I really enjoyed the RE0 for a while, but the sound was lacking bass. This happened if  it was not driven properly out of the uDac or any other amp. Straight out of the iPod, there was something 'off' and it wasn't natural. The RE0 doesn't go particularly low.
On the other hand, the highs are excellent. So are the mids. 
For the current price, they are a must-have.

 
Music I enjoy most at the moment: Fleetwood Mac, Mike Oldfield, David Bowie, Gipsy Kings, Cat Stevens, Tom Waits and America. I will be basing my review on the JH13s on one track of each band/artist.

The Package

To be honest, the package was fairly disappointing. Other than an Otterbox, I expected to receive a little more than just a velvet pouch, a cleaning tool and a manual. Delivery, on the other hand, was very fast. It took 2 days to reach England and I didn’t have to pay any surcharge for the import. What surprised me the most was the incredible low weight of the monitors. I had a fairly similar situation with Grado, when I first lifted up one of the lower-end models. In summary, although I was a little saddened at fist, once I held the JH13s in my hands, I was as blissful as ever.

Build Quality, Cable and Fit

The quality of the earpieces themselves came out very well. The simple design of my choice was reproduced 1:1 from my mental picture. I went for a black cable, because of the apparent colour change with the clear cable. I was very surprised with the fit. My impressions were made by an audiologist, who has never even heard of a custom monitor before. She specialised in Hearing Aids, so I just decided to take my chances. At first, I had to get used to the presence of the JH13s in my ear. After wearing them for hours and hours on successive days, I am now happy to report, that I can barely even feel them anymore. Extreme comfort.

Sound in a Nutshell

Due to the JH13s extremely linear frequency response (yes I am aware of the bump at around the 50hz mark), they sound natural. I have never listened to metal before in my life, but yesterday the JH13s scared me. The soundstage, the handling of complex passages and the realness of the songs I listened to were more than enjoyable. What are the JH13s able to achieve? They are lightening fast. They paint consistent mental imagery. They are involving. They deliver micro-detail like you have never heard it before. Most of all however, they sound real, which is in my opinion their best quality.

Individual Tracks

Fleetwood Mac’s “The Chain”

The first few seconds made me laugh. There is a very subtle but noticeable swear word right at the beginning. Micro details immediately jumped to my attention, which made everything sound so extremely real. The drum kicks in. Bass on the JH13 is astonishing. The bone conduction allows me to feel the bass, something which I was missing with my previous headphones. The vocals are very smooth& have great separation. The cymbal is beautifully extended, which goes to show how detailed& natural the highs on the JH13s are. I love the weight of the sound, which paints realistic pictures of the band arrangement in my head. All in all, “The Chain” is a great song on the JH13s. There are not too many complex passages in this song, but I feel that it demonstrates and highlights certain qualities of the JH13s very well.

Mike Oldfield’s “Muse”

This track particularly highlights the JH13s ability to handle several acoustic guitars and retain a very strong presence of tones. The picking style does not challenge the mids, every detail is preserved. I enjoy the colour and effortless presentation of the sound. The sound stage is vast; still I am able to accurately determine the location of instruments, which I lost with the IE8s. The only instrument I can handle at the moment is guitar and without a doubt, listening to a track has put me the closest to actually playing it. A great track, if you enjoy laid back& relaxing sound.

David Bowie’s “Starman”

A classic from Bowie and actually my favourite of his work. In my opinion, a great demonstration of his voice, which is emotionally involving and more real than ever if listened to it through the JH13s. Furthermore I loved that the monitors completely disappeared, which made the effects of this song more apparent. The dramatic collapse in soundstage, the unique sound of the guitar and the dynamics were handled extremely well. To sum up, I find that this song is brought up to another level. It is very emotionally involving and complex, but it never brings the JH13s even close to the edge.

Gipsy Kings’ “Bem, Bem, Maria”

The raw speed of the JH13s is brought out. I love this track; it is upbeat and extremely complex. All the details are there, I was very much overwhelmed by analysing certain aspects of this it. The decay is perfect. The attack is fast. Raw speed. I was only able to pick up a slight echo, which is due to the recording. I also find that even though the musicians are quite far away from my head, they reach out and grab my attention with their ability to play guitar. On the JH13s this track is very musical, whilst still retaining every possible disturbance& inaccuracy.

Cat Stevens’ “Father And Son”

This has been a very emotionally involving track for me. The arrangements of the instruments are beautifully held in place. Most of all, however, I find that the JH13s show others how vocals are done. You hear every breath, every movement of the lip. All the details that got lost are retrieved, which allows the listener to connect. The message of this song is sad, and is only underlined by the sheer beauty of the harmony and tones. Overall, I experienced that the JH13s make this song come alive, which again, justifies their high price tag. Now I can save the money I spend on concerts, I found a satisfying alternative.

Last Thoughts

I will update this review with more songs as time goes by. For now, I think you should get the picture that I am trying to paint. I love the JH13s!