Both are portable players, $799 against $949. This page puts them side by side on the only three things a maker can be held to — power, output impedance and noise — and then asks the question that actually matters: which headphones do they treat differently?
On raw power they are level: each reaches 100 dB on 566 of the 567 non-electrostatic models here.
| Specification | FiiO M15S | iBasso DX260 MK2 |
|---|---|---|
| Power into 32Ω | 580 mW | 262 mW |
| Power into 150Ω | 150 mW | 56 mW |
| Power into 300Ω | 93 mW | 28 mW |
| Power into 600Ω | 47 mW | 14 mW |
| Output impedance | 1.4 Ω | 0.6 Ω |
| Output noise | 3.2 µV | 1.0 µV |
| Price | $799 | $949 |
| Headphones it reaches 100 dB on out of 567 | 566 | 566 |
A figure marked not published is missing from the maker’s own material, which is not the same as being good or bad. Where one of these two publishes a number and the other does not, the comparison on that axis cannot be made at all — and saying so is more useful than guessing.
| Load | FiiO M15S | iBasso DX260 MK2 |
|---|---|---|
| 32 Ω | Published | Derived |
| 150 Ω | Derived | Derived |
| 300 Ω | Published | Derived |
| 600 Ω | Derived | Derived |
Only one of these two columns starts from a power rating. FiiO M15S publishes one at 32 Ω and at 300 Ω; iBasso DX260 MK2 publishes none at any of these four loads, so its column is worked out from power it published at other loads. Both are arithmetic on a maker’s own figures rather than guesses, and the method used for the iBasso DX260 MK2 understates rather than flatters — but at 32 Ω and at 300 Ω are the only loads here at which its maker can be held to a figure.
What each of these labels means, and why a derived figure is still worth printing, is set out in how this data was built.
On power they are interchangeable across this whole database: there is no headphone here that one reaches 100 dB on and the other does not.
50 headphones are left alone by the iBasso DX260 MK2 under the one-eighth rule but coloured by the FiiO M15S (64 Audio Aspire 1, 64 Audio Fourte, 64 Audio Nio, 47 more).
21 headphones stay below the audible-hiss threshold on the iBasso DX260 MK2 but cross it on the FiiO M15S (64 Audio Fourte, AFUL Performer 8, Campfire Audio Andromeda 10, 18 more).
566 of the 567 models here reach 100 dB on both. That is a power count and nothing more; whether either source suits a given headphone also depends on the two lines above.
The counts above say how many models the two treat differently. This says by how much. The same 8 headphones appear on every page of this kind, ordered from the easiest to drive to the hardest, so a row can be read across pages as well as across columns. Headroom is at a 100 dB SPL peak.
The widest gap on the list is the Sennheiser HD 600: FiiO M15S has +11 dB of headroom there against +6 dB. 5 dB is about 3.3 times the power, which matters for peaks rather than for how loud the music sits.
Hiss is this source’s own noise, in decibels SPL, in that headphone — not a rating. Below about 20 dB SPL it is under the threshold of hearing in a quiet room; a negative figure means it is far below it.
| Headphone | Impedance | Needs | FiiO M15S headroom | iBasso DX260 MK2 headroom | FiiO M15S hiss | iBasso DX260 MK2 hiss |
|---|---|---|---|---|---|---|
| Shure SE846 | 9 Ω | 0.04 mW | +39 dB damping | +39 dB | 25 dB | 14 dB |
| Campfire Audio Andromeda 2020 | 9 Ω | 4.0 mW | +19 dB damping | +19 dB | 5 dB | -6 dB |
| Audeze LCD-2 Classic | 70 Ω | 0.79 mW | +26 dB | +22 dB | 3 dB | -7 dB |
| Beyerdynamic DT 1990 Pro (250Ω) | 250 Ω | 0.63 mW | +22 dB | +17 dB | -2 dB | -12 dB |
| HiFiMAN HE400se | 25 Ω | 7.9 mW | +18 dB | +16 dB | -3 dB | -13 dB |
| Audio-Technica ATH-R70X | 470 Ω | 1.6 mW | +16 dB | +11 dB | -9 dB | -19 dB |
| Sennheiser HD 600 | 300 Ω | 6.6 mW | +11 dB | +6 dB | -13 dB | -23 dB |
| HiFiMAN Susvara | 60 Ω | 50 mW | +8 dB | +4 dB | -15 dB | -25 dB |
The iBasso DX260 MK2 costs $150 more than the FiiO M15S. Out of the 567 models here, that difference buys 50 more models left alone under the one-eighth rule and 21 more models kept below the audible-hiss threshold.
Nothing runs the other way: there is no axis here on which the cheaper of the two does better.
Everything in this paragraph counts only figures the two makers published. An advantage on an axis one of them leaves blank cannot be counted, and is not counted — how often that happens is its own page.
Each has a page of its own with every power figure traced to what the maker published and a full headphone list: FiiO M15S and iBasso DX260 MK2. Or put either against your own headphones in the source comparison tool.