Brands and models tested
• AKG K452
• AKG K518 DJ
• Beats by Dr. Dre Solo HD
• Bose OE2 Audio Headphones
• Logitech UE 4000
• Monster DNA On-Ear Headphones
• Technics RP-DH1200
• Panasonic RP-DJS400A
• Philips SHL5505BK
• Sennheiser HD 229
• Sennheiser Momentum On-Ear
• Sennheiser PX 200-II
• Sony MDR-10RBT
How we test
Five expert listeners appraise each headphone for use with a variety of music genres (classical, popular and rock).
• Each tester rates all test samples twice at different times
• A high quality CD player is used and amplification is via two identical headphone amplifiers
The following music and speech samples are used for the listening test:
• Classical music: Taken from the CD Die Stereo Hörtest CD, Vol. 6, Track 1, Tchaikovsky: Mazeppa – Hopak. This track contains both delicate single instruments like triangles and quiet orchestral passages, as well as dynamic orchestral sections with big timpani and both wind and string instruments.
• Jazz music: Taken from the CD The Molly Johnson Song Book from Molly Johnson, Track 6, “Ode to Billie Joe”. This track contains piano, double bass as well as brass and female voice parts.
• Rock music: Taken from the CD Oracle from Godsmack, Track 9, Crying like a bitch. This track contains drums, electric guitar and voice. It allows a good evaluation of the balance of frequency bands.
• Female speech: Taken from the CD “SQAM” (Sound Quality Assessment Material) of the European Broadcasting Union, Track 53, female speech
• Male speech: Taken from the CD “SQAM” (Sound Quality Assessment Material) of the European Broadcasting Union, Track 54, male speech
Comfort after being worn for about 30 minutes is rated for the following items:
• Stability of the adjusted position
• Secure fit when moving the head
• Static pressure and heat accumulation on the ears
• Subjective feeling of the weight of the headphone
• Mechanical noise caused by the ear cup attachment or head band when moving the head
• Friction noise from the cable when it rubs on clothes
Ease of use
Ease of use is rated by five testers, three of whom normally wear glasses.
They give ratings for the use of the headphone with regards to the following items:
• Quality and visibility of the left-right inscription
• Ease of putting on the headphone and controlling by feel
• Ease of adjusting the headphone
• Resistance against unwanted adjustment of the headphone
• Presence of sharp edges or similar
In addition the headphone is rated on how it can be used when someone is handicapped, i.e. by use of one hand.
We also assess the user guide for clarity and completeness.
We check the ease of folding and opening the headphone as well as putting it into its bag (if appropriate).
We assess the portability of the headphone when it’s packed in its case.
The headphone is placed on an artificial head and torso simulator (HATS) which features
artificial ears with an ear impedance simulation based on IEC 60318-4.
The following items are checked:
• The similarity of the sound pressure frequency response of left and right channel
• The similarity of the impedance frequency response of left and right channel
• Determination of the minimum impedance
• Frequency of the impedance minimum
Based on DIN EN 50332-2 the required input voltage at the headphone plug is determined to achieve a sound pressure level of 94 dB (A) at the HATS.
We measure how much sound is irradiated from the headphones to the surrounding environment. The sound pressure level at the artificial head (HATS) is set to 90 dB(A). A high efficiency microphone is placed 0.2 metres away and the irradiated sound pressure level is measured. To avoid environmental noise the measurement is performed in an anechoic chamber.
The insulation from surrounding noise is measured in a reverberation room, to provide diffuse field conditions, with an approximated pink noise signal of about 85 dB(A).
The headphones are dropped from a height of 1.8 metres onto a wooden floor. We look for:
• Mechanical damage after ten drops, respectively if damages occur after a lower number of drops
• Audible degradation after the drop test
• Noticeable changes in the technical testing
• In cases where damage occurs a second sample is checked
Checks on Bluetooth models
Bluetooth ease of use is rated for the following:
• Ease of pairing
• Presence of an NFC feature and if it helps the pairing process
• Transmission problems when other devices are used nearby
• Feedback for the operation state and charging state
If a sample features Bluetooth the following items are checked:
• The playing time for music listening, while maintaining a sound pressure level of 74 dB(A). The measurement is done after five charging/discharging cycles and a further full charging cycle.
• After the unit is fully discharged the charging time is determined when using a USB AC charger which is able to provide up to 2.1 A charging current
• The power consumption during charging is checked if an AC charger is supplied
• Presence of an automatic power-down without BT connection
Speech quality via microphone
If the headphone features a microphone for mobile phone use, the quality of the microphone is checked using a PESQ (Perceptual Evaluation of Speech Quality due to ITU-T P.862) measurement.
Compatibility of the remote control
The compatibility of the remote controls (if featured) is checked with different smartphones. The following smartphones are used:
• Apple iPhone5s
With every smartphone the following functions are checked:
• Samsung Galaxy S4
• Nokia Lumia 625
• HTC Desire 600
• Skip forward
• Skip backward
• Voice dial
• Accept call / end call
• Refuse a call