ZMF Headphones Vibro MK II
This Timber has Timbre!
How far can mods take a headphone's performance? That's the key question when looking at headphones like ZMF Headphones’ Vibro Mark II; but instead of answering the question, the Vibro has opened the door of awareness to whole new possibilities! Yes, ZMF has objectively improved the technical performance from the original, subjectively changed the flavor to amazing tonal richness, and re-forged the set to make a strong new impression.
Sound signature
I invited a music enthusiast friend over, let's call him "Tin Ears" to protect his freedom to blurt out his unfiltered mind and reflect his gear-noob status. On the way, he was very excited as we talked about different technical aspects of sound and songs that would really strike us in the feels, but I refused to tell him how the Vibro sounded to me or hype him other than to say he was in for a treat. He walked in, continuing the conversation, but I cut him off with "Here... Have some chocolate!"
"Woah the wood looks amazing! These pads are HUGE!!"
He put them on. I started playing one of his favorites, The English Beat's "I Confess."
"Holy [nsfw] man. Holy [NSFW]!" Pause... "Damn, this is so good, it makes me want to... To punch a hole in the wall, hahaha!"
The Vibro MkII is, on the frequency graphs, definitely colored and a "fun" headphone with a moderate V-shape (what I'd call a "u" shape). The response starts out with a few decibels bass boosted above neutral that smoothly curves down partway into the midrange, levels out, and starts lifting up a few decibels into the treble "hump" (smoother than your typical "spike") peaking at around 7kHz, beginning to roll back down around 9kHz, and coming back to level with the mids around 12-13kHz and continuing to smoothly roll off past the audible hearing range. So, yeah - energetic midbass and plenty of sub-bass extension (especially with a more-powerful-than-average amp and a DAC better than your phone), nicely balanced against the treble lift. To make a “fun” sound signature, the fundamental midrange needs to be relatively lower so that there is some excitement at the extremes. I specify "u" shape because the slope is gentle; still the mids have a nice presence.
Beyond the frequency range, the Vibro is also endowed with rich timbre, unforced detail, and low fatigue from the treble. I hear the thicker, richer timbre and I think of another headphone that tried to have similarly solid mids/midbass (introduced at $1k, now selling for half that) while also having good detail, soundstage, transparency... and this Vibro achieves that solid weightiness without the bloom, slower decay, nor sacrifice as much of inner detail as that other headphone. Note attack has a solid THUMP that can be felt on the surface of the ear. The Vibro doesn't decay as sharply as my Vintage Stax (what does?!), but coming from another mid-fi headphone like my AKG K612, the Vibro will raise the bar for resolution without sounding artificially enhanced or pressed into the spotlight. Since it doesn't try too hard to spotlight detail from etched or spiked treble, it's easier to listen to for longer times. As a closed headphone, it presents soundstage depth differently than an open headphone, but if you get used to it, the Vibro will show you a room inside your head and do a Hi-Fi job of strongly placing each instrument distinct from each other with only a little concentration. The headphone definitely encourages you to sink in and in and in, and then grooves you with some serious mojo.
What does this mean? I can listen to Margot sing "Walking After Midnight" (Cowboy Junkies, Trinity Session) and really enjoy the varying softness of the electric guitar plucks, hear the ambient decay from Margot's tapping foot inside the church with surprisingly good imaging from a closed headphone, and actually enjoy the spice from the harmonica's high notes. I LOVE the impact of the drums and great gritty texture of the bass guitar on "Heart of the Sunrise" by Yes. I can play an intense game of Call of Duty: Black Ops 3 or Destiny without the crack of guns or booms of grenades fatiguing me, yet still use virtual surround processing to predict right when an enemy will appear around the corner and that I'll have to escape that firefight coming up from behind. The thunder inside the Vault of Glass in Destiny sounds so cool and powerful. The Vibro sounds especially magic with Electronica, Alternative, Rock, Jazz, Pop... Not the last word in detail for large orchestral ensembles or recreating the sound of standing out in the rain, but the Vibro still plays with the intensity of the musicians. Go ahead and put anything on, you'll have a good time.
Design
Perhaps it shouldn't come as a surprise, but the carved wood earcups, super-plush pads, and planar magnetic drivers contribute a lot to the sound and ergonomics. Vibro Mk II's start their life as a Fostex TRP-series headphone (Fostex is an OEM Manufacturer). Vibro Labs lathes out the jointly-designed earcups out of "A solid block of premium forestry" as per ZMF's website; mine is carved out of a dense but sustainable Sapele wood, most are Cherry. Meanwhile, Zach tunes and rewires the drivers with premium OCC Litz copper, reassembles the headphone with some massively thick pads and the customer's choice of earcup and adjustment "arm" finish. The cables have a new mini-XLR detachable system that clicks into place smoothly and solidly; Zach (and his wife) make them out of 4-strand wire and terminate the cable with whatever plug the customer wants. I suggest 1/4" or XLR.
A factory-stock Fostex T50RP is pretty good, but a Vibro coaxes better sonic refinement and comfort (and aesthetics) out of what parts are reused. A Vibro is more comfortable due to the more deeply plush, malleable, and slightly breathable earpads and plush "pilot pad" headband. The wood and padding put the Vibro on the heavier side of headphones, plus they're pretty large, but I wore them while gaming for 5 hours with minor weight shifts, and I don't mind wearing them 1-2 hours without fussing with them (at room temperature). The Vibro MkII cups also have a cool cup mounting system, with wiggle room to pivot the cups a bit in any direction to sit flush against your ears and head. The earcups also have three tuning ports which add about +1 dB of midbass for each unplugged port; I most often listened with the default two-pegged-ports which is just slightly "fun" of neutral but still seems faithful of timbre, while all ports unplugged made my bassy V-Moda M-100 seem redundant. The bass tuning plugs are fun, but feel more like different flavors of one headphone rather than 4 different headphones. Go back to the T50RP, and the sound will be more etched in the treble and have more bloom in the midbass, with less pleasurable and believable timbre.
Part of the Vibro's impact and... vibrancy comes from the different-than-usual Planar Magnetic drivers. Most headphones use the Dynamic cone drivers like most home-theater speakers use, but Planar drivers use a super low-mass film that can change direction super fast from the electromagnets set on one or both sides of the film. The much flatter waves and speedy responsiveness from the film benefit the listener with less distortion and basically immunity to effects from an amplifier's output impedance. The downside is that the Vibro is the most power hungry headphone I have had in my house, yet. At work, I had to turn up my poor iPhone 5s to just two ticks shy of maximum volume to get my regular listening volume, and even max was less than what several coworkers wanted to set it. The darling O2 amp on 3x gain can reach adequate volume easily, but still sounds a bit dull and fails to articulate the bass and soundstage depth as well as my more transparent Cavalli Liquid Carbon (connected via XLR) and Theta Basic II DAC at home... The Vibro definitely scales up with a better system.
Cool Factor
Want a unique headphone? One with that hand-crafted feel, with natural wood grain (that you can still feel) in either nude "natural," "stained," or "burst" finish echoing acoustic guitars, one that is collectable and just perhaps as much an heirloom to an audiophile as a Gibson is to a musician? The Vibro delivers.
Secondly, or perhaps more importantly, you'll want to hold onto your custom Vibro because it sounds so addicting. I'm a firm believer that there is no single "best" headphone that will be everyone's favorite... but Tin Ears was just one among three friends, three family members, five coworkers, two GameStop workers ("Astros are best!"), and one random customer at GameStop who all wanted to listen to several songs, all heard something new, all came away impressed, and half softly spoke expletives. That makes the Vibro a pretty easy recommendation. Even if you one day get a technically better performing summit-fi headphone costing twice as much or more, the Vibro still earns its place as the non-fatiguing, toe-tapping alternative for when a harmonica sounds too shrill or a j-pop singer is too sibilant.
Best Use Scenario
The Vibro MKII is best kept near a desk at home or work where you can connect it to a brawny amp and set it down when you need to get up and walk somewhere. The pads and cups seal in the sound quite well with above-average closed headphone comfort. The Vibro serves well in an environment where you need to cut down ambient noise, but you can't wear IEMs, because you frequently need to hear a coworker or say hi to your Fiancé/Spouse (face the door!!).
Overall, the Vibro is pretty close to ideal for what I would look for in a closed headphone. It is pretty much for home use, is a little heavy, and requires a desktop-class amp, but it has great strengths in addicting sound, extended-wear comfort, good sound seal and isolation, and frankly is a unique looking headphone with that "custom, handmade" feel. It satisfies on it's own against many hi-fi headphones in the sub-$1000 bracket, but also makes a great compliment to own alongside a very technical, transparent headphone that may stray too close to analytical for some songs. You might as well spring for the stain or "burst" finish if you like that look, and a stand or the case, because the Vibro will be just as much a conversation starter as a Swarvosky Crystal statuette. The slight cost will be amortized as the Vibros will be around for a loooooong time for you, for whenever you want to bring some magic to the most popular music genres on the planet.
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I'd like to give a big Thank You to Zach of ZMF Headphones for letting me borrow these Vibro's after I asked to review them. I also appreciated Zach's quick service when I had a shorting issue with one of the cables... it was well worth hearing the headphone on my best setup!
