This is the place to discuss all things to do with the Fiio FT-1 Pro, which is a $200 open back planar magnetic headphone.
Fiio were kind enough to send DMS and I each a unit for review, which we’ll be working on soon.
In the meantime, here are the measurements:
Frequency response (HpTF variation)
Resolve Unit (GRAS KB50XX and B&K 5128)
DMS Unit (GRAS KB50XX and B&K 4128c)
What is this? This indicates the headphone’s behavior variation across different heads and ears, providing a better indication of how they are likely to vary across human heads as well - absent other factors like leakage effects from glasses for example.
Why is this? We have a video on the channel explaining why this type of visualization is likely necessary for headphone measurements. This should ideally evolve the more heads and ears we can test these products on, but the older paradigm of showing a single line on a graph to indicate headphone performance is insufficient.
Raws
Resolve Unit
DMS Unit
Drivability:
- Sensitivity - 95dB/mW@1kHz
- Impedance - 20 ohm
Channel matching
There are many factors that can contribute to channel balance issues, often the most significant of which is pad asymmetry. And, when you find such issues it usually looks worse than it sounds. But in this case I wanted to isolate the cause, so I measured them both in free air with the pads removed to eliminate that variable. Here’s what I got:
The drivers actually seem very well-matched, with the exception of that one scrungle around 4.5khz, which shows up as a fine-grained imbalance in practice with the pads back on.
While this isn’t likely to be all that perceptually relevant with music, you’d like to see better consistency here. I also expect the dip feature is the intended response, given DMS’s unit seems to also have that there.
The stuff that doesn’t matter unless it’s awful 
Distortion at 94dB
Distortion at 104dB
Distortion at 110dB
Not the best performance for harmonic distortion - at least for a planar. It still won’t be audible with music under normal conditions, but boosting the bass to the high heavens may yield certain high order products creeping in. I’d be more worried if you saw those same high order products higher up in frequency, but still something to note.
Driver Damping (Resonance frequency with an intentional air gap)
Minimal driver damping (noted by the width of the bass rise in the presence of a leak), and a low resonance frequency. Make no mistake, this is a very good result. They seem to have also incorporated an intentional leak into the design to get a slight bass rise even when coupled, which is very smart given the typical limitations of open back headphones in the bass.
Excess group delay (checking for internal resonances):
No reason to care about time domain information here as it’s clearly minimum phase (behaving well) and therefore it’s all proportional to the FR.
Notes
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For the price, I think this headphone has the potential to be very competitive with the other heavy hitters in that space - like the Edition XS and the HD 6XX. The tonality is actually somewhere in between the two.
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Better bass extension than the HD6XX, still with a forward midrange character, at the cost of some emphasized lower treble harmonics, and the FT1 Pro loses out a bit in terms of smoothness and timbre (as do most headphones).
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It’s actually very similar to the HiFiMAN Edition XS in that it has that midrange dip to a similar degree around 1.8khz. I do find the Edition XS to have a more balanced mid-treble presentation but also a bit more zingy in the upper treble, so it’s kind of a trade off there depending on what you’re looking for.
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It is notably better than the FT5, and speaking of which, the Fiio headphone lineup can seem a bit odd. The FT1 is a dynamic driver closed-back headphone, the FT1 Pro is an open back planar and so there’s really not that much unifying the two other than the name.
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Comfort is not bad, it’s not heavy like many planars are, coming in under 400g. I feel the headband could use a bit more padding underneath.
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For its mechanical design, it has a really convenient pad swap system, so I’ll be trying that out with this one to see how it changes with different pad options. I have to stress… this headphone’s general design is my favorite thing about it, and I hope they do more with this.
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Additionally, while the channel matching is mostly very good, it’s worth noting the driver-based feature on this unit around 4.5khz, and I’d like to see the QC ensure stuff like this doesn’t make it through - even if it’s not really noticeable with music.
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Overall the FT1 Pro is a good platform with some excellent design choices, like using the low driver Fs to get a subtle bass lift, as well as the mechanical design in general. For $200 I’d have no problem recommending this. I find it to be a slightly more midrangey sounding Edition XS, just with a hint of excess energy in the upper mids and lower treble, depending on how you define that, and it may be exactly what folks who aren’t into the HiFiMAN designs are looking for. So take note… Fiio is doing interesting things in the over-ear space.
