The ZMF x Vibro Mk II Will Take You On A Trip Around The Sun

It’s not often I have the chance to review products as high-end as the ZMF x Vibro MK II. I approached Zach in July, and asked for a loaner unit. One wasn’t readily available, but boy was it worth the wait.

For those of you who aren’t aware of ZMF, it’s a small company run by Zach Mehrbach, where every pair of ZMF headphones are custom built to user specifications, and can even be tuned to your specific tastes. Furthermore, if Zach doesn’t get your tuning right on the first time around, he will gladly do a re-tune for free.

The Vibro Mk II can be bought from ZMF here starting at $479.

Disclaimer: This review is based upon a loaner unit provided to me by ZMF in exchange for my honest opinion and un-edited words. I do not profit in any way from the writing of the review. I would like to thank Zach for giving me this opportunity.

Preference and Bias: Before reading a review, it is worth mentioning that there is no way for a reviewer to objectively pass judgment on the enjoy-ability of a product: such a thing is inherently subjective. Therefore, I find it necessary for you to read and understand what I take a natural liking to and how that might affect my rating of a product.

My ideal sound signature would be an extended sub-bass with a leveled, but textured, bass. The mids should be slightly less pronounced than the treble, but still ahead of the bass. I prefer a more bright upper range.

Source: The Vibro Mk II was powered like so:

PC USB -> Sound Blaster E3 3.5mm out -> RCA Adapter -> Sherwood AD230B 1/4in out.

Standard 3.5mm out from both my Nexus 6P and HTC One M8 was inadequate to drive the Vibro Mk II.

All music was served as MP3 @320Kbps or as FLAC. I found low-quality recordings and low-bit-rates to not play nicely with the Vibro Mk II.

Sound Signature

Initial Impressions:

I don’t have the best gear available, that’s a given. I mean, take a look at my setup; It’s a Frankenstein-mashup of used DAC’s and a hand-me-down amp. However, the Vibro Mk II doesn’t care. As long as you have the amperage, the Mk II’s got the music. I was immediately impressed with how minute the hiss on the Vibro Mk II is. My Sherwood AD230B amplifier is a brute, so while it does have a very large amount of power available, it usually creates a high noise-floor. The actual sound signature of the Mk II appears to be neutral, with some elevated highs and warmer mids. However, the tuning and flavoring of the Vibro Mk II still allows it to play a large variety of very different genres of music equally well — something that I rarely see in warmer headphones and earphones.

Treble: Songs used: White Flag, Midnight City, Outlands

I am very impressed at how well the Vibro Mk II can reproduce upper-treble without causing sibilance. White Flag does a good job of drawing out those trouble frequencies, and the Vibro Mk II doesn’t even seem to notice it. The various electronic effects within the song don’t get in your face too much, but are perfectly happy to sit in the background. The impressive part is how well they stay resolved without smudging or becoming lost. Furthermore, extension into the upper-treble, while not emphasized, is still noticeable. I am consistently wowed by the delicacy the Vibro Mk II.

Midnight City was a treat. The treble contrasted the warm mids very nicely, and created a cohesive but distinctly tuned sound. I consistently heard new sounds and layers to the music that I’d not even begun to notice. The song seem to be rather politely in its presentation, as the kick drum and cymbals didn’t pierce through the song or try to bust your eardrums.

The violins of Outlands were presented in a very relaxed manner. They didn’t have any harsh edges to them and lacked the taught and poised timbre I am used to getting from them on my Pisces BA. It’s not a bad change, and is something I am really growing fond of as I listen more. Furthermore, it sounds like the violins are actually pushed backwards, such that they do not completely dominate the song. This establishes a balance I’ve not really heard from the song on other earphones.

Mids: Songs used: Flagpole Sitta, Jacked Up, I Am The Highway, Good Life

Flagpole Sitta is a song where the Vibro Mk II displays its great restraint when it comes to warming up the mids. The guitars and bass guitars are easily distinguishable from the rest of the song, as are the various drum beats unlike some offerings from Thinksound and such.

The pianos of Jacked Up are really what struck me. They sounded so naturally and were placed so well that I turned around in my chair to see what was making noise in my room! Weezer’s vocals were also very pleasant. The guitars and drums are well-bodied and have a lot of life to them.

I really enjoyed the intro. The boosted lower-mids really help the song pull off its intended sonorous and lonely tone. My only complaint is that the vocals sat a little too far back.

Good Life’s mids were presented in a very mellow way. One Republics’ vocalist’s voice meshed very well with the rest of the song, given it a very organic and smooth sound.

Bass: Songs used: Lights, Gold Dust, 99 Problems (Hugo Cover), Leave Me

The Vibro Mk II’s bass is probably my favorite part of it. While not bass-head levels, I find its presence to be almost perfect, especially considering how well the mid and sub-bass are “attached” to the rest of the sound signature. This really lends Lights a helping hand, giving it depth that colder earphones simply cannot.

Mid and sub-bass presence is high enough to listen to bass-heavy songs like Gold Dust without any issues. Flux Pavilion’s wet bass-drop is presented remarkably well, even if it doesn’t shake your skull.

99 Problems also performed well, benefiting especially from the mid-sub-bass synergy. Furthermore, the bass never overwhelms and blots out the mids or lower-mids.

Leave Me is my ultimate test of bass-drop responsiveness. If a pair of headphones can perform well enough on this song, it’s generally a sign that it has good potential for other bassy electronic genres. The Vibro Mk II certainly does fit the bill, despite it not overflowing with rumbliness or boominess.

Clarity: Songs used: Throne, Map of The Problimatique, I’m Not Alright

Clarity is top notch. While it doesn’t extend as far as possible into the upper-treble and sub-bass as other, more expensive offerings, I find it to be at TOTL levels. Everything from layering to detail retrieval to background resolution is hard to complain about, even on demanding songs like Throne. I won’t write out a separate analysis of each song, considering the fact that it performs equally well on each of them.

Sound Stage

Sound staging is very well done. It’s not hugely expansive, but is still larger than average. Interestingly, in certain songs, the Vibro Mk II really opens up, allowing for an almost symphonic experience. However, these songs are few and far between. Instrumental separation is excellent, with no noticeable smudging, blurring, or background loss. Furthermore, Luke and Zach did a great job engineering the Vibro Mk II to be airy, but not thin. You never get the feeling that any two instruments are on top of each-other, something I hadn’t experienced before I’d hear the Mk II.

Packaging / Unboxing

I received a thoroughly used loaner unit, so it arrived in a very nondescript white box with a peeling-ZMF sticker on top. I won’t be taking any pictures, since it in no way represents what a retail unit will look like.


Construction Quality

Zach and Luke did an excellent job transforming what I would call a visually uninspiring pair of headphones, the Fostex t50rp, to a solid and plush looking one. It’s evident, even after the use my loaner unit has gone through, that these things are meant to last. From the removable head-band cushion to the dense wood-cups, I find the workmanship to be remarkable.


The Vibro Mk II is rather heavy for a pair of headphones, owing mostly to the large amount of cushioning and the wooden cups. However, even after listening for well over three hours, I found them to not be too noticeable. The weight distribution is designed well, and keeps my head feeling perfectly fine — something that I cannot say for the majority of headphones, both on and over-ear, that I’ve tried. ZMF offers three kind of ear pads, built from either lambskin, cowhide, or “protein”. All three offerings are angled, giving the your headphones very good isolation regardless of which kind you choose.


The ZMF x Vibro Mk II is a power-hungry planar-magnetic headphone with a warm, yet versatile, sound signature sure to make you smile. It’s relaxed and mellow sound signature will let you sink into the music you are listening to, and its comfort is second to none. Factor in the phenomenal support you get from Zach at ZMF and if you’ve got the cash, you’d be hard pressed to find a better value.

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