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Penon Serial : Musicality to the forth


From being one of the prolific online seller in the world to a cable then IEM brand, Penon has ventured deep into the Audiophile market. They have been making good amount of IEMs for various type of consumers. They have single DD to multi BA and multi hybrid IEMs under their belt and the Penon Serial is their latest addition. It’s an unique kind of IEM with 3 dynamic drivers in a 3 way crossover. The tech is not exactly new in the market but the implementation of the UM 3DT wasn’t exactly excellent. Penon has a different strategy here. They have a 10mm bio DD for bass, 8mm titanium plated driver for mids and 6mm PU DD for highs, interesting combination of drivers I must admit.

Penon has been making excellent sounding IEMs and I am expecting a pleasing experience with the Serial. Priced at $299 it comes in only black color and goes head-on against the CFA Satsuma, UM3DT and many other DD based IEMs.

Get one from here:


The IEM ships with the usual Penon style box and has 7 pair of tips.


Serial has a unique kind of shell. The body is mostly made out of resin for better stability and durability but the back plate has pieces of stabilized wood on it with layers of resin on it. As usual the shell the solid to the hand and feels light weight. There is a single vent on the side of the shell. The metal nozzle looks good but isn’t really premium feeling. What’s odd is that even with a resin body the IEM doesn’t have a more ergonomically designed wing. This should have been better but thanks to light weight and deeper insertion serial is fairly comfortable.


Penon Serial ships with an 8 core OCC + SPC cable. Its Not the most premium cable in the market but it still looks good and somewhat compliments the IEM aesthetically. A silver coated cable could have made this pairing more appealing. It’s an supple and soft cable without much memory problem. It barely has any microphonics to worry about. What I really like is the lack of cable guides. There are some stress relieving at the jack end but doesn’t have much protection anywhere else. The cable splitter looks nice while chin slider is a bit too big. Sound wise this cable is not bad, upgrading to something like Effect Audio Grandioso or similarly priced Silver cable will make sense, or else it does the job.


Serial just like any other DD based IEM doesn’t really care a lot about the source but it enjoy power without any guilt. The worst performance is with mobile devices but that too is above average while driving it from something like Fiio KA3 and Qudelix 5k brings out the best of it with better details and transparency.


It has 3 DD in a 3 way cross which delivers one of the most cohesive sound in any price range. Cohesive has been a great USP for Penon. Their ORB too was excellent in this regard. This takes it even further. It has a reasonably balanced sound with a Slightly W shaped feel. The mid range is not drowned while the lower end and lower treble region are a bit more forward.

There is little to no coloration while having one of the most uniform notes presentation. I love this. No note feels out of place or gives an odd vibe.

I am using Tri-TK2 and stock tips for this review while changing cables.


Serial is very pleasant sounding IEM with exceptional lower end abilities. I can write the conclusion here. You read it right, you can stop reading here and grab the Serial for it’s lower end quality. There is no other IEM in the market which can deliver an lower end like this under $500. If you are a bass lover, want to enjoy the goodness of lower end without any guilt, this IEM will do wonders. The sub-bass extension is excellent, very deep, rumbly and has the eargasmic air moving quality. The whole lower end feels meaty and full which gives it the cohesive but this does lack the speed one might look for at times. The layering and definition of notes are exceptionally good in the lower region.

Now the question arises, Is it an IEM for bass heads? Yes and no. Yes because it’s layered and defining prowess with weighted notes make it a delight to use but then it doesn’t have the area or volume of a bass-head IEM like Satsuma or ISN D10. Serial’s lower end has tunnel like feeling while others are flat.


Loved the lower end. But there is more to it. Bass is excellent, so are the vocals and mid range instruments. It’s not the most detailed mid range by some margin but the rounded notes with thicker fuller and weighty nature gives it a calming and soothing signature. If an Audiophile who wants details and finishing definition, let me tell you, this might not be for you. It has very good edge definition with excellent texture on both vocals and instruments. Both male and female vocals have some of most pleasing tonality and timber with a throaty feel. Female vocals don’t feel unnaturally thick, that’s the beauty.

Another remarkable feature is it’s reverb. This reverb gives the Serial an captivating quality. It’s simply feels hypnotizing at times. It simply submersive.

Instruments have good details but the resolution and level of transparency is not high. Upper mids have good energy and details but the instruments before and after the vocals can be slightly mushy.


What? Are you still here? Are you not convinced? This is the IEM for you!! Go get it.

If you still are reading on, either you are just curious or like to do some critical listening at times, if you do, this IEM might not be for you. The treble region is not bad, it has good extension and reasonable relevance but doesn’t have a lively feeling to it. The spark isn’t good. It’s doesn’t have any offensive feel to it, which is a positive. Layering and separation are not class leading. Micro details are not exactly present in the treble region.. This has two conclusions. 1. It’s a bass lover’s delight, let’s you enjoy without interruption. 2. It’s not for those looking for treble details.


Serial has good stage expansion, it’s not very big though. Stage height is good near the head but gets better at the upper mid lower treble region which are placed out of the head. The Z-Axis is very good for the price but the X-axis could have been better.

Nearly 80% of the lower end notes are placed inside the head. Vocals have reasonable presence out of the head while 95% treble notes are placed out of the head. Cue placing abilities of this IEM is very good too. It’s dynamically adjusting stage gives it very good sonicality.



VS Audiosense T800 and Campfire Honeydew:


Hmm, waited for the conclusion? Aight, let me give it to you in simpler words.

Serial is for a bass lover who wants excellent texture, layered notes, excellent sub-bass with meaty mid bass. It does not unload a huge punch or volume but the experience is satisfying. The slower decay helps a lot too. Serial is suited for enjoying the music, its melodious and calm. If you want a lot of details, attack and traction, you can look at other options like Audiosense T800 and even the Shozy B2 makes more sense.

This is it guys, enjoy!!



Suman Sourav Meher

Suman Sourav Meher

My humble audiophile journey started in 2010, when I was in college, where I fell in love with the elements, nuances, and variations of this mesmerizing world. The ability of tiny earphones to recreate amazing sounds made my bad days tolerable and good days better! Now I am a full-time audiophile with a preference for musical tracks, especially vocals and engaging ones. I must admit I am addicted, but not to drugs or alcohol, but to earphones. Come join me as I share my experiences, bad or good, and let’s have some fun!


One Response

  1. The review style is awesome. Penon Serial, indeed is a tempting iem with its gorgeous looks and sound profile. Thanks for making it obvious!

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