I take no pleasure in relaying negative experiences with ambitious products like theKIWI Design K4 Duo. The stagnant Meta Quest 3/3S strap market needs to see innovations like the Duo’s built-in headphones, but that same feature has multiple fatal flaws that counteract its positive qualities.
KIWI Design K4 Duo AIO Audio Head Strap With Battery
A Meta Quest 3 and 3S head strap with a cushioned overhead strap and headrest, a battery to charge the headset, and headphones attached to its hinges.
Specifications
The KIWI Design K4 Duo AIO Audio Head Strap with Battery retails for $160. It doesn’t come with a USB-C cable or power adapter to charge its internal battery pack, so you’ll need to supply your own.
The K4 Design Is Great
The K4 Duo is quite literally aK4 Boostwith on-ear headphones attached to it. The K4 line has proven to be a fan-favorite elite-style strap design that perfectly balances comfort and affordability, and at least when it comes to that former quality, the K4 Duo continues this lineage.
Its detachable memory foam headrest and Velcro overhead strap are lined with soft cushioning, aiding the K4 Duo’s overall lightness in reducing pressure. It’s easy to find a proper fit thanks to the smooth and granular size adjustment dial behind the headrest, as well as a hinge system that helps ensure the strap is properly situated on your head. An added plus of this hinge design is that it lets you easily lift the Meta Quest 3 without removing the entire headset.
Given its sheer comfort, I find the K4 straps to be among the easiest to lock my face into with enough force that the headset doesn’t jostle during gameplay. The reason to get an elite-style strap is the image stability that comes with clamping the headset to your face, and the K4 design shines by significantly reducing the ensuing pressure. This remained true across multiple facial interfaces I tested alongside the K4 Duo.
If there’s one aspect of the K4 Duo’s strap design that’s underwhelming, it’s the somewhat flimsy plastic. It didn’t impact the usability of the product, but given that the Duo doesn’t reside in the same budget price range as its siblings, I would’ve expected a bump in material quality.
Headphone Hinges Are the K4 Duo’s Fatal Flaw
All this praise makes the K4 Duo seem like an easy recommendation, but unfortunately, the implementation of the headphones completely undercuts it. This largely boils down to how their hinges work. They snap between two positions: splayed outward and tucked entirely inward. There’s constant pressure placed on your ears due to how hard they clamp down, resulting in physical discomfort and regular nausea.
I have pretty reliable VR legs for most games, yet this pressure on my ears caused even simple games that require no physical or camera movement to trigger motion sickness. I used my usual techniques to assuage this, such as blasting myself with a floor fan and staying seated whenever possible, but even with these countermeasures I was left feeling unwell after only short periods of play. Longer sessions required regular breaks that intruded on the medium’s trademark immersion.
Often, I would switch back to the Meta Quest 3’s built-in speakers, something made convenient by a switch on the strap that swaps between outputs. However, the pressure on my ears was great enough that I could still feel it—and the rub of the padding’s rough texture—for some time after lifting the headphones. Playing with the headphones positioned away from my ears wasn’t a suitable alternative either, as they can easily snap back down with enough force to cause actual pain. This also occurred when lining the headphones flush with the strap as suggested by KIWI.
Ultimately, if you aren’t using the K4 Duo’s headphones, then there is no reason to be shelling out more than twice the cost of the $70 K4 Boost for them. While it’s possible some people may be able to better handle the pressure, it was such a deal-breaker for me that it negated the otherwise positive qualities of the strap. It’s unfortunate as more adjustable hinges could’ve circumvented this issue entirely.
Respectable Audio Quality
Design issues aside, the headphones sound pretty good for what they are.
The headphones provide a notably different sound profile than the headset’s built-in speakers, most characterized by its soft but thumping bass. Expect lush lows and clear mids, but tinny highs. It’s virtually the complete opposite of the speakers’ profile, which doesn’t have the same richness of bass but offers a little more range.
There are better headphones for the $90 price gap between the K4 Boost and K4 Duo, so you’re paying for the novelty of having them attached to the headset. This would be a reasonable consideration if not for the issue-riddled hinges. As it is, though, I’d recommend pairing your own headphones with a no-frills strap, regardless of whether sound quality is a concern.
The Battery Pack Underwhelms
The Meta Quest 3 is notorious for its poor battery life. This is why straps with pre-installed or hot-swappable battery packs have become the number one must-have accessory for the headset.
However, with arated (usable) capacityof 3000 mAh and an inefficient charging speed that can’t keep up with the Meta Quest 3’s battery consumption, the K4 Duo doesn’t provide enough extra juice, especially given the price. KIWI touts roughly 2.5 hours of extended battery life, but in my experience, it was more like 1.5 hours.
While other battery straps have similar struggles, what makes it a particular issue with the K4 Duo is that the headphones also require the USB-C port. This means that if you plan to supplement the strap’s battery with anexternal option, you’re also losing access to the headphones in the process. Even for people who find the fit of the headphones more tenable than I did, this may be a deal-breaker. If KIWI were to revise this model, I’d love to see the addition of Bluetooth connectivity for the headphones.
Should You Buy the Design K4 Duo?
TheKIWI Design K4 Duois a cool concept with a clumsy execution that makes it impossible to recommend, even before factoring in the $160 price tag. I hope that KIWI can go back to the drawing board on this one as it embodies an innovative spirit that the VR strap market needs more of.
What I can easily recommend is theK4 Boost($70). This strap ditches the headphones, allowing the comfortable fit of the strap to shine through. If you want to shed the unimpressive battery as well, thestandard K4($40) is arguably the best value-for-money elite strap on the market.
