Sennheiser IE 40 Pro vs iBasso IT01S

Short answer: the Sennheiser IE 40 Pro. It ranks #355 of 450 in-ear headphones by sound quality, rated 3.5/5, at $109. The iBasso IT01S ranks #362, rated 3.4/5, at $89.95, $19.05 cheaper, which does not close the gap in sound quality.

The case for the Sennheiser IE 40 Pro: Oratory1990’s measurement shows bass 1.0 dB and low mids 1.4 dB above target, a gentle warmth that suits relaxed listening, and the preference score of 67 is acceptable. The tradeoff: Presence is 4.5 dB under target across 3 to 6 kHz, with a 6.4 dB dip near 3.1 kHz, so vocals and guitars sound recessed and detail is dulled.

Why pick the iBasso IT01S: A Harman score of 66 in Crinacle’s measurement shows the tuning lands reasonably close to what most listeners prefer. Watch for: Deviation from the target averages 2.84 dB, so the response is not especially smooth.

Buy the Sennheiser IE 40 Pro. It is rated higher for sound quality, and saving $19.05 with the iBasso IT01S does not make up for the sound-quality gap.

Want more options? Browse the full Headphones rankings.

Specifications Side By Side

Related Headphone Comparisons

More top alternatives to Sennheiser IE 40 Pro:

• KZ PR1 vs Sennheiser IE 40 Pro
• Sennheiser IE 40 Pro vs FiiO FH3
• Sennheiser IE 40 Pro vs Shure SE215
• iBasso IT01S vs Shure SE215
• iBasso IT01S vs Sennheiser Momentum True Wireless 3

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

Sennheiser IE 40 Pro: $109.00 Amazon eBay

Pros: Oratory1990’s measurement shows bass 1.0 dB and low mids 1.4 dB above target, a gentle warmth that suits relaxed listening, and the preference score of 67 is acceptable. A 20 ohm impedance and 115 dB SPL/V sensitivity mean a phone drives it with ease, which suits monitoring and portable use. The balance leans toward warm and V-shaped tastes.

Cons: Presence is 4.5 dB under target across 3 to 6 kHz, with a 6.4 dB dip near 3.1 kHz, so vocals and guitars sound recessed and detail is dulled. Sub-bass is 3.6 dB light, so deep rumble is absent. Then the top end swings the opposite way, with a peak of 8.3 dB at 11.9 kHz and air 5.7 dB over target, which can add a brittle sheen. Tonal balance is clearly uneven, with a deviation of 2.94 dB.

Full Sennheiser IE 40 Pro review and specifications →

Back	Closed
Connection	Wired
Deviation From Target	2.94 dB standard deviation
Driver Type	Dynamic
Drivers	1 x 10mm dynamic
Form Factor	In-ear
Frequency Response	20Hz - 18kHz (Manufacturer specified)
Harman Preference Score	67 (measured by oratory1990, via AutoEQ)
Impedance	20 ohms
Sensitivity	115 dB SPL/V
Sub-bass Extension	Within 6 dB of target down to 20 Hz (-5.1 dB at 30 Hz)
Tonal Tilt	+0.03 (negative is warmer, positive brighter)

EQ preset to match the Harman target

Set a preamp of -5.6 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	+5.6 dB	0.70
Peak	2,997 Hz	+5.7 dB	1.48
Peak	75 Hz	-4.1 dB	0.38
Peak	1,267 Hz	-0.8 dB	2.09
Peak	261 Hz	-1.1 dB	1.70
High shelf	10,000 Hz	-3.7 dB	0.70
Peak	9,787 Hz	-3.3 dB	1.71
Peak	4,341 Hz	+1.1 dB	3.77
Peak	6,644 Hz	+2.1 dB	5.97
Peak	7,958 Hz	-1.2 dB	5.41

• Reviews, Comparisons and Sound Samples
  • AutoEQ results for the Sennheiser IE 40 Pro (oratory1990 measurement)
• Head-to-Head Comparisons
  • Sennheiser IE 40 Pro vs KZ PR1
  • Sennheiser IE 40 Pro vs FiiO FH3
  • Sennheiser IE 40 Pro vs Shure SE215

iBasso IT01S: $89.95 Amazon eBay

Pros: A Harman score of 66 in Crinacle’s measurement shows the tuning lands reasonably close to what most listeners prefer. The 16 ohm impedance and 109 dB/mW sensitivity mean a phone can drive it to loud levels. At 8 g per earbud with a 10mm dynamic driver, it is a light, simple wired set.

Cons: Deviation from the target averages 2.84 dB, so the response is not especially smooth. Without an inline microphone it cannot be used for calls, and the KZ PR1 has a higher rating.

Full iBasso IT01S review and specifications →

Back	Closed
Built-in Microphone	No
Connection	Wired
Deviation From Target	2.84 dB standard deviation
Driver Type	Dynamic
Drivers	1 x 10mm dynamic
Form Factor	In-ear
Frequency Response	10Hz - 43kHz (Manufacturer specified)
Harman Preference Score	66 (measured by crinacle, via AutoEQ)
Impedance	16 ohms
Sensitivity	109 dB/mW
Tonal Tilt	-0.22 (negative is warmer, positive brighter)
Weight	0 lbs (8 g) per earbud

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	+3.1 dB	0.70
Peak	169 Hz	-4.1 dB	0.49
Peak	918 Hz	+3.6 dB	1.10
Peak	9,169 Hz	+3.5 dB	2.61
Peak	3,523 Hz	+2.8 dB	4.61
High shelf	10,000 Hz	+0.4 dB	0.70
Peak	5,075 Hz	-6.1 dB	5.81
Peak	6,349 Hz	+3.1 dB	5.89
Peak	4,021 Hz	+2.0 dB	5.78
Peak	2,467 Hz	-0.5 dB	5.37

• Reviews, Comparisons and Sound Samples
  • AutoEQ results for the iBasso IT01S (crinacle measurement)
• Head-to-Head Comparisons
  • iBasso IT01S vs Sennheiser Momentum True Wireless 3
  • iBasso IT01S vs FiiO FH3
  • iBasso IT01S vs KZ PR1
  • iBasso IT01S vs BGVP DN3
  • iBasso IT01S vs Shure SE215