HIFIMAN RE400 Waterline IEM review.


HIFIMAN have not paid or sponsored me for this review.
The views and opinions in this publication are unbiased and my own.

Mark & the team at HIFIMAN have been very kind and sent out two of their IEM’s to review. The RE400 Waterlines are the first of those two reviews.

The RE400 Waterline are priced at $79 at the time of this publication.

You can find them on HIFIMANs website by following this link –

Review equipment and software used:

iBasso DX80.
Samsung Galaxy Note 10+.
Qobuz Studio Premier.
Spotify Premium.
Audioquest Dragonfly Black V1.5.
Audioquest Dragontail.

Music used:

Gregory Porter – “All Rise” ( 24-bit Hi-Res / up to 192 kHz )
Norah Jones – “Pick Me Up Off The Floor” ( 24-bit Hi-Res / up to 192 kHz )
Von Meyer – “Once Upon A Dime” ( Hi-Res 48.0 kHz )
Brendon Moeller – “Dub Caravan” ( 16-bits / 44,1 kHz )
Marantz Hi-Res demo playlist on the DX80 ( FLAC )

Packaging & accessories:

The packaging these come in is basic but generous with a good quality zip up pouch with plenty of room for the IEMs, spare tips and a 1/4″ adaptor.

7 silicone ear tips.
10 spare filters. ( helps protect the earphone’s inner components from dust )
1 shirt clip.
1 carry pouch.

Quality of build and ease of use:

The HIFIMAN RE400 Waterline are one of three models in the RE400 range.
In addition to the RE400 Waterline there is also an RE400i and an RE400a, both offering an inline solution for iDevices & Android respectively.
The RE400 Waterline that I am reviewing today sports a regular cable with no inline mic.

For a sub $100 IEM I am impressed with the quality of materials and finish.
The body is a matte silver metal which has a very high grade finish, is pleasant to look at and lightweight.
The cable is something I noticed straight away as being very well made with a premium feel.
It’s non detachable with a nylon sleeve, robust silicone y-splitter, metal cable cinch & a solid and beefy right angled 3.5mm jack HIFIMAN are off to a very good start. I wish that other brands with similarly priced IEMs with non detachable cables would take note and make a more robust cable like HIFIMAN have done with the RE400.



Diaphragm: Titanium Diaphragm.
Magnet: Neodymium magnet.
Frequency Response: 15~22 kHz.
Sensitivity: 102dB.
Impedance: 32 Ohms.
Cable Type: OFC copper cable.
Cable Length: 1.33m.
Plug: 3.5mm.



The RE400s are, once you find the best fitting ear tip very comfortable.
Due to their compact and lightweight design they sit in your ear canal without feeling intrusive. I could listen up to a few hours with no discomfort or fatigue.
I noticed no microphonics from the cable.



The soundstage I get from the RE400 is not wide but focused with depth.
It is a forward sounding IEM with immediacy and detail.
The RE400 has a sharp extended midrange which compliments vocals and brings them to the fore with a sense of clarity and precision.
Highs are crisp and clear. They are an organic sounding in-ear yet with exceptional precision at this price range.
The bass is hefty in the mid bass range packing a decent punch. Bottom end sweeps low and fast, especially when listening to electronic music.
I would conclude that the HIFIMAN RE400 is a lively, punchy sounding IEM with emphasis in the midrange and mid-highs that works well with electronica and EDM. They also sound excellent with jazz, acoustic and classical music.

Summary & recommendation.

A high quality, lively IEM that is a great all-rounder.
The RE400 is very good at reproducing a respectable level of accuracy and weight when considering it is in the sub $100 price range.
I noticed that these perform especially well when listening to any digital music. From techno, through drum & bass to synth pop and electonica the RE400 is relentless in it’s hefty mid bass, lows and crisp highs.

If you’re looking for an affordable pair of IEMs to suit most genres that are both comfortable and robust then the RE400 is for you.
Whether it’s the RE400 Waterline, RE400i or RE400a, give them a look and follow the link at the beginning of this review.

Thanks for reading and your continuing support of The Audiophile Cafe.
All my best, Paul.

The Audiophile Cafe is sponsored by a number of brands, enabling me to improve content.

Thanks to Custom Cans for your ongoing support!

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