Personal Audio
HD 448 - Sennheiser USA
Article No. 502767
Key Features
- Lifelike stereo sound experience
- Ultra-ergo headband adds comfort
- Includes an carrying pouch and extension cable
- Closed, around-the-ear design blocks outside noise
Headphones - Stereo Headphones
$129.95
Related product
$129.95
General Description
If you want to get closer to your music and movies without distractions the HD 448 will take you there. Using specially tuned acoustic transducers, the HD 448 reproduces clean, intimate sound waves directly into your ears for a lifelike sound that helps you rediscover your music all over again. The leatherette earpads block out ambient noise, allowing you to listen at a safer levels with a much greater attention to the enhanced detail this headphone provides. The included cable extension adds length on-demand for listening on-the-move or at home.
Features
- Advanced neodymium magnet acoustic system delivers a huge, lifelike sound experience
- Closed, around-the-ear design blocks ambient noise-- enhancing detail
- Ergonomic design provides for a superior fit for long-term critical listening
- Adapts to your listening application: 4.6 ft cable includes a 1/4" adapter and 5.2 ft extension cable
- Includes a headphone pouch for storage and transport
- Optimized for iPod, iPhone, MP3 and CD players
- Built-tough with a 2 YEAR warranty!
- *iPhone and iPod are trademarks of Apple Inc., registered in the U.S. and other countries
- Compatible (listen only) with latest generation of tablets
Delivery Includes
- HD 448
- 5.2 ft extension cable
- 1/4 inch (6.3 mm) adaptor plug
- Carrying pouch
$129.95
Technical Data
| Frequency response (headphones) | 16 - 24,000 Hz |
| Impedance | 32 ohms |
| Sound pressure level (SPL) | 114 dB (1kHz/1Vrms) |
| Total harmonic distortion (THD) | <0.1% (1kHz/100dB) |
| Ear coupling | Around-the-ear |
| Transducer principle | Sealed (closed) |
| Cable length | 4.6 ft OFC with 5.2 ft OFC extension |
| Weight incl. cable | 6.9 oz (196 g) |
| Headphone connector | 1/8 inch (3.5 mm) |
| (*) | --------------- |
| UPC code | 615104167957 |
| EAN code | 4044155043495 |
| Dimensions (single) | 8.1 x 9.3 x 3.7 inches |
| Weight (single) | 15.9 oz |
| Dimensions (master carton) | 25.3 x 18.1 x 11.3 |
| Weight (master carton) | 20.5 lbs |
| Master carton quantity | 12 |
$129.95
Recommended Accessories
| Part/Accessory | Article No. |
| Ear cushions | 534441 |
|
Earpads for the HD 428, HD 438, and HD 448. Available in fabric or leatherette. |
|
| Extension cable | 534446 |
|
Extension cable for the HD 448 |
|
| Universal adapter | 077046 |
|
Universal Gold-plated 1/4" Adapter |
|
Glossary
| Cable length |
| The cable length is usually measured between the anti-kink sleeves of the cable (cable length without connectors). |
| Ear coupling |
| A distinction is made between headphones which are worn on the external ear (supra-aural) and those which surround the ear (circumaural). Open headphones have foam ear pads that rest on the ears or ring pads that surround the ears. Closed headphones, on the other hand, nearly always have circumaural ear pads. |
| Frequency response (headphones) |
| The frequency response of a pair of headphones is given within limits defined by the manufacturer. |
| Impedance |
| Impedance expresses the AC resistance of a microphone or a set of headphones. It is dependent on frequency and is given at 1 kHz as the so-called nominal impedance. Impedance is measured in ohms. In recent years, an industrial standard has developed, setting the impedance of headphones at 50 or 600 ohms. Sennheiser headphones are manufactured according to this standard, thus practically ruling out connection problems. With microphones, the input impedance of the following microphone amplifier should have at least three times the value of the nominal impedance, in order to prevent it from unnecessarily attenuating the microphone signal. |
| Sound pressure level (SPL) |
| Due to the impractical numerical values, the sound pressure is usually given as the logarithmic value of the sound pressure level according to the equation: dB SPL = 20 x log (po / 0.00002 Pa). The abbreviation SPL (sound pressure level) is added in order to make a clear distinction from other uses of dB. The reference sound pressure, which is at the same time the threshold of hearing, is then 0 dB SPL. The threshold of pain is 140 dB SPL. A difference in the sound pressure level of 1 dB is just about perceptible, while a doubling of the sound pressure corresponds to 6 dB and a doubling of the volume corresponds to a rise of 10 dB. |
| Total harmonic distortion (THD) |
| Total harmonic distortion is a measure of non-linear harmonic distortion and is given in %. Non-linear harmonic distortions are signals which were not present in the original before the signal was converted by the headphones. These unwanted signals are caused by the diaphragm, whose movements do not precisely move in time with the electric signals that cause it to move. Unfortunately, this is a feature of all electroacoustic transducers. Although it cannot be completely eliminated, suitable steps can be taken to minimise it. However, the user is not interested in why this distortion takes place but in how great the level of distortion must be for it to become perceptible. According to the findings of several research projects, a total harmonic distortion of 1% in the frequency range of 100 to 2000 Hz is imperceptible. Below 100 Hz, the perceptibility threshold lies at 10%. |
| Transducer principle |
| Two transducer principles have become established for the conversion of electric energy into mechanical energy: electrodynamic and electrostatic transducers, whereby the latter is only to be found in audiophile systems, due to their relatively high manufacturing costs. Electrodynamic transducers basically consist of a ring-shaped permanent magnet and an oscillation coil, which is fixed to the receiver diaphragm. When an audio-frequency alternating current is passed through the oscillation coil, it is caused to vibrate in accordance with the audio-frequency alternating current, thus causing the diaphragm to vibrate in the same way. |
