Siren Song - Hidizs MS4 Mermaid Review

Project A³  |  December 15, 2019

Disclaimer: HIDIZS has graciously provided us with this sample unit in exchange for an honest review. The views discussed below are a reflection of Project A3's thoughts surrounding the product. In order to obtain an apropos result of the review, the target sample has been run in for at least 50 hours before reviewing.

Hidizs made a name for themselves way back when they had the crowd-funded AP200 hit the audiophile community by storm, at the time players capable of operating a non-gated build of android was not the norm it is today, and they've since followed it up with a many different successes, including the AP80(Stay tuned for that), and now they've decided to enter the IEM market as well with the MS4, an ambitious entry sporting a 4*(One of the drivers being a Knowles dual unit.) driver hybrid that isn't entirely all that common at the manufacturer suggested retail price of $269 and sometimes on sale. How does the Mermaid perform? How does it compare to the rest of the pack? Finn out in the full review below.

● Delivers on a cohesive sound for a hybrid.
● High quality build and included accessories.
● Engaging and fun sound signature, that still delivers a resolution.
● Strong forward vocals, crisp treble, and full bass.

● Bass can lose focus at times.
● Shell is slightly large and a bit heavy.

10.2MM High Density Polymer Diaphragm Dynamic Driver
Knowles 33518 Balanced Armature
Knowles 30017 Dual Balanced Armature
CNC Aluminum Housing
15Hz-40KHz Frequency Response
112dB Sensitivity
12 Ohms Impedance at 1KHz

Gear Used & Tracklist:
Shanling M0 | FiiO Q1 Mk II | Hiby R6 | Zorloo ZuperDAC | MassDrop x Cavalli CTH

The Mermaid comes in a large that slides out to reveal the IEMs, some warranty cards and instructions, a bevy of tips, and a very very attractive structured brown leatherette case that had a magnetic closing mechanism with a soft fabric lining and a net compartment for any accessories you might want to bring. It is very spacious and could fit not just the IEM but even some tips and a dongle or even a small player like the AP80 or my M0. (More on the Packaging quality below)

The Mermaid is an easy to drive model, anywhere from phones to dongles and beyond are capable of driving the Mermaid. If anything there might be benefits if the unit you have is lacking in power or you are experiencing hiss, an upgrade would reveal an upgrade most notably in bass perception and control as well as the muting of the hiss would open up the sound more, something I noticed when plugging into my laptop. However, this is only really applicable for very very underpowered devices and most modern mid to high-end phones or anyone with a dongle DAC, DAP, Amp that is pushing more power one shouldn't really feel a huge difference in terms of scaling, and gains in that end will only be meager.

The Mermaid is a CNC Aluminum shell that is on the larger side of things, but not heavy for the size. Though the volume can be explained due to the fact that it does have 4* drivers, and the 10.2mm DD is nothing to sneeze at. This may lead to minor difficulty in fit for those with smaller ears, but the construction itself is smooth and contoured so that there isn't any general discomfort with the fit in itself. But for most as long as they don't mind the IEM sticking out just a bit, then there really isn't much to worry about in terms of it. They aren't as heavy as they seem to either so unlike other models that are full metal built units they will not weigh down on your ears so quickly.

Sound Signature:
The Mermaid has what I would describe as a W shaped tuning that gives mild boosts in both bass and treble, but relatively to the mids less than that of V or even U shaped tunings, plus pushes the mids at a bit above the 1KHz mark to give a forwardness to the vocals. Overall the tuning is very musical and engaging without being too tiring or overbearing, fully utilizing the hybrid drivers without sounding disparate even though it doesn't totally juggle everything flawlessly.

The bass response from the mermaid is boosted with only a dip as it transitions into the midrange, with an impressive sub-bass response that delivers the feeling of percussive impact without losing control. Rolling bass drums deliver the slam and rumble with medium decay. The mid-bass, on the other hand, is equally impressive in the impact delivery and thickness but can feel like it loses definition especially when track complexity increases thus losing some of the coherence in the response. In simpler tracks, however, the bass is thick without being bloated providing a boost for the musicality that is one of the highlights. Overall the bass is good and delivers excellent performance in its class, a powerful bass response that is mostly a technical upgrade without taking over the entire signature even when it loses focus.

Thanks to the particular way the midrange is tuned vocals are generally forward giving them good vibrancy, resolution, and they will usually shine in the mix. There is a slight inclination towards female or higher register vocals but overall the entire vocal range is well-represented lending to clear uninhibited vocals that cut through even in more complex track layouts. This goes mostly the same for melodies and instrumentation, seemingly slightly less pronounced but instrument riffs are well defined soft. This leads to a midrange that is coherent, engaging, and avoids being dull and dry, that is one of the qualities that Mermaid has that pulls you in as a listener.

The utilization of a multi-driver hybrid setup shines in the Mermaid and the treble is easiest to pinpoint factor about it. Highs are crisp, sparkly and full of air and openness, without feeling like it is out of place. With another dip in the lower treble-upper mid area, a lot of the harsh qualities associated with high frequencies are minimized and it still offers a lot of clarity and transparency. There's a quality to the treble that is rather pleasant, and while it's never uncomfortable, some treble sensitive listeners may find some fatigue in listening to it after long periods, however, it's what gives the Mermaid the extra edge to really set it apart from competing products as a fun, exceedingly musical all arounder.

Soundstage & Separation:
The Mermaid exhibits a good extension of the soundstage, managing to have a left to right perception that extends beyond the head. The 3D expansion is also good as generally there is no feeling of claustrophobia even in "tighter" songs. However, the thick bass obscures some positional identifiers, especially as the compositions increase in complexity, especially when it's not the vocals, which still manage to break apart from the signature. 

I pitted the Mermaid with a natural counterpart in the Shozy & Neo BG that fills an almost inverse niche to show the vast array of options you can find at this price point, and as an extra challenge, I pitted it against the first generation Polaris, a long-time favorite of mine for having some similar aspects tuning philosophy wise, of course, the Polaris was still a step above in many facets but at nearly double the price it isn't a surprise and the Mermaid fills a lot of the same needs without breaking the bank. Overall the MS4 feels more adaptable over the more specialized competing products and it held up extremely well compared to a well-regarded product from one of the more lauded manufacturers.

To view the full original article, click here.