BASN Metalen 4 Drivers HiFi (2DD+2BA) In-Ear Monitor Headphones (Black)

Very good fit. Sounds great. Case and spare parts are a bonus!

I used the Basn Metalen Pro for Gaming and it works absolutely perfect for me. The Bass Sound on these headphones were amazing it was very clear and no issues that I came along with the sound it was loud and clear enough for me to hear EVERYTHING. The Quality and Stability of the headphones are perfect they never fall out of your ears they always stay in the whole time your using them never once I had to keep pushing them on, they just always stayed on and the product feels amazing very small but fits enough to hold in my ear very use. Also what I love about these is that they have different These headphones are an absolute must if your looking for headphones with great bass to them giving you outstanding sound that’s very clear and that’s a great fit for your ears that are very very comfortable in your ears and on your ears every use.

[Update 04/23/24]
I reached customer service and I got to say that they are excellent at responding you. I spoke with Nancy and she and the BASN team sent me a replacement that works perfect!

Comfort and Quality really feels at the moment you start using them.

And most importantly, as a Drummer you got to protect your ears and with the BASN Monitor I feel safe every time I play.

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[First review]
Ear plugs works great, but....
The product I got has manufacturing errors.

Im a Drummer, and Ive used this IEM 3 times and I noticed since my firt time I tried them that my right side ear plug looses sound every time I make small natural movements.

I have to stay super steady to avoid loosing sound on my right side and as a drummer it is almost impossible to not make movements at all.

I just reached customer service, As soon as they give me an answer im going to update this review.

I didn't want to spend $250-400 on my IEMs, as I'm not sure where our band is going quite yet. I'm a vocalist for a 70-80-90s cover band. I was very pleased when I received these, pulled it out of the box - put the medium black foam ear pieces on - and plugged them into a few devices (computer, iPhone, iPad). The difference in sound between these and my old Shure E2s - which were fantastic for the price 20 years ago - is night and day better. You won't be disappointed in these despite the fact these are from a relatively unknown (Be A) Silent Newcomer. I'm eager to purchase the next step or two up, when appropriate - and perhaps try molded ear canal inserts for even better noise cancellation. Until then - these have been very comfortable for 2+ hours of rehearsal a couple times a week.

First of all, I want to thank BASN's customer service team (Nancy specifically). BASN was unknown to me initially, so I asked many questions before buying this one. Every time, a quick and detailed reply was provided within 12 hours (mostly within 1 or 2 hours). From her, I know BASN is mainly marketing in musical and stage equipment field, kind of a little less in Hifi field. However, one can still find some online (video) reviews targeting Hifi users on some models they produced. ALL of those gave out positive results and praise. This is a reflection of overall good quality of BASN IEMs. Their team actually did a lot ODM work, so they have much experience in IEMs.
The Metalen's build is the main reason I chose it initially. Its body is made of metal, cut smoothly by CNC machine and promised to be sweatproof. The vent holes into the inside are placed where sweat can hardly go in. I believe to gain better sweatproof, one should use foam tips instead of silicone ones. The diameter of its tube is big. My Comply T500 fits well and kind of easy to detach (NOT loose), while T200 is tight fit and hard to detach. So T400 may be best, but I don't have one to test. The entire line of Metalen (and Pro) looks classic, which is my taste (No, I don't like Linsoul's skins).
The BASN team did a good job on the tuning of Metalen. They definitely know how to dig the potential of the 4 sounding units (2BA+2DD) at this price. As this pair is mainly for stage monitoring, I believe they focused on some points more than others. Bass: I can hear powerful while not exaggerated drums. Sub-bass and mid-bass is there too, with less amount than mid-bass. Mid: I believe this is the area Metalen really shines. Guitar and Piano is quite accuracy and easy to hear without much "alternation". The voice of female singer is brought front purposely (I believe), while the voice of male is not brought front but not recessed. Treble: I think certain area of high is purposely raised, like violins and saxphones, providing a somewhat airy high. Soundstage: Good separation (of course with 2BA+2DD), good imaging and good spacial feeling. Resolution: The resolution is good but not as unaltered as pure monitoring IEMs. Overall, I believe Metalen's tune is more tending to brightness while not bold or "warm". It should be good for stage monitoring as instruments are heard quite well. I don't have the equipments to get the response curve. Judging from my listening experience and testing curve got from Nancy, it's not a typical U or V-shape IEM for Hifi users. However, it's definitely good for casual music/pop listeners, as it provides a non-bold sound for longer time listening without fatigue. Basshead may not like it. Who would like critical monitoring should not choose it too.
Drawbacks? No!!! (at least for me). Remember this is a $100-range IEM, and don't expect it competing with ones within much higher price range. If regardless of price range, there are two things can be improved: 1. Sub-bass should be a little more. As the mid-bass is increased a little, with current amount of sub-bass, the drum may sounds a little "dry". 2. Overall the treble is "altered" too much, some range sounds airy, sometimes a little harsh. I also notice certain range of high is somewhat recessed, which hampers the sound stage a little. Again, I don't call the two points as drawbacks. You are buying $100 sets, not $1k sets. It competes quite well with those IEMs at the same price range. I'd say it possesses an outstanding value to price ratio.
Recommend? Yes!!! If you got the money and want a better overall sets, I also recommend MTPro planar from them. After I bought Metalen and got a good experience, I bought MTPro too. Metalen is beaten by MTPro, of course. MTPro provides a different sound signature with bolder, warmer, and passionate sound while not harshing at all, still easy to listen for a long time.
BTW: BASN's full name is "Become A Sincere Newcomer". I believe they are one already, and even better than that :)