Superlux HD 681 vs Koss KPH40

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 KPH40 ranks #182, rated 2.8/5, and costs $39.99, so there is not much of a tradeoff to weigh.

The Superlux HD 681 is the better-sounding choice. 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 catch: 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.

The case for the Koss KPH40: It is one of the cheapest options in its class, and the open-back design gives a more airy, spacious feel than most closed budget headsets. The tradeoff: Sub-bass rolls off about 7 dB below target under 60 Hz, so kick drums and synth bass lack rumble.

Buy the Superlux HD 681. It is rated higher for sound quality than the Koss KPH40 and costs less, which makes it the one to get unless you need something the other one does better.

Looking for alternatives? See the complete Headphones rankings.

Specifications Side By Side

Related Headphone Comparisons

How Superlux HD 681 compares with other leading options:

• 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 KSC75

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
  • AutoEQ results for the Superlux HD 681 (oratory1990 measurement)
• Head-to-Head Comparisons
  • Superlux HD 681 vs HyperX Cloud II
  • Superlux HD 681 vs Koss KSC75
  • Superlux HD 681 vs Koss KPH30i
  • Superlux HD 681 vs FiiO EH11
  • Superlux HD 681 vs Superlux HD 660 Pro 150 Ohm

Koss KPH40: $39.99 Amazon eBay

Pros: It is one of the cheapest options in its class, and the open-back design gives a more airy, spacious feel than most closed budget headsets. Bass between 60 and 200 Hz sits about 2 dB above target and the lower mids are slightly full, which suits a warm, relaxed listener. Sensitivity of 101 dB at 60 ohms means a phone can drive it.

Cons: Sub-bass rolls off about 7 dB below target under 60 Hz, so kick drums and synth bass lack rumble. A 14.5 dB dip near 4.4 kHz makes vocals and instrument detail sound distant, and treble is about 4 dB low overall, so the sound is dark and muffled. Open backs also leak sound and offer no isolation.

Full Koss KPH40 review and specifications →

Back	Open
Connection	Wired
Deviation From Target	3.35 dB standard deviation
Driver Type	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 38 Hz (-9.1 dB at 30 Hz)
Tonal Tilt	-1.21 (negative is warmer, positive brighter)

EQ preset to match the Harman target

Set a preamp of -6.1 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	+7.5 dB	0.70
Peak	79 Hz	-7.6 dB	0.37
Peak	3,725 Hz	+4.9 dB	3.94
Peak	614 Hz	+1.5 dB	2.05
Peak	37 Hz	+3.9 dB	1.16
High shelf	10,000 Hz	+1.9 dB	0.70
Peak	7,429 Hz	+4.0 dB	0.78
Peak	5,445 Hz	-7.7 dB	4.24
Peak	1,941 Hz	-2.0 dB	2.35
Peak	1,012 Hz	+0.3 dB	1.84

• Reviews, Comparisons and Sound Samples
  • AutoEQ results for the Koss KPH40 (oratory1990 measurement)
• Head-to-Head Comparisons
  • Koss KPH40 vs Koss KSC75
  • Koss KPH40 vs HyperX Cloud II
  • Koss KPH40 vs Koss Porta Pro
  • Koss KPH40 vs Razer BlackShark V2 X
  • Koss KPH40 vs Koss KPH30i