7Hz Eternal Review

7Hz Eternal Review

This is a review of the 7Hz Eternal which is a new 14.5mm dynamic driver IEM launched in celebration of the company’s 10-year anniversary. It is priced at $249.

Disclaimer: This was sent to us as a sample for our honest opinion. Headfonics is an independent website with no affiliate links or services. We thank the team at Linsoul for giving us this opportunity.

To read more about 7Hz products we have previously featured on Headfonics click here

Note, that this article follows our latest scoring guidelines which you can read up on here.

7Hz Eternal Review
7Hz Eternal Review
Despite the similar form of the 7Hz Eternal to the 7Hz Timeless, the tuning of both monitors is completely different. One thing’s for sure though - it is refreshing to get a mid-centric monitor in the abundance of V-shaped monitors in the $200-$250 market.
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Accurate midrange
Premium build
A little light for sub-bass
Reader's Score

The 7Hz Eternal is, in essence, an IEM to recognize or celebrate the company’s 10-year anniversary of operation. 

Some might also see it with a degree of familiarity on the outside. Indeed, it is from the same brand that brought us the famous and hyped 7Hz Timeless IEM, Headfonics’ 2021’s Bang for Buck Universal IEM.

Despite its recent success with the 7Hz Timeless planar drivers, the 7Hz Eternal goes back to its roots using a similar faceplate shape replaced with dynamic driver internals. Priced at $249.00, it competes just a little above the budget level where the competition starts to thin out but the expectations are that much higher.

Tech Highlights

7Hz Eternal is a universal IEM equipped with a 14.5mm LCP Dynamic Driver with a complementary N52 magnet. The Liquid Crystal Polymer or LCP diaphragm is specifically designed to achieve an ultra-broadband response and dynamic range.

It also has a unique cavity structure, similar to the 7Hz Timeless. The cavity is made up of CNC aluminum, along with a unique sapphire optical glass faceplate, which is commonly seen in high-end wristwatches. Despite being made of glass, rest assured that the sapphire coating is tempered to withstand wear and tear, even with accidental falls.

7Hz Eternal Review


The Eternal is stunningly beautiful. When I saw it in person, it looks exactly, if not better, like the ones I saw online. The mix of CNC aluminum and sapphire crystal elevated the overall look of the monitor. The choice of a bronze-brown outer shell is one of its kind, leaning more on a modern classic design.

The shape of the shell is also unique. It is the same with the 7Hz Timeless, a circle flat faceplate. Inside the crystal, a circular pattern can be seen, similar to what you might see inside the crystal of a camera lens.

7Hz Eternal Review

Comfort & Isolation

The monitors are incredibly light with each earbud weighing only 6 grams. The shell fits perfectly in my ears. It has the right amount of insertion to create a good seal. Thanks to its lightweight design, wearing the Eternal feels seamless even when moving around.

Isolation is nothing exceptional but does a fairly well job. Outside and low noise are blocked while listening to comfortable levels.


The packaging comes with a rather generous number of tips. There are 3 pairs of different colored tips in 3 different sizes (S, M, L) and 1 pair of dome-shaped white silicon tips.

Surprisingly, tip rolling does make a noticeable difference on these pairs. The stock tips, the one installed when you get the monitor, give a more mid-centric tuning, with less bass, fuller mids, and fewer highs. The translucent blue tips elevate the bass with a deeper rumble while the white tips have less bass and better highs.

7Hz Eternal Review

Stock Cable

The Eternal’s stock cable is made of an OCC wire consisting of a single crystal copper with single-crystal silver. The outer layer of the cable is coaxially shielded, to create a natural sound reproduction and transparency.

The termination on the IEM side is an MMCX Connection. It does have some difficulty and resistance to removal. This Eternal can also be bought with different jack terminations including a SE 2.5mm TRS, balanced 2.5mm TRRS, and 4.4mm Pentaconn plugs.

Visually, the cables complemented the IEMs well as they are the same shade of brown as the driver shells. Moving around with them was a seamless experience. The connector side of the cable also has a memory wire with good retention, which allows it to sit comfortably at the back of the ears.

Putting it in and out of the case as easily as the case provided enough room. The cable is also designed well to reduce tangling when kept and used.

7Hz Eternal Review

Packaging & Accessories

The unboxing experience is completely identical to the 7Hz Timeless. The only difference between the two is the color of the inserts with the Eternal being extra colorful with red and light blue accents. However, it’s still underwhelming for a $249 monitor, which 7Hz makes up for it with the abundance of accessories included.

Eternal comes with a similar heavy durable metal case in bronze color, complementing the colors of the shell. Inside the case, you get the monitors and cable nearly placed inside the velvet interior.

Another box contains a plastic organizer containing 3 sets of 3-sized tips (S, M, L) – a translucent blue that looks like Acoustune AET08, translucent white that looks like Acoustune AET07, and white silicone tips.

Externally, the translucent blue and white tips are dome-shaped while the white are wide bore tips that mimic the shape of memory foam tips – straight and narrow. Aside from the color, there are no noticeable differences between the translucent blue and translucent white tips.

Sound Impressions

The 7Hz Eternal is a mid-centric monitor. It emphasizes more on the mids, along with a laid-back bass and treble tuning.


For a single dynamic driver monitor, I was expecting a deeper sub-bass response. I find the sub-bass to be lacking for my taste. For example, only faint rumbles on known deep bass tracks are heard when listening with the Eternal.

As for the mid-bass, it has an adequate amount, although, still quite recessed. It’s there but does not give quite an impact. Just right to distinguish solo bass performances and the like.

One redeeming quality of the Eternal’s lows is the good level of control and for my ears a fairly natural response. It is fast and clean with no unusual blooms heard in the upper bass region. No unusual decay with its fast attack either.


The Eternal’s midrange is thick and lush, clearly the star and emphasis of this pair. This is tuned to have an elevated midrange, perfect for audiophiles looking for a vocal-centric IEM.

As expected with dynamic drivers, the midrange sounds natural, while being adequately articulate. Although tuned to be forward it still sounds comfortable, neither feeling too aggressive nor shouty. Details are retrieved well and busy tracks with multiple vocals are handled with ease.

Both male and female vocals are rich, articulate, clear, and transparent. Vocal textures are accurately captured, without making them sound artificially smooth. A rough raspy voice can be heard accurately and silky-smooth vocals are replicated as well.

Instruments have a warm and lush timbre. Listening to classical music, each instrument is easily distinguishable, with enough sound textures, especially with wind and string instruments.


Treble on the Eternal is tuned on the safe side – a more comfortable tuning, especially for treble sensitive. Although the treble takes a back seat, it’s still tuned to be neither dark nor bright, with just enough presence to make the midrange shine.

The Treble extends well with a good level of overall airiness. Cymbals and hi-hats lack the luster with each crash, a bit rounded, unfortunately. Although, the overall presentation is quite pleasing, with a clear and crisp light presentation. 

The treble’s good control is quite evident. No harshness or sibilance is felt, despite reaching extended high frequencies. The treble is tame and tuned to be comfortable in extended listening.


In terms of soundstage and imaging, the Eternal is competitive with the other monitors in its price range. It is above average, but nothing exceptional. The soundstage has a good width, lacking in-depth, but enough headspace to have a good musical presentation.

Imaging is fairly accurate. Accurate layering replication is evident with busy tracks with multiple vocals in varying depths. Sound is projected in a 3d space, with a properly spaced spread.

7Hz Eternal Review



With an impedance of 30Ω and sensitivity of 109dB, the Eternal is easy to drive. Even a smartphone is powerful enough to drive it to good comfortable volume levels.

Do note that listening through a DAP is a more pleasurable listening experience with soundstage and imaging notably improved.


The 7Hz Eternal is a mid-centric IEM, which is easy to pair, depending on preference. Powering the Eternal with the Hidizs AP80 Pro-X has shown improvement in the recessed sub-bass region.

Furthermore, manipulating its MSEB can push more elevation on the lows, however, this results to bleed to higher frequencies. The Hiby R3 Pro is also a good pair with the Eternal. Aside from a good soundstage, it also further extends the treble. An airier and crisper upper end can be enjoyed with this pairing.

7Hz Timeless

Select Comparisons

7Hz Timeless



The 7Hz Timeless has a magnetic planar driver with an ultra-thin diaphragm and a 14.2mm Planar Driver. The 7Hz Eternal follows suit with a similar-sized driver at 14.5mm but this time it is a dynamic version.


The shell of both monitors is similar in shape and size. The only difference between the two is their color and faceplate design. Timeless is black all over with a textured metal disc faceplate while the Eternal is of a bronze-brown colored shell with a textured metal inside a sapphire crystal glass.

Both IEMs have an ear-hook design with an MMCX termination. The cable on both IEMs feels the same, although different in outward color – Timeless with a silver one and Eternal with a brown one. The cable on both monitors is terminated with a 4.4mm straight jack.


I was surprised that the Timeless has the better sub-bass with a deeper thump, with a meatier rumble. The lows on the Timeless have more weight. The Eternal, with its recessed bass, perhaps, is tuned to have more emphasis on the midrange region.

The midrange of both monitors is very similar, with good detail retention. One thing to note is that the midrange on the Eternal sounded thicker and more natural compared to the Timeless. The Timeless has a similar presentation with planar drivers, incredibly articulate but with a hint of coldness to it. The Eternal has a more true-to-life presentation, with a fuller-bodied midrange.

Even the Timeless has a more elevated treble. Timeless’ treble, despite being a bit artificial, is airier and crisper. The Eternal has a more comfortable treble tuning which is less fatiguing for longer periods.

The soundstage and imaging of the two monitors are more or less the same, with no advantage with one or the other. Both have an above-average soundstage and imaging, respectable for their price range.

For these two monitors, it boils down to personal preference in tuning. Audiophiles that prefer a more comfortable treble tuning might like the Eternal more.

Softears Volume

Softears Volume



The Softears Volume has a hybrid configuration with a 10mm dynamic and 2 balanced armature configuration. The Eternal on the other hand has a single large 14.5mm single dynamic driver.


The looks on both monitors are opposites. The Volume has a green-colored ergonomic shell made of resin and a metal faceplate. The Eternal on the other hand has an aluminum shell with a sapphire crystal on its faceplate.

The cable terminations also vary, although both monitors have an ear hook design. The Volume has a more common 2-pin 0.78mm – 3.5mm termination while the Eternal has an MMCX-4.4mm termination.


Although the Softears Volume is a bit on the shy side as far as bass goes, the 7Hz Eternal has more recessed lows. The sub-bass on the Volume has a deeper rumble and meatier punch. The Eternal’s sub-bass felt flat when compared side by side with the Volume.

The Eternal does have a more forward midrange and a presentation that is lusher and thicker, although, the Volume does not fall far behind.

Treble tuning on the Eternal is more conservative. Guitar strums are not as crisp and sharp compared to the Volume which has an airier and more open presentation. Both monitors display impressive treble extension, which is evident when going into the higher frequencies.

The Volume has a wider soundstage, although the Eternal has a respectable depth and width. Imaging is also above average on both monitors, although the Volume appears to be more accurate. Vocal layering is presented well on both monitors, projected in multi-directions.

7Hz Eternal Review

Our Verdict

Despite the similar form of the 7Hz Eternal to the 7Hz Timeless, the tuning of both monitors is completely different. One thing’s for sure though; it is refreshing to get a mid-centric monitor in the abundance of V-shaped IEMs in the $200-$250 market.

There are a lot of single dynamic driver monitors in this price range, and to be honest, the Eternal does stand out with its tuning. Bass is not its forte, but instead, it is more focused on the midrange. The timbre is pretty natural and rich, perfect for audiophiles who like a thicker midrange.

It would also do well with veteran audiophiles looking for a different flavor with their listening sessions. For audiophiles looking to side-grade with a more mid-centric tuning, this might be the pair for you.

7Hz Eternal Specifications

  • Resistance: 30ohm
  • Sound pressure level: 109db/1khz
  • Frequency response range: 10-20000hz
  • THD: <0.2%/1khz
  • Driver: 5mm moving coil
  • Product weight: about 6g single earbud
  • Connector MMCX


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