alive with the 64Audio U4s - a quad-driver hybrid IEM designed and tuned to deliver a fun, engaging, and exciting sound for audio lovers looking for the best sound enjoyment.
Everything you need is included with the 64Audio U4s IEMs!
The U4s is packed with proprietary 64Audio technologies:
The 64Audio U4s delivers a cohesive musical sound that's nothing short of exemplary.
Driving the low frequencies is a dynamic driver for unmatched bass tone and punch. Midrange is handled by a pair of Balanced Armature drivers tuned to deliver exceptional vocal and instrument clarity, while the highest frequencies are handled by 64Audio's tia high driver for unbelievable air and sparkle.
Whether you're listening to Pop, Rock, or Electronic music, the 64Audio U4s will reproduce your favorite tunes with renewed clarity and energy.
One look at the U4s and you already know you're getting a well-built shell in a shape that you can wear for hours without fatigue.
The 64Audio U4s features 64 Audio's industrial half-moon shell design that's specially designed to provide a comfortable fit no matter your ear type.
Exclusive to the U4s is the Slate Blue paint inspired by blue-dial watch faces. Meanwhile, the unique faceplate design takes inspiration from Muonionalusta meteorite fragments for that strikingly unique look.
Traditional acoustic dampers produce vibrations that can introduce unwanted distortion - you won't have to worry about that with the U4s.
The 64Audio U4s uses a Electrical Low-Pass Filter, eliminating distortion before they ever reach the drivers.
Enjoy distortion-free sound and hear your music the way the artist intended with the 64 Audio U4s.
The 64Audio U4s is built around two of 64Audio's tia systems - tia driver and tia open-bore.
Both systems are designed to help the U4s deliver extended highs while eliminating distortion for a truly high-resolution listening experience.
64Audio's Air Pressure Exchange technology (Apex) protects your ears from dangerous in-ear pressures by venting out extra air, while also extending the soundstage for a comfortable and immersive sound.
The U4s comes with three Apex Modules out of the box - the mX, m15, and m20. You can swap these out anytime to tune the U4s to your preferred pressure relief and sound.
Hybrid in-ear monitors like the 64Audio U4s employ various driver types, each possessing unique electrical resistance characteristics. The differences in resistances translates to uneven sound when listening to various sources.
Like most 64Audio IEMs, the U4s comes with Linear Impedance Design or LID - a patented circuity that corrects uneven electrical resistances between the dynamic driver, BA driver, and tia driver inside the U4s.
The result is ultra-consistent sound reproduction no matter the source, so you can enjoy your music the way the artist intended.
Included with your purchase is 64Audio's premium black cable - soft to the touch and capable of carrying every bit of information to your IEMs.
The U4s offers wide frequency coverage, starting at 10hz and extending to 20kHz - allowing for a wide range of frequencies to be reproduced precisely.
U4s:
4 Drivers
10hz – 20kHz Frequency Response
11Ω Impedance @1kHz
Integrated 4-way Passive Crossover
U12t:
12 Drivers
10hz – 20kHz Frequency Response
12.6 +1/-2 Ω Impedance from 10hz – 20kHz
Integrated 4-way Passive Crossover
Our Analysis:
The 64Audio U4s is one of the most affordable 64 Audio in-ear monitors you can get. At just $1,099, the U4s offers energetic sound with wonderful details very few IEMs in the same price bracket can match.
| Specification | Description |
| Driver Configuration: | 1 tia High Driver – 1 High-Mid Driver – 1 Mid Driver – 1 Dynamic Low Driver |
| Frequency Response: | 10hz – 20kHz |
| Sensitivity: | 107 dB/mW Sensitivity @1kHz |
| Crossover: | Integrated 4-way Passive Crossover |
| Impedance: | 11Ω Impedance @1kHz |
| Apex Technology Isolation: | Apex Technology Isolation: -20dB, -15dB, -10dB |
Shipping is FREE on all orders to customers within the USA.
We don't want to mess around with fine print and extra charges. We like things to be simple and easy.
Here's how shipping works around here:
We get it. Audio gear can be subjective. That's why we offer our industry-leading 365 day return policy. Here's a quick rundown;
We get it. You've got a lot of choice when it comes to online retailers. Here's why we think you should shop with us at HiFiSoundGear.
Amazing customer service. Adam went into great detail with his experience on these IEMs. Would definitely go to him again!
Good communication throughout the process with fast shipping.
It's such a pleasure doing business with Adam and Lauren that I am honestly looking for an excuse to buy more equipment there. I don't really have a good personal audio store anywhere around; and while I am not exactly morally opposed to Amazon or whatever, it's so much nicer dealing with real people and a small business. I cannot even imagine what else I could ask for.
Great work, to communicate every step along the way. Very personal touch. I will visit the office one day to personally thank them. I love the website. I love the product. I love the state where they are located. Awesome awesome awesome!
Everything went really smoothly and I'm enjoying the headset I purchased. It shipped quickly and arrived well packaged. I had a question about my purchase and received a quick response from the seller. I would buy from HiFiSoundGear again.
Unexpected as in very pleasantly surprised at the sound quality coming out of these :)
I took my Mega5-EST and hooked em up wirelessly and don't miss the wire sound AT ALL!! IMO the wireless sound was 98% of the wired sound without the PIA of the wire. Unless you have some amazing source gear, which thanks to Adam at hifisoundgear I do, you would be hard pressed to hear a massive difference. Especially with a phone as your source.
I did A/B noble Fokus Prestige vs Go pod w Mega 5 and gotta say l, there is more balanced sound with the Go pod chain then the Prestige on its own. To be fair the Mega 5 punches WAY above its price... so the 2 are a match made in heaven.
I find the connection very stable as well. I've used my iPhone AAC/SBC as well as with FiiO BT11 to get other than Apple codecs and was pleasantly surprised as well.
The ear hooks are very comfortable. Actually prefer them to the wire hanging over my ear with a tie behind my neck. For some reason that's hard to get used to and pulls as I wear loose shirts. The hooks stay in as I like to move around a bit. Also the weight is better distributed than other wireless IEMs as the components are in the hooks. The prestige, unless I have foam tips, which I'm not a fan of, will pop out of my ears when I move around. These stay stable and I do not have to re-seat the IEMs to get that great bass nearly as often with other wireless IEMs.
Battery level has been all day 10 hrs so far with intermittent breaks and still have 28% left.
The case also is deep enough to fit the Mega w hooks as it charges which is very convenient. Some IEMs may be too big but they fit with a tad bit of room to spare.
Of course having the flexibility to swap out your favorite IEMs as needed is awesome!!
5 stars for the Go pod and more importantly 5 stars to Adam and his team for such amazingly awesome customer service!! You guys ROCK!! Thanks :)
The iFi Audio iDSD Diablo 2 is an absolute masterpiece in the world of portable amps. It delivers an audio experience that redefines what’s possible in a compact, travel-friendly device.
To all the "haters" out there who mention that the 5180mw output is an overstatement and the "balanced" is not a true balanced output... I say whatever... it drives anything I throw at it with aplomb! FostexTH900mk2, ZMF Caldera Open and Closed, ANY IEM my friends and I have tried ...too many to list. If you need more power than this portable titan.... well you may have hearing loss. And it drives all I mentioned without using "beast mode" (they refer to it as Nitro (1 of 3 settings)). If anything, it could use a lower gain option / IEM match for some sensitive IEMs.
The implementation of BT 5.4 (supports all codecs) is a welcomed addition for quality, but in general, the distance it can be from the source is very small for consistency. That is not a Diablo issue, but a BT5.4 issue IMO.
As for the sound quality...simply unparalleled. I have compared this to desktop headphone amps in the same price range and I would put it toe to toe with them. It even ran close to my buddy's Burson Soloist 3x!!! and the Diablo 2 is portable :)
I run it using A&K SP3000T and it oozes warmth and richness in the lows and highs WITHOUT covering/smoothing anything up in the mids, which is my jam.
It is on the heavier side and will still fit in a pocket... barely. built like a brick. At the limit of what I would like to carry but totally worth it! I get about 6 hours of the 8 rated battery with constant listening, no Bluetooth on, hard wired, IEMs / Caldera tested on the battery life.
In conclusion, the iFi Audio iDSD Diablo 2 is nothing short of extraordinary. It’s the ultimate portable amp for those who refuse to compromise on sound quality, power, or versatility. If you’re serious about your audio and want the best experience on the go, the Diablo 2 is the perfect choice.
Shout out to Adam, a massive THANK YOU!!! for your absolutely OVER THE TOP customer service and shopping experience :) :) Seriously, your dedication and attention to detail have been nothing short of exceptional.
With all the online ordering over the years, HifiSoundGear provides the best service I have encountered. It was as though they were good friends. They responded so nicely to all my questions about the product and shipment. As it works out, while I liked the IEM's, I concluded they were not sufficiently different from the ones i had been using. Again, for the process of returning and getting a refund, they could not have been nicer. Buying from them was a first rate experience.
Recently had a great experience with Adam and Laura. I requested a price match for the FiR KR5 and it was such a painless process. Adam and Laura’s communication is top notch! Adam even sent me a personal thank you video. In my experience, this level of service is hard to come by these days. I highly recommend going through HifiSoundgear for your audio needs….I know I will be going forward! Thanks Adam and Laura!
The quality of service, level of help provided, and overall customer satisfaction is beyond anything I have experienced. I cannot say enough good things about the people who belong to this company!
As for the U4S, these are my first foray into 64 Audio but I am SO thankful that I got to experience them! My goodness the soundstage, bass response from the m15 module, and overall quality is just great!
Please, buy from these wonderful people! And if you can swing it, get a set of U4S! You will not regret it!
Only complaint is the cable. For the price, I expected better, but it works well and is just fine.
Thank you HiFi Sound Gear! I look forward to purchasing more from you in the future!
These are the closest TWS gets to pure IEM listening. You get the wide soundstage. They scale quickly. They have that satisfying bass slam often missing in TWS. The layering is just right and resolution is mesmerizing. Oh yes, you get the convenience of taking them on the go and they are truly comfortable. Noble has achieved a superior status in my eyes with the FoKus Prestige. I look forward to listening to them on my walks when I don’t have to take my DAP. Adam is one of the greats in this business. His commitment to customer service is exceptional. You aren’t a customer, but a client. He helped me after losing my first pair and just went above and beyond to ensure that I was shipped a new pair in less than two days. I am completely satisfied and impressed. You will be too. Thank you and looking forward to my future purchases from your establishment.
HifiSoundGear offers exceptional quality products and unparalleled customer service. Their wide selection of high-end audio gear, including in-ear monitors and amplifiers, are praised for delivering outstanding sound clarity, detail, and an immersive listening...
