Even the clearest of recordings are useless without a good loudspeaker
The modern loudspeaker, as demonstrated by the Monitor Audio Apex series, produces sound by converting electrical signals from an audio ampliļ¬er into mechanical motion, from which sound waves emanate. Loudspeakers can consist of an individual transducer (audio driver) or a series of drivers encased within a large chassis, each dealing with a certain frequency band to improve the overall gamut and ļ¬delity of reproduced sounds.
For example, larger subwoofer speakers deal with low frequencies, while smaller speakers called tweeters deal with high frequencies. These various drivers are controlled by a ļ¬lter network, which organises the different frequency signals coming from the ampliļ¬er and directs
them to the driver most suitable to deal with it.
The construction of a single loudspeaker driver is a complex process, the central element of which is a concave plastic or paper conical disc. This is the part that moves backwards and forwards in the generation of sound, ļ¬ xed in the centre of a concave metal frame. Attached to the cone is a hollow cylinder of aluminium and a pair of wire coils suspended by a ļ¬exible fabric disc. These coils are attached to the ampliļ¬er and positioned inside a narrow cylindrical groove in the centre of a magnet. By doing this, every time a signal travels through the wires, the coil emits a magnetic ļ¬eld that pushes or pulls the cone backwards or forwards, forming sound waves.
The modern loudspeaker, as demonstrated by the Monitor Audio Apex series, produces sound by converting electrical signals from an audio ampliļ¬er into mechanical motion, from which sound waves emanate. Loudspeakers can consist of an individual transducer (audio driver) or a series of drivers encased within a large chassis, each dealing with a certain frequency band to improve the overall gamut and ļ¬delity of reproduced sounds.
For example, larger subwoofer speakers deal with low frequencies, while smaller speakers called tweeters deal with high frequencies. These various drivers are controlled by a ļ¬lter network, which organises the different frequency signals coming from the ampliļ¬er and directs
them to the driver most suitable to deal with it.
The construction of a single loudspeaker driver is a complex process, the central element of which is a concave plastic or paper conical disc. This is the part that moves backwards and forwards in the generation of sound, ļ¬ xed in the centre of a concave metal frame. Attached to the cone is a hollow cylinder of aluminium and a pair of wire coils suspended by a ļ¬exible fabric disc. These coils are attached to the ampliļ¬er and positioned inside a narrow cylindrical groove in the centre of a magnet. By doing this, every time a signal travels through the wires, the coil emits a magnetic ļ¬eld that pushes or pulls the cone backwards or forwards, forming sound waves.
Multi-driver loudspeaker enclosures
The enclosure of any loudspeaker plays a highly signiļ¬ cant role in the reproduction of sound, as well as providing a unit in which the speaker’s drivers, electronic circuitry, crossover control and ampliļ¬er are all mounted.
Current state-of-the-art enclosures are built from composite materials and include numerous struts, bafļ¬ es air ports and acoustic insulation materials and adhesives. These work together to reduce echo and reverberation caused by rearward sound waves generated by the speaker’s drivers reļ¬ ecting off the back and sides of the case. This is important for audio ļ¬ delity and accuracy of reproduction, as rogue or errant sound waves can interfere with forward-generated waves, distorting them
and adding effects not part of the original recording. The enclosure, thanks to its complex construction, is also the key factor in reducing vibrations caused by the back and forth movement of the driver diaphragm, shake of the driver chassis and rumble of any subwoofer.
Historically, in early forms of loudspeaker, drivers were often left exposed completely or partially due to heatrelated issues with their electronics, as well as because of the ļ¬xed, unsuspended nature of the driver chassis and the difļ¬culty in securing a consistent airļ¬ow. Further, the materials used in these early loudspeakers (usually heavy metals) were prone to vibration issues and did little to prevent standing waves, while their chunky and bulky designs caused diffraction of sound waves from their sharp edges.
Today, these ļ¬ aws are minimised by audio-friendly, lightweight polymer casing materials, which are manufactured with smooth edges to reduce refraction and coated with resonance and vibration damping adhesives. Single component plinths, bafļ¬ es and struts, as well as lightweight driver chassis also aid the accuracy of sound reproduction and, thanks to the inclusion of transmission lines (an internal structure within the loudspeaker enclosure designed to guide up to 90 per cent of a driver’s rear wave output away from distortion-prone areas) in modern cabinets, has allowed sleeker and more compact driver arrays.
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