Dome speaker
A dome loudspeaker is a dynamic loudspeaker whose membrane forms a spherical dome, i.e. is arched in the shape of a dome . Cone speakers with a dust cover do not fall under this category.
General
In contrast to cone loudspeakers, the voice coil starts at the outer edge of the membrane, at the transition to the bead . A convex (outwardly directed) membrane curvature results in a wider angle of radiation at higher frequencies compared to the cone. However, this design limits - not least for reasons of stability - the practical size; The dome-shaped mid-range speakers that were common in the past are rarely built in this form today.
Sometimes manufacturers also refer to ordinary mid-range speakers and woofers as domes if their membrane is "pulled through" in one piece, i.e. does not have a separate dust cover or phase plug in the middle . Real dome loudspeakers that can also emit lower frequencies with serious volume are very rare (such as the - high-priced - transducers from Accuton, with concave ceramic diaphragms).
Today, the dome construction is mainly used for tweeters.
Dome tweeter
While dome tweeters with a nominal diameter of 20 millimeters were the most widespread in the past, the 25 and 28 mm types are mostly used today. Thanks to the larger voice coil, the thermal load capacity increases; lower resonance frequencies also enable a deeper coupling. Due to the principle, however, the expansion of the diaphragm diameter is at the expense of the omnidirectional behavior, i.e. H. the high frequency level drops more rapidly outside the auditory axis.
Short horn attachments integrated into the front panel - also called "waveguides" - may increase the overall sound pressure; however, they in turn narrow the radiation angle and often limit the frequency response linearity . To improve the omnidirectional behavior, small dispersion cones are sometimes positioned in the middle in front of the membrane.
Membrane materials
Coated fabric (such as silk ) is usually used as the membrane material . Thanks to new manufacturing techniques, it is now also possible to use the advantages of hard materials: They are characterized by their particularly clear and detailed reproduction. There are membranes made of aluminum , ceramic , titanium , beryllium and even diamond on the market . To protect these touch-sensitive domes, corresponding tweeters often have a metal grille in front of them.
Special forms
In the case of loudspeakers with an "inverse dome", the membrane is not curved outwards but inwards (concave).
With the ring radiator, the center point of the spherical cap is fixed. This results in a design in which the sound is emitted over two concentric beads; In the literal sense, it is no longer a "dome" loudspeaker.
literature
- G. Schwamkrug / R. Römer: Loudspeakers - Poetry and Truth , Elektor Verlag, Aachen 1986, ISBN 3-921608-45-7 .
- Hans Herbert Klinger: Loudspeakers and loudspeaker housings for HiFi , Franzis' Verlag, Munich 1981, ISBN 3-7723-1051-6 .
Individual evidence
- ↑ Accuton ( Memento of the original from October 11, 2013 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. - Homepage
