Picture Sunday: Acoustune HS1551 CU

Acoustune HS1551 CU
Disclaimer: Today's Picture Sunday post features the Acoustune HS1551 CU, an IEM of Japanese mindset. To see our latest Picture Sunday posts click here.


Maybe Balanced Armature monitors are still mostly dominating the sector, but we, as HFN, haven’t lost our interest in Dynamic Driver IEMs. I’ve recently received the Acoustune HS1551 CU via our Japanese friends from Acoustune. It has a 10mm Single Dynamic Driver, with a %100 CNC miled brass housing. There’s also a model that has a full aluminum shell as well, and the two models are claimed to sound different.

Acoustune HS1551 CU

Acoustune HS1551 CU

This Acoustune HS1551 CU model has a phenomenal build quality. The shell, the nozzle and mmcx sockets are all exceptional in terms of build and I think this IEM can be used for years without a problem. Looks-wise these are definitely eye-catching with a shiny blue-gold color combination. The cable is also built perfectly, and it even feels like a headphone cable of high quality.

Sound-wise it’s quite early to make conclusions but for first impressions; it has great lows and treble is also high-class. Mids are in a different tonality but that can change with some burn-in time. Sound stage and stereo imaging are impressive, together with good separation. The star of the show for now is the bass though, strong and controlled at the same time.

This IEM really rocks for build, and not to mention the impressive and very practical leather carrying case it comes with. Full review will be on Headfonia when its turn comes.

Acoustune HS1551 CU

Acoustune HS1551 CU

4.8/5 - (16 votes)

A keen audiophile and hobby photographer, Berkhan is after absolute perfection. Whether it is a full-frame camera or a custom in-ear, his standpoint persists. He tries to keep his photography enthusiasm at the same level as audio. Sometimes photography wins, sometimes his love for music takes over and he puts that camera aside. Simplistic expressions of sound in his reviews are the way to go for him. He enjoys a fine single malt along with his favourite Jazz recordings.


  • Reply February 26, 2018

    Bob Marley

    Hello. How well do they sound with Chord Mojo? It would be my next pairing. Thank you very much.

    • Reply February 27, 2018


      I’ve never had a Mojo but it could be a very nice pair.

      • Reply March 11, 2018

        Bob Marley

        The clarity and separation of instruments is not ideal. Also bass and mids are so dominant, that both subbass and highs may get hidden behind it. Also occasionally the song may sound messy. I would like to ask you for a recommendation of aftermarket cable that would help Mojo to clean the sound a little and get these weak points of otherwise very rich and thick sounding earphones under control. What kind or material would you recommend for me to choose and do you have any particular recommendation in 200-300usd range? Thank you.

        PS I wonder what material is stock cable made from.

        • Reply March 13, 2018


          I think an aftermarket cable won’t solve the issue, as it looks like a matching problem. As it seems, Mojo is not the ideal match up in your case.

          Maybe you need a different source. But if I have to repeat my basic knowledge, a silver cable would be good for that.

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