Zero Audio Carbo Tenore

The Zero Audio Carbo Tenores have been my go-to whenever someone asks me for an in-ear recommendation. Clear, detailed, and fun, with a reasonable price, they are hard to beat.

Fit and Form

 These headphones came to me in a fairly mundane package, nothing too spectacular. They come with a cloth carrying bag that I found to be only marginally useful. They come with a good assortment of ear tip sizes, and luckily some small enough to fit well in my ears. They are supremely light and small, and I have had no issues with them falling out or losing grip on my ears.

The design itself is attractive and amicable. They are essentially small tubes leading up to the ear tips, with what I believe to be a real, but thin, carbon fiber inlay that wraps around them. The design is fairly minimal and unobtrusive, but appreciable up close. Microphonics are fairly noticeable, but only in movement.

The 1/8” connector has a right angle and is all plastic. The cable and connector are both very thin, almost delicate. In my two years of owning these, however, I have had no issue with stress breaking any connections or cabling.


These are an incredibly fun pair of headphones. Their V-shaped sound signature is emphasized, but not overly so, and they remain clean, detailed, and articulate in all ranges, with a hint of sibilance in their treble. The soundstage is fairly impressive, particularly with binaural recordings. They have good radius, good front presentation, and good height, especially for a pair of IEMs. Separation and imaging are good, but not stellar. There is a little bit of blurriness in the distinction of instruments and of placement.

This headphone performs well with most any genre. They do particularly well with more bass and treble heavy genres, as their mids are slightly recessed. I found they did best with modern pop, electronica, and hip hop. However, I really cannot overemphasize that these are great all-arounders.


Songs used: Viol by Gesaffelstein, Helix by Flume, and I Never Woke Up in Handcuffs Before by Hans Zimmer

The bass on these headphones is very, very satisfying. Although it isn’t the cleanest in the world, it certainly isn’t muddy by any means. There is little bleed into the mids. It has good punch and slam, with satisfactory depth, all the way into its sub-bass. The driving bass that underlies “Viol” shines through clearly without overpowering the other frequency ranges. Additionally, it is reasonably fast and responsive, although it can get tolerably sluggish in dense, intense sections.

Key descriptors: impactful, fulfilling, and dense


Songs used: How Far I’ll Go by Lin-Manuel Miranda, Spain by Jake Shimabukuro, and Jolene by Dolly Parton

Although I mentioned above that the mids are slightly recessed, they are absolutely stellar. To me, they are the highlight of this headphone. They are lush and detailed in comparison with headphones and IEMs that are far out of their price range. The delicate and intricate plucking of Jake Shimabukuro in “Spain” are nothing but beautiful through these IEMs. You can, however, notice their recession in the vocals of “How Far I’ll Go”, as the vocals sound just ever so slightly under-mixed. The same effect was noticeable to me in “Jolene”. Overall, the mids that are presented by these headphones, if slightly recessed, are detailed, responsive, and warm.

Key descriptors: lush, detailed, and fast


Songs used: Morphogene by Machinedrum, Ageispolis by Aphex Twin, and Davy Jones’ Locker by Panda Bear

This range is the low point of the headphones for me. It is a relatively high low, if that makes sense, but compared to the other ranges, it still ranks slightly lower. The treble is very detailed and (inspired by “Morphogene”) squeaky clean, but they err on anemic and can get a little bit sibilant at some volumes and in some tracks. However, when they are not sibilant, they remain clean and clear.

Key descriptors: clean, detailed, and sharp

Minutia and Miscellaneous

There isn’t much minutia to these headphones; they are simply a relatively cheap, engaging, and fun pair of headphones. Isolation is extremely good with little leakage; you may find yourself the victim of being snuck up on when you have these in while playing at reasonable volumes.


If you’re in the market for a reasonably priced pair of IEMs with a fun sound signature that doesn’t throw out detail, separation, and soundstage, these are for you. They are budget beaters with good sound, a good design, and are just all around good. My only gripe is that the treble can become sibilant in some tracks at some volumes, but I rarely had that issue in general use.


These headphones were not provided to me by Zero Audio, 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, a Moto X, and by whatever soundcard is in the motherboard of my computer.

I have had these headphones for two years, and they were my main driver for about six months.

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