HiFiMan GR8 – what happens when a hi-fi company gets involved in bone conduction headphones

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I need not give you much of an introduction to HiFiMan. I have worked with them on reviews for 6 years. This is why I am able to bring some exclusives from time to time. This is one. I have been sent a sample of what HiFiMan have been selling in India only up til now. They intend to introduce the GR8 to the rest of the World in due course, so this is my chance to introduce it to the subjective clientele.

About bone conduction headphones

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Bone conduction headphones do not go into the ears. They produce sound by sending vibrations onto the contours of your face. The drivers, normally larger than your usual earbuds, sit close the bottom of the ears and rest against the top of the cheekbone. The headset is weighted down equally on either side with a box of circuitry which provides a gentle pressure to keep the driver in place. The headband tends to be a semi rigid,rigid,rubberised plastic design which is not adjustable.

When it comes to this type of headset, I am in virgin territory. I know of the AfterShokz, know rebranded as Shokz, they seem to be the leaders in this niche market. I have never tried a set, but I am increasingly seeing them being used by runners. As a runner myself, it was inevitable that our paths would cross sooner or later. Why do they seem to be the domain of the runner? Runners make a lot of noise. They grunt and puff their way through the streets of our towns and cities and are seemingly oblivious to the rest of the World around them. Commuters who are wearing earphones don’t have the problems of the runner. They are isolated from the outside World, sure, but they have more time to look around them and they are seeing potential dangers in slow time and have plenty of time to react. They are not sweating profusely like the runner, so they don’t have issues with potential ear infection, build up of wax inside the ear canal, or damage to their earphones or the cups of their headphones. The commuter is not moving their earphones around vigorously like the runner – fit is not a concern. Many a runner will tell you how uncomfortable they have felt on a run, either by needing to ram the earphones deep into the ear canals, constantly having to readjust the position in the ears or by noise vibrating into the entrance of the ear canals – the list goes on and on. Furthermore, and most importantly of all, the volume that a runner needs to generate to block out the noise they are making is far beyond that of the pedestrian. Inevitably the volume has to be pushed into the red on a conventional set of earphones/buds/headphones. This may lead to premature hearing loss. Despite all of the risks I’ve just mentioned I’d argue that the recreation of running was made for listening to music. Unless you are lucky enough to be part of a running club, or running with a companion, this is a solitary occupation, and for many, it can be an exhausting chore. The music provides a rhythm to your stride, a distraction from the toil, and a sense of wellbeing to your day, adding to the endorphins one produces, a chemical process triggered in the brain which is also known as the “runner’s high”. Having convinced you of the benefits of going out for a run, 🏃‍♂️how do I now ensure your safety? The bone conduction headphone was made for this purpose. I have hitherto avoided the bone conduction for one reason only – sound quality. I have long been aware of the reputation of the bone conduction tech being somewhat lacking in this department. The limiting factor of having a set of earphones which do not go into the ears convinced me that I would not be satisfied with the experience of this weird science.  I resisted the temptation to buy a set to hear for myself whether here was anything to this. Until now! I now have a set! I have no choice ; I am compelled to bring you my findings.

This is a surreal experience

I trust by now that most of you will have had a look at the video above, and can see how mystified I was about the GR8. Forget everything else ; I have to get my head around the concept of bone conduction before I can talk about what HiFIMan’s version sounds like. It took some getting used to, lemme tell you! I did not expect to put the headset on and be wowed, my preconceptions were too strong for that. Compared to normal in ears, the bass is the first thing that struck me as different. At first I thought it was non existent! However, there is bass. It is produced by vibrations onto the cheekbone. It is more subtle than the rest of the frequency range. It is a little time before my brain was able to sense what was going on and tune in. I have done some experimenting; if you are determined to try these out at home, you’ll benefit from a better bass performance. Not only does the bass makes it’s presence felt at lower volumes, you won’t be deadening the effect by the constant pounding of your feet on the roads when you’re out for a run. I have decided that that the bass effect lessens as the volume gets louder. As time goes by and my head gets around this new way of listening that impression may change. For now, I’m reasonably confident that’s a result I can share with you. My next observation is that the sound out of the box can be changed. Whether in time the brain adjusts to the way the default GR8 sound like is not a subject for this review ; we need it to be listenable right now – life is too short:smile_phones: I am lucky enough to have a sub app called Morphet attached to my Android app USB Audio Player Pro. Morphet takes a set of frequency curves from many of the most famous headphones/earphones/earbuds out there. There are literally 100s to choose from. I scanned through a few of the presets and settled on the tuning of the Stax SR009. This changed the sound quality radically. The electrostatic needs more bass and less higher frequency boost do the majestic quality of the tech and the drivers. Therefore, I have a slightly rolled back but bass boosted set of bone conduction earphones. You may prefer another entirely different pairing, but I’d recommend this as a starter. It may be useful at this juncture to explain how I’m finding the GR8’s compared to every other method of listening to music. Believe you me ; this is unlike anything else! Think of listening to a set of speakers that are being placed close to your ear and a set of IEM’s that are seated really deep in your ear canal but that you have on low volume. Couple that with the pressure of hundred’s of the tiniest hands massaging your cheekbone. It’s somewhere near that  feeling. There are plusses here, even listening to the GR8 in the comfort of your own home. There is zero listening fatigue. There is no discomfort. Vocals are an absolute doddle to follow. Every hour listening causes a much needed adjustment to the sensory perceptions of the sound. You can easily hold a conversation while wearing them, and you can hear everything that’s going on around you.

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There are negatives. The wife, already able to swear she can hear your IEM’s when you’re wearing them beside her, even when they’re not playing music, will take a great delight in telling you that she can hear the music as plain as day. The missus will try and prove a point by talking to you in an extra low voice so you can’t hear her clearly. Don’t worry ; these things are perfectly normal and nothing to be overly concerned about:beerchug: You will be itching to take these out for a run ; the feeling will become almost unbearable

About the GR8

The headset comes with the HiFiMan brand, which is usually an indicator of at least a certain level of quality. “In HiFiMan we trust”, and all that sort of stuff. I am therefore working under the assumption that HiFiMan have added their engineering pedigree to the bone conduction market, cos it has their name on it. They have made a tentative step of introducing these into the Indian marketplace before any other territory. I make another assumption that this was successful enough that I have been sent a set to talk to you about, with the intention of sending it out to the rest of the World.

The set was for sale in India for RMB 249, which my research tells me is approximately £30. It is on sale at an outlet I don’t recognise, so therefore cannot recommend at present, for £42. Expect the GR8 to go on sale for something around that price mark. My research tells me that Shokz headsets are considerably more, although I’ve yet to compare the sound quality of these against HiFiMan’s. What do you get for your money? The headset looks pretty much the same as most bone conduction’s ; the driver design looks different than Shokz’s in that theirs appears to be a smaller, longer rectangular affair. HiFiMan’s is a larger, circular shape and looks like a more traditional earbud driver, if somewhat bigger. The GR8 has bluetooth 5.0. You can pair these with 2 bluetooth devices. That means you don’t have to disconnect one before using the additional device. Just switch your GR8’s on and play the music on whichever device you choose and it’ll do the rest. Bluetooth 5.0 means low latency, low battery consumption and higher range and signal quality. The ipx rating is 4. This is against a maximum of 7 and a low of 1. A rating of 4 will get you a showerproof, sweat proof, condensation proof headset. You can’t swim or surf or dive with these, but a quick dip in the shower or a wallow in the bath may well be achievable. The battery life is 7 hours. I’ve yet to work out how long it takes to recharge, but 7 hours is too long for a run, more than long enough for a walk and not quite enough for a day in the office, if you are lucky enough to be able to be allowed to do such a thing and are efficient enough at multitasking to be able to do so with enjoyment. That is not the way of the audiophile, of course!

 I assume, again, that this takes not too long at all to get enough charge on it to get you back out on the streets for some exercise or to make the commute home survivable. There are a series of functions that you’d expect on a bluetooth device – they all work easily enough, and are illustrated below,  for your convenience and reference :

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In use, as per the video (and please refer back to that if you need to) without previously having the above instructions, I was able to get to grips with how to operate the GR8’s. They’re logically thought out and contain the usual features you’d find in a bluetooth device. That is, part from noise cancelling and ambient sound – for, of course, you don’t need these features on a pair of bone conduction headphones.

Conclusion 4 Star rating from 5

It was a long time coming. Finally, I succumbed to the bone conduction experience, despite my previous reservations. It was not an altogether unpleasant experience. As I sit here writing this article with the GR8’s buzzing away on my cheeks, there are worse things in life than this. How do I get to a rating of 4 out of 5 for a device I have never come across? I looked at what I expected from these ; and they were able to surpass my expectations. I looked at how much they would retail for, and, at a guess, this is likely to be more reasonable than I would’ve expected from a HiFiMan product, and looking at the rest of the market represents value for money. The GR8’s won me over enough to dispel much of the prejudice I felt about the concept of bone conduction. This is one of the first articles I have ever written about audio where I was actually able to listen to music at the same time, usually IEM’s and headphones are too much of a distraction, but not so with these. I found 4 positives and each 1 is comfortably worth a star, don’t you think? Now, if you don’t mind, it’s a lovely Sunday morning, and it’s about time I got out there and feel some fresh air. The call of the Nike’s is no longer resistible ; I need to head out for my run. I’ll see you in an hour.

The true test

Of all head gear – the run. This task is a measure of all the attributes of a headphone – pounding feet reduces the bass effect, opening the mouth changes the fit of an iem completely, cables are slapping against the body, sweat is being produced in alarming quantities, covering the cable, around the ear, in the ear, on the driver of the iem or the cups of the headphone, sound has to be turned up to drown out harsh breathing and pounding feet, nothing can be heard from the outside World. The abilities of an IEM to remain in place with all this going on is tough, to say the least. There are various noise cancelling and ambient sound effects built into some clever little TWS and bluetooth devices. They use external mics to listen out for louder than usual noises and mute your music down to draw your attention to them. When running, in all cases, even the slightest wind noise is picked up by the mics and pushes a hollow whooshing sound into the ear canal. Other sounds from a distance sound eery and unnatural. Sound quality is being sacrificed over safety, which I agree is a price worth paying, but what if it didn’t have to be that way? The GR8 has found a way to overcome all of these problems.

My findings on the run

Using the bone conduction headset on a run is like not using a headphone at all. Yet you can still hear your music. What’s more – there were added benefits that I had not thought before I put my running shoes on. I could hear everything from the outset of my run. My breathing, my pounding feet; neither can be heard at all whilst I am out for my usual run. Being able to hear that somehow changes the experience ; it makes it feel less alien. I can hear all noises around me, despite setting the volume of the GR8 to maximum. I can hear cars approaching me, and all sounds are natural. I get the pleasant feeling of wind around my ears, which were sweat free for the entire hour. The sound quality now takes on a different flavour. This is because the performance of the bone conduction is dependant on the interaction with the surface of the face. When you run, you naturally will open your mouth, as you are forced to take in more air as your lungs expand to cope with the exertion. This pushes the jaw forward, the ears outwards and the cheekbone will move up slightly. These actions will cause a greater pressure to be placed against the bone conductors. The result is a louder, more detailed sound with a significantly better bass response. That is just with me at a jogging pace. For those that can push it harder I’d expect even better results. The bass response is no longer dependent on how heavy footed a runner you are. Once you are out on the run the bass remains consistent, the volume remains consistent, and it can be heard in spite of what is going on around you. Quieter genres of music, such as classical music, are now audible throughout the entire track ; they aren’t affected by the harshness of your breathing. The fit is perfect. There is no other way to describe it. I needed no adjustment to the headset and felt no effect of sweat on the GR8, despite seeing plenty of that when I took them off on finishing my run. I found myself wondering why I had put up with so much discomfort, so much disembodiment up til now. I have a feeling that my runs will never quite be the same again. For the runner, these have to be 5 out of 5 on the star rating. I hesitate to change the star rating to 5 out of 5. This is because people would be tempted to buy a set thinking that bone conduction headphones are the holy grail of sound quality. Inevitably, they’d be disappointed. The finger of blame would point to me. Let us keep the star rating at 4 as a more universal appraisal of the HiFiMan GR8. This gives some wiggle room and throws down the gauntlet for HiFiMan to find a way to come up with a little more bass. Now that would be a crowd pleaser.