Fosi Audio i5 Open-Back Planar Magnetic Headphones

I have multiple headphones from different manufacturer's, including a vintage planar technology one. The Fosi i5 headphone reproduces any type of music with the highest fidelity possible. I was very skeptical purchasing it, because even though Fosi had released decent audio products in the past, it had no experience designing and manufacturing sound driving products. It was delivered 2 weeks after the order. Excellent packaging, with all components very well protected. I’ve connected it to different pre amps listening to all types of music, including classics, vocals, pop, instrumental and it performed surprisingly well with very balanced, neutral and precise reproduction. I’m curious how it will perform after the burn in period. Congratulations to the Fosi engineers designing such a wonderful piece of art and making it affordable to most of the audiophile community. It would be nice if Fosi released a good headphone amp matching the i5’s quality.

Used with: Fosi Audi GR70 Tube amp, Schiit dac.
I backed these originally on Kickstarter, and have no regrets at all taking a chance on these.
They have a lovely sound, with a nicely detailed higher end and a wide sound stage that occasionally surprises me. I actually had to stop listening to Ludovico Einaudi's Seven Days Walking album a couple times because I could swear I was hearing something in my apartment, but it was actually the soundstage picking up the piano's key clacks.
I will say that while the response charts show the bass extension as rather weak on the headphones, with even just a moderate amount of EQ (like adjusting the bass up on the GR70), I don't notice it at all. Maybe if you are a bass head, you'd need more, but I think for 90% of listening simple or no EQ will still result in a great listening experience.

I was initially unsure of supporting a headphone from a company that doesn't have a track record making headphones, but Fosi has sold me on their process (also using early reviewers as stress testing beta testers, essentially, but more importantly, LISTENING to their reviewers) and making changes before it goes into production filled me with confidence. I'm eager to try out their Luna turntable and see if they can hit it out of the park again when push their comfort zone and make new products!

The Fosi i5's are fantastic sounding headphones, with great detail and a spacious sound. Very comfortable to wear even though they aren't the lightest - and are quickly becoming my favourite pair. And good looking too!

There is a point of return and then there is spending too excess. I know there are many more costly headphones out there. But at some point you spend more than you get back. I think for most this is a very good place to stop. The I5 is a spacious sound with a neutral tune that most will appreciate. Knocked it out of the park with this one. Thanks Fosi

I've listened to Stax electrostatics (experience an empty wallet prices) with their distinct lack of bass. The Fosi i5s are up there with their clarity, detail, balance, huge soundstage but also have a perfect dry, hard, punchy bass to compliment the rest of the neutral frequency spectrum. Nothing harsh or shouty about these headphones. Once you start listening you can't stop - they're addictive. And an excellent price. Also supremely comfortable. Wearing them now! Astell & Kern SR35 drives them beyond painful levels without high gain. Sheer bliss!