[Earphones] Acoustune HS1551cu : Looks Cyberpunk and Sounds Classical

To be a specialist in one field, must be unique and different than others. 'Acoustune' is an earphone brand of Japanese company 'DICS' which produces 4.4mm balanced Pentagon terminal which is internationally accredited.

This company developed a special driver called 'Myrinx' designed as a human artificial tissue close to the eardrum, producing a variety of earphone products ranging from the HS1004 to the current lineup. Let me introduce HS1551cu, a representative product of this company.

HS1551cu, its package is quite impressive. 8 pairs of ear-tips in a separate plastic case, an exclusive leather case for earphone and a leather cable tie, and a hard-carrying-case for them all. The accessories are all set for practical use so that you will not have to buy additional.

The gold-colored chambers of HS1551cu's earphone bodies are made of brass and have each one ‘Mirinx’ drivers. The backs of the chambers act as a handle, so you can hold HS1551cu tight when you wear or when you disconnect its cable. The MMCX connector terminal can be matched with various upgrade-cables and not loosened easily due to its high-quality finishing.

The cable which I have used is old-version, is difficult to wear due to their thick thickness and stiff insulators. But now, have been improved to give more flexibility and thinner thicknesses so that can wear HS1551cu easier. Even with these improvements, its bores are short and the red shells surrounding its brass chambers are large, may not be worn easily for some users.

HS1551cu tends to be warmer sound-signature than colder. The impression of dense and deep reverberation from the bass and the expression of sharply smooth mid and treble make this tendency stronger. The middle and lower range of the mid-range is emphasized, and the vocals and the instrument played in the main are pulled forward, and other sessions show around, so it has a good performance of listening to music as well as other media such as video contents.

Because of its bass which has a dense reverberation like small particles jammed together with strongly emphasized on lower-bass, it delivers a tightly packed ambiance. It will give a nice appreciation by the exquisite harmonious combination of the brass instrument and the bass drum reverberation details in a song Moanin’ from ‘Art Blakey and The Jazz Messenger’. However, due to the strong reverberation emphasis and slow response characteristics of bass, there is a limit to catch up the bass details of fast bass.

There is a strong roll-off in the upper-treble. Because of this feature, the overall sound-signature is slightly suppressed and gives a gentle propensity, but the dynamic range is wide enough so that doesn’t blunt the clarity or sound darker. Even though with a dynamic driver type diaphragm, the detail of the midrange is good. It has less reverberation and faster response-characteristic than the low frequency so that it has a moderate temperature and gives a clear sound expression. So, you don’t have to be tricky about choosing music genres regardless of vocal’s voice-tone.

Depending on the quality of the audio source, the variation of bass detail is very large. In a low-quality performance or less power device environment, the change in middle and treble is not that severe, but the bass response changes unstably, making the impression that the bass is cluttered and distorted. If you want to hear more clear bass detail when using the 1551cu, should consider improving the audio system.

As a company that designs 4.4mm balanced terminals, it performs well on devices with 4.4mm balanced terminals. Its dynamic range of the bass gets extended so that make overall sound-stage more natural and wide. If want to do that, I recommend matching it with Acoustune’s upgrade-cable called ‘ARC03’ (MMCX to 4.4mm BAL).

Usually, it suits some upgrade-cables which shows strongly emphasized mid and smooth treble. But, most of the cables show bad results, Since the midrange’s phase is unstably changed when using balanced terminals, it sounds awkward to hear, so upgrade-cable matching is quite tricky.

Claimer

The in-ear headphone is offered by ‘Acoustune’. The content of the review has been written without any restriction because the authors' freedom is respected.

Photo & Review by Bigheadfiler