The MDR-J12G are a sporty, my term, pair of over the ear earbuds. The construction is mostly hard plastic, the only exceptions being the wires and jack.
Sound Quality The MDR-J12G has mediocre sound. There is no bass to speak of and the midrange and treble are at best decent. The sound is good enough for spoken word, but music playback will be a constant disappointment. In fairness to Sony, this is typical for all earbuds in the below U$25 price range. While some may believe that this gives Sony a pass, I think they are tricking us by branding crappy sounding equipment.
Comfort. The MDR-J12G's plastic body makes it durable, but the lack of soft edges makes for an uncomfortable fit. My specific complaint involves the tendency of the buds to rub against my ear. The speakers in the bud are attached to a separate bit of plastic, so there is a seam where it connects with the housing. While it doesn't pinch, it appears to run against the inside of the ear. This easily leads to soreness after a few days of use, and may eventually cause bruising. Which would explain why I rarely use them.
Durability The MDR-J12G comes with a pretty short limited warranty, I remember it being 90 days. On the positive side, they use the angled jack which is less likely to break - in my experience. The cables also seem as durable if not more so than the average headphone in the price range.
I rarely use these uncomfortable earphones, so durability is not an issue but I suspect the weak spot would be the connection between the cable and the earphones. I would also note that for U$60-70 you can buy a vast superior pair of earbuds. If they were U$10 and less, they would be a good buy, but not the U$25 I paid.
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