Short answer: the Superlux HD 681. It ranks #165 of 216 over-ear headphones by sound quality, rated 3.1/5, at $33.29. The Koss KSC75 ranks #183, rated 2.8/5, at $19.99, $13.30 cheaper, a saving that is not big enough to make up the sound-quality gap.
The Superlux HD 681 is the better-sounding option. A very low price and a 32 ohm, 98 dB/mW load make it an easy pick for use straight from a phone or laptop. The tradeoff: Sub-bass sits 9.7 dB below target in oratory1990’s measurement and falls 6 dB short by 42 Hz, so bass sounds thin and lacks impact.
What the Koss KSC75 does well: An extremely low cost and a featherweight 0.1 lbs (43 g) clip-on design make it easy to carry and wear for long stretches. The tradeoff: Sub-bass is about 17 dB below target under 60 Hz, so there is almost no rumble and bass-heavy music sounds thin.
Buy the Superlux HD 681. It is rated higher for sound quality, and the $13.30 you would save on the Koss KSC75 does not close the gap.
Still deciding? The full Headphones rankings cover every ranked option.
Specifications Side By Side
| Superlux HD 681 | Koss KSC75 | |
|---|---|---|
| Price | $33.29 | $19.99 |
| Ranked | #165 of 216 in Over-Ear Headphones | #183 of 216 in Over-Ear Headphones |
| Form Factor | Over-ear | Over-ear |
| Harman Preference Score | 61 (measured by oratory1990, via AutoEQ) | 54 (measured by oratory1990, via AutoEQ) |
| Deviation From Target | 2.58 dB standard deviation | 3.33 dB standard deviation |
| Tonal Tilt | +1.34 (negative is warmer, positive brighter) | +1.22 (negative is warmer, positive brighter) |
| Sub-bass Extension | Falls 6 dB below target at 42 Hz (-9.8 dB at 30 Hz) | Falls 6 dB below target at 67 Hz (-19.2 dB at 30 Hz) |
| Connection | Wired | Wired |
| Back | Semi-open | Open |
| Driver Type | Dynamic | Dynamic |
| Drivers | 1 x 50mm dynamic | 1 x 35mm dynamic |
| Impedance | 32 ohms | 60 ohms |
| Sensitivity | 98 dB/mW | 101 dB SPL/1mW |
| Frequency Response | 10Hz - 30kHz (Manufacturer specified) | 15Hz - 25kHz (Manufacturer specified) |
| Built-in Microphone | No | - |
| Weight | 0.5 lbs (230 g) | 0.1 lbs (43 g) |
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More worthwhile head-to-heads for Superlux HD 681:
- Superlux HD 660 Pro 150 Ohm vs Superlux HD 681
- FiiO EH11 vs Superlux HD 681
- Koss KPH30i vs Superlux HD 681
- Superlux HD 681 vs HyperX Cloud II
- Superlux HD 681 vs Koss KPH40
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
Superlux HD 681: $33.29 B&H Photo Video eBay
Pros: A very low price and a 32 ohm, 98 dB/mW load make it an easy pick for use straight from a phone or laptop. From the upper midrange through the air band its response stays within 2 dB of target on average, which suits listeners who like a bright or studio-flat balance. It rates higher than the Koss KPH40 at a similar price.
Cons: Sub-bass sits 9.7 dB below target in oratory1990’s measurement and falls 6 dB short by 42 Hz, so bass sounds thin and lacks impact. A 5.7 dB peak at 4.8 kHz right next to a 5.1 dB dip at 4.1 kHz can make vocals and guitars edgy, and the semi-open back lets some sound escape. The AKG K240 Studio and HyperX Cloud Alpha rate higher for a little more money.
Full Superlux HD 681 review and specifications →
| Back | Semi-open |
|---|---|
| Built-in Microphone | No |
| Connection | Wired |
| Deviation From Target | 2.58 dB standard deviation |
| Driver Type | Dynamic |
| Drivers | 1 x 50mm dynamic |
| Form Factor | Over-ear |
| Frequency Response | 10Hz - 30kHz (Manufacturer specified) |
| Harman Preference Score | 61 (measured by oratory1990, via AutoEQ) |
| Impedance | 32 ohms |
| Sensitivity | 98 dB/mW |
| Sub-bass Extension | Falls 6 dB below target at 42 Hz (-9.8 dB at 30 Hz) |
| Tonal Tilt | +1.34 (negative is warmer, positive brighter) |
| Weight | 0.5 lbs (230 g) |
EQ preset to match the Harman 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 AutoEQ from its measured frequency response.
| Filter | Frequency | Gain | Q |
|---|---|---|---|
| Low shelf | 105 Hz | +5.8 dB | 0.70 |
| Peak | 496 Hz | +2.4 dB | 1.05 |
| Peak | 1,105 Hz | -1.8 dB | 0.57 |
| Peak | 5,194 Hz | -6.1 dB | 4.12 |
| Peak | 174 Hz | +1.0 dB | 1.11 |
| High shelf | 10,000 Hz | -3.2 dB | 0.70 |
| Peak | 7,758 Hz | -2.3 dB | 3.68 |
| Peak | 3,826 Hz | +3.2 dB | 5.94 |
| Peak | 2,458 Hz | -1.4 dB | 3.46 |
| Peak | 65 Hz | -0.5 dB | 2.20 |
- Reviews, Comparisons and Sound Samples
- Head-to-Head Comparisons
Koss KSC75: $19.99 Amazon eBay
Pros: An extremely low cost and a featherweight 43 g clip-on design make it easy to carry and wear for long stretches. The midrange is close to target, with the low mids within 0.2 dB, so voices sound natural, and the slightly lifted treble of about 2 to 3 dB adds clarity. The open back gives an airy sound, and 101 dB sensitivity at 60 ohms works from a phone.
Cons: Sub-bass is about 17 dB below target under 60 Hz, so there is almost no rumble and bass-heavy music sounds thin. Bass in the 60 to 200 Hz range is also about 2 dB low, and a 4 dB peak near 5.3 kHz can add some edge. The open design leaks sound and gives no noise isolation.
Full Koss KSC75 review and specifications →
| Back | Open |
|---|---|
| Connection | Wired |
| Deviation From Target | 3.33 dB standard deviation |
| Driver Type | Dynamic |
| Drivers | 1 x 35mm dynamic |
| Form Factor | Over-ear |
| Frequency Response | 15Hz - 25kHz (Manufacturer specified) |
| Harman Preference Score | 54 (measured by oratory1990, via AutoEQ) |
| Impedance | 60 ohms |
| Sensitivity | 101 dB SPL/1mW |
| Sub-bass Extension | Falls 6 dB below target at 67 Hz (-19.2 dB at 30 Hz) |
| Tonal Tilt | +1.22 (negative is warmer, positive brighter) |
| Weight | 0.1 lbs (43 g) |
EQ preset to match the 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 AutoEQ from its measured frequency response.
| Filter | Frequency | Gain | Q |
|---|---|---|---|
| Low shelf | 105 Hz | +6.2 dB | 0.70 |
| Peak | 610 Hz | +2.2 dB | 0.63 |
| Peak | 2,358 Hz | -3.4 dB | 1.92 |
| Peak | 169 Hz | -2.3 dB | 0.77 |
| Peak | 74 Hz | +2.0 dB | 2.94 |
| High shelf | 10,000 Hz | -3.0 dB | 0.70 |
| Peak | 4,033 Hz | +3.3 dB | 5.88 |
| Peak | 5,191 Hz | -3.4 dB | 5.53 |
| Peak | 7,220 Hz | -1.5 dB | 2.25 |
| Peak | 4,517 Hz | +0.7 dB | 4.34 |
- Reviews, Comparisons and Sound Samples
- Head-to-Head Comparisons