After long and tiresome search, I've finally found my outdoor HDPs
For the record, I've had the Sony's new EX300 (£30), Goldring GX200 (£18), EP630 (£NA), Klipsch Custom 2 (£50) and I can safely the EP830 takes the cake. I've also had the pleasure of testing the HD485, HD595 and the ATH-AD700, which I currently own

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Out of the box, the sound quality was superb and well defined, which shocked the **** out of me because I wasn't expecting that from a £13 set. Sure, the EX082 is still superior (slightly), but that's only due to the hybrid design.
On the EP830, I found the mids to be well defined (and better than my AD700 and on par with the EX082

), the highs were superb, but the bass is somewhat overpowering at times, which can bother some users. It also has extremely minimal (and in most cases, completely inaudible) metallic sound. I'm sure that will vanish after proper burn-in, which can take several hundred hours.
I also have to add that listing to "
Utada Hikaru - Passion" was quite pleasant (considering the price tag). The sound signature wasn't far off from the EX082.
The default earbud (medium) was a perfect fit for me. It immediately established perfect seal, which was again surprising (cos others have failed in that category, accept the Sony). The noise isolation was very good, even at low volumes. I can hardly hear the underground at mid-volume.
Unlike the others, the cord was easier to manage, but it was a bit too long for me. I wish they've included an extender so that users are free to customize the length. But you really can't fault it.
Finally, the built quality is excellent for a budget in-ear. I couldn't find any visible manufacturing defects and the design is excellent IMO. It by no means 'feel' or 'look' cheap.
The Sony EX300 sound quality was utter disappointment. It had minimal soundstage and the overall sound appeared rather damped/harsh (lack of definition). Listening to Nelly Furtado's Promiscuous was an absolute toucher.
Sound quality of Klipsch Custom 2 was beautiful, but it had two major flaws: One, higher-end of the highs were virtually non-existent. Two, it's very hard to put them on and create a perfect seal. I found to be rather impractical in the real-world to be honest.
Goldring GX200 was one of the worst in-ear HDPs I ever had/used. There was no soundstage, highs were damped and it's impossible to create even a semi-perfect seal. The quality and design was also poor. One can easily mistake the GX200 for something one would buy from a pound shop

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To sum it up: If you're in the market for a quality passive noise isolation headphones, seriously consider the EP830. It's worth the risk in my opinion.
Thanks for reading
PS: I never written a review before, but the EP830 definitely deserved it. If I've made any errors, please let me know.
PPS: I found the following tracks to be excellent for benchmarking headphones. Let me know what you what you think

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- Passion by Utada Hikaru
- Beautiful World by Utada Hikaru
- Free and Easy by Ayumi Hamasaki
- Fallen Icons by Delerium
- Deep Forest - Yuki Song
- Deep Forest - Yuki Song Remix (Essence of the Forest Album)
- Deep Forest - Sweet Lullaby 2003 Version
- Still Alive by Lisa Miskovsky (Mirror's Edge Soundtrack, which is free to download).
Edit: I currently use the EP830 and the EX082 with my Sony A816.