Written by YouTube reviewer and Headfi reviewer Andrew Barlow (AndrewChoppa)
The 7Hz Sonus II isn’t just an IEM; it’s an acoustic arranged marriage between two wildly different driver families that should, by all laws of engineering physics, hate each other.
Priced at $80 USD, this dynamic-planar hybrid tells a tale of high-drama, precision-engineered harmony, and a couple of stubborn quirks that refuse to go away.
It was provided by Linsoul for this review.
Now once upon a time in the audiophile kingdom, there lived two distinct tribes. There was the Dynamic Driver Clan—masters of heavy, room-shaking bass and slow, soulful thuds. High above them perched the Planar Magnetic Guild—obsessives of blinding speed, razor-sharp transients, and detail retrieval so clean it could spot dust on a master tape.
Often, when you shove these two in the same shell, you get carnage and chaos. The bass feels like an old pickup truck trying to drag race a Formula 1 car.
But 7Hz stepped in as the ultimate diplomat. They crafted a triple-layered peace treaty consisting of precise steel mesh, tuning cloth, and acoustic foam. They stuffed a custom dynamic driver in the back, locked a high-frequency planar driver in the front, and capped it with a 24K gold-plated acoustic cover—because no peace treaty is complete without a bit of royal bling. Right??
Specs-wise, it has an impedance of 29 ohms and a sensitivity of 108 dB/V.
Let’s open ‘em up!!!
Unboxing is a simple affair. Nice sleeve, colourful orange box and the bad boys them selves looking up at you.
I LOVE the look. Mine were black (you can get silver/clear too). They look like mini stained glass windows, reflecting light at every angle, with the 7hz logo in the middle.
They’re light (ish) and medium sized and they fit perfectly in my head-holes.
They come with a nice black leather carry case with 8 sets of tips in total.
I would have liked an explanation of what each set brings to the sound – I guess that’s what the interwebby thing is for. I tried the dark tips that came on them and tried to roll to the thicker silicon matte tips but COULD NOT get them on. The bore was just too stiff.
I reverted to my Prism wide-bores and used them for this review.
The cable. Hmmm the cable. I want to love it. I want to hate it. It’s perfectly fine and doesn’t have memory or microphonics but it reminds me of the old retro floppy drive flat fat cables insie old computers. I simply can’t shake that image!!!
Ok, so how do they bloody sound??????
I did all my testing on my NiPO N2 Dap which is an absolute cracker, and the Laiv Crescendo Verse Dac/amp (upcoming review), streaming Tidal and Qobuz.
Testing new music (always testing new music!!) but this is wow!!!
One of my fav bands – Vanishing Point, have a new single after almost 10 years….
Bring Me the Night. And what a cracker it is!!!!!
It has power, depth and sheer excitement on the Sonus IIs. It’s full and frenetic and the Sonus II can separate the cacophony quite well.
Silvio’s vocals are very present but not overpowering. And the guitars crunch, the synth is clean and detailed. Everything works well here. I’m left drained after that one! But in a good way.
Up next Talk – a Canadian behemoth of a vocalist who has such a powerful voice and amazing melodies!
On Harder It Breaks, it starts off with sounds all around. The staging is quite holographic.
Bass guitar and drum hit at 10 seconds and it’s deep. It’s powerful. Talk’s vocals are forward and the main meal here. He’s certainly out there in front. There’s plenty of upper register detail and resolution. On this song there is a little bit of crispness up top, but only a hint. Treble-shy fold might find it a tad too much.
We go metal x techno next with Electric Callboy’s Every Time We Touch. It begins soft and synthy with clean and present vocals. Transients are fast and it builds to a dance-beat quickly. Bass is deep and well controlled, with no bleed into the lower mids.
Clean vocals sound natural and rich, death growls are handled well too, with no muddy patches.
It’s another great listen on the Sonus IIs. The techno beat goes low and pumps excitement into my ears. And resolution is excellent. There’s no harsh crispness here at all.
And now for something COMPLETELY DIFFERENT – Dido by Aria (Armin Van Buuren’s Universal Religion Mix) is a trance/techno track with an atmospheric introduction, featuring real NASA transmission footage from the Apollo 7 mission in 1968. Rain plays in the background as the astronauts talk to each other in my left and right ears. The staging and imaginbg placement here is excellent. I feel like I’m standing outside, listening to the broadcast live.
Strings come in softly and everything is clean, resolving but mellow too.
The track builds in intensity like a film score and the rain dissipates, the chatting continues then we hit the trance beat/
It’s really clean, snappy, fast (transients) and energetic. The synth bass hits and it’s powerful and has a nice weight to it.
It’s not ocean floor deep – these aren’t bass canons, but they handle bass very well. It’s part of the team, not the major player.
The Sonus IIs are great for EDM/Techno/trance. They’re exciting and vibrant with great detail and snap.
I’ll finish with an absolute classic – Paranoid by Sabbath (Vale Ozz-Man!).
Tommy starts way left of me and Geezer’s off to the right. There’s great staging and placement on the Sonus IIs, I genuinely feel like I’m inside the studio (horrible cliché) with the band all around me. Ozz Man sounds great but almost a tad distant on this song. I’ve heard him up closer on other iems. This is weird as I heard Talk up in my face earlier on. He’s not recessed, he’s just not up front like he sometimes is. He sounds great though.
Instruments have really good weight and sound natural. The down-tuned guitars have a great resonance to them.
Another great song on the Sonus IIs.
Comparison:
I chose the Tipsy M1 for a battle her folks – it’s a $99 USD single DD with a bamboo fibre diaphragm.
I reviewed it a while ago and really rated it.
It’s an interesting battle here - the M1 features a warm, dark, and smooth sound signature with relaxed treble. This creates a sharp contrast against the Sonus II, which uses its planar driver to deliver sharper detail, faster treble transients, and greater airiness.
Tipsy offers a natural decay here and musical rhythm over raw speed. Comparing it to the Sonus II highlights the 7Hz’s multi-driver’s ability to provide slightly cleaner instrument separation, wider soundstage imaging, and better control over complex tracks.
The M1 is a more musical, organic listen, while the Sonus II offers better resolution up top. The M1 sounds great with Jelly Roll’s Hand’s Up, featuring natural guitars and Mr Roll’s powerful and rich voice. The Sonus II has it in the bag for EDM/Trance/Techno. The likes of Pit Bailay’s (Vivaldi) Winter (New Club Remix) hits hard down low and keeps the upper registers tight and snappy with fast transients.
For vocals, the Sonus II has better technicality over the M1. The M1 presents a smoother, warmer male vocal while the Sonus has better attack and note weight. Both sound natural but different.
And staging and imaging go to the Sonus II for me. It throws a decent soundstage but the separation within the stage is excellent on the Sonus II, with instruments spread out further and it gives a sense of being inside the performance on many songs.
But what are the cons??
Is this iem perfect? No. Of course not.
It has the occasional treble spike but I wouldn’t call it an issue at all. Mids were forward on some songs and back further in the mix on others. This can also be the gear used when testing and the particular track too (mixing, recording etc).
The cable is still out for me – old internal computer ribbons coming back to haunt me….
And I couldn’t fit the stiffer tips on the nozzle, but that’s just me…….
So what’s the verdict????
But seriously, for $80, I’m actually very impressed. It looks and feels great, fits well and has a dynamic sound profile that excites, invigorates and makes you get up and dance.
I think this will suit many listeners out there who want energy, fun and a party vibe in your ears. Plus, it looks great with the stained glass window effect.
For under a Benjamin Franklin, this is a no-brainer for me. Well done 7hz.
Thanks to Linsoul for providing this unit for review.
This is a paid review but as you can read, all thoughts are my own without influence or bias.
