CustomArt Harmony 8 Pro – Mindblowing

Everything has been very positive up to the treble and the H8P’s treble certainly is good but I do have a remark here where I hardly have any with the bass and mid section. The Pro version of the Harmony basically delivers more extended treble but there’s a but. I’m a Beyerdynamic fan and I can really enjoy a lot of good treble but sometimes there’s something not quite right with it. With most of the songs in my collection treble is extended, detailed, airy, nicely fresh and crispy. Nothing to complain about yet once and a while I hear treble going a bit overboard where it becomes overly sharp and a tad metallic sounding. Don’t get me wrong: most of the time you’ll love every single bit of it, I might be nitpicking, I know. It’s just that everything else is so good that it’s a shame I sometimes have this little treble issue. In general though, treble really is good and you won’t need any special silver cable to make the treble shine. It does that already.

As I already mentioned in the cable section, believe it or not, the cable certainly has an impact on the sound. While I really like listening to the stock cable, I did try it with some Linum cables and the Effect Audio Thor. My first experiment with the balanced 2.5mm Linum cable for Astell&Kern wasn’t a big success. Listening to the H8P in balanced made the sound too wide and too thin for my taste and with the decreased bass it wasn’t really something I wanted to listen to. The stock cable actually is good, it gives the right amount of body for the bass and mids and with the H8P already being spacious, detailed and wide, it makes a perfect combination. One of my favorite cables with several monitors is the Effect Thor copper cable but it isn’t so for this ciem. There’s too much bass and body and it’s taking out what the H8P is doing really well. I did us a Linum BaX cable as well and it more or less gives the same result as the stock cable but with a little more refinement and a little less bass. As soon as my stock cable stops working, I’ll be switching to the Linum Bax.

7. Competitors

At the time of typing this review, the H8Pro is the only 8-driver I have in my possession.

Cosmic Ears’ CE4P: I recently got hold of this one after sending back my BA4F to Cosmic Ears for an upgrade. Compared to the BA4F, the CE4P is more linear, has a tighter and faster sound and more detail. The CE6E adds detail and a bigger sound stage to everything the CE4 has. It’s also smoother sounding and has more bass because I have the “E” version. While the sound stage and detail retrieval of the 4 and certainly the 6-driver is really good, it is no match to the detailed wide and deep sound stage of the Harmony 8 Pro.

Out of all my customs my two absolute favorite ones are the H8P and the CE6E. The big difference between both is that the H8P has more detail and a bigger sound stage. The presentation of the H8P is more linear and closer to neutral, while the CE6E is more musical and smoother. When I’m going out, I always use my 6 driver. When I’m at home, I use the H8P with my Astell&Kern AK240 cause there’s no external noise coming at me and I can really enjoy the fine quality of the H8P. To use an analogy, you could say the Harmony is a Lamborghini: perfect in the right conditions and hard to beat but not always the best car to be driving around with in a busy city. The CE6E is more like a BMW M5. Easy in the city and still pretty darn good on a track. Sure it’s not the same level of the H8P but it’s still very good and you can use and enjoy it everywhere, all the time.

1964Ears V6S: The H8P is more linear where the V6S suffers a bit from recessed mids. Detail wise the V6S is close to the H8P but the CA monitor still is better. Both have a really good sound stage but the H8P again is better there. Treble wise the H8P might go a little further but the V6S just might have the edge over the CA monitor there as the H8P’s treble, as I said, can sometimes sound rather sharp and metallic. (The only real down side I could find in the H8P)

Comparing the H8P to the Rhines Stage 5 is like comparing apples and oranges. Sure they’re both fruits but that’s about it. The S5 has a warm and dark signature with a strong focus on bass, the H8P clearly has not. The H8P has a lot less bass body and it is also a lot faster sounding.

Of course you will want to know how it compares to monitor x or y but unfortunately I don’t own all the monitors on the market (yet 😉 ). Of course Nathan also reviewed quite the number of customs but he unfortunately doesn’t own the same ones as I do (that wouldn’t be logic either) so we’re kind of limited with the comparisons I suppose.

8. Driveability

The CustomArt Harmony 8 Pro (50Ω@1kHz) isn’t hard to drive but it isn’t the easiest either. Out of all the customs I have, the H8P is the one where volume goes up most. Sometimes, depending on the music I’m listening to and the quality of the file, I notice myself increasing the volume more than with any of my other IEMs. Probably to get that extra bass feeling.

CustomArt advises to use an external amplifier at all times but basically, the H8P still is easy to drive and all the DAPs I tried it with made it sound very good. Of course if you add in a portable amp like the CypherLabs piccolo, you get a slightly warmer and more bodied sound with some extra bass. My favorite DAP with the H8P is the iBasso DX90. It gives the monitor a tad more bass body and adds a bit of warmth. Together with the clarity and detail of the H8P, I find the combination to be ideal. Those who like to get even more detail and clarity could use it with one of the AK players. You’ll get a top class sound and it’s as if these two units were made for each other if you’re looking for clarity and detail. I did not like the match with the new Fiio X3 Second Generation, as it sounded rather lifeless on the headphone out. Custom art states that “these IEMs are meant to be used with either low or high impedance sources for best possible performance. High impedance sources will not have effect on bass response and will decrease high frequencies”.

9. Conclusion

Congratulations to Piotr and CustomArt. The Harmony 8 Pro is wonderful. I have been impressed with the CAH8P from the first day it arrived. I do look forward to receiving the Earwerkz Legend R, I have a feeling they’ll be close to each other performance wise.

If you want a TOTL monitor with a reference tuning you should really, and I mean really, check out the Harmony 8 Pro. Besides sometimes the treble, there really is little that isn’t spot on.

You can buy the CustomArt monitors directly from their website. Over the last few weeks, CustomArt has also launched two sales on Massdrop where you get a really nice discount as soon as a certain number of orders is reached. Maybe you’ll get lucky when they decide to do another one.


Lieven is living in Europe and he's the leader of the gang. He's running Headfonia as a side project next to his full time day job in Digital Marketing & Consultancy. He's a big fan of tube amps and custom inear monitors and has published hundreds of product reviews over the years.


  • Reply February 26, 2015

    George Lai

    After hitting 8, there’s no stopping you at 10/12-driver customs.

  • Reply March 21, 2015


    What amp would you recommend for these ciems ?, especially for use with idevices ?

    • Reply March 21, 2015


      Seems like Nathan loves the OPPO HA-2. The Cypherlabs Picollo is also awesome, but that’s just an amp (but an awesome one)

  • Reply February 9, 2016


    No updates yet when compared to Earwerkz Legend R Lieven?

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