Short answer: both are discontinued, and they are rated the same for sound quality, though neither ranks well in its class. (#905 and #907 of 909 in-ear headphones). Either one is only an option used, so choose on condition and price. Both are rated below 3.0/5 among the 909 in-ear headphones; for better sound, the ThieAudio Monarch MKIII ranks #1 at $999.
The case for the Westone UM Pro 20: It uses 2 x balanced armature with an easy 27 ohm load. The tradeoff: Discontinued, so it is mainly found used.
What the Westone UM Pro 50 does well: It uses 5 x balanced armature. The catch: Discontinued, so it is mainly found used.
Buy the Westone UM Pro 20 or the Westone UM Pro 50, whichever you find used in better condition; both are discontinued. For a new speaker, start with the ThieAudio Monarch MKIII instead.
Still deciding? The full Headphones rankings cover every ranked option.
Specifications Side By Side
| Westone UM Pro 20 | Westone UM Pro 50 | |
|---|---|---|
| Price | Discontinued | Discontinued |
| Ranked | #905 of 909 in In-Ear Headphones | #907 of 909 in In-Ear Headphones |
| Form Factor | In-ear | In-ear |
| Connection | Wired | Wired |
| Driver Type | Balanced armature | Balanced armature |
| Drivers | 2 x balanced armature | 5 x balanced armature |
| Impedance | 27 ohms | 45 ohms |
| Sensitivity | 119 dB/mW | 115 dB/mW |
| Frequency Response | 20Hz - 18kHz | 20Hz - 20kHz |
| Weight | 0 lbs (12.7 g) | 0 lbs (12.7 g) |
| Harman Preference Score | 17 (measured by crinacle, via AutoEQ) | 9 (measured by crinacle, via AutoEQ) |
| Deviation From Target | 5.97 dB standard deviation | 6.52 dB standard deviation |
| Tonal Tilt | -1.99 (negative is warmer, positive brighter) | -2.26 (negative is warmer, positive brighter) |
Related Headphone Comparisons
More top alternatives to Westone UM Pro 20:
- Westone UM Pro 10 vs Westone UM Pro 20
- Westone UM Pro 20 vs Westone UM Pro 30
- Westone UM Pro 10 vs Westone UM Pro 50
- Westone UM Pro 30 vs Westone UM Pro 50
- Campfire Audio Dorado 2020 vs Westone Pro X50
Prices on this page were last checked October 13, 2026 at 3:17 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
Westone UM Pro 20 Discontinued eBay
Pros: It uses 2 x balanced armature with an easy 27 ohm load.
Cons: Discontinued, so it is mainly found used. A tonal tilt of -1.99 makes it sound dark, with bass well ahead of the treble. Its 5.97 dB spread from the target means a noticeably uneven response. A Harman score of 17 places it in the lower part of the in-ear rankings.
Full Westone UM Pro 20 review and specifications →
| Released | 2013 (13 years ago) |
|---|---|
| Connection | Wired |
| Deviation From Target | 5.97 dB standard deviation |
| Driver Type | Balanced armature |
| Drivers | 2 x balanced armature |
| Form Factor | In-ear |
| Frequency Response | 20Hz - 18kHz |
| Harman Preference Score | 17 (measured by crinacle, via AutoEQ) |
| Impedance | 27 ohms |
| Sensitivity | 119 dB/mW |
| Tonal Tilt | -1.99 (negative is warmer, positive brighter) |
| Weight | 0 lbs (12.7 g) |
EQ preset to match the Harman target
Set a preamp of -7.2 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 | -0.5 dB | 0.70 |
| Peak | 234 Hz | -7.8 dB | 0.44 |
| Peak | 3,522 Hz | +6.7 dB | 0.30 |
| Peak | 1,460 Hz | -3.6 dB | 1.68 |
| Peak | 10,000 Hz | +2.8 dB | 4.62 |
| High shelf | 10,000 Hz | +4.7 dB | 0.70 |
| Peak | 9,581 Hz | -2.9 dB | 5.72 |
| Peak | 71 Hz | +0.5 dB | 1.90 |
| Peak | 142 Hz | -0.6 dB | 1.70 |
| Peak | 251 Hz | +0.3 dB | 1.70 |
- Reviews, Comparisons and Sound Samples
- Head-to-Head Comparisons
Westone UM Pro 50 Discontinued eBay
Pros: It uses 5 x balanced armature.
Cons: Discontinued, so it is mainly found used. A tonal tilt of -2.26 makes it sound dark, with bass well ahead of the treble. Its 6.52 dB spread from the target means a noticeably uneven response. A Harman score of 9 places it in the lower part of the in-ear rankings.
Full Westone UM Pro 50 review and specifications →
| Released | 2014 (12 years ago) |
|---|---|
| Connection | Wired |
| Deviation From Target | 6.52 dB standard deviation |
| Driver Type | Balanced armature |
| Drivers | 5 x balanced armature |
| Form Factor | In-ear |
| Frequency Response | 20Hz - 20kHz |
| Harman Preference Score | 9 (measured by crinacle, via AutoEQ) |
| Impedance | 45 ohms |
| Sensitivity | 115 dB/mW |
| Tonal Tilt | -2.26 (negative is warmer, positive brighter) |
| Weight | 0 lbs (12.7 g) |
EQ preset to match the Harman target
Set a preamp of -6.4 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 | -0.6 dB | 0.70 |
| Peak | 211 Hz | -7.9 dB | 0.52 |
| Peak | 4,189 Hz | +6.7 dB | 0.20 |
| Peak | 1,570 Hz | -7.8 dB | 1.84 |
| Peak | 523 Hz | -2.0 dB | 0.92 |
| High shelf | 10,000 Hz | -0.4 dB | 0.70 |
| Peak | 2,457 Hz | +2.0 dB | 5.31 |
| Peak | 1,977 Hz | -1.3 dB | 4.94 |
| Peak | 61 Hz | +0.4 dB | 1.77 |
| Peak | 34 Hz | -0.3 dB | 1.95 |
- Reviews, Comparisons and Sound Samples
- Head-to-Head Comparisons