7Hz Salnotes Zero Review: Chu Better Watch Out
August 8, 2022 Andrew Cheng

While the future of IEMs seems to be steering towards planar magnetic driven ones like the 7Hz Salnotes Dioko, traditional dynamic drivers are not going anywhere anytime soon. Expanding upon its affordable “Salnotes” lineup, 7Hz has released the Zero – a humble single dynamic driver earphones.

More specifically, the Salnotes Zero sports a 10mm dynamic driver with a metal composite diaphragm. The latter looks to be a popular piece of tech in the ChiFi space lately; the BLON Fat Girl we previously reviewed is one such IEM that uses a similar diaphragm. Just like that IEM, the Zero is also very affordable.

Retailing at just $19.99 (about RM90) on Linsoul, the Salnotes Zero competes directly with the Moondrop Chu, an IEM that is currently dominating this price bracket…as well as several tiers above. We actually have a unit of the Chu, and you can bet we are comparing it to the Zero in this review.

What It Is

As mentioned, the 7Hz Salnotes Zero uses a 10mm dynamic driver with a metal composite diaphragm. 7Hz doesn’t really say how this type of diaphragm affects the sound profile of the Zero, though the company did mention it’s made of high quality materials, “making it easier to resonate or vibrate along with sound waves.”

Packaging of the Zero is nothing out of the ordinary. You get the earphones themselves, a detachable 4-core high purity oxygen-free copper cable, as well as an assortment of standard and narrow-bore ear tips. Similar to the ones included with the Dioko, basically.

The Salnotes Zero’s shell has a fairly unique look to it. The housing is said to be made from an environmentally-friendly plastic, along with a stainless steel faceplate with the name of the IEM on the side.

You get the option of three colour options for the shell of the Zero: Black (as pictured here), White, and Blue. The shape of the Zero fits well in my ears too, but it doesn’t offer the best isolation. The cable is also not free of microphonics, but at least there is a chin slider.

How Does It Sound?

The sound signature of the 7Hz Salnotes Zero can best be described as neutral, with (at most) a hint of brightness. While I wouldn’t consider the Zero to be laid back, it’s far from the most energetic IEM. Its flat tonality might even be a tad boring to some folks, but personally, I just find myself yearning for a bit more warmth and body in the notes.

Detail retrieval is about what you might expect from a dynamic driver; that is, it’s not particularly amazing, and the same can be said about instrument separation. Beyond that, 7Hz must have taken notes from Crinacle during their recent collaboration on the Dioko, as the neutrality of the Zero is organic and well-tuned, to say the least.


First off, the sub-bass of the Zero is surprisingly well-extended. It isn’t overly boomy or punchy, but you do get an interesting “tingling” sensation in your ears and head from the vibrations of the driver as the bass rumbles. This sensation is particularly evident in the opening to Blackpink’s Whistle, where the bass rumble decay lingers and reverberates clearly.

Also rather surprising is the mid-bass of the Zero. It’s tame and flat, but it is also tight and controlled. There’s no aggressive bump that you’d normally find with budget IEMs like these, so unfortunately for bassheads, the Zero’s listening experience is not super exciting.


The neutrality present within the bass of the Zero is true for the mids as well, and perhaps to a fault. Though not recessed, the mids don’t stand out in any particular way, it’s merely…present. It isn’t thick by any means, and it is not especially light or breathy. Vocals are also, to my ears, relatively natural, though it could do with a tad bit more weight and warmth.

To better describe this, the acoustic version of NIKI’s La La Lost You seems a tad “floaty” with the Zero; it lacks body and definition. The breaths that NIKI takes between lines are also subdued, making the track lose its almost ethereal quality.

This remains true for male vocals. While I can feel the drum that’s thumping in the background in Sam Smith’s Stay With Me, his vocals are a bit cold and thin, and it almost gets outshined by the track’s tambourine, cymbals, and aforementioned drums.


As with the bass and mids, the treble of the Salnotes Zero continues the mostly flat and neutral presentation. There is some detail present, but there’s a hazy, veiled quality to the treble that makes these details less obvious. There’s also an abrupt end in the decay of the treble instead of a smooth roll-off, which makes the presentation harsher than it should be.

Omen by Disclosure (featuring Sam Smith) is a track with snaps, claps, and cymbals throughout, but the Zero’s muted treble makes the song lose some of its energy and excitement. But there is a bright side to this: it’s not a fatiguing pair of earphones, so it should be good for longer listening sessions.


The Salnotes Zero makes up for its lack of height and depth with above-average width in the soundstage. But it isn’t completely an “in-your-head” listening experience, as you still get some vertical depth. It’s just…relatively meagre, though not unexpected.

Comparison to Moondrop Chu

It’s a great time to be in the ChiFi hobby now: you can pay as little as $20 to get the sound quality of IEMs at much higher price points. This “budget” category initially started with sub-$100 IEMs, which progressed to the sub-$50 category, and has now reached the astonishingly low price of below $20.

One of the most popular options in the sub-$20 price point is the Moondrop Chu, and it is now joined by the Salnotes Zero. These two IEMs are actually quite similar to each other (aside from their respective tunings), and there are a few physical differences between them that are worth pointing out.

First and foremost is the lack of a detachable cable with the Moondrop Chu. This might not seem like a big deal to some, but having the flexibility of using different cables allows you to get an ever so slightly varied sound signature, depending on the cable used.

Oh, you’d also be able to terminate at different jacks like 2.5mm or 4.4mm, not to mention the freedom to switch up the aesthetics a bit with third-party cables.

The fit of the Chu might not be for everyone as well, as the IEM’s earhook (or lack thereof) may prove difficult to get a secure fit. The hooks and overall shape of the Salnotes Zero allow me to get a snug fit easily, while the Chu took a bit of adjustment for me to get the same fit. But of course, everyone’s ears are shaped differently, so your mileage may vary.

A big selling point of the Moondrop Chu is the fact that it comes with a full set of Moondrop’s own Spring Tips. These tips would normally cost you around $13, and the fact that it comes bundled with the $19.99 Chu is fantastic value. However, while I really like how soft and comfortable the Spring Tips are, I’m not too fond of what they do to the sound profile of earphones.

In my experience, the Spring Tips tend to flatten the bass and treble of IEMs fitted with these tips, lowering the dynamics of said IEMs for a more “smooth” sound signature. That being said, you should definitely try the Spring Tips for yourself first and see if they’re actually to your liking.

Now, let’s talk about their sound profiles. If the Salnotes Zero has a neutral tonality with a hint of brightness, the Moondrop Chu has a more apparent neutral-bright sound signature. The latter has more forward upper-mids, so it has a crisper high end too, though this also results in the Chu being more susceptible to shouty highs.

Aside from that, the Chu has noticeably less sub-bass than the rumbly Zero, even if the former has a punchier and tighter mid-bass. The vocals on the Chu are a tad more natural and forward too, which I personally prefer.

If you want a sound signature that’s more tuned to the Harman target, the Moondrop Chu is your best bet. If you prefer something a little more flat – or if you’re sensitive to forward upper-mids – then the Salnotes Zero is the way to go.

Is It Worth It?

While the 7Hz Salnotes Zero doesn’t particularly excel in any one area, it’s also hard to find any major fault with it, especially at this price point. Again, for only $19.99 on Linsoul, the Zero is great to use as a daily driver. Given just how affordable it is, you can just toss it in your bag without worries and listen to it on the go.

Whether you prefer the more evident bass response of the Salnotes Zero or the Moondrop Chu‘s crisper highs, you really can’t go wrong with either options. Both of them are currently going for only $19.99 on Linsoul, and at this price point, you’re getting absolutely fantastic value for your money.

Li Jin Soh contributed to this review.