-Introduction-​

Penon Audio is a chinese web-store founded in 2013. They've been pretty active since then, and often have competitive pricing on many of the IEMs we here at Head-Fi buy. They have recently started to sell a self-branded IEM, the Penon IEM. Since it's release, it has already been revised, giving it a better cable and tuning. That is the version I'll be reviewing now. 
 
You can't buy the Penon IEM alone, but can pick it up for $10 when you buy $99 or more on Penon Audio.
Disclaimer: This review is based upon a sample unit provided to me by a manufacturer or distributor in exchange for my honest opinion and un-edited words. I do not profit in any way from the writing of the review. I would like to thank Penon Audio for sending me this review unit
Preference and Bias: Before reading a review, it is worth mentioning that there is no way for a reviewer to objectively pass judgment on the enjoy-ability of a product: such a thing is inherently subjective. Therefore, I find it necessary for you to read and understand what I take a natural liking to and how that might affect my rating of a product.
My ideal sound signature would be an extended sub-bass with a leveled, but textured, bass. The mids should be slightly less pronounced than the treble, but still ahead of the bass. I prefer a more bright upper range.
Source: The Penon IEm was powered like so:
PC optical out-> HifiMe SPDIF 9018 DAC 3.5mm out-> earphones
All music was served as MP3 @320Kbps or as FLAC.

-Sound Signature-​

Initial Impressions: The Penon IEM has a really good response to panning. Many songs which I've never noticed had panning in them were immersive with the Penon IEM, and performed generally well. I'm hearing a slightly V-shaped sound signature, leaning more towards the flat side. Articulation is good with the exception of a small band of frequencies in the upper and lower-mids, where detail can get lost. Most of the time, I didn't notice it, but it came through quite often in alternative-rock songs where guitars can occupy a wide variety of frequencies.
 
Treble: Songs used: White Flag, Midnight City, Outlands
 
Background treble effects aren't nearly as noticeable on the Penon IEM as some other, brighter IEMs. In fact, there is a bit of treble roll-off. Songs like White Flag do generally loose some detail. Midnight City shares a similar story. The treble roll-off affects the drums, making them come out of no-where and sound fairly unnatural. However, it's not all bad news. Outlands' violins had a fantastic presentation, and were poised correctly, giving them a fairly symphonic sound. They're immersive nature allowed Outlands to really draw you into the song.
 
Mids: Songs used: Flagpole Sitta, Jacked Up, I Am The Highway, Good Life
 
This is where the Penon IEM truly shines. Vocals aren't too forward, but never loose control. Guitars and drums sit nicely within the mid, and don't smudge all over each other. Flagpole Sitta's bass guitar never fell out of audibility, something I am really impressed with, given it's relatively low positioning in the mids. Harvey Danger's vocals were also toned very well, with an overall pleasant timbre. Jacked Up's pianos were also presented well. While they could have had a harder edge to them, I certainly wasn't bothered too much during my listening session. The electric distortion of the guitars also played out nicely within the song. Chris Cornell's voice in I Am The Highway sat very well in the song, and wasn't super forward, like many "vocal boosted" IEMs. 
 
Bass: Songs used: Lights, Gold Dust, 99 Problems (Hugo Cover), Leave Me
 
Bass is north of neutral, but isn't in "bass heavy" territory. Songs like Lights and 99 Problems that rely on good bass presence and extension to have depth were treated well by the Penon IEM. Unfortunately, the Penon IEM simply doesn't extend far enough to give bass-heads a truly good reproduction of songs like Gold Dust. It seems like the Penon IEM's sub-bass rolls off pretty early, leaving bass-drops a little unfulfilling. Leave Me's story reads similarly. Not enough sub-bass shirks what, to many, is the main appeal of the song: the drop.
 
Clarity: Songs used: Throne, Map of The Problimatique, I’m Not Alright
 
Clarity is fairly good, but definitely not perfect. Throne and I'm Not Alright really pushed the Penon IEM right up to it's breaking point, causing bits of distortion to slip in here and there. Unfortunately, even when there wasn't too much distortion, detail and layering was lost.

-Build-​

Construction Quality
 
The Penon IEM seems to be built fairly well. The magnesium housing is hard and light, while the cable is of a reasonable thickness. Starting with Revision 2 of the Penon IEM, the cable starts out as a 2-core, then splits at the Y-splitter in its usual single-core structure.This really makes the cable look nicer, and may have even given the sound quality a boost separation-wise. The 3.5mm jack has also gotten a make-over, sporting a new stress-relief system that appears to be far more comprehensive then the first revision's did.
 
Comfort
 
It's decently comfortable. While I can't quite find the perfect fit, I didn't experience any discomfort during extended sessions.
 

-Summary-​

Penon Audio did a great job re-vamping what was initial a pretty underwhelming offering. I have absolutely no problem recommending this as a beater IEM for as a gift to someone just recently starting their entrance into the audiophile world. While it's not exactly easy to get, it's worth it once the right conditions are met. However, if you are in the market for a new IEM and have $110 or more to drop on new gear, there are certainly better options out there.