By aspect — in detail
The reason the set exists, and still an argument. Everyone describes the same low end — deep, clean, and conspicuously free of mid-bass bleed — and then splits on how much of it there is. Two thirds hear a genuine subwoofer shelf; the rest hear something merely tidy and modest. The graph says both are reading the same curve.
Measured
Three independent rigs agree on the shape. Relative to each rig's own 500 Hz level, the shelf measures +7.3 to +10.0 dB at 20 Hz and +7.8 to +8.7 dB at 40 Hz, then falls away steeply — +4.3 to +4.9 dB at 100 Hz, and −0.3 to +0.3 dB by 200 Hz. The minimum sits at 250-300 Hz, 0.5 to 1.3 dB below the 500 Hz reference. Kiwi Ears' claim that the bass is cut at 300 Hz is real; the cut simply completes nearer 200-250 Hz, which is what Headphonesty also found on his own coupler.
⚠ vs. listeners — The graph does not settle the argument so much as explain it. The shelf is genuinely large in absolute terms, but the ear-gain peak is almost exactly as large (+8.4 dB at 3.5 kHz), so the set does not read as bass-tilted the way the raw shelf suggests. The second factor is mechanical rather than acoustic: the reports of thin or absent bass cluster among reviewers and owners who also reported a poor seal, and nothing drains a sub-bass shelf faster than a leak.
Where it splits
a real subwoofer shelf — physical, deep, bass-head territory66%
“Some tracks such as Iori Hobby Shop is downright entertaining with Singolo due to the physical sensation of the bass notes.”
nk-tran, In-Ear Gems
Sources split almost evenly, and they are describing the same two design decisions. One camp hears the scooped lower midrange as clarity — clean, uncoloured, natural. The other hears it as missing body, with a presence lift that turns shouty on loud female vocals. Nobody disputes the tonal shape; they disagree on whether it flatters music.
Measured
The lower midrange is deliberately unlifted: 200 Hz sits level with 500 Hz and 250-300 Hz sits about a decibel below it. Ear gain then peaks at +8.4 dB, and on all three rigs that peak lands around 3.5 kHz rather than the more usual 2.5-3 kHz. A scooped 250 Hz plus a high-placed presence peak is the exact recipe for vocals that read clean and forward to one listener and thin and forced to the next.
Where it splits
clean, natural, uncoloured — clarity without shout44%
“The upper midrange has slightly more energy than the lower frequencies, which gives the sound a lift but doesn’t veer into shoutiness territory.”
Trav Wilson, Headphonesty
thin and hollow low, shouty high — body traded for clarity56%
“I miss a bit richness in his voice and find that the shoutiness of his voice was highlighted more than my preference.”
nk-tran, In-Ear Gems
Broad agreement on the shape — soft, safe, and rolled off up top, with no sparkle to speak of — and a genuine minority who find the 4 kHz rise bites on the wrong material. The disagreement is mostly about whether a deliberately quiet top end counts as restful or as missing.
“Treble reproduction on the Singolo is comfortable but significantly rolled off in the upper frequencies.”
Trav Wilson, Headphonesty
“it lacks the treble extension after around 8kHz. I sometimes joke that this IEM is a simulation of hearing lost that younger audiophiles would eventually have.”
nk-tran, In-Ear Gems
“Sibilance is occasional (a curse of having a rise in the 4kHz region), with resonant peaks enunciating treble glare above my comfort levels.”
Kevingzw, The Headphone List
Measured
Energy falls away from 5 kHz up — about +2.5 to +5.6 dB at 5 kHz, and −7.1 to −11.6 dB by 16 kHz. The rigs disagree about the 8-10 kHz band: two show a bump near 8 kHz followed by a 4-5 dB trough at 10 kHz, the third puts the dip at 8 kHz instead. That is the region couplers of this type read least reliably, so the feature is real but its depth is a strong hint rather than a hard number.
Tonality
Strong consensus · 8 srcThe clearest point of agreement in the whole set. Whatever else reviewers argue about, they describe the same balance: a bass shelf sitting under an otherwise level, gently warm and deliberately safe tuning, with no peaks that call attention to themselves.
“the Singolo is a neutral-warm IEM with a proclivity for gentler, less edgy notes”
Kevingzw, The Headphone List
“It has to be the most colorless IEM from Kiwi Ears as it barely has any unnatural thickness anywhere in the spectrum.”
Suman Sourav Meher, The Headphone List
“the Mids do have a natural tonality and present almost Neutral”
Greg, Headphones and Coffee
Measured
Outside the bass shelf and the 3.5 kHz ear-gain peak, the response is unusually featureless: 500 Hz to 1 kHz moves by only 0.3-0.4 dB on every rig, and there are no narrow peaks between 200 Hz and 2 kHz. That flatness is what the word 'safe' keeps standing in for.
Soundstage
Contested · 8 srcA clean four-against-four split, and it tracks the reviewer rather than the music. Half describe a presentation that stays firmly inside the head; half call it decently wide for the money. Both groups agree depth outruns width and that nothing sounds congested.
Where it splits
average to wide for the price — never cramped47%
“This isn’t a massive sounding iem that stretches the stage in width, but it also isn’t congested sounding.”
Chris Love, Mobile Audiophile
intimate — the stage stays inside your head53%
“The soundstage is mostly in the head with more width (left-to-right separation) than depth (front-to-back separation) and height.”
nk-tran, In-Ear Gems
The most material-dependent aspect here, and reviewers split on how often it bites. On sparse or mid-forward tracks, separation is described as clean and well placed. On dense, fast, bass-heavy material the low end takes up enough room that layering starts to collapse — and reviewers disagree about how much of your library that covers.
Where it splits
separation holds up — clean, well-placed, easy to follow54%
“Separation of elements within the imaginary stage are well parsed-out and delineated from one another.”
Chris Love, Mobile Audiophile
layering collapses once the bass gets busy46%
“Layering is not significant due to the weaker instrument separation.”
nk-tran, In-Ear Gems
Called average for the class by most of the field — resolving enough that nothing is obviously missing, but not a technical standout. The sharpest dissent is a direct comparison finding no advance over the Moondrop Aria, an IEM three years its senior.
“Detail retrieval is another area that I’d say is about average as a whole.”
Chris Love, Mobile Audiophile
“In direct comparison against the Moondrop Aria, I was disappointed to find that not much progress has been made on the resolution front.”
nk-tran, In-Ear Gems
“declaring a medium resolution and a rather average technical behaviour”
cqtek, Hi End Portable
The most consistent criticism in the set. Six of eight sources describe soft transients and a low end that is slow to clear — pillowy rather than punchy — and several link it to the subdued treble. One reviewer flatly disagrees and calls the dynamics best-in-class under $100; that outlier is kept here rather than averaged away.
“The bass punch is pillowy and lacks macrodynamic slam by its slower dynamics.”
Kevingzw, The Headphone List
“the transients (volume spikes) are not snappy and sharp, likely due to the more subdued treble response”
nk-tran, In-Ear Gems
“Its dynamics are one of the best under $100.”
Suman Sourav Meher, The Headphone List
Comfort
Contested · 10 srcThe sharpest split in this record, and the one that decides most of the others. The shells are small, light and smooth — nobody argues with that. The nozzle is short and wide, and reviewers and owners divide roughly 60/40 on whether it reaches deep enough to seal at all. When it does not, the sub-bass simply vanishes.
Measured
The physical numbers behind the argument: a 4 mm inner nozzle diameter with an outer crown of roughly 6.55 mm and a total spout length of about 4 mm, with the maker recommending 4-4.5 mm tips. That is a wide, shallow spout — short tips often fail to reach, and long ones can fight the nozzle's angle. Both sides of the split agree the supplied tips are too flimsy to hold a seal regardless.
Where it splits
fits fine — light, smooth, sits snugly once you tip-roll41%
“As long as I get some tips that work, the Singolo fits like a glove.”
Chris Love, Mobile Audiophile
will not seal — the nozzle is too short and sits at an awkward angle59%
“the nozzles of Singolo are simply too short. Moreover, the bulk of the DD tend to force the nozzle to sit at a slightly awkward angle.”
nk-tran, In-Ear Gems
Isolation
Strong consensus · 3 srcEvery source that raised it called it good — better than typical for a vented dynamic-driver IEM, with the single pressure vent not costing anything. The obvious caveat is that isolation and the contested seal are the same thing: if the set does not seal for you, none of this applies.
“Isolation is reliable and above average for a dynamic-driver-powered IEM.”
Kevingzw, The Headphone List
“the isolation, using my homemade tips, is very good”
cqtek, Hi End Portable
“The Medical grade resin is comfortable and despite the short nozzles I found the isolation good as well as the fit.”
Greg, Headphones and Coffee
Two verdicts inside one aspect. The earphones themselves are consistently praised — clear 3D-printed resin, well finished, light, with the resonator visible inside. What comes in the box is consistently panned: a thin cable, flimsy tips, and no case at all at a launch price of $79.
“The build quality is actually very good.”
Chris Love, Mobile Audiophile
“The build quality is good. The accessories are not.”
Trav Wilson, Headphonesty
“Packaging and accessories: Quite modest. In fact, I would say Singolo is downright below average on this aspect.”
nk-tran, In-Ear Gems
“The stock tips and cable are literally EWaste. Total junk.”
Buck-O, r/iems, via RedditRecs
The most one-sided of the contested aspects, and the one most changed by time. At $79 the majority called it outclassed in an exceptionally strong sub-$100 field; a minority argued it earns its keep precisely because nothing else at the price does the bass trick. Almost none of that was written at today's price of roughly a third as much.
Where it splits
worth it — nothing else at the price does this37%
“at $79, I would say that the Singolo is a successful litmus test of KARS in a romantic, friendly and inviting sonic package”
Kevingzw, The Headphone List
outclassed — the sub-$100 field is simply too strong63%
“I cannot recommend Singolo in 2024 unless you are would like to support the company and the tuner.”
nk-tran, In-Ear Gems
