Disclaimer, these are the first IEMs I own. Before this, my only experience with iems is a small listening session with the Fiio FH1 and the FA5. The in-ears I have listened to the most are the AKG buds that came with my Samsung S9 (which are surprisingly good actually)
I found the Fiio FD1 for sale on a local classifieds site, for the equivalent of 52Eur (59USD), which I thought is a very good deal and low enough price not to be sorry if they were broken, so I called up the seller. I was actually surprised to find out that they were practically new. The seller tried them with his own tips for 2-3 hours, did not like them and put them up for sale.
First impression, connected to a BTR5, with foam tips, using the unbalanced 3.5mm cable they came with: a bit to many highs (harsh, sometimes sibilant) in certain songs, but they have potential, so, I left them playing metal, electro, jazz, classic, at 50% volume out of the MusicBee / BTR5 for about 20 hours.
I know, I know, burn in snake oil, but what harm can it do?
Well, it seems It actually did good. Now, after listening to them for a few more hours with the foam tips on, they have definitely relaxed, but in certain songs they still sound a bit harsh (Pendulum’s Immersion album for example, but this might be a mixing issue as well).
In most of the songs I listen to (metal in general) the highs are a bit more highlighted, but they are not fatiguing. Nothing I cannot fix from the BTR5’s equalizer if it gets annoying though.
Bass is nice and detailed. I managed to understand instruments and separate them better than with my AKGs. In some metal tracks I wished for a bit more bass “slam” though, but I never wished for less, which is more important to me.
Regarding the mids, sadly I have too little experience to explain how they sound. All I can say is that voices and brass instruments sound really enjoyable.
The songs Utopia, After Time, La Viflaim Colo-n Jos, Summer Dreams, are spot on for what I consider to be really enjoyable listening to subbass, lowbass, midbass, mids and some highs.
A little fearful I decided to try my benchmark song for highs and “speed”, Exercises in Futility V, especially starting from min 2:57. Conclusion is, YES, I APPROVE (also I can full on headbang with them in my ears)!!!
P.S.: As a curiosity, I did a low frequency test, starting from 5hz and up to 30. I can start hearing them from 13hz up (the official specs say they start at 10 hz), so, it seems they can go pretty low.
Also, here’s an image with how they fit in my ear.