Fosi audio i5 headphones coming soon

[solderdude]

An amplifier rated at 250mW in 32Ω is more than enough to drive this headphone to impressively loud levels.
For normal to somewhat loud levels 1V (20mW) will already be what most people will rarely need.
RME ADI2 DAC FS is more than sufficient and can drive the i5 to very loud levels.
With 108dB/V you can reach a deafening 124dB peak !

As for the PEQ I can't help.
Review will be online on Aug 15th (official launch date)

 

[Jeromeof]

Does anyone know of the PEQ settings to flatten the freq response of the i5? I'm debating on what I will use to drive them. Either a basic dac/headphone amp or my RME ADI2 DAC FS which has peq built in.

It is very uneven in the midrange so it will be hard to perfectly flatten that aspect of the FR. I noticed my measurements of the midrange were slightly different than other peoples, probably both due to unit variations but also different measurements setups. So it is not as simple as applying a wide qValue in specific ranges.

 

[Luvchampagne]

It is very uneven in the midrange so it will be hard to perfectly flatten that aspect of the FR. I noticed my measurements of the midrange were slightly different than other peoples, probably both due to unit variations but also different measurements setups. So it is not as simple as applying a wide qValue in specific ranges.

What headphone amp are you using?

 

[Luvchampagne]

An amplifier rated at 250mW in 32Ω is more than enough to drive this headphone to impressively loud levels.
For normal to somewhat loud levels 1V (20mW) will already be what most people will rarely need.
RME ADI2 DAC FS is more than sufficient and can drive the i5 to very loud levels.
With 108dB/V you can reach a deafening 124dB peak !

As for the PEQ I can't help.
Review will be online on Aug 15th (official launch date)

Just received today. Unfortunately the SMSL 300 does not drive it sufficiently especially with RCA. Balanced is better but still at max volume setting, output is moderately loud and beginning to distort. Conversely, RME ADI2 DAC FS drives it very well. Even though the RME DAC/headphone amp only has RCA out for headphones, it has plenty of power to drive the I5.
Can't wait for the PEQ so I can test it.

 

[Raymond lin]

I have had mine since Monday and have been listening to it mostly on the X9 (it sounds better on the X9 than the DX5II), purely in bypass mode, no PEQ applied and I find the headphone to be very pleasant listening experience. It is soooo comfortable despite the size and weight. It hugs the sides of my head with 2 giant pillows and the strap spreads the weight on the top of my head evenly. I have to put it at the maximum extension though.

The bass part isn't a problem, the RING mod they applied can be removed easily by the user if we want, best of both worlds. I don't find the weird midrange in the graph to be a problem or audible. Music sounds good.

 

[Luvchampagne]

Tried the i5 with my Fiio BTR3. Not good. Barely any sound emitted.

 

[Tatr76]

Plenty of power on Hidizs s9 pro dongle connected to phone.

 

[Raymond lin]

Tried the i5 with my Fiio BTR3. Not good. Barely any sound emitted.

Really?

I got it powered with the Onix (photo) fine, was listening at 30%.

 

[Luvchampagne]

Plenty of power on Hidizs s9 pro dongle connected to phone.

Interesting.
According to a review I found.on the Hidizs s90 Pro - Powerful Drive Ability. 200mW BAL / 100mW SE

SMSL M300 SE - 148mW of power to 32Ω headphones - unbal and Balanced is 2x that.

Fiio Btr3 -

About 25mW (32Ω loaded)

About 33mW (16Ω loaded)

RME ADI2 DAC FS - 1.5 watts at 32 ohms.

Onix (guessing Alpha) up to 500mw

Based on the specs above, that seems to make sense.

Fiio btr3 only 25mw. Just too low.

Smsl m300 se - balanced was Good, not great as distortion started appearing at higher levels. Rca just ok as volume tapped out and distortion started at med low levels

RME ADI2 DAC FS - a beast. Totally handles the i5. Even better with the PEQ.

Topping L70 - even more. My upstairs rig.
7500mW x 2 @32Ω / 1150mW x2 @300Ω maximum output power
Impressive. Not even straining at low gain and -30. However, no peq on this rig and I do miss that.

 

[barbagris]

My 0,02. Had mine since Last Friday and I like the overall sound. I drive it off a HiBy R6 III and had to move the gain from low all the way to high.

They came with a nice 4.4 balaced cable so they are connected with said cable and I run the Hiby as Class A.

Don't know enough about the science - but my ears/brain say they're an improvement over my Meze 99 Classics.

 

[Raymond lin]

Yes, it's the Onix Alpha and I was using the Bal 4.4mm output.

 

[Luvchampagne]

Makes sense since it goes up to 500mw.
Does it have PEQ and if so, how many bands?

 

[Raymond lin]

Makes sense since it goes up to 500mw.
Does it have PEQ and if so, how many bands?

No PEQ in the Onix.

 

[wilhelm2015]

I have had mine since Monday and have been listening to it mostly on the X9 (it sounds better on the X9 than the DX5II), purely in bypass mode, no PEQ applied and I find the headphone to be very pleasant listening experience. It is soooo comfortable despite the size and weight. It hugs the sides of my head with 2 giant pillows and the strap spreads the weight on the top of my head evenly. I have to put it at the maximum extension though.

The bass part isn't a problem, the RING mod they applied can be removed easily by the user if we want, best of both worlds. I don't find the weird midrange in the graph to be a problem or audible. Music sounds good.

topping dx5ii has similar specs, do you have a theory on where the extra price went to for luxsin x9 which improved the sound?
can you maybe do a test on luxsin dac with dx5ii amp and dx5ii amp with luxsin dac to see if the improvement can be pinned down to the dac/amp?

 

[Raymond lin]

topping dx5ii has similar specs, do you have a theory on where the extra price went to for luxsin x9 which improved the sound?
can you maybe do a test on luxsin dac with dx5ii amp and dx5ii amp with luxsin dac to see if the improvement can be pinned down to the dac/amp?

The margins are small and hard to really put it into words. I just listen to both and find myself drawn to the X9 more. It could be placebo but it's the gear that makes me tap my feet more.

 

[solderdude]

Here is my review for the Fosi Audio i5 that launched today (August 15 2025)

i5

back to Fosi Audioback to measurementshome published: Aug-15-2025, updated Sept-15-2025 NO SMOOTHING is applied to the shown plots. Most measurement sites have some smoothing applied which ‘irons f…

diyaudioheaven.wordpress.com

 

[Down South]

I would appreciate suggestions for new cables for these cans. I have 2 h/phone amps but prefer to use the h/phone section of my Marantz 6007 - it's excellent. What I don't like about the supplied Fosi cables is that they are too short. I sit in my comfortable armchair and I don't want to sit so close to my equipment rack - a 2.5M cable would be good using a 6.3mm connector. I don't like using adaptors because it's another interruption in the chain.

I used to make analogue cables for amps etc. I and my buyers all preferred high silver content over silver plated cables but copper is acceptable. There are a lot of grossly over priced cables on the market. Any suggestions appreciated.

 

[solderdude]

Any aftermarket cable that works with hifiman will do.
Many people seem to love 'open heart' cables.

 

[wilhelm2015]

Here is my review for the Fosi Audio i5 that launched today (August 15 2025)

i5

back to Fosi Audioback to measurementshome published: Aug-15-2025, updated Sept-15-2025 NO SMOOTHING is applied to the shown plots. Most measurement sites have some smoothing applied which ‘irons f…

diyaudioheaven.wordpress.com

well that is pretty bad ringing, making it necessary to make it essentially fosi i5 veiled

thank you so much for your review!

 

[Down South]

Update on my first post. The CD of Making Music I now realise is far lower in output compared to ECM LP. I don't find the treble of the h/phones to be sharp at all, I can listen for hours. Beyers I have never liked because the top end is uncomfortable and impossible to listen to for hours. The balance and detail are great but I agree two things that stop these h/phones from being truly excellent - there is a slight veiling and bass whilst very clean could be just a bit deeper. Madonna's Hard Candy is one of the best dance LPs ever. The deep clean bass is a feature across the whole LP and this shows up this bass lightness.

I don't find the weight to be a problem. If Fosi could deal with these two issues - the very slight veil and deeper bass these would be excellent h/phones.