The OLLO Audio S5X is 50Ω with a sensitivity of 95.2 dB/mW, which is 108.2 dB/V. To reach 100 dB SPL — genuinely loud, louder than most people listen — it needs 3.0 mW, or 0.39 V across the drivers.
That puts it in the easy category. A phone, a laptop headphone jack or the cheapest USB dongle will drive it to painful levels. Of the 280 sources in the database, 257 have at least 10 dB of headroom and another 23 have enough. The cheapest portable source that does the job is the Apple USB-C dongle (US) at $9.
Sensitivity here is in dB per milliwatt. Why the unit matters.
OLLO Audio states this as 106 dB at @ 1kHz RMS @ 0 dBu (i.e. SPL at a stated input VOLTAGE, not per milliwatt) — an SPL at one specific drive level expressed in dBu, the studio unit, rather than per milliwatt or per volt. 0 dBu is 0.7746 Vrms, so at 50Ω that level is a known power and the 95.2 dB/mW above is the result. It is a real published figure, just written in a unit nothing else in this database uses — and reading it as if it were dB/mW would make this headphone look 11 dB easier to drive than it is.
The maker adds a power recommendation of its own: OLLO publishes no power handling and no recommended amplifier power; the product page's only drivability statement is the impedance line "~50 ohm - smart devices ready".
Source: olloaudio.com, olloaudio.com, cdn.shopify.com. How this data was built.
| As it is labelled | As printed | Tolerance | Standard |
|---|---|---|---|
| Frequency range | 15 Hz - 22 kHz sweep 1/3 oct p-p range (+/-1) 14.5 dBSPL | 14.5 dB peak-to-peak | not printed |
| Frequency range | 20 Hz - 20 kHz sweep 1/3 oct p-p range (+/-1) 12 dBSPL | 12 dB peak-to-peak | not printed |
OLLO Audio prints two frequency ranges for the OLLO Audio S5X. The wide one carries no conditions at all; the narrow one names a measurement standard and a tolerance. Only the second is a specification — the first is a headline.
This is the most careful frequency row in the whole audit. OLLO does not print a range and leave it there: it prints how much the response moves inside that range — 14.5 dB peak-to-peak over 15 Hz to 22 kHz, 12 dB over the audible band — measured in third-octave sweeps. The figure is not flattering, which is rather the point.
This is one of only 58 models — out of the 490 whose maker prints a range at all — that also print the tolerance. That is what makes it a specification rather than a headline.
Only what the maker printed; maker by maker.
| Level | What it is | Power | Voltage | Current |
|---|---|---|---|---|
| 85 dB SPL | quiet background listening | 0.10 mW | 69 mV | 1.4 mA |
| 95 dB SPL | normal listening | 0.95 mW | 0.22 V | 4.4 mA |
| 100 dB SPL | loud listening | 3.0 mW | 0.39 V | 7.8 mA |
| 105 dB SPL | very loud | 9.5 mW | 0.69 V | 13.8 mA |
| 110 dB SPL | peaks on dynamic music | 30 mW | 1.23 V | 24.6 mA |
Most people listen between 75 and 85 dB; the 100 dB row leaves room for peaks.
The 15 cheapest of the 280 sources here that reach 100 dB SPL into 50Ω with at least 10 dB of headroom and no known hiss or output-impedance problem with these headphones. All 280 sources, judged for these headphones.
| Source | Type | Price | Power into 50Ω | Headroom | Verdict |
|---|---|---|---|---|---|
| FiiO KA11 | USB dongle | $29 | 128 mW | +16 dB | Comfortable |
| Tanchjim Stargate II | USB dongle | $40 | 48 mW | +12 dB | Comfortable |
| ddHiFi TC35AL | USB dongle | $46 | 134 mW | +16 dB | Comfortable |
| ddHiFi TC35Air | USB dongle | $46 | 134 mW | +16 dB | Comfortable |
| Fosi Audio N3 | Bluetooth receiver | $50 | 88 mW | +15 dB | Comfortable |
| Hidizs SD2 | USB dongle | $50 | 45 mW | +12 dB | Comfortable |
| FiiO BTR13 | Bluetooth receiver | $59 | 64 mW | +13 dB | Comfortable |
| iFi GO link | USB dongle | $59 | 47 mW | +12 dB | Comfortable |
| Kiwi Ears Allegro Pro | USB dongle | $60 | 44 mW | +12 dB | Comfortable |
| ddHiFi TC35Pro (Mountain2) | USB dongle | $66 | 42 mW | +11 dB | Comfortable |
| iBasso DC03 Pro | USB dongle | $69 | 63 mW | +13 dB | Comfortable |
| DUNU DTC 480 | USB dongle | $70 | 42 mW | +11 dB | Comfortable |
| EPZ TP35 Pro | USB dongle | $70 | 72 mW | +14 dB | Comfortable |
| Tanchjim Space | USB dongle | $70 | 80 mW | +14 dB | Comfortable |
| Truthear SHIO | USB dongle | $70 | 80 mW | +14 dB | Comfortable |
Hiss. At 108.2 dB/V these are sensitive enough to reveal a source's own noise floor. The noisiest source in the database, the Schiit Mjolnir 3, would put its hiss at roughly 16 dB SPL in these headphones — clearly audible in quiet passages. Check your own source.
Output impedance. At 50Ω these want a source output impedance below 6.25Ω to satisfy the one-eighth rule; 34 of the 192 sources that publish one miss it. Check yours here.
30Ω · 93.0 dB/mW · Easy
See requirements →250Ω · 102.0 dB/mW · Easy
See requirements →250Ω · 102.0 dB/mW · Easy
See requirements →250Ω · 102.0 dB/mW · Easy
See requirements →25Ω · 92.0 dB/mW · Easy
See requirements →120Ω · 98.7 dB/mW · Easy
See requirements →