I have had them for a month and I am very satisfied. The sound of these headphones is neutral, without coloring the mids and highs. However, the bass is definitely somewhat emphasized. This suits some songs in my opinion, but not so much others. I think this is reasonable. But I like it because they always deliver a full sound even at low volumes.

But how do they perform at high volumes? THEY ARE AMAZING. They can play really loud without any distortion anywhere. They are made for very loud listening without any issues. The driver really kicks hard and there is no distortion. And the sound is always full. I am sure there is nothing similar in this price range. It is obvious to me that AKG has released a headphone that competes comfortably with more expensive ones.

I also have the DT990 Pro 250ohm in the same price range and they are not like this. Okay, the sound can be nice but that is subjective. I understood that they are for relaxed listening, but after a certain point they will distort, and that is objectively clear. AKG headphones are not like that.

Finally, good construction with iron and leather, minimalist design. Comfortable with good sound isolation. They are mainly driven by the Fiio K5 Pro ESS, and sometimes I use them with the Fiio Q11 for portable use.

I would definitely buy them again. Especially at this price, there is definitely nothing like it.

Absolutely satisfied with my purchase.
I don't have much experience with headphones, but lately I will be working and using headphones, one open and one closed.

For the closed back, I chose these knowing that they are not flat and have bass, but they have very good build quality, isolate sound, are very comfortable for me, and the pads are amazing. They fold, come with 3 cables, have a 32ohm impedance that is easily driven with satisfactory volume and quality even from the ps5 controller or mobile phone. These characteristics make them a perfect choice for everyday use.

For studio use, they are very good for recording as even when playing music at high volume, there is no bleed into the microphone. I wear them literally all day and they don't tire me. For mixing, they provide detail, and I consider the soundstage and imaging to be okay for closed back. Also, maybe their sound is not flat, but personally I think they are suitable for semi-professional use.

In general, I use them all day and they play with volume wherever you connect them. However, they work flawlessly with the minifuse sound card and with an old Marantz SR4500 amplifier

What can one say about these headphones. I really couldn't believe that you could find such sound, comfort, especially in closed back, at such a price. To explain, I come from hd555, hd650, lcd2 classic, m50x, fidelio x2hr, and iems fiio fh3, fh1s.

COMFORT: The most comfortable thing I have ever worn on my head, simply put, you can wear them for hours, super lightweight. Comfort ranking k371>hd555>hd650=m50x>lcd2 classic>fidelio x2hr

BUILD: Decent. lcd2 classic>hd650>fidelio x2hr>k371>m50x>hd555

BASS: Tremendous bass, specifically sub-bass that easily reaches 20Hz and is slightly more boosted than the Harman target. The mid-bass doesn't bleed into the mids. Of course, it doesn't reach the texture of the lcd2 classic, but it definitely satisfies. lcd2 classic>k371>fidelio x2hr=m50x (bleed into the mids)>hd650 (no sub-bass)>hd555 (Bass? What is that?)

MIDS: Good mids, they are a bit grainy on some tracks. hd650>k371>lcd2 classic>hd555>fidelio x2hr>m50x

TREBLE: Perfect for those who are treble sensitive, sacrificing a bit of airiness. They are slightly recessed and not fatiguing. lcd2 classic>k371>hd650>fidelio x2hr=hd555>m50x

SOUNDSTAGE: Personally, I found them quite wide for closed-backs without having a great depth. lcd2 classic>fidelio x2hr>k371>hd650>hd555>m50x

IMAGING: They lack a bit here, they are a bit hazy. lcd2 classic>fidelio x2hr=hd650>k371>m50x=hd555

VALUE: Extreme. k371>hd650>lcd2 classic>fidelio x2hr>m50x

DRIVABILITY: You won't need an external amplifier, they perform satisfactorily even from your mobile phone. They have low impedance and high sensitivity. k371=m50x>fidelio x2hr>lcd2 classic>hd650

They were driven by Fiio e10k and Fiio k5 pro amplifiers and the Fiio m6 DAP.

TL DR If you are looking for headphones in the sub-300€ category, look no further. If you would like a slightly milder sub-bass and high treble, I would try the same company's k361 at an even lower price.

PS for the price of the hd650, I would easily go for the Hifiman Sundara.

From the first moment someone uses the K371 headphones, even without comparing them to other headphones, they immediately understand the exceptional sound they produce. Full of bass, you feel like it will hit you in the chest, but it doesn't happen, as immediately after you realize that you are not listening to monstrous speakers but to headphones!
The voices are crystal clear and the highs are crystal clear!
Honestly, the price-to-sound quality ratio is excellent.
Additionally, adapters and cables of different lengths are provided, as well as a spiral cable together with a carrying case.
Their construction is excellent. However, there are some points that need correction, such as the relatively long plug of the cable that connects to the headphones and due to its length, it bothers the collar.
Also, the soft foam cushions have a synthetic (plastic) coating and when it's hot, you sweat, which I find annoying. On the other hand, all the headphones I have used so far with such cushions have them. Something in fabric would be very positive for me at least.

After so much noise, I decided to try an additional closed back.
Positively, it is lightweight and well-built for AKG's unacceptable standards. The pads are definitely better than the 550 and more comfortable.
The sound signature is to my liking and close to Harman. The low end is very good and does not overshadow the mids like the M50 and 99c, and it is not as cold as the 770pro.
Negatively, the highs can become grainy depending on the recording. The mids resemble the 600, but they certainly don't have the background and resolution. In terms of soundstage, it is larger than the M50 but smaller than the 770, in my opinion, it is perfect and accurate as it should be. Unfortunately, they don't perform well in terms of imaging separation, but it is perfectly logical.
For their cost, comfort, closed back type, noise isolation, lightweight construction, and Harman target, they are impeccable and definitely left a positive impression on me.

A good choice in the low-end category that comfortably stands in the midrange of 200-300 euros.