Linsoul TIN HiFi T4 10mm Carbon Nanotube Dynamic Driver in-Ear Monitor Earphones, Ultra-Sleek Metal Housing, with Silver-Plated MMCX Cable

Unreal.
First of all I want to address something up front. My Tin T4 came in a white box, not a black box. Everything else was identical except for the cable. It’s not the same cable that’s pictured or that you’ve seen in reviews. In my opinion, it’s an even better cable. It’s a 4-core or 6-core braided cable with a 90-degree 3.5mm plug, but it feels very nice and is very flexible. The terminal is not as beefy as it is on the pictured cable, but this is a small gripe because this cable is seriously very, very nice. Additionally I found the mmcx connectors on this cable to be buttery-smooth and had no difficulty getting them connected properly.
Sound quality is superb. Beyond superb. These IEMs have the widest soundstage I have ever heard on am IEM and they really let everything breathe and sound fantastic, particularly on very fast or very complex tracks. The detail is amazing, especially at this price point. These produce some serious details. Additionally, instrument separation is extremely impressive for a sub-100 dollar IEM. I mean really, there’s nothing these little IEMs can’t handle.
Let’s talk about the low-end for a little bit. You read a lot of reviews stating that these don’t have enough low-end for a basshead, and that may be true. But for the average listener I would say this low-end is more than enough to be satisfying. Kick drums are percussive just as they should be. There’s decent rumble when it’s called for — but it’s all so incredibly well-controlled and detailed that it works perfectly. Very, very tight bass with fast attack and excellent decay. There is no bleeding whatsoever into the mids.
Mids are slightly forward without being biting. They sound nicely detailed. Vocals sound lively and superb, a lot of weight to vocals here. The treble is bright and crystal clear, and very airy. These are definitely a bright-neutral IEM and the detail and clarity they reproduce — especially for under 100 dollars — is simply stunning. There is no harshness at any frequency and no sibilance to speak of, it’s a perfect balance of detail and clarity without anything grating happening. Regardless of what I’ve listened to, I’ve experienced no fatigue whatsoever and honestly, the day I got these I wore then for 12 straight hours. No exaggeration.
The comfort is stellar, as you might have guessed by my wearing them for 12 hours at a time. I do it often. I am always listening to music. And everything — absolutely everything — sounds good on these. Maybe some electronic stuff won’t have the bass you’re looking for, but that’s only a maybe, because again I feel that for the average person, these have plenty of (well-controlled, detailed) bass, even with electronic music. These are an absolute steal at 99.00 dollars. Buy them.

Awful
I purchased the T4 based on very favorable reviews I saw on youtube. The sound quality and presentation did not meet my expectations, especially given the price.
The form factor is good. I like the fit, choice of ear pads, and the cables.
The tweeter is good, very detailed.
The midrange is brassy, thin and has a frequency range with distortion that hurts my ears.
The base response is non-existent.
I used an HRT Headstreamer dac listening to lossless .wav file songs.
I also tested on my CD player
Very fatiguing, could not do more than a song
Returned and got a whole 20 dollars refund.

Bad Cable And Ear Tips
Decided to give in to the hype. Had to try them out for myself. They come in a pretty fancy box. They have a nice leather box to store them in. They come with 3 red and clear silicon tips and 3 black silicon tips. Plus one pair of memory foam tips. That’s my favorite and offer the best sound in my opinion. The only bad thing about the memory foam tips is they wear out fast and need replaced often. Maybe even the cable too. The cable snaps into the earphones and can swivel to fit your ear. Coaxial design. However it also become lose over time and doesn’t have a solid connection. Although the cable has never came detached from the earphones while in my ears. The sound does cut in and out. It makes a scratchy sound. I like how the cable wrappes around the back of my ear helping secure the earphones in my ears. From my experience. I feel that they put most of the money in the sound quality. Some say they don’t have bass. It really depends on what you have them connected to and type of music. My pair offers awesome deep lows and that’s coming from my phone. I will say they don’t isolate the sound very well. I can still hear conversations taking place in the same room. When I have them in. The quality of the earphones are pretty good. But the ear tips and cable are terrible in my opinion. But what you get straight from the box at this price is an incredible value. I do highly recommend them. Hopefully TinHiFi can offer an upgraded version for a bit more in the future. I’m having a hard time finding a replacement cable and replacement tips.

Worst earphone i have ever used, uncomfortable, bad sound.packaging is worth more than the earphone.

I’m not sure why Crin et al, are so so about these headphones; they rock!. Seriously, their bass is extremely tight, exhibiting no bloat, and communicative; they have excellent detail and what I would consider a perfect balance of mids and highs (neither fatiguing, boring or shouty). They don’t come between you and the music; these are the first IEMs I’ve heard, which I could listen to, as easily as my favourite over-ear headphones.