Loudspeaker with a wave guide

#The present invention relates to loudspeakers. In particular, the present invention relates to loudspeakers with a wave guide.

#To be exact, the present invention relates to the preamble e portion of claim 1.

#In the prior art especially loudspeakers with two or more drivers have had problems with diffractions created by discontinuities on the front surface (Face) of the loudspeaker. In practice the high frequency driver (tweeter) has been the most critical part in this relation and the applicant of the present application has created solutions where the surroundings of the tweeter have been created as a continuous wave guide for high and mid range audio signals either merely for a tweeter or alternatively for a coaxial mid-high range driver.

#In the following, certain preferred embodiments of the invention are described with reference to the accompanying drawings, in which:

#FIG. 1 presents a front view of a loudspeaker according to one preferred embodiment of the invention.

#FIG. 2 presents a cross section of a loudspeaker according to FIG. 1.

#List of used terms: 1 loudspeaker 2 enclosure 3 wave guide driver, also coaxial drive or tweeter only 4 woofer, low frequency driver 5 openings for the woofer, low frequency driver 6 acoustically selectively transparent layer 7 support structure for the acoustically transparent layer 8 three dimensional wave guide surface, also a front surface (Face) of the enclosure 2 radiating the acoustic power having a smooth continuous surface with axially symmetrical features around the centre of the wave guide driver 3 9 sweet spot for multiple loudspeakers 10 first acoustic axis 11 second acoustic axis 12 tweeter 13 mid range driver B1 frequency band of the wave guide driver 3 B2 frequency band of non-coaxial driver 4 C cross over frequency band between bands B1 and B2

#In accordance with FIG. 1 one embodiment of the invention the loudspeaker 1 includes a coaxial wave guide driver 3 comprising a tweeter 12 and a mid range driver 13 around it. The coaxial driver 3 is positioned in the centre of the three dimensional wave guide surface 8, also a front surface (Face) of the enclosure 2. The wave guide surface 8 radiates the acoustic power of the driver 3. The wave guide 8 has a smooth continuous surface with axially symmetrical features around the centre of the wave guide driver 3. Two woofer elements 4 are positioned on both sides of the wave guide driver 3 and suitable openings 5 are formed for the woofers 4 in order to let the acoustic energy out from the enclosure 2.

#With reference to FIG. 2, the openings 5 are covered with an acoustically transparent layer 6 forming part of the wave guide surface 8. If needed the acoustically transparent layer 6 may be supported from below with support bars 7. The woofer element 4 is typically spaced from the acoustically transparent layer 6.