Sennheiser HD 518 - Over the Ear Heaphones

The HD 518 is the evolution piece in the Sennheiser HD 5X8 series audiophile headphones; with the HD 558 and HD 598 following in succession respectively. All headphones in this series are circum-aural or over the ear headphones with open back earcups.The Sennheiser HD 518 being the starting piece in this series is also the cheapest costing about $129.95. They are all built with the same technological concept but with progressive refinements across the series.

The Sennheiser HD 518 also features the innovative E.A.R. technology, which ensures accurate channeling of audio signals into your ears and the DuoFol diaphragms that minimize sound distortion. Additionally, the ear pads are generously padded and headband cushioned to enhance wearing comfort for extended listening periods.
These headphones are supplied in a beige-colour with high-gloss burl wooden parts and matching ear pads in a sophisticated premium finish.

Features of the Sennheiser HD 518 Headphones

• Open circum-aural headphones with E.A.R. technology 

The Sennheiser HD 518 are full size headphones whose generously padded earcups fully wrap around your ears. They are designed to provide maximum wearing comfort during long listening sessions while ensuring impeccable sonic accuracy and clarity through Sennheiser's intuitive "Ergonomic Acoustic Refinement" (E.A.R.) design.  The E.A.R design ensures all audio signals are directly into your ears while ensuring maximum comfort.

• DuoFol Diaphragms adopted for the HD 518

DuoFol diaphragms are a thin membrane attached to a voice coil. They are designed to provide a wide sound stage with ultra-fast response and rest times for improved sound transparency and reduced distortion. The diaphragm geometry is tailored to keep intermodulation distortion minimal. Intermodulation occurs when an audio signal known frequencies passes through an imperfect audio system giving rise to several noise frequencies in the output signal, which are either multiples, sums and differences of frequencies contained in the original audio signal but weaker than the desired output audio signal frequencies. This distortion however, becomes significant when the volume is turned up!

• Neodymium Ferrous Magnet and Aluminum Voice Coils

The permanent magnets adopted for the Sennheiser HD 518 are specially optimized and field-strengthened neodymium ferrous magnets. This coupled with lightweight aluminum voice coils provide a superior dynamic response and efficiency.

• Soft Ear pads and Cushioned Headband

The Ear pads of the HD 518 are generously padded with very soft material, while the headband is also cushioned with an equally soft material to provide luxurious wearing comfort during your extended listening sessions.

• Versatile connectivity options

The HD 518 can be invariably used with HiFi system, TV set, Headphone amplifier, Home Audio, etc, without any noticeable drop in quality of sound output. This is because of its low output impedance that closely matches with these audio systems.

• Eye catching grille-like ear cup casing design

The Sennheiser HD 518 feature an distinctive eye catching grille like design that makes them fairly attractive at first glance.

Design attributes of the Sennheiser HD 518 Over the Ear Headphones

• Dynamic Transducer type

The Sennheiser HD 518 headphones use the dynamic transducer principle. This means that once a varying current is applied to the voice coil suspended within the magnetic field of the neodymium ferrous magnet, it creates a magnetic field which changes polarity and direction at the rate of the input current. When this dynamically changing magnetic field interacts with the field of the neodymium ferrous magnet, it creates a repulsive force when the polarities of the two fields match and an attractive force when the polarities are different. This causes the voice coil to vibrate several times a second [depending on changing current] carrying the duofol diaphragm with it, and consequently the air around it - creating music sound.

• Frequency response

The Sennheiser HD 518 headphones are designed to respond to an incredibly wide audio frequency spectrum, going from as low as 14Hz  and to as high as 26kHz. If you are an audiophile, the HD 518 has got you covered for you will never regret because it pumps out some quality sound yet costing only $129.95!

• Input Impedance

The Sennheiser HD 518 is a low impedance headphone. Its input impedance is only 50 Ohms. This gives you the flexibility to use them with your TV set or home Audio which have low impedance output headphone jacks.

• Sensitivity

Sensitivity of a headphone determines how loud a headphone is for a given level of an acoustic signal input. It is measured in decibels of Sound pressure level (SPL). Sound Pressure Level (SPL) is the change in local air pressure that results due to a disturbance caused by a sound wave. For the Sennheiser HD 518, the SPL value has measured to be 108 dB at 1kHz for an amplifier input voltage of 1Vrms. The normal headphone range of SPL is between 85dB to 120dB; with 85dB corresponding to the lowest  and 120dB the highest volume.

• Total Harmonic Distortion (THD)

Total Harmonic Distortion (THD) is a widely and intentionally misrepresented concept by most audio equipment manufacturers. The value of the THD ratio ideally should represent how much of the unwanted frequencies (harmonics) a given audio system has at its output for an entire audio signal range of 20Hz - 20kHz. This value is expected to be larger for an entire signal range! Traditionally, this is quoted by manufacturers as measured for a single frequency. For the Sennheiser HD 518, this value of THD is <0.2% at 1kHz, and 100 dB SPL.

• Dimensions and weight of the HD 518

The HD 518 is shipped in a product packaging that measures (L x B x H): 205 x 100 x 240 mm and  weighs a net weight of 286 g. 

•   In The Box?

A 3 meter, single sided and changeable OFC, 4-strand copper cable, a gold-plated 6.3 mm stereo jack with a 3.5 mm gold-plated adaptor and Sennheiser HD 518 headphones.

Buying guide

• The headphones sound really good for an open back earcup design and for such a price. Plus, you enjoy the flexibility of hooting them up to any audio system to enjoy quality sound without requiring a headphone amplifier.

• The soft ear pads and cushioned headband of Sennheiser HD 518 provide wearing comfort for use over long periods.

• Open back earcup designs normally have problems with poor Bass. But with the HD 518, the Bass is clean and fairly deep. 

• Like all open back earcup designs, the HD 518 leak out quite a lot of sound. Be sure to use them in the comfort of your home. You cannot use them while on your travels; on the Airplane for instance or in a public place.