The AKG K371 is one of my favorite headphones. It was one of the best headphones I reviewed in 2019. Its sound signature sticks closely to the Harman acoustic target, the result of a multi-year scientific study to make headphones sound exceptional. To this day, it’s one of the best-performing headphones on the market in terms of sound reproduction at any price.
I’ve been excited for the Bluetooth version since its announcement, but I’m rather late reviewing it because of…everything that’s happened in the last year. This isn’t the first notable attempt at a Bluetooth version of a classic studio headphone; that distinction belongs to the M50XBT. However, there’s still plenty of room for the iconic sound of studio pairs in the wireless headphone world, and I had high hopes that AKG would deliver. After all, the industrial design of the K361 and K371 already looked like it was secretly made for a Bluetooth headphone when compared to other popular models.
The K371-BT keeps essentially everything that makes the original version great, but then throws in many puzzling changes and tweaks that feel like they came from a different design team.
I bought the pair reviewed here with my own money. None of the links in this piece are affiliate links, as I don’t think those have any place in reviews.
At a price of $179 (official site here), the K371-BT comes in at just thirty dollars more than its wired cousin. That’s a great way to start, as the market standard “Bluetooth Tax” is usually $50-$100. In the box, you get the headphones, a nice carrying bag, a 6.3mm adapter, and three aux cables with a 4-pin mini-XLR plug on one end and a threaded 3.5mm connector on the other. Both a 1.2m straight and coiled cable are included, alongside a 3m straight cable. Rounding out the package is a micro-USB charging cable, which feels like a lost relic from the past considering how ubiquitous USB-C now is.
If you click through to that official page above and scroll around, you may notice that there’s a quote from my original K371 review shown in one of the image carousels. I received no compensation for this quote, and in fact, AKG didn’t even reach out to let me know that they were going to use it. I discovered I was quoted there while doing research for this review. It’s a little strange that they would quote my review of the wired version on the page for the wireless pair.
Anyway, the package of included extras mimics the set included with the wired version, and this is great. The M50XBT is the closest competitor to this pair, and it comes with fewer cables than its wired counterpart, and a fifty dollar standard price premium.
With the marketing promise that the K371BT’s titanium-coated drivers are tuned to the same Harman target as the wired version, a 40 hour rated battery life, and such a small upcharge, the Bluetooth model should be the obvious choice right?
Not so fast.
The K371-BT is indeed tuned to the same awesome sound signature as the wired model, and it sounds mostly the same…when used in wired mode. It has a smooth and punchy bass response that’s accurate to the source, a beautiful midrange, clean fatigue-free treble, and impressive imaging and soundstage for a closed pair.
In Bluetooth mode, things take a small step backwards, by about ten percent or so. The overall sound is a touch more muddy and warm, and the highs are a little less clean. It’s not a huge difference. There’s not a dramatic amount of EQ going on or anything. But it’s a noticeable difference if you listen back-to-back.
They sound a bit better than the M50XBT, and very similar to the $199 Razer Opus. If you forced me to pick between the wired and wireless K371 models, I’d pick the wired version for raw sound quality…and for a number of other reasons, too.
This is where things start to come crashing down for the K371-BT, and where I start to die a little inside because these problems are so silly.
The ear cups on the 371-BT are about five millimeters thicker than those on the wired model. You can see this obvious extra thickness by looking at the flat part of the frame just beyond where the pad attaches to the cup. Presumably, this extra thickness helps the 371-BT contain its Bluetooth antenna, amplifier, USB port, and impressive battery.
No attempt was made to tweak the profile of the headband to account for this extra thickness. Instead, the engineers at AKG just shaved a few millimeters off the thickness of the ear pad foam. The result is a headphone that fits more or less the same on my head as the wired model…but has less room inside the ear pads for my ears.
I understand these were probably made with a design goal to re-use as many parts from the wired model as possible, but this is a baffling change and it nearly ruins the headphones. The K371-BT has a strong clamping force just like its wired cousin. This means that for the first several days of wear, the hard back plate inside the ear cups squished into my ears.
This was borderline intolerable, causing notable pain in my ears after about an hour of use. After a few days, the clamp did loosen, and now I can wear them for longer sessions…but the back of the ear cup is still a constant presence upon the back edge of my ear. The padding itself is still a nice memory foam that seals decently around my glasses, but getting a comfy fit requires a lot of careful fiddling with its position to try and minimize the pressure on the back of my ear while still keeping a good seal.
I don’t have this problem with the wired version. The pads are thick enough that it was comfy from day one, and remained so over time. Further, the BT version is also heavier than the wired model due to the battery and Bluetooth components. AKG did seemingly slightly thicken the headband padding to compensate for this, meaning I now wear these with three extra clicks of adjustment instead of four on the wired pair.
I’m baffled that these thinner ear pads got through any sort of testing. I wish that AKG had found a way to re-use the original pads, or sprung for a slightly wider headband to compensate for the wider cups. Sacrificing ear space was the worst way to handle this, in my opinion.
Aside from the thicker ear cups and thinner pads, the build is mostly identical to the wired K371. It uses the same style-headphone-inspired visual design, with thin contours and basic branding. The leatherette material across the top of the headband is much softer to the touch than the wired version, which is an unnecessary extra coupled with a materials cost that I wish had been devoted to pad foam instead.
The metal ear cup supports still feel fine, and the same ratcheted hinge system is back as well. The adjustment sliders on my pair are stiffer than my wired version, which is good because that seems like an easy point of failure. The matte finish of the ear cups seems prone to scratches and dust, and the headband pad still also picks up hair and dust the moment you look at it.
Some folks have had build issues with this headphone family. Notably, Youtuber Wheezy Reviews went through five wired pairs to get a good one. Then, he managed to get a K371-BT with a busted driver. Both those videos are worth watching if you want a different perspective on these, and while I’m relieved that I haven’t personally had those issues, it’s probably good to buy these from a place with a return policy if you decide to go for it.
The same baffling spirit that led to thinner pads returns in many of the new aspects of the design for this wireless model. The mini XLR port for wired connections is a 4-pin variant, as opposed to the 3-pin port on the wired version. This serves no real purpose other than making the two sets of cables incompatible and irritating me. With no apparent support for balanced audio, there’s zero reason for the K371-BT to use a 4-pin XLR jack. Were they just trying to frustrate users who also owned the wired version? Did they discover a bunch of 4-pin ports in a warehouse and want to blow through them? I don’t understand this.
From the same bin of questionable design comes everyone’s “favorite” feature: touch controls. The AKG logo on the back of the left ear cup is a touch pad. You can swipe up and down for volume, left and right for track selection, and double-tap to play and pause. These work right about 90 percent of the time, and are just laggy enough to feel unsatisfying. The only other control is a power switch that also auto- activates Bluetooth pairing. There’s no way to force it to disconnect from your current device on the headphone side, and no support for multiple device connections. If you have Bluetooth mode on and plug in an aux cable, the headphones power off.
On the plus side, the inclusion of Bluetooth 5 means these have an impressive wireless range. I can walk forty feet away with multiple walls between myself and my device and the connection stays stable. That’s an impressive feat in my apartment, considering it’s full of wireless interference.
Battery life is also excellent, and the forty hour rating seems right in my tests, listening at around 55 percent volume. Recharging takes a few hours over micro USB, which is enough time for you to wonder why this pair of headphones uses micro USB.
As in the above categories, it all falls down a bit on closer inspection. The Bluetooth connection only supports SBC and AAC codecs, which would be fine if these were better tuned in wireless mode. The M50XBT offers AptX support, which provides higher quality audio and better latency.
The included microphone is a little too quiet and thin-sounding to be useful outside of a quiet room. I had to talk at a loud almost-shouty volume for someone on the other end of a phone call to hear me comfortably. There’s no way to adjust mic volume or sensitivity. The AKG K371-BT has no app support of any kind on mobile devices, so there’s no EQ adjustments or easy access to future firmware updates. Those are increasingly standard in Bluetooth headphones from numerous other companies.
The AKG K371-BT takes the same beautiful-sounding speaker drivers from the original wired pair and surrounds them with a slightly worse headphone that fails to live up to modern standards for features and comfort. It has thinner pads, iffy touch controls, basic Bluetooth support, no app, and an uncommon 4-pin XLR connector jack for no reason at all.
I still love how they sound, and I don’t hate wearing them after they stretched out, but I can’t think of a single reason to recommend them over the wired edition, even with the small and fair price premium. They’re a little bit worse-sounding and worse-feeling to wear, and they cost more. Is Bluetooth support worth these changes? No.
The M50XBT offers a more time-tested fit and a frame that has a wide variety of aftermarket pads available, alongside better Bluetooth features and a more common cable connection. The Razer Opus offers similar sound performance, nice noise cancelling, and a much comfier fit out of the box for just twenty dollars more.
The AKG K371-BT proves just how important every small aspect of a headphone’s design is, and why it’s not always enough to have peerless audio quality. If AKG ever takes a crack at updating it, I’ll be there day one. Their core sound signature is still probably my personal favorite I’ve heard in headphones of any price, and that shines through as a proud achievement even in these disappointing headphones.