TFZ Series 4 featured

TFZ Series 4 review

TFZ is an audio company that has had a fast rise in popularity since they started with their Series 1, 3 and 5 earphones. I’ve been a long time fan, especially since I reviewed the TFZ Balance 2M which is a great sounding IEM. Recently their latest Exclusive series won the Japanese VGP authority awards 2017. So now, welcome to my TFZ Series 4 review. Let’s see how it stacks up.

The TFZ Series for retails for $99 at the time of writing and is available from Penon Audio.

This product was provided for the purpose of an honest review. I’m not affiliated with the company and all observations and opinions here are my own.

  • Great design
  • Ergonomics and comfort
  • Eartip variety
  • Shouty upper midrange


  • Driver: 12mm dual magnetic circuit graphene driver
  • Sensitivity: 108dB / mW
  • Impedance: 16 ohm
  • Frequency response: 5-40kHz
  • Connectors: 2-pin 0.78mm
  • Lowest power:8MW
  • Microphone: None
  • Plug : 3.5mm
  • Cable length: 1.2M

Packaging and accessories

The TFZ Series 4 comes in a long, slender black box with the logo and model printed on the front in silver. After opening you see a long card with a couple of slogans on it. Lifting out the card reveals the earphones secured in a plastic tray and a smaller cardboard box beneath that. I quite like this unboxing experience. It’s nicely presented and not over the top. Here’s what you get inside:

  • TFZ Series 4 earphones
  • Shirt clip
  • User manual & warranty card
  • 3x pairs of wide bore silicone tips
  • 3x pairs of narrow bore silicone tips
  • 1x pair of foam tips
  • Soft carrying pouch
  • Detachable 2-pin cable
  • Velcro cable tie

It’s great to see some different eartip styles included in the package. The shallow fit, wide bore tips are actually big enough for my large ear canals and of good quality and very comfortable.

While the carry pouch is good for storing the earphones it won’t give much protection if you’re carrying it around in a bag or pocket. A clamshell case would be preferred but of course, a carry pouch is better than nothing at all and is a welcome addition.

The included cable is an improvement over the one that comes with the Exclusive King. It’s similar in style and build but is more substantial and thicker below the Y-split while retaining the same pliability. It comes with a pre-shaped, clear plastic tubing which I find a much better solution than memory wire. The Y-split is a circular, translucent plastic with the TFZ logo on it. It’s a little large but I like it. Kudos to TFZ for having the balls to do things differently. Similarly, the straight plug is made of the same translucent plastic. It’s wider than average which might cause difficulty with some phone cases but for me is not an issue whatsoever. Strain reliefs are good from top to bottom.

Build, comfort and isolation

This model comes in two colour variants, grey and blue. Like all of TFZ’s recent models, the TFZ Series 4 is drop dead gorgeous for a UIEM. It’s similar in size and shape to the Exclusive King and in my opinion, looks better even than that.  With its transparent plastic housing and metal faceplate, both of which are immaculately joined together with a uniform and very tidy seam.

An angled nozzle with protective metal mesh protrudes from the housings and includes a proper lip to secure the eartips. All the edges on the IEM are rounded and smooth and there are no visible inconsistencies or flaws found anywhere. There’s a nice weight to them that makes these feel substantial and premium. From the inner side, you can clearly see the large 12mm dynamic driver.

Like all recent TFZ releases the Series 4 comes with detachable 2-pin 0.78mm cable which for me is a welcome change from the often unreliable MMCX type. Build quality overall is exceptional for an earphone at this price.

In terms of comfort, I find the Series 4 to be really good. I can wear these for hours on end no problem at all. The shape of the housings with their smooth edges, the angle of the nozzle and over-ear wear combine for a comfortable experience.

Isolation is about average for me personally but I feel that those with smaller outer ears will likely find them above average for blocking outside noise.


Gear used for testing

TFZ IEMs have always been easy to drive and the TFZ Series 4 is no exception with its 16 Ohm impedance and 108dB / mW sensitivity. These can be paired with any low powered device like a smartphone and still sound good.

The general signature of the TFZ Series 4 is a punchy but still linear bass with a boosted upper midrange and well-extended treble. There seems to be a definite trend in a lot of Chi-Fi IEMs that boost the upper mids and reduce the bass to achieve a more “audiophile” type tuning but in a lot of cases it comes across as a cheap fix. Luckily TFZ gets it largely right but it’s not perfect.

Note that my measurements are not 100% correct but you can get a pretty clear idea of the general frequency response.


The bass is a high point in the TFZ Series 4, just as it was with the Exclusive king. It’s fast and punchy without being overbearing or showing signs of bass bleed. The sub-bass, in particular, is really nice. It has a physical presence that you can feel in your ears but just like the mid-bass it’s more linear and plays its role rather than trying to be the star of the show. Daft Punk’s “Lose Yourself to Dance” is a great track to highlight the Series 4’s fantastic sub-bass control. Overall it’s tight and well presented with good texture.


The midrange has a nice energy for sure but that upper midrange emphasis can become fatiguing after a while. It gives an impression of extra detail but when things get busy on a track you can hear things becoming congested and layering is only average. There’s a dip in the lower mids that can make it sound a little thin and anything falling into the upper midrange tends to dominate the overall sound which isn’t always a bad thing, for example when people want to get close and personal with female vocalists. Clarity is excellent and what’s particularly impressive is that despite the emphasis on upper mids there’s very little to no sign of sibilance.


Treble has good extension and timbre but sits at the back of the upper mids so tends to get a little lost on occasion. This does however also mean that it is not harsh and has good control. The sheen of cymbals sound natural with some air and sparkle but the treble, for the most part, is a bit distant.


Soundstage is one area that TFZ does really well and that’s the case again with the Series 4. It has more width than depth but feels pretty expansive for something in its price range. Listening to “Mob Mentality” by Earthside presents the vocals up front and centre with instruments reaching out to the edge of the headspace. There are good spacing and positioning of separate elements making music immersive with touches of excitement.


Kinera H3 ($99 USD)

The H3 is an interesting IEM with lots of potential but some drawbacks that make it ultimately mediocre. It has slightly less mid-bass and noticeably weaker sub-bass than the S4. It’s just as comfortable if not even more so with its more rounded contours. The lower treble peak makes it quite sibilant and edgy to listen to. Its vocals are a little more recessed in comparison to the TFZ. While both are competent entry-level IEMs The Series 4 has an edge in audio quality. The H3 does, however, have a more comprehensive accessory bundle including a very nice carry case and an excellent cable.

Toneking Nine Tail ($125 USD)

The 9T is more evenly spread across the frequency response making it less in your face but ultimately more relaxing and better for longer listening sessions as the Series 4 demands a little too much of your attention and can be fatiguing to listen to depending on the type of music. Bass levels on the 9T are a bit lower and it doesn’t have the same reach in sub-bass nor is it as textured as the S4. The midrange has more body on the 9T and is more even without any noticeable peaks. Toneking’s offering has better layering and separation and overall a more cohesive and organic sound as well as the custom tuning options provided by the various filter combinations.

From lower left to upper right: TFZ Series 4, Toneking 9 Tail, Kinera H3

TFZ Series 4 Conclusion

TFZ remains one of my favourite entry-level earphone brands. With each new release, their sound becomes more refined but the real standout is their impeccable style and build quality. They produce some of the best looking IEMs under $100 without a doubt.

The TFZ Series 4 is a great sounding earphone, particularly if you’re a fan of boosted upper midrange. The bass is exquisite, carrying texture and authority while retaining a linear level and the sub-bass is among the best in its class.

Build, aesthetics, detachable cable and good accessory bundle – what’s not to like? Simply put, the Series 4 is a perfect example of why TFZ is well deserving of their fast rise in the IEM market and I’m already looking forward to seeing what they bring out next.

You can buy the Series 4 at Penon Audio HERE.

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