Sennheiser HD 660 S vs HD 599: Which Headphones Are Better? - RTINGS.com

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Sennheiser HD 599

Sennheiser HD 660 S

Tested using Methodology v1.5

Updated Feb 06, 2026 06:21 PM

Tested using Methodology v1.5

Updated Sep 23, 2025 05:25 PM

Sennheiser HD 599 Picture

Sennheiser HD 660 S Picture

TypeOver-ear

EnclosureOpen-Back

WirelessNo

TransducerDynamic

Noise CancellingNo

MicNo

TypeOver-ear

EnclosureOpen-Back

WirelessNo

TransducerDynamic

Noise CancellingNo

MicNo

Our Verdict

Sennheiser HD 599

Sennheiser HD 660 S

The Sennheiser HD 599 and the Sennheiser HD 660 S are very similar over-ear headphones. Despite both being open-backs, the HD 599 have a much more speaker-like passive soundstage performance, as well as a bass and treble response that more closely resembles our target Harman-based curve. This makes the HD 599 a bit better for audiophiles looking for a neutral sound, They're also more comfortable and breathable. On the other hand, the 660 S have a much better build quality and a more stable fit on your head.

Variants

HD 599 SE (Black)
HD 599 (Ivory)

HD 660 S

Review

See Sennheiser HD 599 Review

See Sennheiser HD 660 S Review

Check Price

Black

HD 599 SE

Standard

HD 660 S

Ivory

HD 599

Standard

HD 660 S

Standard

HD 660 S

Standard

HD 660 S

Standard

HD 660 S

Main Differences for

Neutral Sound

Threshold

0.10

Neutral Sound

0.0

0.0

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Full Comparison

Neutral Sound

0.0

0.0

Commute/Travel

0.0

0.0

Sports/Fitness

0.0

0.0

Office

0.0

0.0

Wireless Gaming

0.0

0.0

Wired Gaming

0.0

0.0

Phone Calls

0.0

0.0

Design

Style

Design Picture 2

Sennheiser HD 599 Design Picture 2 Sample

SAMPLE

for pictures & test results

Sennheiser HD 660 S Design Picture 2 Sample

SAMPLE

for pictures & test results

Type

Locked

Locked

Enclosure

Locked

Locked

Wireless

Locked

Locked

Transducer

Locked

Locked

Show Text

Comfort

N/A

N/A

Comfort Picture

Sennheiser HD 599 Comfort Picture Sample

SAMPLE

for pictures & test results

Sennheiser HD 660 S Comfort Picture Sample

SAMPLE

for pictures & test results

Weight

Lock lbs

Lock lbs

Clamping Force

Lock lbs

Lock lbs

Show Text

Controls

N/A

N/A

Controls Picture

Sennheiser HD 599 Controls Picture Sample

SAMPLE

for pictures & test results

Sennheiser HD 660 S Controls Picture Sample

SAMPLE

for pictures & test results

OS Compatibility

Locked

Locked

Ease Of Use

Locked

Locked

Feedback

Locked

Locked

Call/Music Control

Locked

Locked

Volume Control

Locked

Locked

Microphone Control

Locked

Locked

Channel Mixing

Locked

Locked

Noise Cancelling Control

Locked

Locked

Talk-Through

Locked

Locked

Additional Controls

Locked

Locked

Breathability

N/A

N/A

Breathability After Picture

Sennheiser HD 599 Breathability After Picture Sample

SAMPLE

for pictures & test results

Sennheiser HD 660 S Breathability After Picture Sample

SAMPLE

for pictures & test results

Avg.Temp.Difference

Lock °C

Lock °C

Show Text

Portability

N/A

N/A

Portability Picture

Sennheiser HD 599 Portability Picture Sample

SAMPLE

for pictures & test results

Sennheiser HD 660 S Portability Picture Sample

SAMPLE

for pictures & test results

L

Lock" (Lock cm)

Lock" (Lock cm)

W

Lock" (Lock cm)

Lock" (Lock cm)

H

Lock" (Lock cm)

Lock" (Lock cm)

Volume

Lock in³ (Lock cm³)

Lock in³ (Lock cm³)

Transmitter Required

Locked

Locked

Show Text

Case

N/A

N/A

Case Picture

Sennheiser HD 599 Case Picture Sample

SAMPLE

for pictures & test results

Sennheiser HD 660 S Case Picture Sample

SAMPLE

for pictures & test results

Type

Locked

Locked

L

N/A

N/A

W

N/A

N/A

H

N/A

N/A

Volume

N/A

N/A

Build Quality

N/A

N/A

Build Quality Picture

Sennheiser HD 599 Build Quality Picture Sample

SAMPLE

for pictures & test results

Sennheiser HD 660 S Build Quality Picture Sample

SAMPLE

for pictures & test results

Show Text

Stability

N/A

N/A

Stability Picture

Sennheiser HD 599 Stability Picture Sample

SAMPLE

for pictures & test results

Sennheiser HD 660 S Stability Picture Sample

SAMPLE

for pictures & test results

Show Text

Headshots 1

Angled Picture

Sennheiser HD 599 Angled Picture Sample

SAMPLE

for pictures & test results

Sennheiser HD 660 S Angled Picture Sample

SAMPLE

for pictures & test results

Side Picture

Sennheiser HD 599 Side Picture Sample

SAMPLE

for pictures & test results

Sennheiser HD 660 S Side Picture Sample

SAMPLE

for pictures & test results

Headshots 2

Front Picture

Sennheiser HD 599 Front Picture Sample

SAMPLE

for pictures & test results

Sennheiser HD 660 S Front Picture Sample

SAMPLE

for pictures & test results

Rear Picture

Sennheiser HD 599 Rear Picture Sample

SAMPLE

for pictures & test results

Sennheiser HD 660 S Rear Picture Sample

SAMPLE

for pictures & test results

Top

Top Picture

Sennheiser HD 599 Top Picture Sample

SAMPLE

for pictures & test results

Sennheiser HD 660 S Top Picture Sample

SAMPLE

for pictures & test results

In The Box

In The Box Picture

Sennheiser HD 599 In The Box Picture Sample

SAMPLE

for pictures & test results

Sennheiser HD 660 S In The Box Picture Sample

SAMPLE

for pictures & test results

Show Text

Sound

Sound Profile

Frequency Response

Sennheiser HD 599 Frequency Response Sample

SAMPLE

for pictures & test results

Sennheiser HD 660 S Frequency Response Sample

SAMPLE

for pictures & test results

Bass Amount

Lock dB

Lock dB

Treble Amount

Lock dB

Lock dB

Show Text

Frequency Response Consistency

N/A

N/A

Consistency L

Sennheiser HD 599 Consistency L Sample

SAMPLE

for pictures & test results

Sennheiser HD 660 S Consistency L Sample

SAMPLE

for pictures & test results

Consistency R

Sennheiser HD 599 Consistency R Sample

SAMPLE

for pictures & test results

Sennheiser HD 660 S Consistency R Sample

SAMPLE

for pictures & test results

Avg. Std. Deviation

Lock dB

Lock dB

Show Text

Raw Frequency Response

Raw FR L

Sennheiser HD 599 Raw FR L Sample

SAMPLE

for pictures & test results

Sennheiser HD 660 S Raw FR L Sample

SAMPLE

for pictures & test results

Raw FR R

Sennheiser HD 599 Raw FR R Sample

SAMPLE

for pictures & test results

Sennheiser HD 660 S Raw FR R Sample

SAMPLE

for pictures & test results

Bass Accuracy

N/A

N/A

Bass

Sennheiser HD 599 Bass Sample

SAMPLE

for pictures & test results

Sennheiser HD 660 S Bass Sample

SAMPLE

for pictures & test results

Std. Err.

Lock dB

Lock dB

Low-Frequency Extension

Lock Hz

Lock Hz

Low-Bass

Lock dB

Lock dB

Mid-Bass

Lock dB

Lock dB

High-Bass

Lock dB

Lock dB

Show Text

Mid Accuracy

N/A

N/A

Mid

Sennheiser HD 599 Mid Sample

SAMPLE

for pictures & test results

Sennheiser HD 660 S Mid Sample

SAMPLE

for pictures & test results

Std. Err.

Lock dB

Lock dB

Low-Mid

Lock dB

Lock dB

Mid-Mid

Lock dB

Lock dB

High-Mid

Lock dB

Lock dB

Show Text

Treble Accuracy

N/A

N/A

Treble

Sennheiser HD 599 Treble Sample

SAMPLE

for pictures & test results

Sennheiser HD 660 S Treble Sample

SAMPLE

for pictures & test results

Std. Err.

Lock dB

Lock dB

Low-Treble

Lock dB

Lock dB

Mid-Treble

Lock dB

Lock dB

High-Treble

Lock dB

Lock dB

Show Text

Peaks/Dips

N/A

N/A

Peaks/Dips Graph

Sennheiser HD 599 Peaks/Dips Graph Sample

SAMPLE

for pictures & test results

Sennheiser HD 660 S Peaks/Dips Graph Sample

SAMPLE

for pictures & test results

Peaks

Lock dB

Lock dB

Dips

Lock dB

Lock dB

Show Text

Imaging

N/A

N/A

Group Delay

Sennheiser HD 599 Group Delay Sample

SAMPLE

for pictures & test results

Sennheiser HD 660 S Group Delay Sample

SAMPLE

for pictures & test results

Phase Response Mismatch

Sennheiser HD 599 Phase Response Mismatch Sample

SAMPLE

for pictures & test results

Sennheiser HD 660 S Phase Response Mismatch Sample

SAMPLE

for pictures & test results

Weighted Group Delay

Lock

Lock

Weighted Phase Mismatch

Lock

Lock

Weighted Amplitude Mismatch

Lock

Lock

Weighted Frequency Mismatch

Lock

Lock

Show Text

Passive Soundstage

N/A

N/A

PRTF

Sennheiser HD 599 PRTF Sample

SAMPLE

for pictures & test results

Sennheiser HD 660 S PRTF Sample

SAMPLE

for pictures & test results

PRTF Accuracy (Std. Dev.)

Lock dB

Lock dB

PRTF Size (Avg.)

Lock dB

Lock dB

PRTF Distance

Lock dB

Lock dB

Openness

0.0

0.0

Acoustic Space Excitation

0.0

0.0

Show Text

Virtual Soundstage

N/A

N/A

Virtual Soundstage

Sennheiser HD 599 Virtual Soundstage Sample

SAMPLE

for pictures & test results

Sennheiser HD 660 S Virtual Soundstage Sample

SAMPLE

for pictures & test results

Head Modeling

Locked

Locked

Speaker Modeling

Locked

Locked

Room Ambience

Locked

Locked

Head Tracking

Locked

Locked

Virtual Surround

Locked

Locked

Weighted Harmonic Distortion

N/A

N/A

Weighted Harmonic Distortion

Sennheiser HD 599 Weighted Harmonic Distortion Sample

SAMPLE

for pictures & test results

Sennheiser HD 660 S Weighted Harmonic Distortion Sample

SAMPLE

for pictures & test results

WHD @ 90

Lock

Lock

WHD @ 100

Lock

Lock

Show Text

Test Settings

Firmware

Locked

Locked

Power

Locked

Locked

Connection

Locked

Locked

Codec

Locked

Locked

EQ

Locked

Locked

ANC

Locked

Locked

Tip/Pad

Locked

Locked

Microphone

Locked

Locked

Show Text

Isolation

Noise Isolation

N/A

N/A

Noise Isolation

Sennheiser HD 599 Noise Isolation Sample

SAMPLE

for pictures & test results

Sennheiser HD 660 S Noise Isolation Sample

SAMPLE

for pictures & test results

Isolation Audio

Overall Attenuation

Lock dB

Lock dB

Noise Cancelling

Locked

Locked

Bass

Lock dB

Lock dB

Mid

Lock dB

Lock dB

Treble

Lock dB

Lock dB

Show Text

Leakage

N/A

N/A

Leakage

Sennheiser HD 599 Leakage Sample

SAMPLE

for pictures & test results

Sennheiser HD 660 S Leakage Sample

SAMPLE

for pictures & test results

Leakage Audio

Overall Leakage @ 1ft

Lock dB

Lock dB

Show Text

Microphone

Microphone Style

Integrated

Locked

Locked

In-Line

Locked

Locked

Boom

Locked

Locked

Detachable Boom

Locked

Locked

Mic

Locked

Locked

Recording Quality

N/A

N/A

Microphone Frequency Response

Sennheiser HD 599 Microphone Frequency Response Sample

SAMPLE

for pictures & test results

Sennheiser HD 660 S Microphone Frequency Response Sample

SAMPLE

for pictures & test results

Recorded Speech

LFE

N/A

N/A

FR Std. Dev.

N/A

N/A

HFE

N/A

N/A

Weighted THD

N/A

N/A

Gain

N/A

N/A

Noise Handling

N/A

N/A

SpNR

Sennheiser HD 599 SpNR Sample

SAMPLE

for pictures & test results

Sennheiser HD 660 S SpNR Sample

SAMPLE

for pictures & test results

SpNR

N/A

N/A

Noise Gate

Locked

Locked

Speech + Pink Noise Handling

N/A

N/A

Speech + Pink Noise Audio Sample

Speech + Subway Noise Handling

N/A

N/A

Speech + Subway Noise Audio Sample

Active Features

Battery

N/A

N/A

Battery Type

Locked

Locked

Continuous Battery Life

N/A

N/A

Additional Charges

N/A

N/A

Total Battery Life

N/A

N/A

Charge Time

N/A

N/A

Power-Saving Feature

Locked

Locked

Audio While Charging

Locked

Locked

Passive Playback

Locked

Locked

Charging Port

Locked

Locked

App Support

N/A

N/A

App Picture

Sennheiser HD 599 App Picture Sample

SAMPLE

for pictures & test results

Sennheiser HD 660 S App Picture Sample

SAMPLE

for pictures & test results

App Name

Locked

Locked

iOS

Locked

Locked

Android

Locked

Locked

macOS

Locked

Locked

Windows

Locked

Locked

Equalizer

Locked

Locked

ANC Control

Locked

Locked

Mic Control

Locked

Locked

Room Effects

Locked

Locked

Playback Control

Locked

Locked

Button Mapping

Locked

Locked

Surround Support

Locked

Locked

Connectivity

Bluetooth

N/A

N/A

Bluetooth Version

Locked

Locked

Multi-Device Pairing

Locked

Locked

NFC Pairing

Locked

Locked

Line Of Sight Range

N/A

N/A

PC Latency (SBC)

N/A

N/A

PC Latency (aptX)

N/A

N/A

PC Latency (aptX HD)

N/A

N/A

PC Latency (aptX-LL)

N/A

N/A

iOS Latency

N/A

N/A

Android Latency

N/A

N/A

Non-Bluetooth Wireless

N/A

N/A

Non-BT Line Of Sight Range

N/A

N/A

Non-BT Latency

N/A

N/A

Wired

N/A

N/A

Cable Picture

Sennheiser HD 599 Cable Picture Sample

SAMPLE

for pictures & test results

Sennheiser HD 660 S Cable Picture Sample

SAMPLE

for pictures & test results

Analog Audio

Locked

Locked

USB Audio

Locked

Locked

Detachable

Locked

Locked

Length

Lock ft (Lock m)

Lock ft (Lock m)

Connection

Locked

Locked

Analog/USB Audio Latency

Lock ms

Lock ms

Show Text

PC Compatibility

Analog

Locked

Locked

Wired USB

Locked

Locked

Non-BT Wireless

Locked

Locked

Show Text

PlayStation Compatibility

PS4 Analog

Locked

Locked

PS4 Wired USB

Locked

Locked

PS4 Non-BT Wireless

Locked

Locked

PS5 Analog

Locked

Locked

PS5 Wired USB

Locked

Locked

PS5 Non-BT Wireless

Locked

Locked

Show Text

Xbox Compatibility

Xbox One Analog

Locked

Locked

Xbox One Wired USB

Locked

Locked

Xbox One Non-BT Wireless

Locked

Locked

Xbox Series X|S Analog

Locked

Locked

Xbox Series X|S Wired USB

Locked

Locked

Xbox Series X|S Non-BT Wireless

Locked

Locked

Show Text

Base/Dock

N/A

N/A

Type

Locked

Locked

USB Input

Locked

Locked

Line In

Locked

Locked

Line Out

Locked

Locked

Optical Input

Locked

Locked

RCA Input

Locked

Locked

Dock Charging

Locked

Locked

Power Supply

Locked

Locked

Check Price

Black

HD 599 SE

Standard

HD 660 S

Ivory

HD 599

Standard

HD 660 S

Standard

HD 660 S

Standard

HD 660 S

Standard

HD 660 S

Sennheiser HD 599

Sennheiser HD 660 S

Comments

Comparison

• Posted 2 years ago

Sennheiser HD 599 vs Sennheiser HD 660 S: Main Discussion

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