Personal presentation and test of the Fosi Audio i5 open back Planar magnetostatic headphones.
My opinion is formed only by me, not influenced by the manufacturer. I always prepare my reviews honestly and based on my own user experience.
This year has already brought more and higher quality products from Fosi. I was really looking forward to these planar magnetic headphones. I fell in love with them since I see the first product photos.
The box is much nicer than the usual ones:
Now it has finally arrived, let's unpack what we got right away:
As we see the contents: i5 Headphones
Symmetrical 4.4 mm cable
Asymmetrical 3.5 mm cable
1pc 6.35 to 3.5mm adapter
User manual
Optional sponge headphone holder from the middle of the box
Fosi Audio i5 specifications:
Driver: 97 mm planar magnetic
Impedance: 28Ω
Sensitivity: 98dB/mW @ 1 kHz
Maximum sound pressure: >120 dB SPL
Frequency response: 10Hz-50kHz
THD power: <1% @ 100 dB SPL
Weight: 550 g
First, let's look at the use of materials and the build quality:
The i5 itself is very large and a bit heavy in the hand. The use of materials is very higher quality. Solid steel top strap, suede leather headband, nice aluminum rear grille, nicely machined walnut frame between the ear cushion and the aluminum rear grille. Mine didn't get a completely uniform color finish. This is not a big problem, but in this price range it is does matter! No problem, it helps me orient myself. The darker color is on the right.
The construction of the Fosi Audio i5 open-back planar headphones build quality is very good and solid. It feels luxurious both from the look and the touch... The size of the i5 is very large.
The ear cushion is thick, but closes very gently and firmly. I hardly felt the weight of the i5, which is a little lot (550 grams). Not even after hours. The wide headband and the huge thick ear cushions distribute the weight very well on our heads. Another good point is that I never felt for a moment that the temples of my glasses were pressed into my head. It fits perfectly even with glasses. I did not experience any discomfort during long use. Despite its size and weight, the i5 is very comfortable. The headband is infinitely adjustable by pulling.
The cables: Detachable/Replaceable. Well, they seem very high quality to me. Although it is true that they are thick, they are still soft enough. Of course, they can be replaced with something else, or we can use them with our existing cables. The only problem I have with the cables is that they are very short. I measured it, including the plugs it's 155 cm. Listening to music while leaning back in a larger armchair is out of the question because the length of the cable does not allow it. So it can only be used when sitting very close to the amplifier.(The required length is usually 3 meters for comfortable listening to music) Otherwise, the cables are of high quality. They have metal closures on the cable ends. And their coating seems to be wear-resistant.
The sound quality:
The environment is a laptop with a USB cable, Foobar2000 and Jriver player lossless and dsd files – Fosi Audio Q6 dac - Fosi Audio GR70 headphone amplifier/preamplifier - Fosi Audio i5 headphones.
After the i5 arrived, it spent four full days playing music at medium volume. I actually locked it in its own box and didn't listen to it. The actual listening to music only happened after that.
Well, the sound: Fantastic! But literally. Warm, clear, lively. I like to listen to new stuff mostly with the music that I like anyway. I know them well and if I hear a change in a positive sense, I can immediately and with complete certainty determine it. Of course, I use certain popular music and also some that I use only to check the frequency range. I won't go into artists. I find it unnecessary. I can't listen to some of the music I read in recommendations. Not i liked all music. This is a matter of taste for everyone. I pay attention to the detail of the music, the fidelity of the instruments, the airiness. Their placement in space and the clarity and lifelikeness of the vocals. I look for the persistence of the smallest vibrations and decays and their real-looking sound. The i5 creates space fantastically. It's as if we were in the same room with the band or singer. We can almost see where the drumstick where it touches the cymbal and the drum skin. You can feel the tension of the skin on the drum. The body of the double bass, the sound of the fingers hitting the wood, and the sounds of the wind instruments are also quite good. It is breathtakingly detailed, yet it does so not in a sterile, analytical way, but in a very musical way. It provides a very enjoyable listening experience. It presents the music to us in a concert hall-like manner. The space is lifelike. The sounds are beautiful. I cannot deny that I am completely enchanted! The my i5 new version, which, had a closing ring installed to extend the lower regions of the bass. The more and longer decaying bass obtained with the ring supports the midrange of the vocals very well, and the vocals get more body.
I regret that I was not able to try both versions at the same time. (ring off and with ring) For example, I do not like the completely V-shaped sound. So the depth of the version without the ring might have been enough for me. I might still try how it sounds without the ring. Although I would definitely lose the amount of lower regions and the decay of the bass would be shorter. I would probably move a few rows back from the band and the singer and the space would be even more relaxed. This only takes a few minutes.In any case, this is just a matter of experimenting. I am extremely satisfied with the sound of the i5! Of course, you can drive it with a better amplifier. I had this GR70 at home and even my retro devices have their own headphone outputs. I can't write anything else but that it is impressive. You can listen to it for hours without the sound sounding flat or boring. Or even feeling its weight or tightness. We get an extremely entertaining performance. Absolutely lifelike, musical, airy, with live full bodie instruments and enough air around them. For those who love bass, the volume of bass is definitely enough with the ring, it is not overwhelmingly power loud, or a bit exaggeratedly impressive as is common in games, but its musical performance is not only enough for musical instruments, but also holds its own when listening to electronic music or any other style. The i5's performance is linear and warm. The walnut frame may play a role in this. The high-quality aluminum rear grille stiffens the structure perfectly, is vibration-absorbing and very beautiful. Some notes: let's take some time to burn in. Except for the box, I experienced some anomalies at the very first listen, which quickly disappeared as time passed. Since then, since I've been using it for at least a week, every sound is in place. I've experienced improvement everywhere. At first, there was some mush sounds mostly in the mids that slipped into the lower region of the highs. But I also experienced distortion in the lows at high volumes. Most of these disappeared within a day. Now everything is clear. Every sound is in its place! The highs are also clear. The clarity could be a little better in high. Overall, all the sound ranges are adequate. Perhaps the highs are a little more restrained in the horns for flute and vocalsand in the highest registers. We can use some EQ here. Everything depends on the individual, hearing and taste. It also matters how we drive it. I used one of the manufacturer's tube headphone amplifiers, the GR70. It's not a full perfect pairs, but I liked it.
One more comment. I use two playback programs. Although both use the same codec and both have EQ turned off. Still, the music played with Foobar2000 seemed a bit “shoutier”. Although it was still below my stimulus level, I thought about taking out the rings several times so that the midrange wouldn’t be crowded due to the extra bass, but when I listened to the same music with JRiver, I didn’t experience any shouting. I consider the manufacturer’s first product of this kind to be a really great headphone. A strong start for sure! The i5 plays beautifully! The price was obviously the most favorable during the Kickstarter campaign.
The i5 headphones cost around $550. You can definitely find a competitor in terms of price/quality ratio, but I definitely recommend them in terms of musical sound. Not for studio work, but for a pleasant musical journey. For long-lasting, enjoyable listening. Fantastic!
In my review, you can count on the fact that these are my first planar magnetic headphones. So far, I have only used dynamic headphones with much smaller diameter drivers. In the review, I can only describe the user experience I received. I have no direct comparison with other, or perhaps several, planar headphones.
Pros: Very good spatial representation
Exciting, very good sound
Instrument-like realistic sounds
Comfortable
Solid and made of very good quality materials.
Very beautiful
Cons: The cable length is short. I would like to lean back and listen to music comfortably.
The highs could be a little clearer. The spikes visible in the measurement diagrams could be smoothed out, but it is not bad in its factory condition, it just needs a little refinement.
