Libra

Under $10 the best is the KZ EDC PRO (edx pro is another iem), use it with Kbear 08 eartips. In Aliexpress (sometimes using coins) you can get for $8-15 the ND planet, KZ Castor Pro/OG, KZ Libra Balanced/Hi res/X, KZ Saga balanced/bass, KZ ZVX pro, all of them have good reviews and comments. The Kbear 07 and 08 eartips are good for them.

Paul wasabi, an iem reviewer, pointed out rightly that the kz libra are better for gaming due to its ability to highlight game cues.

I got both the Kz gale and Libra X and imho Libra x is still the king for budget gaming set cuz they sound cleaner (irrc Paul Wasabii said the same), gale/edx pro 2 is better for music cuz the Libra x's bass is kinda weak/neutral. 

But the reason I want flat or reference is because I'm using neural DSP and when setting up amps and recording and stuff I want to actually hear what the settings im choosing are rather than coloration from iems with a specific tuning. There's some super cheap iems that punch way above their weight it's called kz Libra x angle ears. It's a single dd with a good freq graph

I have the KZ caster Pro, KZ x Angel ears, KZ × HBB DQ6S, TRN Conch and the TRN V10 Pro ♥

I got a set of each and I could still not fit them, sadly and they were not the smallest I had found either. I got a random cheapo pair off AliExpress and they're about half a millimetre smaller, but still not small enough :(

You can just EQ them for free, but I'd take a $10 KZ Libra (balanced) over those for sound quality.

If you EQ them accurately enough then there's not much to pay for, but in practice might be pretty tricky needing good measurements and a great ear and effort. If you can't do it particularly well then exactly the KZ Libra will already be an improvement.

EM6L, but imo there's no meaningful difference between the good ones even if they sound and stage very differently. I can hear the same things with a Zero Red, G1 or even KZ Libra and get used to the sense of distance etc while the bad ones make it hard toake out where the sound is coming from.

EQ settings are relative to frequency response. It's like asking how much should I add salt to fries without the information if they're already saltes. The question is what kind of a tuning is ideal for metal and as a metalhead at least in my youth I find that a very interesting question. Preferences matter a lot as well and someone who loves the sound of one IEM maybe just hasn't heard something better yet and can't imagine what the improvement might be. The best tuning for metal I've heard so far with maybe fifty IEMs and some EQ on top was Oluv's mainstream preset for the Free Pro 2's. Really fun yet clean bass and you could push the volume really high without any fatigue etc. Gave me chills with a lot of metal music. With IEMs I have to say I haven't found anything excellent yet and actually KZ Libra (balanced) is easily on of the best for that and costs $10. The bass is pronounced, but much cleaner than the measurements seem to imply. The straight rising bass boost might be the reason instead of a bass shelf. Old but gold would be a Tin Hifi T2 Plus as it really pushes vocals pleasantly forward and has that big energetic feel to it. Not detailed etc at all, but really enjoyable. IEMs I love otherwise like Zero Red, Hexa, MP145, Timeless, B2 Dusk, Dusk DSP just don't impress me at all with metal specifically and I would take the Libra over probably all of them for that. You can make an EQ preset for the Chu to match KZ Libra on the AutoEQ website and elsewhere. Give it a try if you want.

Past like $300 preference is all that matters. The top ten most liked would split opinions a lot. There are IEMs suggested here that I would take a $7 KZ Libra over.

Not the Gate for sure. KZ Libra balanced is really good, but a bit still bright leaning with some harsher passages.

They're kinda mid. FT1 is fantastic. For something comprable Chu 2 DSP or KZ Libra (balanced). Better stuff you might find around $100 depending on preference.

KZ Libra is good for gaming.

Massively so. I'd take a $8 KZ Libra (balanced) over most TOTL TWS from Sony, Samsung or Sennheiser. Airpods Pro 2 sound okay, but a dozen sub-$100 options I've heard soubd better.

https://preview.redd.it/wif9xi6tfwye1.jpeg?width=3072&format=pjpg&auto=webp&s=df4e30653755b06184490343ac4da055302d05a8 KZ x Angelears Libra X. My vote for best under $10. And no, that's not the cable it comes with lol But yeah AliExpress for USA right now... RIP

Kefine Klean is way better than Zero Red for almost the same price. My favorite up to $10 - KZ x AngelEars Libra X. Up to $20 - Tripowin Ruta10/Tanchjim Bunny. Up to $40 - Simgot EW200. Up to $50 - Kefine Klean.

KZ & Angelears Libra Hi-Res IEM. I've always had a preference for wired headphones while I'm gaming.

Ah, you are right, they sound safe, that's a perfect way to say it for the Wa'ner, too bad it has big noozles for me. I have the KZ x Angelears Libra High version, and I know now after using it for little that it is not for me, it is too simple for me(it is great for vocals I will give it that). After little thinking I ordered the Aurora Ultra, even got it down to 32$, if nothing else I will have a lot more accessories, and a different driver style to try.

The Zenith is the best one by a large margin for me, the Gale would be my second choice (EDX Pro 2 has the same tuning and about 2-3dB more bass, I prefer the balance of the Gale though, both are an incredible value for the price (+/-$8-9)). I have or had at some point the Hydro, PRX, Saga (both), Castor (both), Libra (hi-res and balanced), ZVX, ZVX Pro, Vader Balanced/Trio, ZS12 Pro X, EDC Pro, D-Fi and Polaris, of this sets I like the Saga Balanced the most.