In this section of my review, I will go over how various earphones and headphones pair up and sound with M9. In every pair up, volume is noted with “V”.
Pair up with Headphones.
Tested in “headphone” turbo mode on M9.
Audio-Technica ATH-R70x (V30) – The soundstage expansion is wide open with 3D holographic imaging. The sound signature is balanced, pushing just a bit mid-forward, and the tonality is natural, transparent, leaning more toward revealing side, and even being a bit cold. The bass performance is tight, with a good sub-bass extension, a polite rumble, and articulate mid-bass punch. The balance of the bass is shifted more toward the mid-bass in this pair up. Mids have natural transparent body, and sound clear, detailed, layered, not too much coloring. Treble is clear and detailed, airy, and with a little extra sparkle. M9 drove these 470ohm cans good, but not sure if it was to their full potential since bass performance was leaning closer to neutral.
As a side note, I finally upgraded my R70x stock 3.5mm cable with DoubleHelix DHC Molecule SE Headphone 4.4mm terminated cable, it was way overdue! R70x is a demanding pair of headphones, and going balanced finally allows me to tap into higher power output of 4.4mm. ATH connectors are rare, not too many aftermarket cables available. DHC cable is very lightweight, supple, excellent build quality and design. I don’t have any other cables, aside from stock, for comparison, but relative to a stock cable the improvement is very noticeable, like a veil lifted off the sound.
MEZE Audio Empyrean (V23) – I hear a very wide-open soundstage with an excellent holographic imaging. Sound signature is balanced, and tonality is also natural, transparent, revealing. Bass has a deep extension with a polite textured rumble and a tight mid-bass punch. Again, more weight is shifted toward the mid-bass punch here. Lower mids have a good amount of neutral body, while upper mids have plenty of natural clarity, exhibiting an excellent retrieval of details. The sound has a great layering in mids. Treble is clear and detailed, has a little extra crunch but nothing harsh or splashy.
Beyerdynamic T5p 2nd (V19) – Another very good pair up with a great soundstage expansion and realistic 3D holographic imaging. The sound is balanced, just with a slightly mid-forward bias. Like in other pair ups, the bass here has a polite sub-bass rumble and tight articulate mid-bass punch. The overall weight of the bass shifts more toward mid-bass. Lower mids were slightly north of neutral, with a good amount of body, while upper mids have more clarity, transparency, and micro-details. Vocals sound clear, detailed, even a bit bright. Treble also has plenty of clarity, details, and natural sparkle with a good airy extension.
I was a bit surprised how in all of these headphone pair ups the focus of tuning was shifted more toward more revealing upper mids, while bass impact was rather polite.
Pair up with IEMs.
Switched headphone turbo mode off, and selected high gain in M9.
Oriolus Traillii w/Chiron cable (V24) – Wide open soundstage with 3D imaging. Sound signature is perfectly balanced, overall tonality is natural and a bit more revealing. Bass goes deep, with elevated rumble and fast punchy mid-bass impact. Mids are natural in tonality, with above neutral amount of body in lower mids and organic detailed tonality in upper mids, quite resolving and revealing. Treble is clear and detailed, has extra sparkle and crunch in mid treble.
Aroma Jewel w/FT cable (V26) – The soundstage is wide open and expanded in all 3 directions with holographic imaging. Sound signature is balanced as well, while tonality is more neutral with a slightly more mid-forward revealing presentation of the sound. Bass goes deep, with a textured sub-bass rumble and a punchy and slightly hollow mid-bass; the bass is tight and articulate. Lower mids are leaner which gives upper mids more transparency, less coloring, making them more revealing but not too bright. Treble is crisp and detailed, not splashy or harsh. In this pair up, Jewel does have a little extra energy in treble, but the treble sill sounds natural.
EE Odin (V23) – I noticed right aware there is no hissing in this pair up. Pitch black background with zero hissing at any gain. Bass is well controlled, with a deep and tight sub-bass rumble and fast, punchy, and articulate mid-bass impact. Mids are leaner, more revealing, layered, micro-detailed, but not bright and not too forward, the overall sound signature is still well balanced, but also has a bit more focus on upper mids. Treble is crisp, clear, detailed, more revealing and yet, still well controlled and without any sign of harshness or splashiness. The soundstage is also big, expanded, holographic.
FiR Audio XE6 (V23) – Wide open soundstage expansion with a slightly out of your head depth and holographic imaging. A mildly U-shaped signature with a powerful speaker like analog bass, thanks to XE6 kinetic bass drivers, natural revealing mids and vocals which are a bit recessed, and a crisp detailed treble. The XE6 kinetic bass punches right though the mix. Also, zero hiss, regardless of the gain. The neutral revealing nature of M9 extracts more details from the mids of XE6.
Campfire Audio Solaris 2020 (V14) – Since this is Campfire Audio iem, the first question will always be about hissing. During playback, the background was black, and I didn’t hear any hiss at all. Interestingly, when I lowered the volume to zero and hit play, there is some waterfall type of hissing, but during the actual playback, I didn’t hear any. The soundstage is big, with an overall sound being holographic and quite expanded. Also, the sound sig is balanced, while the tonality is brighter and more revealing. Bass has a deep sub-bass rumble with a fast well controlled punch. Bass actually has some extra weight and texture. Mids are revealing, and a bit colder in tonality. Treble is still quite energetic, but not too elevated and not that fatigue. I was impressed with this pair up, especially bass performance.
VE EXT (V30) – EXT does need a bit of a power boost, but even in high gain the sound was great without a need to go into a turbo mode. Soundstage is very big in this pair up, expanding wide and deep, along with 3D holographic imaging. Sound sig is quite balanced and W-shaped with a bit extra emphasis on bass and treble. Bass is very powerful in this pair up, going deep with elevated rumble and hitting hard with a very strong punch. Mids have a good balance between lower mids natural body and upper mids clarity, resolution, and details. Mids do truly shine in this pair up. Treble is crisp and airy, clear and detailed. This was by far the best pair up with EXT I heard.