JVC HAFx40 review: Burn them in , Love them.

JVC is a company well established for their earphones, especially with the JVC marshmallows. Now JVC is experimenting with carbon nanotube drivers instead of the traditional neodymium magnets. Headfi has gone near crazy with the JVC Hafx40 as it supposedly defeats earphones 4 to 5 times their price of $20. There has been a recent trend of bang for buck products but can the Hafx40s rise to the top?

The first thing you will notice once the Hafx40s arrive is the box. While just a simple box, it is almost impenetrable but the effort is worth it.  JVC includes the normal small/Medium/Large earphones and also includes a foam earbud and a shirt clip. Unlike the Meelectronics , JVC included a shirt clip with a neat mechanism that allows you to take it off and on more easily. The Foam earbud cancels out a lot of noise and increases the Bass at the cost of the Treble, though it still won’t be enough for bass heads.

The build quality is subpar at best. Unfortunately, this was the major part that was cut out in order to maintain the low cost.  There is only one place of strain protection and that is the straight jack. There is no strain protection on the part that is least likely to break, the part where the cable and the earphones meet. The cables are pretty thin but fairly average for this price. The actual earphone is built quite nicely and looks very great. When most people see this earphone they will probably ask about the nub on the side of the earphone. This nub is so the earphone fits better in your ear. Compared to the Monoprice 8320 or the Meelectronics M9 the Hafx40 is built fairly conservatively other than the nub.

The conservative build allows for the Hafx40 to have a greater fit and greater comfort than other earphones. Not a single time did I have any issues with the HaFx40 slipping out of my ear, even while I was walking. They were also pretty comfortable, with comfort increasing when you use the foam ear tips provided. Isolation is fairly average for the price.


The sound quality of the JVC Hafx40’s is incredible. Not only do they beat most competitors in their price range but they can stand up against $100 – $150 earphones with no sweat, other than the flames of burn in. I recommend burning these earphones for at least 100 hours before listening to them. Their full capability gets reached at 300 hour mark, which is very unrealistic for many mainstream consumers. The high burn in time is due to the carbon nanotube technology in the drivers.

The bass is perhaps the weakest point of the overall sound. Not too say it is bad, it is not, but compared to the treble and the mids bass is kept in the back. The bass is very fast and punchy. Drums sound great and incredibly detailed. You can clearly hear the reverb of the drum and the different ways the drums are being hit. Bass impact gets big as the bass is dropped but this isn’t a bass heavy earphone. Rather than pulling a mainstream bass heavy, JVC has opted to focus on the midrange and treble.

The midrange is absolutely incredible. Vocals sound beautiful and very detailed. You can clearly hear if they were recording in a home studio or in a professional studio. Acoustic guitars sounded absolutely phenomenal as you could clearly hear the individual strums and different strings when the guitarist played. I even preferred the midrange of the JVC HAfx40s to the $200 UE Triple fi 10s. This is the perfect earphone for any rock.

The treble is the best part of the JVC Hafx40’s but also a curse. If you choose to listen to this earphones right after you open them you will hear a lot of sibilance in the treble. The treble, even after 100 hours of burn in, still shows signs of harshness. At 150 hours of burn in most of this harshness is gone. However its long burn in time is the crux that prevents the HaFx40 from getting mainstream attention as the amazing bang for buck it is. Besides this, the treble sounds excellent after burn in. Everything about the treble is very natural and precise. The only thing bad about the treble are electric guitars. Electric Guitars are very slightly recessed and also get better after burn in.


Other than the incredibly balanced sound signature, the HaFx40 also presents another sound aspect unique to this price point, incredible detail. Obviously you can’t be using YouTube ripped mp3s to have this experience, then again why are you ripping mp3s from YouTube? The way the Hafx40 presents details in the sound is absolutely surreal. Listening to Kid A or Dark Side of The Moon sounded 20 times better as I was able to identify details in the sound that I didn’t even hear before.

The details of the Hafx40 also makes the soundstage so much better. While it isn’t as wide as other bang for buck earphones it is still very wide. What the JVC Hafx40 lacks in soundstage width, it makes up with great depth. The soundstage sounded full rather than thin. Instrument separation was also dead on.

Having this kind of sound in a $20 earphone is incredible, even for $50 or dare I say $100 it still would be incredible. Though the build quality is fairly average, the sound quality picks up the slack and makes it a memorable earphone. This is the best sounding earphone I have heard for $20 and I recommend checking the HaFx40s out.


  • A lot of detail in the sound signature
  • Midrange is smooth and is not recessed.
  • Treble is very smooth and has alot of detail
  • Soundstage is relatively wide for this price range and has depth.
  • Overall Presentation is very natural


  • Build quality is average for the price.
  • Electric guitars have a slight recession
  • Bass can be lacking impact.
  • 100+ hours of burn in with bass heavy music is recommended before listening to them and 200+ hours of burn in gets them to their best sound.

Music that fits this earphone: Rock, Jazz, pop, (any vocal centric music)

Music that does not fit this earphone: Rap, Electronic music, (any bass centric music)



The JVC Hafx40 gets a 8.4/10 while it has a great sound that goes beyond its price point of $20 and could be comparable to $50-$60 earphones though it lacks strain protection and its build quality suffers because of that.

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Hydro Ninja

Hey, I am Hydroninja9. I have been in the tech writing biz for 2 years now and I joined TeckComesFirst in February of 2013. I am a gamer , technophile and audiophile. Of course some info about me isn’t known; blame mind control chips for that. I also make YouTube videos on a regular basis.

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