The TRN CS4 ranks #601 out of 1061 total In-Ear Headphones for sound quality. See all Headphones rankings for every top pick.
Brand: TRN
Prices on this page were last checked October 15, 2026 at 5:41 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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#601 TRN CS4: $20.99 Amazon $20.99 eBay
Pros: A very cheap single dynamic IEM. Measurements show full sub-bass to 20 Hz (score 69 across three measurements).
Cons: Its score rests on three measurements.
Is the TRN CS4 right for you?
Buy it if
- you want sub-bass rumble that reaches down to 20 Hz.
- you are happy to use EQ: our preset lifts its Harman match by about 17 points.
Skip it if
- you want the best value: the higher-rated TRN MT5 costs about $6 less.
| Back | Closed |
|---|---|
| Connection | Wired |
| Deviation From Target | 2.25 dB standard deviation |
| Driver Type | Dynamic |
| Drivers | 1 x 10mm dynamic |
| Form Factor | In-ear |
| Harman Preference Score | 69 (median of 3 squig.link measurements, calibrated to AutoEQ) |
| Sensitivity | 106 dB/mW |
| Sub-bass Extension | Within 6 dB of target down to 20 Hz (+0.9 dB at 30 Hz) |
| Tonal Tilt | -0.49 (negative is warmer, positive brighter) |
EQ Presets
Harman target
Set a preamp of -6.3 dB, then add these filters in any parametric equalizer (Wavelet, Equalizer APO, Peace, or a player with parametric EQ). Calculated by Speaker Ranking from the median of 3 squig.link measurements, in the filter layout AutoEQ uses. Predicted Harman match with this EQ: 86 out of 100, up from 69.
| Filter | Frequency | Gain | Q |
|---|---|---|---|
| Low shelf | 105 Hz | -0.8 dB | 0.70 |
| High shelf | 10,000 Hz | -1.7 dB | 0.70 |
| Peak | 174 Hz | -2.6 dB | 0.96 |
| Peak | 718 Hz | +1.4 dB | 2.05 |
| Peak | 2,201 Hz | -2.2 dB | 3.16 |
| Peak | 3,654 Hz | -2.5 dB | 1.43 |
| Peak | 5,738 Hz | +6.0 dB | 4.62 |
| Peak | 6,464 Hz | +1.7 dB | 1.25 |
Neutral 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 Speaker Ranking from the median of 3 squig.link measurements, in the filter layout AutoEQ uses. Predicted Neutral match with this EQ: 87 out of 100, up from 35.
| Filter | Frequency | Gain | Q |
|---|---|---|---|
| Low shelf | 105 Hz | -9.3 dB | 0.70 |
| High shelf | 10,000 Hz | -1.7 dB | 0.70 |
| Peak | 174 Hz | -2.6 dB | 0.80 |
| Peak | 697 Hz | +1.5 dB | 1.81 |
| Peak | 2,206 Hz | -2.2 dB | 3.22 |
| Peak | 3,654 Hz | -2.5 dB | 1.43 |
| Peak | 5,738 Hz | +6.0 dB | 4.62 |
| Peak | 6,464 Hz | +1.6 dB | 1.25 |
Studio flat target
Set a preamp of -5.7 dB, then add these filters in any parametric equalizer (Wavelet, Equalizer APO, Peace, or a player with parametric EQ). Calculated by Speaker Ranking from the median of 3 squig.link measurements, in the filter layout AutoEQ uses. Predicted Studio flat match with this EQ: 86 out of 100, up from 19.
| Filter | Frequency | Gain | Q |
|---|---|---|---|
| Low shelf | 105 Hz | -11.6 dB | 0.70 |
| High shelf | 10,000 Hz | +1.1 dB | 0.70 |
| Peak | 174 Hz | -4.4 dB | 0.78 |
| Peak | 717 Hz | +1.4 dB | 2.34 |
| Peak | 1,854 Hz | -1.1 dB | 2.70 |
| Peak | 4,054 Hz | -3.7 dB | 6.00 |
| Peak | 5,820 Hz | +6.0 dB | 5.65 |
| Peak | 8,000 Hz | +1.3 dB | 2.15 |
Warm target
Set a preamp of -4.7 dB, then add these filters in any parametric equalizer (Wavelet, Equalizer APO, Peace, or a player with parametric EQ). Calculated by Speaker Ranking from the median of 3 squig.link measurements, in the filter layout AutoEQ uses. Predicted Warm match with this EQ: 89 out of 100, up from 76.
| Filter | Frequency | Gain | Q |
|---|---|---|---|
| Low shelf | 105 Hz | -0.6 dB | 0.70 |
| High shelf | 10,000 Hz | -4.6 dB | 0.70 |
| Peak | 174 Hz | -2.4 dB | 1.07 |
| Peak | 729 Hz | +1.7 dB | 1.75 |
| Peak | 2,187 Hz | -2.5 dB | 3.18 |
| Peak | 3,654 Hz | -4.0 dB | 1.27 |
| Peak | 5,226 Hz | +3.5 dB | 5.12 |
| Peak | 5,880 Hz | +5.7 dB | 6.00 |
Bass target
Set a preamp of -6.3 dB, then add these filters in any parametric equalizer (Wavelet, Equalizer APO, Peace, or a player with parametric EQ). Calculated by Speaker Ranking from the median of 3 squig.link measurements, in the filter layout AutoEQ uses. Predicted Bass match with this EQ: 88 out of 100, up from 70.
| Filter | Frequency | Gain | Q |
|---|---|---|---|
| Low shelf | 105 Hz | +3.0 dB | 0.70 |
| High shelf | 10,000 Hz | -1.7 dB | 0.70 |
| Peak | 174 Hz | -2.6 dB | 1.02 |
| Peak | 723 Hz | +1.4 dB | 2.13 |
| Peak | 2,199 Hz | -2.2 dB | 3.14 |
| Peak | 3,654 Hz | -2.5 dB | 1.42 |
| Peak | 5,739 Hz | +6.0 dB | 4.63 |
| Peak | 6,464 Hz | +1.7 dB | 1.25 |
Bright target
Set a preamp of -5.8 dB, then add these filters in any parametric equalizer (Wavelet, Equalizer APO, Peace, or a player with parametric EQ). Calculated by Speaker Ranking from the median of 3 squig.link measurements, in the filter layout AutoEQ uses. Predicted Bright match with this EQ: 75 out of 100, up from 24.
| Filter | Frequency | Gain | Q |
|---|---|---|---|
| Low shelf | 105 Hz | -9.4 dB | 0.70 |
| High shelf | 10,000 Hz | +0.5 dB | 0.70 |
| Peak | 174 Hz | -2.6 dB | 0.83 |
| Peak | 2,299 Hz | -2.7 dB | 1.91 |
| Peak | 5,517 Hz | +6.0 dB | 3.40 |
V-shaped target
Set a preamp of -5.8 dB, then add these filters in any parametric equalizer (Wavelet, Equalizer APO, Peace, or a player with parametric EQ). Calculated by Speaker Ranking from the median of 3 squig.link measurements, in the filter layout AutoEQ uses. Predicted V-shaped match with this EQ: 72 out of 100, up from 64.
| Filter | Frequency | Gain | Q |
|---|---|---|---|
| Low shelf | 105 Hz | +3.6 dB | 0.70 |
| High shelf | 10,000 Hz | +1.2 dB | 0.70 |
| Peak | 174 Hz | -1.3 dB | 1.43 |
| Peak | 2,206 Hz | -2.1 dB | 1.92 |
| Peak | 5,472 Hz | +6.0 dB | 3.16 |
- Reviews, Comparisons and Sound Samples
Frequency Response
How the TRN CS4 measures across the audible range, against the Harman in-ear target that most listeners prefer in blind tests. Where the line sits above the target that range sounds louder (more bass, brighter treble), below it quieter. The curve is the median of 3 independent measurements, so one odd sample or rig cannot skew it, and both lines are shifted so their 500 Hz to 2 kHz average sits at 0 dB.
Measurement data: median of 3 measurements from the squig.link databases of ankramutt, fahryst and ianfann. Thanks to each of them for publishing their work.