General Information

Carbon is unique. Lab grown diamond meets Neil Diamond. The ultimate statement in resolution, with distortion below any other IEM we know of. Transparency starts and stops with C. Enough fun built in to make listening to any style a joy, but revealing enough to hear any detail buried in the mix.

The sleek, all-black construction just screams “I AM SERIOUS”. But the smiles it will induce will call that into question. Perfect with any source, from a tablet to a cellphone to a $10,000 rig. A big-screen experience with the clarity of a microscope. Micro and macro dynamics for an unrivaled listening experience.

The C (Carbon) IEM utilizes a lab-grown diamond layer (8 microns) on our own proprietary high-temperature polymer substrate. All components inside our IEMs was 100% designed and tooled in-house, resulting a totally unique product.

The sonic signature of the C IEM is an interesting mix of Ti and Be, with the enhanced bass response of Ti but the high-end extension of Be. It is well-suited for electronic music or anything with fast transients and extremely wide frequency response. C has the lowest THD of any IEM we have made, by a fairly wide margin.

All our IEMs feature polycarbonate bodies for high strength and zero resonance, custom front-and-rear tuned volumes, MIM logo caps, butyl rubber strain reliefs, and N48H grade magnets. Carbon sports a matte-black rear cap for the ultimate low-key, stealth look.

Latest reviews


Headphoneus Supremus
Pros: decent performance, depending on tip selection and personal fit
reasonably sparkly and extended highs
prominent low end
Cons: below average soundstage size and separation
fairly unremarkable performance-price ratio
non-detachable cable
3.5mm SE is the only option
awkward fit (for me) in terms of getting a good seal
poor L/R earpiece identification
poor value proposition overall

A warm welcome to you all!

Well, today I shall be gracefully gliding into uncharted waters with the second of a pair of reviews of two IEMs by Periodic Audio.

For those who don’t know (and this category of reader until recently included Layman1), they are a California, USA based company, with the apparently revolutionary mission statement of producing portable audio products with “high quality audio performance”.

I’m not sure any portable audio company sets out without that goal in the forefront of their plans, but let’s see if Periodic Audio are able to deliver on this :)
Whilst I’d heard a bit of a positive buzz about the Periodic Audio Be a couple of years back, I had no awareness of the origins or character of the company itself.

I took a look at their website as part of my research for these reviews (Layman1 being the kind of diligent chap who views cutting corners as an activity reserved for Formula 1 drivers etc) and you certainly have to admire their chutzpah :)

I’ll include here a link to the ‘Customer Care’ page on their website.
I encourage you to scroll down to the ‘Returns’ section, and have a read.

It’s quite amusing, although I can see the potential for that humour to backfire somewhat, were a customer to be in the unfortunate position of having encountered a product defect or suffered a cable failure or similar.

Still, I suppose it speaks volumes to the company’s faith in their products. They offer a 5-year warranty, although as ever, it pays to read the small print.

The warranty only applies if you register your product on their website within 30 days of purchasing the product. On behalf of the Layman1 Public Information Service, you’re welcome :)

Furthermore, the warranty period is reduced to 2 years for those outside the USA.
I’m not sure which warranty period would apply if one were to buy the IEMs whilst travelling/working in the USA but then return back to one’s home country and subsequently find cause to make a claim?

Damn it Jim; I’m a reviewer, not a lawyer! I shall leave such ruminations to those with greater legal minds than I, and pray that such a ‘test case’ never has cause to come before a court :)

Well, let us move on to the whole point of this endeavour, namely an IEM review.
Today, I’ll be reviewing the Period Audio Carbon.

By way of a time-saving hint, each model in their entire IEM line-up is named after the material from which the dynamic driver diaphragm is made.

In this case, carbon, which their website reliably informs me is ‘a lab-grown diamond layer (8 microns) on our own proprietary high-temperature polymer substrate’.

They go on to note that ‘The sonic signature of the Carbon IEM is an interesting mix of [the sound signatures of our] Ti and Be IEMs, with the enhanced bass response of Ti but the high-end extension of Be. It is well-suited for electronic music or anything with fast transients and extremely wide frequency response. C has the lowest THD of any IEM we have made, by a fairly wide margin’.

All details can be found on the appropriate product page of Period Audio’s website (link below), and the IEM may be able to be purchased there (it may be listed as ‘out of stock’) and delivered to locations around the globe. It can also be purchased from various other dealers of course too.

It would be remiss of me not to note that they sometimes have an option on the product page to purchase a ‘Blemished’ (a.k.a. ‘B-stock) version of the IEM at a substantial discount.

The RRP at time of writing for a regular unit was a $399, placing it – financially speaking - at what I suppose these days would be around the lower quadrant of mid-range pricing.

My sincere thanks to John at KS Distribution and the team at Periodic Audio, for providing me with a review unit to keep in exchange for an honest review.

For readers in the UK, the IEM can be purchased here (other stockists may be available):

Note that at the time of writing – Dec 2020 – these can be purchased at a 40% discount for £239.40! Offer subject to change and all the usual disclaimers. I’m just informing you all as I noticed this when I went searching for the web link :)

Well, a longer-than-usual preamble today, but I shall leave you waiting no longer.
Let us plough rapidly on ahead like a tractor with the turbo boost engaged (I think I watched too much Knight Rider), and see what this product actually looks like :)


Unboxing, packaging and accessories:

The packaging – in keeping with the mission statement of the company – is what I would tactfully describe as ‘minimalist’, with all unnecessary bells and whistles stripped away.

There’s a pleasingly comprehensive array of eartips provided, two useful adaptors (a double mono airline adaptor and a 3.5 to 6.3mm adaptor) and a carrying case, which Periodic Audio describe as being ‘sized to fit inside the coin pocket of your favourite jeans’.

Layman1 being the kind of dapper gentleman-about-town who would never be caught dead slumming it in a pair of jeans* was forced to seek out an appropriately attired Everyman from amongst the proletariat in the street and beseech temporary usage of the smallest pocket of his jeans. After explaining the subsequent unfortunate misunderstanding to the very nice policeman who intervened shortly afterwards as I was forced to employ my stout stick, I can now confirm that the tin is indeed pocketable, as well as a most vivid – dare I say ‘bling bling’ - golden colour.
*NB: the entirety of this paragraph may in fact be a work of utter fiction.

The cable here is of an unspecified material, thin, glossy black and springy.
The cable feels fine in daily use and I haven’t noticed any other issues with it.
Unfortunately, the pleasant cable feelings ended at this point.

As my regular readers – hello Head-Fi moderators! – will know, Layman1 is of the opinion that a special place is reserved in hell for those manufacturers with the temerity to supply a cable with 3.5mm SE as the only choice on anything above an entry level product.

Worse still would be the cardinal sin of supplying a non-detachable cable. Could you even imagine someone committing both such atrocities?! Oh, the horror! :fearful:

Regrettably, Periodic Audio flagrantly disregard such sentiments on their entire IEM line-up and so here we have a $399 IEM with a fixed, non-detachable cable, terminated in 3.5mm SE. I think I can feel my face twitching convulsively, even as my fists clench involuntarily and I tremble with barely-suppressed fury.

I try to be a self-reflective kind of person, especially when faced with something that I feel is inducing rage-face, spleen-ventage and suchlike :)

So, in fairness to Periodic Audio, they are trying to produce bare bones products where the focus is solely on sound, performance and value for money with all extraneous clap-trap stripped away. Furthermore, they want their IEMs to be able to work on all the most commonly used devices and they engineer them robustly such that mechanical failure should not be an issue (and back this up with the aforementioned warranty).

So, from this perspective, one could argue that the cable configuration here is not an unforgivable act. Still, I really would have liked the option to be able to try out different cable options at home, and certainly to be able to plug the IEMs into the 4.4mm balanced output of my DAP in order to extract a superior performance from them.

Finally, a note about markings. There are no external markings that enable one to determine the left earpiece from the right.

They had what probably seemed like a great idea at the time, of colouring the mesh of the right nozzle red, but I would tactfully suggest that whilst this would be a nice added touch, it cannot be the only such indicator in order for this to be practical and functional on a daily basis. Use of ear tips with built in wax filters immediately negate this functionality, as does the use of the IEMs in anything less than optimal light conditions.

Just poor design choices I feel.

The Fit:

I have now tried a staggering three different IEMs of this cylindrical-barrelled shape and form factor (I think the Flare Audio 2 Pro was the last one) and for some reason they just do not agree with my ear anatomy.

I have tried various tips including my usual go-to options of New Bee foam tips and Sedna Xelastec tips, but I found the foam tips to veil the sound of the IEMs somewhat, reducing soundstage size and separation, whilst making the low end sound somewhat flabby and undefined.

But with the Xelastec tips, I can hear quite significant differences in the sound signature depending on how deeply/tightly they are inserted, and worse still a frequent change in sound signature depending on how my head or jaw are positioned at any one time.

So this has made the review process somewhat challenging, and I trust you will take this into account – as I have – during my impressions.
The flip side of this is that for others, these may well be a perfect fit, with any and all ear tips.

The Sound:

You may or may not be a ‘believer’ of burn-in (or brain burn-in).

I personally feel that with dynamic-driver based IEMs, the burn-in process has an effect on the low-end performance, and with this in mind, I burned in this IEM for around 200 hours. Because I figure that even if I’m wrong, at least I have peace of mind either way, and no-one can later say “oh, but your impressions would have changed if you’d burned them in a bit longer” :)

I used the Sony WM1A (single-ended output, grr..) for the purposes of this review.
Similarly, I used only the stock cable (grr…).

Let’s take a look at what this all adds up to, sound-wise :)

Low end:
Good sub-bass extension and what seems like a fairly equal emphasis on sub-bass and mid-bass; perhaps slightly more mid-bass presence, or perhaps it’s just a bit more noticeable on certain tracks? It has a most pleasing amount of impact and rumble.

I hear it as a faster and more accurate bass than that on the Be model, more in balance with the rest of the sound signature. I suppose the only negative is that it subsequently provides less of the meaty and full-bodied sound that I did enjoy on the Be model (and other IEMs), but that’s just a matter of personal preference.

I feel on some tracks that there’s still a bit of that muddiness in the bass that I disliked on the Be, which decreases my enjoyment of the music and veils the vocals somewhat. This seems to occur on songs that are mastered in a more warm, intimate and analogue way. It’s certainly not as pronounced as I was hearing with the Be, but it’s there sometimes.

The strings on my regular classical opera test track (Alison Lau’s performance of Handel’s Lascia la spina in 24-96 HDTracks) sounded reasonably rich and with a tasteful amount of body and weight.

Her voice, which soars very high indeed in this song, did not trigger my treble sensitivity, although it did come close at times, certainly much closer than with the Be model.

On Paul Simon’s ‘The Coast’ (again 24-96 HDTracks), the levels of detail highlighted were delightful. The imaging is fantastic, but the weak point of the IEMs here is that the somewhat limited soundstage size and separation fail to do justice to the song (or indeed to the imaging abilities of this IEM!).

On ‘Fast Times at Dropout High’ (by The Ataris, and specifically the alternative version from the ‘Silver Turns to Rust’ album) the opening electric guitar has a fair amount of body and weight. There’s a lot of detail and clarity which make for a great presentation and timbre, but still the bassline somehow conspires to add a slight bit of muddiness to the signature, although that may just be down to the mastering of the track.

Again, I find the vocals to sound slightly recessed on some tracks. I think spatially they are positioned pretty much dead centre, but again, something of that slight veil/muddiness seems to make them sound just slightly hidden in the mix on some tracks. Again, this tends not to be an issue on songs where there’s limited bass presence.

This reminds me quite a bit of the Be model.
I hear this as being slightly better and more extended, although with some variability. On songs light on bass activity, it sounds quite extended, with a fair degree of openness and air.

There’s a more sparkle and clarity here too. However, when there’s a solid bass-line in a track that’s mastered warmly or intimately, I do feel these effects to be lessened unfortunately.

Technical Performance:
I found the soundstage size, in all directions, to be just average – or even below average for this price point. That perception is further emphasised on bassy tracks.

Similarly, I felt the layering and separation were acceptable, but nothing praiseworthy stood out to me during all of my critical listening.

Micro detail presentation seemed to be quite good though.

Timbre was a mixed bag; there was a touch of warmth and richness in the mids, which gave a little bit of body to vocals and instruments, but the intimate soundstage and small degree of separation seemed to make the mids and vocals seem a touch recessed and slightly muddy at times.


This has been a tough IEM for me to review, due to the trouble I’ve had with getting a good fit.

I will be the first to put my hand up and declare that – despite trying various ear tips - I’ve never felt like I had a really secure and stable seal on anything but the foam tips, which unfortunately for me had the effect of exacerbating what I found to be the negative qualities of the IEMs, namely a weakness on warm/bassy/intimately mastered tracks, which sometimes limited the performance of the IEMs.

Conversely, with the Sedna Xelastec tips, I could get various different sound signatures depending on how deeply I inserted them or how tight the seal felt at a given moment.

I’d have flashes where the sound signature would lose it’s bassiness and the soundstage would open up, and other times where it sounded more rich and engaging, but the moment I moved my head, or drank something, it would disappear again.

So it’s been quite a challenge to pin down a concrete description of the sound here.

Overall, based on what I've heard, I’d describe these merely as decent IEMs. They certainly aren’t bad, and for those that enjoy a more intimate sound signature, they offer a pretty solid performance.

I do feel that they outperformed the Be model, for my taste, although I did enjoy the meaty and rich mids on that one.

However at this fairly substantial price point, I can’t say that what I’ve heard is good enough for me to enthusiastically recommend these IEMs at $399, especially when I factor in the non-detachable cable and 3.5mm only connection which I personally feel are simply inappropriate for IEMs at this price point.

On top of all that, there’s the poor functionality in terms of clearly being able to identify which are the left or right earpieces due to the ‘coloured grille’ solution employed here.

As ever though, listening to a demo model prior to purchasing is highly recommended.
I’ve seen several 4.5-star glowing reviews for this IEM, so it seems it’s doing the right things for some people! It could simply be down to fit.

The company talk a good talk on their entertaining website, and it’s nice to see IEMs designed and built in the USA. Conversely though, if their latest IEMs (the Ti and Mg models) have been released since the various reviews of this one, then it perhaps shows a lack of engagement and responsiveness if they are still not employing any kind of external markers to help people to identify the left IEM from the right. Ditto the non-detachable cable and plug choice, but that’s perhaps just a design policy decision from the company that may not change.

So overall, I’d encourage you to give these a listen before buying if possible, if my (or other people’s) reviews have piqued your curiosity. And experiment with different tips :)

Ok, Christmas is coming (at least, it was at the time I wrote this!) and so it’s time to wrap things up.

See what I did there?

A belated gift of festive jollity for you all, from Layman1. Ho Ho Ho :D

If my painful attempts at humour haven’t scared you off, I’ll be back in the new year with more reviews. Until then, stay safe and all the best! :)
They do a LOT right but let's focus on the negatives, right? Your review was to advance your agenda. I've listened to enough IEMs to know what sounds good. Periodic Audio is expensive but they are worth it if quality audio and Made in America matters to you. I could care less about cables and the non-sense. These just sound fantastic. The BE's are really, really good, too. I didn't like their Ni Amp. Their Rhodium product is a nice add.
Hey there chaps...might someone venture an opinion on how they think these would go with removed nozzle-filters? I'm not really enjoying them at all, as they sound the very opposite of 'clean' to me.. .everything sounds texturally awful, all 'chewy' and rough as guts, really, and on most tracks i play the bass is just a formless boom.

But i don't want to give up on them! I know how downright weird and surprising the changes in relationships to one's iems can sometimes be.. So again, if anyone is still reading these reviews of C, do you think it will make things better or worse by removing filters?
I have a set of Be's and C's. My 'red' screen fell out after a couple of years of heavy usage. I contacted Dan at Periodic Audio and he said they're there to help keep the drivers clean from ear wax/debris and to identify R/L. I don't notice a difference in sound on my Be's without the right side screen. You can remove the screens on the C's and see what you think but I don't think it will make any difference. My C's a little darker than the Be's but they are far from your description. Defective pair? Poor source quality? Other issue affecting SQ?

Dobrescu George

Reviewer: AudiophileHeaven
Pros: + Great sonic performance for the price
+ Comfort is also great
+ Shape is very basic, stealthy solution
+ Clarity is top notch
+ Deep, but controlled bass, great clarity and depth
+ Easy to drive
+ Great support from Periodic Audio
Cons: - Cable and build doesn't inspire quite as much trust as the sound
- It is a bit pricey
Ready for the Bass - Periodic Audio Carbon IEMs Review

Periodic Audio priced their latest IEM, the Carbon at about 400 USD, which makes it a direct competitor to some really capable IEMs, like Periodic Audio Be, HIFIMAN RE800 Silver, and FiiO FH7. As far as pairings go, we're still waiting for the Periodic Audio DAP, so for now the pairings will include FiiO M11, iBasso DX160, and xDuoo X20. Let the bass cannons loose!


Periodic Audio has had their own thing going on, with using specific materials for their IEMs for a while now, and it has been working quite well. This being said, their IEMs are usually made with non-removable cables, and although most of them hold up really well to the test of time, they aren't exactly the easiest to recommend to those who are concerned about long-term reliability. Periodic Audio decided to do something about this, so they have one of the best warranties I've seen, and they will be happy to help if anything is to happen to their IEMs, so don't be afraid to purchase from them, especially if you're from USA, where their main HQ is. I reviewed their Periodic Audio Be, Periodic Audio Titanium, Periodic Audio Nickel and even the Periodic Audio Magnesium.

It should be noted that I have absolutely no affiliation with Periodic Audio, I am not receiving any incentive for this review or to sweeten things out. I'd like to thank Periodic Audio for providing the sample for this review. This review reflects my personal experience with Periodic Audio Carbon Ca. Every opinion expressed is mine and I stand by it, the purpose of this review is to help those interested in Periodic Audio Carbon find their next music companion.

About me


First things first, let's get the packaging out of the way:

The package of the Carbon is the same as pretty much all of the other Periodic Audio IEMs. It is never boring, and always offers a good half an hour of reading, increasing the knowledge of the buyer with bits of really intriguing information (at least if you're half as nerdy as me).

You also receive the IEMs, a metal carrying case, and a huge number of tips. There's an airplane adapter, and also a 3.5mm to 6.3mm adapter too, designed to make the Carbon usable with as many sources as possible.

Somehow, the package is not bad, and although not everyone will like the overall Periodic Audio package, because they have a really different package from most companies, it includes almost everything that FiiO FH7 includes.

What to look for when purchasing a high-end In-Ear Monitor

Build Quality/Aesthetics/Fit/Comfort

The build quality of the Carbon is good, but this is a really basic IEM. In fact, it is so basic, that people will never know the real price and the real value of them just by looking at them. They will just need to take a listen, and they will understand, but until they do, Periodic Audio Carbon looks really simple and basic. It is different from the other Periodic Audio IEMs in the back, because the cap at the back of the IEM has a darker color than most of them, but otherwise, it is pretty much the same.

The Left and the Right Earpieces are defined by the color inside the earpieces, and the comfort is actually pretty good. There is no driver flex, and no real void, although I would be careful when inserting and taking out the Carbon, as they are dynamic driver IEMs.

The cable is pretty thin and doesn't look quite as trusty as that of other, higher priced IEMs, but that isn't a big issue as most units never had any issues. It is a bit problematic when you look at it though, and for the price of the Carbon, I am hoping that Periodic Audio will include detachable cables in the near future.

For an IEM that is this featureless, and which has a pretty simple dynamic driver inside, there's not much more of an explanation to give about the tech inside, so we can move it to the sound quality, which is the main point of the Periodic Audio Carbon.

The comfort is top notch really, and since you can wear them both straight-down and over-the-ear, I could say that they are versatile in what they give you as options for wearing. The tips included are also pretty good, although I would recommend experimenting with Spinfit too. Foam tips are not really recommended, because the sound is already pretty thick and bassy.

Sound Quality

The sound has bass, bass, and most definitely bass. Of course, it wouldn't be Periodic Audio if it didn't have treble extension, musicality and a nice stage too, but the sound really centers around the bass, which is powerful, and in terms of quantity, may very well be the IEM with the most bass I have heard up to this point. You could say that they are also moderately V-Shaped, because despite the large amounts of bass, Periodic Audio didn't leave the treble out, and the midrange feels recessed when compared to the lows and the highs.

The bass makes itself heard in every track, every song, but it is a fairly clean type of bass without distortions. It is large, but also flows naturally, with excellent extension down to the magical 20 Hz, which makes the Periodic Audio Carbon a really good IEM for bassheads. The bass has that audiophile quality, so I don't feel the need to turn it down, and the even better part is that the bass has a tight speed to it too, so it is never bloated, and I never felt like it was boomy. The entire sound is thickened by the bass, and the midrange has a thicker, smoother presentation, so the bass does bleed a bit in the entire sonic presentation, but it has a good quality to it, makes music enjoyable, very similar to the way FiiO FA7 presented music.

The midrange is recessed when compared to the bass, and the mids feel musical, and somewhat smooth, with the textures being expressed in a musical way, rather than a dry, revealing way. The tonality is fairly good, although in general the Carbon is a slightly sweet sounding IEM, so it works better with happy music, especially EDM, and pop music, rather than sad music. Both female and male voices are fairly natural, and the fact that it is bassy doesn't affect the vocal presentation, although the voices are pushed a bit back compared to the bass and the treble. This works very well for me, and if you don't know yourself to be a mid-forward signature lover, the Carbon will work well for you. This is because most people are actually looking for either a V-Shaped sound, or a moderately V-Shaped sound, rather than a full blown linear sound. The textures are slightly smooth, but the clarity and the detail levels are up to the price point of 400 USD. You could call the mid a full-bodied sound, and a pretty impactful / punchy one too.

The treble is a mixed bag, because it is not recessed, which is great, but it isn't quite where I'd want it to be in terms of sparkle. This is not a negative, and it will be quite excellent for most people, especially since the treble is never sibilant nor fatiguing nor harsh, but the treble can lack that ultimate bit of extension and aggressive touch, so the Carbon is best suited if you enjoy an energetic, yet slightly smoother treble, or if you listen to anything except for metal, which tends to require a slightly more aggressive signature.

In terms of soundstage, I noticed a perfect imaging, really good instrument separation, and a fairly natural soundstage. The dynamics are top notch, and dynamic drivers manage to have quite a bit of headroom and sound quite dynamic, the sound coming through as really punchy and lively. The stage is room sized, and music that's supposed to sound a bit larger will sound a bit larger, but the stage doesn't really go beyond what I would call a room-sized stage.

Portable Usage

The portability of the Carbon is quite excellent, as they have a fairly flexible cable, a great comfort, no driver flex, and can be driven easily too.

This being said, the cable has a tiny bit of microphonic noise if worn straight-down, and especially if you do a lot of activity. If you want to use the Carbon for physical exercise, it is best to wear them around the ear, as straight-down you'll get quite a bit of microphonics.

The drive factor is good, although I would not use the Carbon with anything below a HIDIZS AP80, or a Shanling M2X. FiiO M6 would work fairly well too, and there's also a portable DAC solution that you can go for. You cannot use iBasso DC01 because it is balanced, and you need to search for the single ended one, as the Carbon is single-ended only and cannot be used with a balanced output. This is actually a fairly big thing to take into account, the cable is there to stay, and it isn't quite as good as the default cable that other IEMs in the price range come with, so if you don't like a simple, bland cable, the Carbon may not satisfy.

For the best results, I recommend using a midrange DAP, as the Carbon scales well, so anything like an iBasso DX160, FiiO M11, or even an Opus #3 would do. The Carbon is not quite that hiss sensitive, but they have a low impedance, so something like Hiby R6 is not recommended, as it has a high output impedance and the Carbon will hiss a bit with it.

Periodic Audio Carbon is easy enough to drive that I would recommend using it with something that has a lower output power, and it could do just fine with the likes of Audirect Beam, Earstudio HUD100, FiiO BTR5, FiiO BTR3K, and even something like the Pro-Ject Pre Box S2 Digital. The carbon will pair better with brighter, more neutral sources, rather than smoother sources, since it is already pretty smooth, and it already has a musical sound.

Youtube Video


The comparison list includes Periodic Audio's own Be IEM, FiiO FH7, and HIFIMAN RE800 Silver, all of those making great alternatives, with very different sonic signatures.

All of them have a similar price point too, although from this little comparison list, FH7 cannot be used straight down, while the other two can.

Periodic Audio Carbon vs FiiO FH7 (400 USD vs 470 USD) - FH7 is a bit more expensive than the Carbon, but they also have more overall quality to the build an to the package. The cable is much better for FH7, but they can only be worn straight-down, and the Carbon will work better for smaller ears than FH7. Both IEMs have good comfort, and both come with a large number of tips. The cables for HF7 are detachable, and FH7 is slightly easier to drive than the Carbon, but they are also slightly more sensitive to hiss in practice. The sound is wider, with more overall space for FH7, quicker, but also considerably colder, has less bass, with less emphasis on musicality, and more emphasis on revealing abilities, clarity, and has a more analytic presentation in general. FH7 has considerably more treble sparkle, and it works better for atmospheric music, where the Carbon works a bit better for EDM, Pop and commercial music.

Periodic Audio Carbon vs HIFIMAN RE800 Silver (400 USD vs 600 / 300 USD) - RE800 Silver has a larger package than the Carbon, but with slightly less extras, and with less ear tips included in the package. This being said, the comfort is better on RE800S, because they have a smaller body, and a slightly better cable than the Carbon. The sound of RE800 is much brighter with more treble quantity, but this also means it has better detail, clarity, and a more natural sound. It is less musical and more aggressive in general, and can become fatiguing quicker than the carbon, but the Carbon works more for slower music, Jazz, Classical, Slow Pop, where RE800 Silver works much better for Rock, Metal and uplifting / aggressive music.

Periodic Audio Carbon vs Periodic Audio Be (400 USD vs 300 USD) - The Berilyum is less expensive than the Carbon, but they also have a more musical sound, the same fit and ergonomics, and just like most Periodic Audio IEMs, they have exceptional support from the company selling them. This being said, the sound has less depth to the bass, with a slightly more balanced overall presentation that is quicker in the bass, is thinner, more natural, and with a better extension to the treble. The Carbon feels like it kept the musicality, but it feels like it is darker, thicker, and more impactful / bassy than the Be.

Recommended Pairings

The pairing list includes FiiO M11, iBasso DX160, and xDuoo X20. There are other DAPs that would work well too, and you could go crazy and even use something like the Mytek Brooklyn DAC+ if you wanted, the Carbon scales well up to that point.

Using Periodic Audio's Nickel is also quite a good idea, making the sound even smoother, and giving it more punch / power, but if you need a high-quality DAC/AMP, I would recommend going with Chord Mojo, FiiO Q5s, iFi xDSD, or something like the Earmen TR-AMP. Since the Carbon is easy to drive, even low-power DACs like the Earstudio HUD100 are a great match.

Periodic Audio Carbon + iBasso DX 160 (400 USD + 400 USD) - iBasso DX160 is the most well-rounded midrange DAP in 2020, and it still holds the crown for the easiest to recommend DAP for mid range headphones and IEMs, so it won't be missing from the pairings with the Carbon either. The sound of this pairing is clean, clear, and has the signature that I describe usually for the Carbon, the DX160 is transparent, so it doesn't color the Carbon in either direction, making the best possible out of their default signature.

Periodic Audio Carbon + FiiO M11 (400 USD + 400 USD) - FiiO M 1 1 is a really versatile DAP, with Streaming, good battery life, and way more than enough driving power for the Carbon. The sound of M 11 always had a bit of a digital glare in the treble, and this type of slightly brighter sound works exceptionally well with the carbon, and it makes them more balanced, with more sparkle and more detail, better overall clarity and gives them a slightly wider soundstage, while keeping their exceptional imaging and separation.

Periodic Audio Carbon + xDuoo X20 (400 USD + 200 USD) - X 20 is a DAP that always sounded a bit bright and dry in my experience, and that pairs perfectly with the Carbon, because they are already a bit warm and bassy, so the more analytic character of X20 makes them pretty well balanced and gives the entire sound a good clarity, without taking any of the musicality, and the sweetness out of the mix.

Value and Conclusion

The value of the Carbon is actually fairly good, at least when you consider their comfort, sonic quality, and ergonomics alone. The things that would potentially hold it back are the bland design, that may not work so well for everybody, and the cable, which is not detachable, and which doesn't look quite as strong as other cables, even those of Chifi IEMs.

You can pardon the cable when you unbox them, because they have an awesome package, and you can also stop thinking about it when you wear them. In fact, allowing both straight-down and over-the-ear wearing, the Carob is one of the very few IEMs that is this versatile nowadays, as most really high-quality IEMs are over-the-ear only. This being said, they do suffer from a bit of microphonic while being worn straight-down, but that is not present while wearing them over-the-ear. There is no driver flex, and they are easy to drive, not being very sensitive to hiss either, so most DAPs will do just fine.

The sound is grand, explosive, punchy, and dynamic, with a strong, yet clean bass, a midrange that's slightly recessed, but sweet, musical and fun to listen to, and with a treble that has some bumps, enough to make the sound enjoyable despite the larger bass, but still doesn't come through as fatiguing or as too much.

At the end of this review, if you need a simple-looking but good-sounding IEM, something that places function above form, and has a beautiful warm, bassy, punchy, deep sound, with good imaging and separation, and a sweet tonality, and which is priced at about 400 USD, you should totally check out and consider the Periodic Audio Carbon, which once again, does not disappoint.

Full Playlist used for this review

While we listened to considerably more songs than those named in this playlist, those are excellent for identifying certain aspects of the sound, like PRaT, Texturization, Detail, Resolution, Dynamics, Impact, and overall tonality. We recommend trying most of the songs from this playlist, especially if you're searching for new most, most of them being rather catchy.

Youtube Playlist

Tidal Playlist

Song List

Bats - Gamma Ray Burst: Second Date

Eskimo Callboy - Frances

Incubus - Summer Romance

Electric Six - Dager! High Voltage

Kishida Cult - High School Of The Dead

Dimmu Borgir - Dimmu Borgir

Breaking Benjamin - I Will Not Bow

Thousand Foot Krutch - The Flame In All Of Us

Gorillaz - Feel Good Inc.

Infected Mushroom - Song Pong

Attack Attack - Kissed A Girl

Doctor P - Bulletproof

Maximum The Hormone - Rock n Roll Chainsaw

Rob Zombie - Werewolf, Baby!

Escape The Fate - Gorgeous Nightmare

SOAD - Chop Suey

Ken Ashcorp - Absolute Territory

Machinae Supremacy - Need For Steve

Ozzy Osbourne - I Don't Wanna Stop

Crow'sclaw - Loudness War

Eminem - Rap God

Stromae - Humain À L'eau

Sonata Arctica - My Selene

Justin Timberlake - Sexy Back

Metallica - Fuel

Veil Of Maya - Unbreakable

Masa Works - Golden Japang

REOL - Luvoratorrrrry

Dope - Addiction

Korn - Word Up!

Papa Roach - ... To be Loved

Fever The Ghost - Source

Fall Out Boy - Immortals

Green Day - Know The Enemy

Mindless Self Indulgence - London Bridge

A static Lullaby - Toxic

Royal Republic - Addictive

Astronautalis - The River, The Woods

We Came As Romans - My Love

Skillet - What I Believe

Man With A Mission - Smells Like Teen Spirit

Yasuda Rei - Mirror

Mojo Juju - Must Be Desire

Falling Up - Falling In Love

Manafest - Retro Love

Rodrigo Y Grabriela - Paris

Zomboy - Lights Out

Muse - Resistance

T.A.T.U & Rammstein - Mosaku

Grey Daze - Anything, Anything

Katy Perry - Who Am I Living For

Maroon 5 - Lucky Strike

Machinae Supremacy - Killer Instinct

Pendulum - Propane Nightmares

Sirenia - Lithium And A Lover

Saving Abel - Addicted

Hollywood Undead - Levitate

The Offspring - Special Delivery

Escape The Fate - Smooth

Samsara Blues Experiment - One With The Universe

Dope - Rebel Yell

Crazy Town - Butterfly

Silverstein - My Heroine

Memphis May Fire - Not Over Yet

I hope my review is helpful to you!


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Lance Rothchild

New Head-Fier
Pros: Great clarity
Fantastic, deep, tight bass
5 year warranty
Cons: Build quality
The cable is the victim of a hostage situation
Sad cable :(
Questionable strain reliefs
Soundstage (depending on your preference)
This review was first posted on my website, A huge thanks to Dan Wiggins at Periodic Audio for providing these units.

  1. Introduction

Periodic Audio is a relatively new company founded in 2016, with a mission to create high-quality audio over all else. The Carbon is the latest and most expensive model in Periodic’s lineup, clocking it at $499. The other models in the lineup are Magnesium ($99), Titanium ($199) and Beryllium ($299). You can find them at

  1. Disclaimer

This set of Carbon IEMs was sent to me, very graciously, by Dan Wiggins on Periodic Audio, in exchange for an honest review, which I intend to provide. Dan also sent me the Nickel amplifier, which I’ll be reviewing soon. Both units are cosmetically blemished.

  1. Unboxing

The Carbon IEMs arrived in an unmarked cardboard box, which flipped open to reveal the pieces, as well as a small, presumably aluminum tin for storage. The packaging here isn’t anything spectacular, but it protects its contents well and presents them nicely enough. The packaging, much in the vein of everything else Periodic strives to do, is incredibly functional. I have no problem with this, as long as the audio performance can justify it.

  1. Build Quality

The build quality of the Carbon is similar to its packaging. Extremely functional and utilitarian. The shells are constructed from a sturdy-seeming polycarbonate, and the cable (while regrettably not detachable), is perfectly adequate. Fancy, braided, silver-plated cable this is not. But it gets the job done. My only qualm is the fact that the strain relief coming off of the earpiece looks a little worrying. I’m not thinking it will fail anytime soon, but it’s the only part of the product which I’m legitimately concerned about in terms of longevity.

  1. Comfort

The Carbon is very comfortable, provided you find the right tips. I know this goes without saying, but tips are crucial not only in terms of sound, but also for comfort. I eventually settled on the small, double flanged tips, but may swap them out for foams later. The light polycarbonate shells sit nicely in the outer ear and do not place unnecessary pressure on any ear feature. I have worn these for several hours at a time and never felt fatigue.

  1. Isolation

The isolation provided by the Carbon is above average. It is nowhere near Shure levels of isolation. But much of that is to do with nozzle length and a deeper insertion. Conversely, the Carbon has a much larger nozzle, but with the right tips, isolation still outperforms much of the competition. I took these on a short flight and forgot about engine noise for as long as I had them in. These are great travel earphones, and I am very happy with their isolation performance.

  1. Sound Quality
Overall, the sound of the Carbon is moderately V-shaped with slightly recessed mids and a clear, transparent-sounding tonality across the entire range.

  1. Bass
Definitely prominent in every mix. Although the bass is incredibly prominent, I’m not feeling too many issues with it becoming bloomy. Perhaps that has something to do with the material of the diaphragm? Overall, the bass response feels tight and accurate, with enough punch to satisfy most people. Very realistic sounding bass, with easily identifiable instruments. Listening to Kendrick Lamar’s King Kunta, the bass, while emphasized, does not overshadow Lamar’s vocals, and I find him to still be easily intelligible. This song is carried by its bass, and the C presents it with lots of energy and enthusiasm.

  1. Mids

Recessed. They’re not horribly back in the mix, but they definitely play second fiddle to the low- and high-end. Despite this, there is a high level of detail and articulation present here. Guitar slides sound great, as well as just straight-up guitars anywhere. Oodles upon oodles of detail here. Despite the elevated bass, miss stay crisp, clear, and very resolving. I would prefer them to be a little more forward, but they’re quite good as they are.

  1. Treble

The treble on the C is not peaky AT ALL. I can comfortably say that my treble tests did not make me wince, cry, or curl up in pain. Ever-so-slightly rolled off, they sit right where they should in the mix when fun is prioritized. Mainly because I would not consider getting stabbed in the ear to be a fun experience. These portray really satisfying cymbals and do a good job of representing even more difficult-at-times high-frequency sounds.

  1. Soundstage and Imaging

Yes, of course there has to be somewhere that the Carbon falls short. The soundstage, while providing a decent sense of space and accurately placing and imaging instruments and vocals, is very small. The closed-in nature of these makes much of a lot of songs quite intimate. For some people, this may be a dealbreaker, but the imaging and separation present in the C are very good. Soundstage is small.

  1. Conclusion
Fun. Fun. Fun. These little IEMs are fun. They’re light and comfortable, they’re bassy and unapologetic, they’re incredibly in-your-face, and I happen to like them quite a lot. Many reviewers are making the build quality seem worse than it is. Even if it is as bad as they make it out to be (which it really is not), Periodic has a 5 year warranty policy, which, in my mind, negates that altogether. The C is an incredibly fun earphone that I can find myself coming back to again and again for its big, boomy bass and clarity throughout its range. If you’re looking for fun, the C has you covered.

I'm a little curious to see how these sound compared to Periodic's other offerings...

Lance Rothchild
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Nice, although the cable is really a huge downside. On the other hand, I've seen someone with BTO mmcx pins PA Be, so let your imagination run wild :D.


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