The Pistons have been pretty standard chi-fi fare for a long time running, but I thought I'd throw in my 2 cents on them.
Fit and Form
The headphones came to me in an unlabeled white box, with very little useful documentation. Included is a plastic hard case that holds extra sets of silicon ear tips and a very well designed rubber puck that the headphones can be wrapped into on-the-go.
The included tips cover a very wide range of sizes, and I found that the extra small suited me best. The canals that the ear tips fit onto are smaller than most other IEMs I have used, so Comply tips can be slipped on, then compressed so that they fit; however, I used their silicon tips.
The headphones are well designed and are made of plastic, with a circular metallic inlay on their center. They fit well into my ears and hold fairly well. There is not much isolation, although more than any open set of cans would offer. Leakage is minimal, but at high volumes, some sound leaks out. The cable is cloth up to the splitter and rubber beyond that, with an inline three-button controller that I found worked well with Android. Microphonics are minimal. The 1/8" connector is straight and made of metal; it feels of above average construction.
These are a very fun pair of cheap IEMs. Although they are adequately detailed, you will still miss out on little things that other headphones might pick up. Soundstage is fairly small, but the imaging still provides some distinction in location, although there is admittedly little separation.
This headphone does best, in my opinion, with modern pop, dance, and electronic music, as its V-shaped frequency response offers the ideal sound signature for those genres. However, it is not so accentuated that genres which might benefit from a more neutral sound signature come across as mutated. Classical, jazz, and classic rock all sound, at the very least, appropriate.
Songs used: I Never Woke Up in Handcuffs Before by Hans Zimmer, Spottie by Hypnotic Brass Ensemble, and Monster by Kanye West
The bass in these is very engaging and fun, which seems to be a common thread throughout these headphones as a whole. While it is fairly muddy and not very detailed, it offers decent slam and punch in both sub- and mid-bass. There is, however, considerably more noticeable mid-bass than there is sub-bass. Clarity in general seems to be underpar in reference to other, more expensive ($50-$100) headphones, but is greatly improved compared to other headphones in the price range. As a pair of headphones meant to sheerly enjoy a genre as opposed to appreciate the finer details of it, these more than meet my specifications.
Key descriptors: punchy, round, and warm
Songs used: Treaty by Leonard Cohen, Somebody Was Watching by Pops Staples, and Caralee by Ripe
The mids in these IEMs are understandably recessed. Where the bass and treble seem at least significantly accentuated, the mids feel as though they are left on the back burner. As a result, both male and female vocals (but more so male vocals) feel mixed into the backdrop of the music and don't particularly pop or separate. The mids, in their reduced quantity, are pleasing and satisfactory. Summarily, they are clear, but not particularly forward.
Key descriptors: recessed, clear, and detailed
Songs used: 22 (OVER S∞∞N) by Bon Iver, ما بم هم نمى دسىم by Googoosh, and Did We Live Too Fast by Got a Girl
The trebles in these IEMs are surprisingly detailed and responsive. The Pistons 3s are not as forgiving to harshness and sibilance as their warmer predecessors, but still generally avoid those issues. 22 (OVER S∞∞N), which usually screams sibilance through the majority of headphones that I've tried, was, at the very least, tolerable. Of the three frequency response ranges, their treble was the most detailed, and is generally pleasant.
Key descriptors: detailed, pleasant, cool, and smooth
Minutia and Miscellaneous
I feel the need to additionally commend Xiaomi for their rubber puck. It is incredibly convenient, very well made, and extremely compact. It safely carries the headphones wherever you go, and I'd be comfortable paying the $13 that I paid for the headphones themselves just for a similar puck for other IEMs that I own.
These headphones, on the whole, are an absolutely great deal for their price-to-quality ratio. While they aren't LCD-4s and will miss the occasional detail, they still manage to pick up small things in individual songs that I absolutely would not expect anything in this price range to translate to the listener. Their sound signature is very fun and engaging, while not sacrificing the ability to diversify your listening through them. While they are not bass cannons, they certainly have a slight emphasis on that register.
I highly recommend these to anyone just entering this area that wants to try out something a little off-the-beaten-path for the general public and that offers an almost unbeatable price-to-quality ratio.
These headphones were not provided to me by Xiaomi, they were purchased purely of my own accord. I am not being paid by anyone to write this review, to endorse the product reviewed, or for the content that I put in the review.
These headphones were powered by an Astell&Kern AK Junior, a Google Pixel, and by whatever soundcard is in the motherboard of my computer.
I have had these headphones for a year and a half, and they were my main driver for the first 3 months that I had them. They have since been occasionally rotated in and out of use.