ODA Hesperus A300 Review

ODA Hesperus A300 Review

One Dot Audio – ODA Hesperus A300 Review

ODA Hesperus A300 is a recent IEM by One Dot Audio, a relatively new player in the audiophile earphone market. I reviewed their budget model the Dolphin D100 recently.

Featuring a 3-balanced armature driver design, the Hesperus is positioned to compete in the midrange of the audiophile market. It currently costs $269, which fits in the stereotypical mid-fi category for portable audio.

ODA Hesperus A300 Review


Balanced armature drivers have been widely used in IEMs because of their smallness in size and the ability to produce articulate details. However, BAs are known to have thin timbre and bass. With the 3-BA design, One Dot Audio aims to address these issues through the unique tuning and customization of their Balanced Armature drivers.

For the bass, they have used subwoofer BA drivers which try to amplify the lows. Two  BA drivers were also used to ensure mids extended treble, bringing out detail and air.

A unique offering from the A300 is its custom mid-frequency drivers that aim to give a natural timbre in the midrange region. The A300 also features a 3-way comprehensive passive crossover system, which ensures a smooth transition across various frequencies.

ODA Hesperus A300 Review


Upfront, the shell is a simple smooth blue color with a natural stone textured faceplate design. A molded shell for an ergonomic fit is also evident, observing how it’s curved across all dimensions. It’s nothing out of the ordinary, but very professionally finished.

Wearing the Hesperus A300 is comfortable even for long periods, despite the weight of the cable and drivers combined. It fits perfectly in the ears, thanks to the ergonomic contouring on the shell design.

While wearing the A300, outside noise is blocked out, making it easy to hear minute details in various tracks.

ODA Hesperus A300 Review


One Dot Audio did not skimp on the cable. It’s made up of 4 core ultra-pure grade oxygen-free copper which offers excellent conductivity for clean sound transmission.

From the outside, it’s a 1.2 m four-braided core laminated cable with a grey tint that compliments A300’s shell. It is terminated with a gold 2-pin 0.78mm and has a 3.5mm gold plug.

Stock cables add a noticeable weight when moving around. However, the effect on microphonics was subtle and was not bothersome. The wire sits comfortably at the back of the ears, with good memory retention, which adds a layer of secureness.

ODA Hesperus A300 Review

What’s in the box

Inside the box, we will find 6 pairs of ear tips with wide bore and double flange types in 3 different sizes, and an OCC 4 core cable that has a grey color that matches the in-ear theme. The cable has a 3.5mm termination and a metal Y-splitter. Overall, they are packaged quite well and feel premium for the price.

  • Hesperus A300 earphones
  • 2-Pin 0.78mm to 3.5mm 1.2 meter Cable
  • 6 Pairs of ear tips
  • Cleaning brush
  • Premium leather storage case


  • Drivers: 3 x Balanced armature (BA) drivers on each side
  • Sensitivity: 119dB SPL/mW
  • Impedance: 8 Ω
  • Frequency response: 20-20000Hz
  • Noise isolation: 26dB
  • Earphone type: In-ear
  • Monitor plug:3.5mm connector
  • Earphone end plug: 2Pin (0.78Pin)
  • Cable: 4-strand copper plated sliver plus high pure copper
  • Shell: resin
  • Faceplate: natural stone

I would like to thank One Dot Audio for providing me with the review sample of Hesperus A300.


ODA A300 FR Graph

The sound profile of A300 is V-shaped, focusing on bass and treble, with less emphasis on the midrange. It delivers powerful and deep bass that will appeal to bass enthusiasts. Hesperus A300 excels in controlling distortion even at higher volumes, providing an energetic and enjoyable listening experience. However, it may not be the best choice for those looking for a more balanced or neutral sound.

ODA Hesperus A300 Review


The Hesperus A300 has impressive lows that deliver deep, impactful bass that can be both heard and felt. It offers substantial energy in the low range, creating an exciting experience for genres like hip-hop and EDM. When tested on the SMSL DO300EX, the bass is effortless and punchy with a detailed decay.

When paired with the FiiO Q15 and given more power, the bass becomes firmer and faster, although it remains slightly lacking in the very low end. The tuning of the A300 is well-suited for pop and rock music, with its bold bass and intricate harmonics. It particularly shines with live music that features a lot of drumming and acoustic elements.

The bass line is rhythmic, and the upper strings of the bass guitar are clearly defined. The bass transients of the Hesperus A300 depend on the source. Faster and more powerful amplifiers will enhance the resolution, but even when used with smaller devices like the FiiO KA13 R2R player, it doesn’t sound muffled or unclear.

The bass response of the A300 resembles that of dynamic drivers, providing an airy and relaxing sound. It doesn’t prioritize extracting every detail from the track or boosting certain frequencies for clarity, which may compromise naturalness.

ODA Hesperus A300 Review


The mid-bass on the Hesperus A300 is full-bodied, favoring low-pitched and powerful voices. You can hear the vocal line on top of the bass instruments, presented naturally with a hint of warmth adding to the vocal authority.

The separation power is satisfactory and when paired with a cooler-sounding or powerful source the vocal will cut through the mix more prominently. The Hesperus A300 works well with streamed content which often tunes up the bass and upper mids for clarity and stronger dynamics.

When testing with the FiiO Q15 it sounds more controlled and tightened, bringing more power to the upper mids. Resonating vocal harmonics are well captured too as such older blues and pops with stronger vocal effects from the 80s-90s are a joy to listen to on this pair.

ODA Hesperus A300 Review


The A300’s treble is vivid and energetic, delivering sparkle and crispness without inducing fatigue or sibilance. It beautifully reproduces high treble, with effortless extension to the top octave. The resolution and transparency in this region are impressive, ranking among the best in the thousand-dollar price bracket.

The high-end of A300 is energetic. ODA leaned into a tuning which creates a sound that’s resolving. The highs are elevated, stopping just short of sibilance. Cymbals and upper harmonics resolve beautifully usually reserved for the background, and pop forward surprisingly. It’s crisp, detailed, and etched in its presentation.

While some may find the treble emphasis a bit exaggerated, it adds an extra layer of resolution and vibrancy, benefiting a majority of popular genres. The excitement and vividness of the A300 are attributed to both its bass and this particular range.

Overall, the A300’s sound is a fun-focused, crowd-pleaser tuning that also excels in technicalities which we are going to talk about next.

ODA Hesperus A300 Review


As the vocal penetrates through the mix and stays on top, the Hesperus A300 brings the listener closer to the performer and has its bass slightly elevated such that vocal works sound intimate and immersive.

The vocal image is elaborative, as are acoustic guitars which are well-weighted and it works best with songs that don’t have too many instruments backing the track.

You can feel the presence and picture where the acoustic guitar radiates from as if the performer is pointing the wood cabinet to you a few feet in front.

The cozy, unintrusive tuning does not overly stretch the headroom and it sounds natural with air and harmonics delicately captured. The treble has decent control and even at high volume instruments are still well-defined without blurring all over.

ODA Hesperus A300 Review


In conclusion, the One Dot Audio Hesperus A300 stands out as a remarkable choice for any audiophile, offering an immersive and dynamic presentation across various genres, thanks to its enhanced bass, rich midrange, and crisp treble.

The A300 is not only technically proficient but also immensely fun, offering a listening experience that keeps you hooked.