Firstly before anything, I should note that I paid £17 for my F7's. At that price, nearly anything can be forgiven, so this review is generally much more enthusiastic than it would be if I'd paid £40.That being said, the most important aspect of earphones is the sound quality.
Generally, apart from the really 'thumpy' bass, I find it is acceptable on these Arbily F7's considering their low price.
The sound stage on them isn't great overall. For example on a pair of earphones with decent stage the opening of Baba O'Riley by The Who will make your head spin as you 'physically' follow the sound. The F7's don't have that at all but because the mids and treble are a touch thin, they do have some separation without all the aspects of the music sounding like they're on top of each other.
I don't get too much distortion on the mids and treble either and while I mentioned they sound a little thin for the rest of the signature, they do have quite a neutral sound. Vocals feel adequate if lacking a little clarity but the overall perception is surprisingly clean and pleasant where the music isn't too bass heavy.
The bass, although punchy and very strong, is not particularly toned or defined, leaving you slightly deafened without appreciating it. Think being hit round the ears with cupped palms. I use an equaliser on my phone to reduce it to avoid actual pain on some music tracks.
I would add in it's defence, the problem is not exactly distortion or bleeding like a lot of cheap earphones have, it's just not very balanced with the rest of the sound signature. On heavier tracks, it does take away from the rest of sound. I can't find a response graph but I would guess it's heavily raised on the 10Hz-1KHz side.
The 4 mm diameter sound pipe means that if you have narrow ears like me, these earbuds are mostly comfortable to wear for extended time but the supplied silicone tips are far too shallow. I tried using a double-flange type which I find more comfortable and help with sound quality, however, with these on, the whole earphone doesn't fit back into the carry/charge case.
I finally used some old single-flange Fischer Audio DBA-02 silicone tips which I managed to squash onto the pipe. These are deeper than the supplied tips but still fit into the charge case.
Each earbud without tip (on my kitchen scales) is 5g - so pretty light but I find the size to be quite big. They are around three times the overall volume of a standard in-ear type (e.g. Sennheiser CX300) but oddly not uncomfortable to wear in spite of this.
They fit well into my ears from a comfort perspective but unfortunately don't stay in my ears. They fall out on a fairly regular basis and I certainly couldn't go running in them.
Swapping to the deeper tip has helped, as does putting them in with the microphone bit pointing down and then rotating them about 15 degrees towards horizontal.
If you're looking for a pair for sports that don't fall out, definitely buy ones with hooks on, even if they cost slightly more.
Each earbud has an internal 85 mAh battery. Supposedly this is up to ten hours battery life. The longest I've had them on for is six hours and when I put them back in the charge case, they had one of five 'bars' left. Not quite ten hours but still very respectable. Having recently compared this usage to a KZ bluetooth module, the battery is really first class on the F7's.
My charge case is a 2500mAh model and I find that plenty. I go at least four weeks between charging the case with probably an average of four hours use per day so I can well believe their figure of 140 hours total play time.
The only exception to this was when on a longer holiday I had to charge the case twice in a three week period with very little earphone use. I suspect that the moving around (there was a lot) caused the earphones to bump in the case breaking contact intermittently with the charging pins and shorting out the battery. This doesn't seem to have damaged them or the case in the short term.
Fair warning on the charge time for the case, at a flat 1A charge current, it is very slow. The maths says this should be around three hours to full but I find it more like four suggesting it's not actually charging at 1A. I've changed both the cable and the charging unit so it's not a defect on that side of the process.
On the plus side of the charge case, it has an USB A type as well as the USB C charging port which means you can use it to charge your phone as an external battery if you're out and about.
I find the quality to be reasonable but with a few weak points that drags it down into the problematic. The first issue I have is that on mine the plastic plate and the button cover come clean off quite a few times when they drop out of my ear. This has happened on both earbuds on more than one occasion. The plastic cover is both very thin itself and held on with a couple of tiny plastic clips.
Unfortunately this is now causing problems with the button press where the button doesn't pop out properly due to contact with the cover. You could argue that the solution is not to drop them but I think they should be a bit more robust than they are. This plastic end cap also definitely doesn't have any waterproof sealing.
The second main issue is the magnet that holds the earphones onto the charging pins in the case isn't strong enough. A bit of bumping causes intermittent contact with the pins which I suspect is causing shorting out and probably damaging both the phones and case in the long term.
Other than these two issues, the case is solid plastic and the rest of the earphone housing is solid plastic. The lid hinge isn't too flimsy and doesn't feel like you'll accidentally break it.
They are Bluetooth v5.0 and True Wireless Stereo (TWS) allowing the transmission of the left and right channels separately. I've never had them out of sync with each other and I find the transmitted audio quality very good. I do find that occasionally they cut out for a second but this could be either a Bluetooth issue or the playing device issue rather than the earphones themselves. I haven't yet done any research into this and it could be easy to mitigate.
I also sometimes find the latency unacceptable (up to around 1 second) while using them for watching video content, where the sound gets out of sync with the video. Occasionally popping them back in the charge case and closing the lid to turn them off then reconnecting them helps but not all the time. I also keep a reasonably short buffer time on my devices which helps reduce the lag.
This model is supposedly IPX7 waterproof (submerge for up to 30 minutes at 1m) but I wouldn't like to test that - ever. I've dropped both (out of my ears) and they come apart very easily with the plastic plate round the button coming off exposing a small circuit board beneath which doesn't inspire confidence on the waterproof front.
Microphone and Button Function
As I bought these primarily for listening, I wasn't too fussed about the microphone, which is good, because I find it unusable. I've tried holding phone conversations with them in my ears and while I can be heard, it's not loud enough to be practical.
I tried wrapping one of the earbuds in a rubber band and clipping it to my shirt to bring one microphone closer. Marginally better but still not good enough to hold a conversation. In short, I wouldn't get these for holding phone conversations.
The button functions are passable but are very hit and miss. This might be down to damage from the falls though. The single click to pause and un-pause works most of the time and is a useful, easy to use function.
The two click and three click (track forward and back) functions work so little of the time that I don't use them. As far as I know, there is no ability to change the volume from the earbuds which would be a very useful function for me.
My verdict on the buttons is that I wouldn't miss the function they currently provide if the buttons weren't there at all.