Cons: A somewhat darker sound
My review sample of the Hisoundaudio POP was provided free by Hisoundaudio but I'll try to do an unbiased summary of my thoughts.
The wood used appears to be of high quality. The fire-engine red cable is reasonably thick and stiff and is rather eye-catching. The Y-split could have included a slider for convenience. Personally, I would have preferred a L-shaped jack instead of the straight jack. A plus point is that the cable does not tangle easily. The negative would be the microphonics I've experienced when walking around with it. However, since it is not a sports headphone and no one would likely be using it for that, it should not be too big of an issue.
The number of tips included is commendable, with single, double and tripe flange tips of different sizes. I used the regular small-sized silicone tips as double or triple flange tips do not fit in my ears comfortably, a problem I have with the Monster brand tips as well. The POP sits comfortably in my ears for hours. A shirt-clip is also included.
A carrying case was not included. I feel that there should be one even if it meant a slightly higher price as I have accidentally damaged the audio jack by just carrying it around in my bag. The sound sometimes cut out as I flex the part of the cable connecting to the audio jack.
Right out of the box, at first listen, the bass certainly leaves an impression. The depth and quantity of the bass is better than most of the IEMs I've listened to. The treble sounded recessed.
Jack Fu of Hisoundaudio recommended a burn-in of 100 hours. Following burn-in of about 50 hours, I've noticed that the treble opened up. My following review is based on my listening impression after burn-in of 100 hours.
Soundstage is decent, not closed-in and not very open, of an average level.
The bass is definitely the highlight of the POP. The bass reminds me of my Monster Miles Davis Tribute. The quantity and impact of the bass makes it a favourite on bass dominant music.
In noisy environments such as on a bus or train in Singapore, the excessive bass quantity is balanced out by the noise that leaks through despite the decent isolation by the earphone, which tends to be of low frequency. This works as an advantage for the POP in my point of view.
The mids are good. It does not particularly stand out but it is not recessed either. The vocals are not of a very intimate quality but not distant. It sounds more of a mid-distance away.
The treble would be the weakest quality of the POP. It sounds a little rolled off and recessed. It makes certain music with more treble sound dull. The dynamic feel of some instruments is lost.
The Hisoundaudio POP is a good choice for those who like bass and prefer a warmer sound. I find it enjoyable to listen to especially for rock.