7HZ SALNOTES ZERO Universal IEM

Intro/Disclaimer​

The original 7Hz Salnotes Zero arrived in 2022 to much fanfare and praise. Coming from their highly successful 7Hz Timeless Planar IEM, would 7Hz be able to enter the budget IEM market with a bang? Read on to find out.

I purchased this set of IEMs with my own money and all opinions are my own. My review is solely based on what I hear with my own two ears as this is a very subjective hobby. My ratings are also based on how I think this IEM fares against other IEMs in its price range.

My primary litmus test when it comes to audio gear is whether or not vocals and instruments sound natural/organic. Regardless if the IEM has the biggest bass or the most technical treble. If it doesn’t sound natural to my ears then it’s a red flag. SPOILER: The 7Hz Zero OG definitely delivers on this front.

Packaging and accessories​

The packaging and accessories are pretty basic but adequate for an IEM at this price range. Inside the small white cardboard box are the IEMs, a decent cable, and an assortment of colorful silicone tips.

Build, Comfort and Fit​

I really liked the fit and comfort of the ZERO. While constructed mostly of plastic, it does have a nice metal faceplate on the front of the IEM to give it a more premium look. I also enjoy the plethora of different colors that this IEM comes in. There is a color for everyone!

Sound​

Sources Used
7Hz Salnotes ZERO <- Chord Mojo 2 <- MacMini M1 <- Apple Music Lossless

Songs played









Initial impressions (before brain burn in)
I usually like to jot down my first impressions when it comes to listening to new gear. Because whether you believe it or not, brain burn-in is a real thing.

Upon listening to the first few songs in my library, I was immediately impressed with the wide and spacious soundstage on this $15 IEM. The other standout feature is the clean and natural presentation of instruments. Yes, the bass is somewhat lacking but it more than makes up for it in the excellent mids and treble.

Bass

• Clean and controlled
• Midbass is somewhat lean
• Won’t satisfy bassheads

Mids

• Excellent timbre and tonality
• Female vocals really shine
• Male vocals can sound a bit sterile depending on the artist

Treble

• Good clarity and natural sounding
• Smooth and detailed without being sibilant
• High hats and cymbals sound extremely natural

Technicalities (Soundstage/Separation/Imaging)

• Excellent soundstage and instrument presentation
• Good macro details
• Good attack and decay on vocals and instruments

Comparisons​

While there are many good sub-$20 IEMs in the market now, the 7Hz Salnotes Zero really paved the way for this budget IEM bracket. Obviously most people will compare the OG Zero to the newer Zero: 2 but I will instead compare it to the TangZu Wan’er SG since that’s what I have on my desk right now.

On first listen, I immediately noticed the increased mid bass presence on the Wan’er that is missing from the OG Zero. It makes the music I listen to immediately more fun and engaging. The mid-range on the Wan’er is also quite balanced with good timbre and tonality. Both male and female vocals sound extremely musical. Treble is also smooth but not as well extended or incisive compared to the OG Zero.

So is the Wan’er the better IEM in this price bracket? Not necessarily, if I had to choose, nine times out of ten I would choose the OG Zero. The Zero just has a much cleaner musical presentation of vocals and instruments. Not to mention the above average soundstage and imaging capabilities. I also did not like the fit of the Wan’er compared to the 7Hz Zero.

Conclusion​

So does the 7Hz Salnotes Zero (OG) still compete in 2024? I think so, you can often find the 7Hz Zero OG for around $15USD during sales. The excellent soundstage/imaging also makes this IEM a great pairing for gamers and new audiophiles alike. I would wholeheartedly recommend the Zero to those new to the IEM hobby. The price to performance value you get out of the Zero OG is truly remarkable even by today’s standards.

It has now been a year since these IEMs were introduced. Do they survive to the present day?
I won't repeat points concerning accessories and build quality, as there is plenty to go over and we know a lot about it. I'll just say that for the price, all these points are really good.



The unboxing is similar to the KZ experiences.





For the source of this review I will use the well-known iBasso DC03 Pro.

Technical specifications: Given the features, it could be said to be a relatively difficult device to move. I don't want to say that you need a nuclear reactor but using it in your mobile phone, you won't get the full potential out of it. However, a basic dongle is more than enough to give it that boost.
Instrumental separation is always good considering what you are paying for. The soundstage is pretty average, not intimate at all but it can't be praised for the way it performs either.
The image may not be as holographic but it does stand out more than other iems I have tested.

Sound:

• Balanced signature, analytical side imo.

Bass: Well controlled bass. It gives you an adequate punch but if you are a bass head, look somewhere else. However, those with a more educated ear will find the bass tastes good as it offers a good energy that overall makes it a very versatile pair. If the bass is rhythmic, the presentation will be adequate. The same is the case with mid-bass.

Mid bass: it extends quite well into the lower frequencies. I recommend this headphone for those who are not looking for a big rumble, but don't want to completely fizzle out. Do you want a mid-bass cannon? Look elsewhere

Midranges: well there is a good amount of detail, although the focus is on macro contrast and not so much on miniscule nuances. Either way there is a good resolution in their presentation. The female voices, in my perspective, show a bit more energy, on the other hand, the male voices don't lag that far behind either.
When it comes to instruments, they sound very natural. The guitars sound full-bodied enough, which is important for metal music. Do you want clarity in the guitars? You'll find here.

It's not all rosy, the high mids can be a bit emphatic in certain songs. To control this, I found the eartips with the narrow hole quite useful. It is not a totally harsh earphone but I understand that some people are sensitive to these frequencies. With a moderate volume, we will also manage to control this problem.

Treble: Good amount of detail with sufficient, but not excellent performance. Well, that's about it. Violins, trumpets sound very natural. It is safe behaviour. There will be those who feel fatigued by the quantity offered by the Salnotes. For my personal taste, I would prefer other options in the same price range.

The Zeros prove to be a very good choice for their price range but with a tendency to fail in high midrange range. I understand this point is mostly a personal preference and opinions may change. Even today, their sound is still relevant and interesting. I highly recommend them, of course, if you are interested in the sound they provide.

Introduction
The acclaimed 7HZ Salnotes Zero are IEMs with a single dynamic driver per side that shook the IEM market a few months ago, receiving support from top reviewers and being highly recommended by many users for their excellent performance at a more than acceptable price ($20 USD).
Video Review here
If you wish to read this review in spanish, click here
Unboxing, Build and Comfort
The box is simple but expected in this price segment. Like in most cases, upon opening it, we find the pair of headphones, and underneath them, two small bags: one with the 2 pin 0.78mm cable and another with 5 extra pairs of silicone tips.



The construction of the IEM itself feels cheap. The 10mm driver with a metal composite diaphragm is protected by a plastic molded housing and a metal faceplate with the brand and model inscriptions. A positive aspect of this type of construction is the variety of colors offered for this model, with a total of 6 options: white, black, light blue, red, pink, and orange.



Moving on to the cable, it is quite good for the price. It has good flexibility, doesn't tangle easily, and has a straight 3.5mm connector, relieving the tension at the cable termination point compared to "L-shaped" connectors. As negative points for this cable, it is slightly microphonic when it rubs against clothing, and the plastic ear guides may be uncomfortable for some.



Regarding the silicone tips, I was surprised by the quantity included (6 pairs, counting the ones already on the IEMs). Some of these are "wide bore" tips like the orange ones (which retain better bass and treble frequencies), while others have a narrow bore like the light blue ones (which reduce treble frequencies without affecting the bass, resulting in increased bass emphasis).

Lastly, the comfort of these headphones was excellent from day one. I always used them with the small-sized (S) orange tips, and both the shape of the IEM and those tips contributed to an exceptional seal in my outer ear. They are so lightweight and comfortable that I can wear them for hours without needing to readjust them. They are a great option for anyone needing peace in noisy environments.

Frequency response description

Credits: crinacle.com

• Deep sub-bass extension and well-presented bass
• Smooth transition from bass to the mids
• Mid frequencies following almost strictly the Harman target
• Laid back but airy treble with good extension

Subjective sound description

Bass
The sub-bass has a lot of authority, as demonstrated in songs like "Xanny" by Billie Eilish and "Hot In It" by Tiesto. The sensation of "rumble" in these and other songs is very good, and the sub-bass can be felt in the chest.

On the other hand, the bass frequencies (>50-60 Hz to 200 Hz) are slightly lacking for my taste, as evidenced in EDM songs like "Follow" by Martin Garrix. However, this prevents the bass frequencies from "bothering" the mid frequencies and allows for a smooth transition between them.

Mids
I listened to several different singers to have a good reference for this frequency range. Freddie Mercury, Billie Eilish, Adele, and Calamaro - all these artists sounded correct here.

Both male and female voices are reproduced naturally with more than adequate presence, although female voices have a slightly more authoritative presence, as I heard in "Vivere" where Bocceli sings together with Gerardina Trovato.

The articulation between the different instruments and voices occupying this range is very good, without any interference or "disturbance" between them at any moment.

Treble
In general, the high frequencies may leave something to be desired for those who prefer a brighter and more detailed tuning. However, this is a very positive aspect for long listening sessions, where this IEM will reproduce the entire music library with exceptional musicality. In "Black Magic" by Slayer (Live Undead), the drummer's cymbal in the first 30 seconds is never offensive to the ear and has good presence. In "Revelations" by Iron Maiden, the variety of cymbals played by the drummer during the guitar solos have a gentle presence without being aggressive or overly bright.

Timbre
The timbre of these headphones is something that other companies should take note of. I understand that it's not a bold tuning as it follows the Harman curve, but the instruments are so well represented that despite not being the best IEM in terms of resolution/detail, they can be compared to others that are far above their price range thanks to the excellent execution of timbre. All the instruments in Vivaldi's "Winter: Allegro non Molto" - performed by Fabio Biondi - are excellently distinguished from each other, from the lead violinist to the cellos and double bass accompanying the rest of the violins.

Soundstage & Imaging
As mentioned earlier in the frequency response description, the soundstage or spatiality of the sound is above average. Songs like Iron Maiden's "The Great Unknown" and Queen's "Bicycle Race" reveal that these headphones have a wide soundstage that can be deep when needed. In the latter mentioned song, a well-crafted three-dimensional scene is created, placing all the backing vocals and drums behind Freddie, with one of the cymbals having a distinct presence located behind and to the right during the chorus.

Regarding imaging, this is one of the few weak points I see in the Zeros. In Calamaro's "Alta Suciedad," it's difficult for me to discern between the guitars playing on the right and left channels. The same occurs during the introduction of the Iron Maiden song mentioned in the previous paragraph.

7HZ Salnotes Zero vs KZ DQ6
I decided to make a brief comparison between these two models as they are both in the same price range internationally and in Argentina (Price: $20 USD for any of them)

Credits: crinacle.com

• The DQ6 has more punch and rumble due to a more pronounced elevation in the bass frequencies. They are comparable in the sub-bass range, with the Zero having slightly better extension in this range.
• The more "correct" transition between the bass and mids makes vocals and instruments sound a bit more natural on the 7HZ compared to the DQ6.
• The high frequencies are two opposite poles in my experience: the DQ6 has bright highs at times that help create a sense of detail but may have some small sibilance, while the Zero has more relaxed/dark highs that are not as detailed but contribute to its musicality.
• In terms of timbre, there is no competition; the 7HZ Zero has achieved a better tuning in this aspect.

Conclusion
It is quite obvious that this is a product easy to recommend: good comfort, impeccable tuning for the price, a good amount of accessories of respectable quality for $20 USD. The few negative points I mentioned during my analysis clearly are not enough to lower this product from the pedestal it deserves to be on.