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And what's a Knowledge Zenith anyway?
Metal is the most common — on 16% of the 49 in-ear monitors we've cataloged (of 39).
Wired-3.5mm is the most common — on 92% of the 38 in-ear monitors we've cataloged (of 39).
Silicone is the most common — on 63% of the 52 in-ear monitors we've cataloged (of 39).
True appears on 32% of the 34 in-ear monitors we've cataloged (of 39).
Objective measurements from the SoundGuys test lab — overlay other models to see how this one compares.
Measured frequency response (dB relative) against the SoundGuys Headphone Preference Curve. When the measurement goes above the dashed line, that frequency is louder than our preference curve, and when it goes below: it's quieter. Use the curve for comparison purposes only, as your taste may vary.
| Frequency (Hz) | Response (dB) |
|---|---|
| 20 | 5.7 |
| 25 | 5.9 |
| 32 | 5.9 |
| 40 | 5.8 |
| 50 | 5.5 |
| 63 | 5.1 |
| 80 | 4.4 |
| 100 | 3.6 |
| 125 | 2.5 |
| 160 | 0.8 |
| 200 | 1.4 |
| 250 | 0.8 |
| 315 | -0.6 |
| 400 | -2.0 |
| 500 | -3.1 |
| 630 | -1.9 |
| 800 | -1.2 |
| 1000 | 0.1 |
| 1250 | 2.2 |
| 1600 | 6.1 |
| 2000 | 9.2 |
| 2500 | 10.0 |
| 3150 | 7.9 |
| 4000 | 8.4 |
| 5000 | 11.9 |
| 6300 | 6.3 |
| 8000 | 8.1 |
| 10000 | 6.6 |
| 12500 | 0.6 |
| 16000 | -0.5 |
| 20000 | -22.5 |
Passive isolation (dB) with ANC off — how much ambient noise the fit blocks on its own. Higher on the chart means more attenuation.
| Frequency (Hz) | Attenuation (dB) |
|---|---|
| 21 | 4.0 |
| 26 | 3.5 |
| 33 | 2.4 |
| 41 | 2.7 |
| 52 | 3.0 |
| 65 | 3.6 |
| 82 | 4.0 |
| 103 | 6.0 |
| 130 | 2.5 |
| 163 | 2.3 |
| 205 | 7.0 |
| 259 | 9.0 |
| 325 | 9.6 |
| 410 | 9.0 |
| 516 | 9.4 |
| 613 | 9.3 |
| 772 | 12.7 |
| 972 | 12.7 |
| 1220 | 14.1 |
| 1540 | 19.6 |
| 1940 | 25.3 |
| 2440 | 25.1 |
| 3070 | 25.5 |
| 3870 | 19.1 |
| 4870 | 21.5 |
| 6130 | 28.3 |
| 7720 | 19.2 |
| 9720 | 34.6 |
| 12200 | 24.2 |
| 15400 | 29.6 |
| 19400 | 38.2 |
The KZ ZSN PRO X offers superb sound for very little money, like under $30 USD. It has some rough edges with a plastic seam on the cable that can rub on your ear, and the bud is a bit large. The tech isn't cutting edge, but new doesn't always equal better. You should try it.












