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Bass Management
The fundamental principle of bass management (also called LFE crossover) in surround sound replay systems is that bass content in the incoming signal, irrespective of channel, should be directed only to loudspeakers capable of reproducing it, whether the latter are the main system loudspeakers or one or more subwoofers. Mapping There are notation differences between the pre-bass-managed signal and after it has passed through the bass manager. For example, when using 5.1 surround sound: As the table shows, the bass manager directs bass frequencies from ''all'' channels to one or more subwoofers, not just the content of the low-frequency effects The low-frequency effects (LFE) channel is a band-limited audio track that is used for reproducing deep and intense low-frequency sounds in the 3–120 Hz frequency range. This track is normally sent to a subwoofer—a loudspeaker des ... (LFE) channel. However, when there is no subwoofer, the bass manager directs the L ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Surround Sound
Surround sound is a technique for enriching the fidelity and depth of sound reproduction by using multiple audio channels from speakers that surround the listener ( surround channels). Its first application was in movie theaters. Prior to surround sound, theater sound systems commonly had three ''screen channels'' of sound that played from three loudspeakers (left, center, and right) located in front of the audience. Surround sound adds one or more channels from loudspeakers to the side or behind the listener that are able to create the sensation of sound coming from any horizontal direction (at ground level) around the listener. The technique enhances the perception of sound spatialization by exploiting sound localization: a listener's ability to identify the location or origin of a detected sound in direction and distance. This is achieved by using multiple discrete audio channels routed to an array of loudspeakers. Surround sound typically has a listener location ( sweet sp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bass (sound)
Bass ( ) (also called bottom end) describes tones of low (also called "deep") frequency, pitch and range from 16 to 256 Hz (C0 to middle C4) and bass instruments that produce tones in the low-pitched range C2-C4. They belong to different families of instruments and can cover a wide range of musical roles. Since producing low pitches usually requires a long air column or string, and for stringed instruments, a large hollow body, the string and wind bass instruments are usually the largest instruments in their families or instrument classes. Use in composition In musical compositions, such as songs and pieces, these are the lowest-pitched parts of the harmony. In choral music without instrumental accompaniment, the bass is supplied by adult male bass singers. For an accompanied choir, the bass is typically provided by pipe organ or piano (or if a choir can afford to hire one, by orchestra). In an orchestra, the basslines are played by the double bass and cellos, bassoon o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Subwoofer
A subwoofer (or sub) is a loudspeaker designed to reproduce low-pitched audio frequencies known as bass and sub-bass, lower in frequency than those which can be (optimally) generated by a woofer. The typical frequency range for a subwoofer is about 20–200 Hz for consumer products, below 100 Hz for professional live sound, and below 80 Hz in THX-certified systems. Subwoofers are never used alone, as they are intended to ''augment'' the low-frequency range of loudspeakers that cover the higher frequency bands. While the term "subwoofer" technically only refers to the speaker driver, in common parlance, the term often refers to a subwoofer driver mounted in a speaker enclosure (cabinet), often with a built-in amplifier. Subwoofers are made up of one or more woofers mounted in a loudspeaker enclosure—often made of wood—capable of withstanding air pressure while resisting deformation. Subwoofer enclosures come in a variety of designs, including bass reflex (wit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Low-frequency Effects
The low-frequency effects (LFE) channel is a band-limited audio track that is used for reproducing deep and intense low-frequency sounds in the 3–120 Hz frequency range. This track is normally sent to a subwoofer—a loudspeaker designed to reproduce very low frequencies. LFE channels originated in Dolby Stereo 70 mm film, but in the 1990s and 2000s they became common in home theater systems in order to reproduce film soundtracks found on DVDs and Blu-ray discs. Types Low-pitched musical arts LFEs include both low-pitched musical notes and low-pitched sound effects. The musical soundtrack for many films includes bass instruments that produce very low notes. Until the 1970s, most of the low-pitched instruments were natural, acoustic instruments, such as the double bass or the pipe organ's pedal keyboard. After the 1980s, film scores increasingly used synthesized instruments, including synth bass keyboards, which incorporated very low-pitched notes. Sound ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Butterworth Filter
The Butterworth filter is a type of signal processing filter designed to have a frequency response that is as flat as possible in the passband. It is also referred to as a maximally flat magnitude filter. It was first described in 1930 by the British engineer and physicist Stephen Butterworth in his paper entitled "On the Theory of Filter Amplifiers". Original paper Butterworth had a reputation for solving "impossible" mathematical problems. At the time, filter design required a considerable amount of designer experience due to limitations of the theory then in use. The filter was not in common use for over 30 years after its publication. Butterworth stated that: Such an ideal filter cannot be achieved, but Butterworth showed that successively closer approximations were obtained with increasing numbers of filter elements of the right values. At the time, filters generated substantial ripple in the passband, and the choice of component values was highly interactive. Butterwo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sound Production Technology
In physics, sound is a vibration that propagates as an acoustic wave, through a transmission medium such as a gas, liquid or solid. In human physiology and psychology, sound is the ''reception'' of such waves and their ''perception'' by the brain. Only acoustic waves that have frequencies lying between about 20 Hz and 20 kHz, the audio frequency range, elicit an auditory percept in humans. In air at atmospheric pressure, these represent sound waves with wavelengths of to . Sound waves above 20 kHz are known as ultrasound and are not audible to humans. Sound waves below 20 Hz are known as infrasound. Different animal species have varying hearing ranges. Acoustics Acoustics is the interdisciplinary science that deals with the study of mechanical waves in gasses, liquids, and solids including vibration, sound, ultrasound, and infrasound. A scientist who works in the field of acoustics is an ''acoustician'', while someone working in the field of acoustical e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
