The Nicehck M6 is a hybrid (2 dynamic drivers, 4 balanced armatures) in-ear monitor that retails for approximately $111 at the time of this review. The M6 is sold by the NiceHCK Audio Store on AliExpress, which provided me with a sample M6 in exchange for this review. Nicehck offers promotional pricing on the M6 for Head-Fiers, so if you plan on purchasing the M6, be sure to mention that you are a Head-Fier in your order notes before paying. My thoughts about the M6 are my own and I will strive to review the M6 objectively.
I have used the Nicehck M6 with the following sources:
Hidizs AP60II > Nicehck M6
Windows 10 PC > JDS Labs The Element > Nicehck M6
Windows 10 PC > Hidizs AP60II > Nicehck M6
Xiaomi Redmi Note 4 Global > Nicehck M6
I have tested these headphones with local FLAC, Spotify Premium (256/320 kbps Ogg Vorbis), Youtube Music (256 kbps AAC), and Google Play Music (320kbps MP3).
PACKAGING AND ACCESSORIES
The Nicehck M6 comes in a rectangular gold box with the manufacturer’s logo embossed on the front. A sticker on the back indicates the product model, earphone type, driver configuration, cable connection type, and color. Inside this box is the familiar Nicehck-branded semi-rigid zippered carry case, which contains the IEMs, MMCX cable, filter set and eartip selection. The Nicehck M6 comes with three set of silicone eartips (S, M, L) and one set of foam eartips.
BUILD QUALITY / DESIGN
Like the Nicehck EP35, the Nicehck M6 uses an “original manufacturer design” (ODM) which is sold with Nicehck branding. Based on comparisons done by other Head-Fiers, the M6 appears to be identical to the BGVP DMG. The housings are made of anodized aluminum, available in green or gray. Each housing has three vents: a circular vent on the ear-facing surface, an circular vent on the exterior face, and a rectangular vent below the MMCX connector along the seam between housing pieces. Despite these vents, I noticed moderate driver flex when inserting the M6 with certain eartips, including the larger stock ones.
The stock cable is a two strand design, using silver-plated copper with a plastic sheath. The left and right side cables are entwined with each other up to the Y-split in a simple braid. The cable has an L-shaped 3.5mm jack with strain relief, pre-formed plastic earguides, and a chin-adjustment choker that can be raised up to the bottom of the earguides. The MMCX connectors have blue and red markings to indicate the left and right sides.
COMFORT / FIT / ISOLATION
The M6 is intended to be worn cable-up only. The housings are fairly large but are exceptionally ergonomic, using a design that invites comparison to custom-fit in-ear molds, with no sharp edges on any of the ear-facing surfaces. Because of this design, the M6 is very comfortable for extended periods of use. The M6 sits securely in the ear and resists movement. Isolation is above average.
The following impressions were taken while using the stock silicone eartips and a FiiO LC-3.5B upgrade cable, which I prefer for aesthetic reasons. I did not notice a difference in sound quality between the upgrade cable and the stock cable.
The Nicehck M6 has a warm V-shaped tuning. Sub-bass extension is good but is overshadowed by an imposing mid-bass hump which is most pronounced in the transition between sub-bass and mid-bass. The prominence of this region results in a bass response with more rumble than slam. Bass attack is quick but decay is slower, creating a lingering dull rumble in fast or complicated passages. Despite this, bass is highly textured.
The mid-bass bleeds noticeably into the lower mids, which creates an intimate yet murky presentation. The lower mids are gently recessed but are conveyed with a realistic and natural tonality. Male vocals are clear and intelligible. Upper-mids are emphasized, conveying excellent presence without coming across as too aggressive.
Treble is extended but smooth. Clarity is stellar. There is a fair amount of air. Transients are realistic. I would prefer slightly more sparkle.
Imaging and instrument separation are exceptional. Soundstage size is larger than average.
EQ: The biggest problem with the M6’s stock tuning is its mid-bass hump, which bleeds into the mid-range and makes the overall presentation murkier. Cutting the mid-bass dramatically improves definition of the midrange and global clarity. These improvements are possible with limited EQ options, like the 5-band graphic EQ on my smartphone. A 2db cut anywhere between 60 and 150 hz will help.
A note on filters: I did most of my listening with the green “balanced” filters. There is very little difference between the green filters and the silver “treble enhanced” filters. In fact, my listening impressions and measurements indicate that the difference between the green and silver filters is not in the treble but in the upper midrange. The silver filters make the upper midrange a tad more aggressive than the green filters, at the cost of being peakier. Similarly, the gold “bass” filters do not alter the bass response but instead significantly reduce upper midrange energy. I think most listeners will be best served by sticking with the green filters and experimenting with mild EQ.
My measurements were conducted with a Dayton iMM-6 microphone using a vinyl tubing coupler. The measurements are compensated to pseudo-IEC specifications using a mic cal file provided by Crinacle. This mic cal file is designed to be used with a 9k resonance peak, however, for the sake of consistency I have conducted all my measurements at the same insertion depth using foam eartips, so there may be a dip at 9k that is not actually there.
AMPLIFICATION REQUIREMENTS AND SOURCE PAIRING
I do not feel the Nicehck M6 benefits noticeably from dedicated amplification. However, a dedicated DAP may be useful if it provides more EQ options than the average smartphone. The M6 does hiss to varying degrees depending on the source.
Nicehck M6 (green filters, no EQ) vs Meeture MT3
The M6 and MT3 have similar warm v-shaped sound signatures, with a few key differences. The MT3 has more sub-bass quantity relative to the midbass. The M6 has a more prominent mid-bass hump. The MT3 has slightly quicker bass decay, though the M6 has more textured bass. The M6’s bass bleeds into the lower midrange more than the MT3’s does. The two IEMs have similarly recessed lower midranges. The MT3 has a more aggressive upper midrange. The treble on the M6 is more energetic. The M6 has a larger soundstage, better imaging, and significantly better instrument separation. The MT3 is slightly harder to drive from a smartphone. Neither benefit noticeably from dedicated amplification.
Nicehck M6 (green filters, no EQ) vs Mee Audio Pinnacle P1
The M6 is uniformly warmer than the P1 across the bass region. The P1 has faster bass. The M6 has slightly more textured bass. The two IEMs have similarly recessed lower midranges. The P1 has slightly more upper midrange energy. The P1 and the M6 have similar lower treble dips but the P1 has a much more energetic upper treble region. The P1 has a slightly smaller soundstage. The M6 has slightly better imaging and instrument separation. The P1 is much harder to drive. The P1 benefits from dedicated amplification while the M6 is more source-independent.
The M6 is an impressive earphone that shines on technicalities. Recommended for bassheads and audiophiles who aren’t afraid of EQ.