Review - Kiwi Ears Allegro

Review - 7Hz Salnotes Zero (Sub 50€)

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Also available on YouTube in Spanish: Acho Reviews YouTube 

The 7Hz Salnotes Zero have been sent to mby Linsoul in exchange for the publication of this review. They have not requested anything specific and I will, as always, aim to be as unbiased as possible. However, you should always consider the fact that these IEMs have not cost me anything.

You can find the 7Hz Salnotes Zero on Linsoul here:

(non-affiliate link)


When I received the Zero, they were not yet on sale and I had no idea what the price was. Since then, they have become available on Linosul at a price of less than 20€, placing them firmly inside the sub 50€ bracket that I consider ultra-budget orientated.

7Hz are a brand that have made quite a name for themselves recently, with the 7Hz Timeless, a breakthrough in the planar IEM market, and the recent Dioko (in collaboration with Crinacle), amongst a couple of other models. The Zero I believe is their attempt at entering this ultra-budget IEM market with a single dynamic driver set of IEMs.


As is to be expected for less than 20€, the presentation is rather basic. Arriving in a plain box that a plastic covered tray slides out of, these are very reminiscent of some of the KZ presentations.

Inside the box we get the IEMs, the cable, the user manual and the same collection of multicoloured tips that were included with the Dioko that I reviewed recently.

I really can’t see any reason to complain here, as I would much rather IEMs in this price range have as much budget put towards the actual IEMs as possible.

Build and aesthetics…

The Zero are available in various colour options, these being black, blue and white. The version I have received are the blue ones, a colour that I would actually refer to as “smurf blue”.

I have to say that I have not had a set of IEMs come across my desk in this colour, so bonus points for originality, even if I do find them to look a bit like a toy (especially with the red tips that they arrive with).

The build is a combination of a plastic shell along with a metal faceplate. The shape is also original, with the use of plenty of straight lines, forming a shape that I really wouldn’t know what to call. This may mean that for some people with smaller ears, the square corners may result in some discomfort but I haven’t personally noticed any.

To be honest, I am not quite sure what to say about build quality. As I said, they do look a bit like toys and there is a clear seam where the shells are fixed together but at the same time, I really can spot anything that shouts “this is going to break”.

The included cable is nice enough, although a little stiff. It does refrain from tangling though and in general does its job, so I don’t have any complaints either. Yes, the cable included with the Dioko was much nicer (at 5 times the price) but this is still far better than many other cables included with ultra budget sets.

At the end of the day, aesthetics are very personal and while I am not a huge fan, I am also not going to put too much into how a set of 20€ IEMs look.


(Note: As always, tracks mentioned are clickable links that will open the referenced track in the streaming service of your choice)

This is the category that is “make or break” for an ultra-budget set of IEMs in my opinion. I mean, sound is obviously the most important part of any IEM (maybe along with comfort) but in this price range, if something manages to sound good, it is 99% of teh way there (in my opinion of course).

So, here is the usual graph comparing them to my personal preference target:

I have said it before but I will say it again, my target is just a guide, I don’t always like things that are very close to it and I don’t always dislike things that aren't. Saying that, on paper, we are off to a good start with the Zero tuning.

Starting off with the subbass frequencies, there is enough for my tastes, giving a nice sensation of rumble when the track calls for it, such as in the case of my usual test track, “Chameleon”. They also stay fairly clean and articulated in these lower ranges, without giving a sensation of muddying up the low end.

I am not sure if these IEMs were developed after the Crinacle collaboration but I must say that the bass in general is very reminiscent (in quantity) of the Dioko, something that I find very positive.

Midbass is more of the same story, not overly done and staying out of the way of the lower mids. This makes for a very clean bass region in general, allowing me to appreciate what is going on in the low ranges, even in complex songs. Ok, the speed may not be up to that of certain planar models, or other dynamic drivers in higher categories, but is is still pretty good, better than a lot of models I have heard coming in at many times the price of the Zero.

As with the low end of the Dioko, this tuning may sometimes give the impression that the lower notes of guitars are missing a little bit of body, maybe the guitar of Johnny Cash in “Hurt” being a good example, yet I would much rather take this presentation over something that is too bloated. 

The mids are very well balanced and follow my preferences almost exactly. This, in my opinion, gives just the right amount of presence and balance to vocals and instruments located in these frequencies. There is no huge dip in the mids, nor is there a huge spike at the top of the mids that is needed to compensate for any lack of lower midrange. The presence between 2kHz and 4kHz is almost perfect (again, in my opinion), starting to roll off before we hit 5kHz, a range that I am very sensitive to.

This is actually something that I equalized the Dioko to while I was testing it and it resulted in things becoming rather harsh in this area, that does not seem to be the case with the Zero. In the track “Don’t You Worry Child” by Beth, her voice can become very harsh and almost unlistenable on many set that have too much in the higher mids, in the case of the Zero, she is still harsh (the recording is harsh itself) yet listenable.

Moving into the upper ranges is where I find the issue with the Zero. There is plenty of extension and feeling of air, yet there is also a spike that does make these upper ranges a little brutal on occasions. This peak does not actually create too much sibilance as “Code Cool” is a little hot but not painful (which can certainly be the case), yet there is a bit of a metallic shine to the upper range, making it not feel natural.

My guess is that 7Hz have used this extra presence in the upper ranges to make the Zero seem like it has more details than it actually does. This is something that many brands have done with various models to give that impression of detail. This is something that can make a set of IEMs sound very impressive during the initial listening phase, yet can be fatiguing on longer listening sessions. 

My take on this is that the Zero don’t really have a huge amount of detail. I mean, they are not bad, certainly more than acceptable for the price range that they sit in, but they are not as detailed as that upper range peak would like you to think. To be honest, this does give the sensation that they extend much better in the treble than other dynamic driver sets, yet they really don’t, it is more of an illusion created by that peak.

Soundstage is not bad but is another thing that is conditioned a little by that upper peak. That sensation of more air does sometimes add to the sensation of more space, yet when isolating certain instruments and sounds (such as in “Bubbles”), the soundstage is actually around average for a set of IEMs.


Everything was going so well with the Zero until that upper peak. Now, that does not mean that they are a bad set of IEMs, far from it, they are a great set of IEMs for their price (and could could probably compete with sets priced quite a bit higher), I think it is more of me finding so many good things about the tuning that the one error, or maybe that is not the correct word, let’s say that one “choice”, is something that was probably more of a let down due to everything else being so surprisingly good.

Obviously this can be corrected (again, maybe corrected is not the right term) with a little eq, but I actually feel that maybe it is simpler than that and it can be corrected with a filter that just tames those highest ranges a little. When I get a chance (I have quite a list of backlogged items) I will certainly try a couple of things because I feel that these IEMs are almost perfect as far as tuning in their price bracket.

Again, please do not take this as a negative review, the 7Hz Salnotes Zero do almost everything much better than can be expected for their price.

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