Short answer: the Superlux HD 660 Pro 150 Ohm. It ranks #57 of 216 over-ear headphones by sound quality, rated 4.1/5, at $34; the Koss KPH30i ranks #104, rated 3.7/5, at $29.99. Close enough in price that the sound-quality gap is the deciding factor.
The Superlux HD 660 Pro 150 Ohm is the better-sounding option. A preference score of 83 in oratory1990’s measurement is remarkable for a budget headphone, with sub-bass and bass about 1 dB above target down to 20 Hz for a full, punchy low end. Watch for: A 6.1 dB peak near 6.4 kHz can make sibilance and cymbals splashy, and a 7.2 dB dip near 9.4 kHz follows it, so the treble sounds uneven.
What the Koss KPH30i does well: A very low price makes it an easy disposable or backup pair, and the 60 ohm, 101 dB sensitivity runs from any phone. Watch for: Sub-bass is nearly 12 dB under target below 60 Hz, so there is no rumble and deep bass is essentially missing.
Buy the Superlux HD 660 Pro 150 Ohm. It is rated higher for sound quality, and the $4.01 you would save on the Koss KPH30i does not close the gap.
Want more options? Browse the full Headphones rankings.
Specifications Side By Side
| Superlux HD 660 Pro 150 Ohm | Koss KPH30i | |
|---|---|---|
| Price | $34 | $29.99 |
| Ranked | #57 of 216 in Over-Ear Headphones | #104 of 216 in Over-Ear Headphones |
| Form Factor | Over-ear | Over-ear |
| Harman Preference Score | 83 (measured by oratory1990, via AutoEQ) | 76 (measured by oratory1990, via AutoEQ) |
| Deviation From Target | 2.24 dB standard deviation | 2.62 dB standard deviation |
| Tonal Tilt | -0.22 (negative is warmer, positive brighter) | -0.38 (negative is warmer, positive brighter) |
| Sub-bass Extension | Within 6 dB of target down to 20 Hz (+1.2 dB at 30 Hz) | Falls 6 dB below target at 50 Hz (-13.9 dB at 30 Hz) |
| Connection | Wired | Wired |
| Back | Closed | Open |
| Driver Type | Dynamic | Dynamic |
| Drivers | 1 x 40mm dynamic | 1 x 35mm dynamic |
| Impedance | 150 ohms | 60 ohms |
| Weight | 0.7 lbs (323 g) | - |
| Frequency Response | 10Hz - 30kHz (Manufacturer specified) | 15Hz - 25kHz (Manufacturer specified) |
| Built-in Microphone | No | Yes |
| Sensitivity | - | 101 dB SPL/1mW |
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More worthwhile head-to-heads for Superlux HD 660 Pro 150 Ohm:
- Superlux HD 660 Pro 150 Ohm vs FiiO EH11
- Superlux HD 660 Pro 150 Ohm vs Superlux HD 681
- Koss KPH30i vs Superlux HD 681
- FiiO EH11 vs Koss KPH30i
- Koss KPH30i 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 660 Pro 150 Ohm: $34 Thomann eBay
Pros: A preference score of 83 in oratory1990’s measurement is remarkable for a budget headphone, with sub-bass and bass about 1 dB above target down to 20 Hz for a full, punchy low end. It rates well above the Koss KPH30i and the AKG K240 Studio. The closed back isolates outside noise, suiting tracking and commuting.
Cons: A 6.1 dB peak near 6.4 kHz can make sibilance and cymbals splashy, and a 7.2 dB dip near 9.4 kHz follows it, so the treble sounds uneven. The 150 ohm impedance means some phones will run out of volume, and at 323 g it is not light.
Full Superlux HD 660 Pro 150 Ohm review and specifications →
| Back | Closed |
|---|---|
| Built-in Microphone | No |
| Connection | Wired |
| Deviation From Target | 2.24 dB standard deviation |
| Driver Type | Dynamic |
| Drivers | 1 x 40mm dynamic |
| Form Factor | Over-ear |
| Frequency Response | 10Hz - 30kHz (Manufacturer specified) |
| Harman Preference Score | 83 (measured by oratory1990, via AutoEQ) |
| Impedance | 150 ohms |
| Sub-bass Extension | Within 6 dB of target down to 20 Hz (+1.2 dB at 30 Hz) |
| Tonal Tilt | -0.22 (negative is warmer, positive brighter) |
| Weight | 0.7 lbs (323 g) |
EQ preset to match the Harman target
Set a preamp of -3.7 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 | +2.1 dB | 0.70 |
| Peak | 2,024 Hz | -3.9 dB | 3.50 |
| Peak | 52 Hz | -5.2 dB | 1.11 |
| Peak | 144 Hz | -4.3 dB | 4.46 |
| Peak | 104 Hz | +2.9 dB | 3.92 |
| High shelf | 10,000 Hz | -2.8 dB | 0.70 |
| Peak | 6,206 Hz | -8.9 dB | 5.22 |
| Peak | 5,370 Hz | +3.7 dB | 1.39 |
| Peak | 532 Hz | +3.7 dB | 4.78 |
| Peak | 224 Hz | +2.4 dB | 4.96 |
- Reviews, Comparisons and Sound Samples
- Head-to-Head Comparisons
Koss KPH30i: $29.99 Amazon eBay
Pros: A very low price makes it an easy disposable or backup pair, and the 60 ohm, 101 dB sensitivity runs from any phone. It has an inline microphone for calls and the open on-ear design is light and airy. Bass from 60 Hz to the upper mids stays within about 0.6 dB of the Harman target, which gives a fairly balanced core.
Cons: Sub-bass is nearly 12 dB under target below 60 Hz, so there is no rumble and deep bass is essentially missing. An 11.8 dB dip near 4.2 kHz makes vocals and detail recede, and treble from 3 to 10 kHz is about 2.8 dB low. The open back leaks sound and offers no isolation, so it suits quiet rooms only.
Full Koss KPH30i review and specifications →
| Back | Open |
|---|---|
| Built-in Microphone | Yes |
| Connection | Wired |
| Deviation From Target | 2.62 dB standard deviation |
| Driver Type | Dynamic |
| Drivers | 1 x 35mm dynamic |
| Form Factor | Over-ear |
| Frequency Response | 15Hz - 25kHz (Manufacturer specified) |
| Harman Preference Score | 76 (measured by oratory1990, via AutoEQ) |
| Impedance | 60 ohms |
| Sensitivity | 101 dB SPL/1mW |
| Sub-bass Extension | Falls 6 dB below target at 50 Hz (-13.9 dB at 30 Hz) |
| Tonal Tilt | -0.38 (negative is warmer, positive brighter) |
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 | +6.8 dB | 0.70 |
| Peak | 109 Hz | -4.7 dB | 0.47 |
| Peak | 2,979 Hz | +1.7 dB | 0.18 |
| Peak | 1,956 Hz | -4.1 dB | 2.01 |
| Peak | 49 Hz | +2.5 dB | 2.08 |
| High shelf | 10,000 Hz | +0.1 dB | 0.70 |
| Peak | 5,070 Hz | -5.0 dB | 5.22 |
| Peak | 3,844 Hz | +2.9 dB | 5.95 |
| Peak | 6,348 Hz | +2.6 dB | 5.99 |
| Peak | 502 Hz | +0.3 dB | 1.44 |
- Reviews, Comparisons and Sound Samples
- Head-to-Head Comparisons