Short answer: the OLLO S4R. It ranks #171 of 216 over-ear headphones by sound quality, rated 3.0/5, at $289; the Austrian Audio Hi-X55 ranks #178, rated 2.9/5, and costs $315.71, which makes this an easy call rather than a real tradeoff.
What the OLLO S4R does well: It is a closed back wired headphone with a 50 ohm, 106 dB SPL sensitive 50 mm driver that plays loudly from a phone or interface without a dedicated amp. The tradeoff: Its preference score is only 60.0 with a 3.28 dB deviation, so the tonal balance is uneven overall.
Why pick the Austrian Audio Hi-X55: The closed back blocks outside noise and keeps sound from leaking, so it works in shared rooms and studios. The tradeoff: oratory1990’s measurement shows a deep 9.9 dB dip near 2.3 kHz and presence about 3.9 dB below target, so vocals and guitars sound recessed and distant.
Buy the OLLO S4R. It is rated higher for sound quality than the Austrian Audio Hi-X55 and costs less, so only choose the other one for a particular feature it does better.
Looking for alternatives? See the complete Headphones rankings.
Specifications Side By Side
| OLLO S4R | Austrian Audio Hi-X55 | |
|---|---|---|
| Price | $289.00 | $315.71 |
| Ranked | #171 of 216 in Over-Ear Headphones | #178 of 216 in Over-Ear Headphones |
| Form Factor | Over-ear | Over-ear |
| Harman Preference Score | 60 (measured by oratory1990, via AutoEQ) | 56 (measured by oratory1990, via AutoEQ) |
| Deviation From Target | 3.28 dB standard deviation | 3.63 dB standard deviation |
| Tonal Tilt | -0.85 (negative is warmer, positive brighter) | -0.79 (negative is warmer, positive brighter) |
| Sub-bass Extension | Within 6 dB of target down to 20 Hz (-0.6 dB at 30 Hz) | Within 6 dB of target down to 20 Hz (-2.7 dB at 30 Hz) |
| Connection | Wired | Wired |
| Back | Closed | Closed |
| Driver Type | Dynamic | Dynamic |
| Drivers | 1 x 50mm dynamic | 1 x 44mm dynamic |
| Impedance | 50 ohms | 25 ohms |
| Sensitivity | 106 dB SPL @ 0 dBu | 118 dB SPL/V |
| Weight | 0.9 lbs (420 g) | 0.7 lbs (305 g) |
| Frequency Response | 15Hz - 22kHz (Manufacturer specified) | 5Hz - 28kHz (Manufacturer specified) |
| Built-in Microphone | - | No |
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More worthwhile head-to-heads for OLLO S4R:
- Sony MDR-M1ST vs OLLO S4R
- OLLO S4R vs Focal Listen Professional
- Sony MDR-M1ST vs Austrian Audio Hi-X55
- Austrian Audio Hi-X55 vs KLH Ultimate One
- Austrian Audio Hi-X55 vs Focal Listen Professional
Prices on this page were last checked October 11, 2026 at 4:59 PM UTC. Product prices and availability are accurate as of that date/time and are subject to change; the price and availability shown on Amazon at the time of purchase will apply to the purchase of this product.
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The Two Headphones In Full
OLLO S4R: $289.00 OLLO Audio eBay
Pros: It is a closed back wired headphone with a 50 ohm, 106 dB SPL sensitive 50 mm driver that plays loudly from a phone or interface without a dedicated amp. In oratory1990’s measurement, bass holds within 2 dB of target at 30 Hz and upper bass gets a 2.5 dB lift, which suits listeners who like a warm, bass forward tone. It is rated a touch higher than the more expensive Austrian Audio Hi-X55 and Focal Listen Professional.
Cons: Its preference score is only 60.0 with a 3.28 dB deviation, so the tonal balance is uneven overall. A deep 13.9 dB dip near 7 kHz and treble averaging 5.7 dB below target from 6 to 10 kHz make cymbals and detail sound muffled. At 420 g it is also on the heavy side.
Full OLLO S4R review and specifications →
| Back | Closed |
|---|---|
| Connection | Wired |
| Deviation From Target | 3.28 dB standard deviation |
| Driver Type | Dynamic |
| Drivers | 1 x 50mm dynamic |
| Form Factor | Over-ear |
| Frequency Response | 15Hz - 22kHz (Manufacturer specified) |
| Harman Preference Score | 60 (measured by oratory1990, via AutoEQ) |
| Impedance | 50 ohms |
| Sensitivity | 106 dB SPL @ 0 dBu |
| Sub-bass Extension | Within 6 dB of target down to 20 Hz (-0.6 dB at 30 Hz) |
| Tonal Tilt | -0.85 (negative is warmer, positive brighter) |
| Weight | 0.9 lbs (420 g) |
EQ preset to match the Harman target
Set a preamp of -6.2 dB, then add these filters in any parametric equalizer (Wavelet, Equalizer APO, Peace, or a player with parametric EQ). Calculated by AutoEQ from its measured frequency response.
| Filter | Frequency | Gain | Q |
|---|---|---|---|
| Low shelf | 105 Hz | +2.6 dB | 0.70 |
| Peak | 188 Hz | -5.9 dB | 0.48 |
| Peak | 409 Hz | +9.7 dB | 1.70 |
| Peak | 2,060 Hz | -3.3 dB | 2.18 |
| Peak | 7,656 Hz | +4.9 dB | 3.00 |
| High shelf | 10,000 Hz | -0.1 dB | 0.70 |
| Peak | 36 Hz | +3.9 dB | 4.97 |
| Peak | 51 Hz | -1.8 dB | 2.71 |
| Peak | 3,962 Hz | -2.9 dB | 5.89 |
| Peak | 3,178 Hz | +2.9 dB | 6.00 |
- Reviews, Comparisons and Sound Samples
- Head-to-Head Comparisons
Austrian Audio Hi-X55: $315.71 Amazon eBay
Pros: The closed back blocks outside noise and keeps sound from leaking, so it works in shared rooms and studios. A 25 ohm load and 118 dB/V sensitivity let it run loudly from a phone or laptop, and it weighs a moderate 305 g. Bass sits about 1.1 dB above target with sub-bass still within 6 dB down to 20 Hz, which suits listeners after a warm, bass-leaning balance.
Cons: oratory1990’s measurement shows a deep 9.9 dB dip near 2.3 kHz and presence about 3.9 dB below target, so vocals and guitars sound recessed and distant. Sub-bass averages 4.1 dB below target, so the deepest rumble is lighter than the midbass suggests. Its preference score of 56 sits far from the Harman target.
Full Austrian Audio Hi-X55 review and specifications →
| Released | 2020 (6 years ago) |
|---|---|
| Back | Closed |
| Built-in Microphone | No |
| Connection | Wired |
| Deviation From Target | 3.63 dB standard deviation |
| Driver Type | Dynamic |
| Drivers | 1 x 44mm dynamic |
| Form Factor | Over-ear |
| Frequency Response | 5Hz - 28kHz (Manufacturer specified) |
| Harman Preference Score | 56 (measured by oratory1990, via AutoEQ) |
| Impedance | 25 ohms |
| Sensitivity | 118 dB SPL/V |
| Sub-bass Extension | Within 6 dB of target down to 20 Hz (-2.7 dB at 30 Hz) |
| Tonal Tilt | -0.79 (negative is warmer, positive brighter) |
| Weight | 0.7 lbs (305 g) |
EQ preset to match the Harman target
Set a preamp of -6.7 dB, then add these filters in any parametric equalizer (Wavelet, Equalizer APO, Peace, or a player with parametric EQ). Calculated by AutoEQ from its measured frequency response.
| Filter | Frequency | Gain | Q |
|---|---|---|---|
| Low shelf | 105 Hz | +1.6 dB | 0.70 |
| Peak | 138 Hz | -7.0 dB | 1.32 |
| Peak | 2,373 Hz | +7.7 dB | 1.17 |
| Peak | 1,284 Hz | -7.8 dB | 2.01 |
| Peak | 53 Hz | +2.7 dB | 0.80 |
| High shelf | 10,000 Hz | -0.9 dB | 0.70 |
| Peak | 472 Hz | +2.6 dB | 1.22 |
| Peak | 234 Hz | -1.7 dB | 2.33 |
| Peak | 946 Hz | -1.7 dB | 3.22 |
| Peak | 6,612 Hz | -1.8 dB | 6.00 |
- Reviews, Comparisons and Sound Samples
- Head-to-Head Comparisons