LOUDSPEAKER WITH REDUCED ROCKING TENDENCY
A loudspeaker ( 13, 16 ) comprises an electro dynamic transducer ( 1 ) and a bass reflex enclosure ( 14, 17 ), in which the electro dynamic transducer ( 1 ) is mounted. The diaphragm ( 2 ) of the transducer, when driven, vibrates in a rocking mode with a rocking frequency and the bass reflex enclosure ( 14, 17 ) is tuned to the rocking frequency.
1 . A loudspeaker, comprising:
an electro dynamic transducer whose diaphragm, when driven, vibrates in a rocking mode with a rocking frequency f rock ; and
a bass reflex enclosures, in which said electro dynamic transducer is mounted; said bass reflex enclosure being tuned to said rocking frequency f rock .
2 . The loudspeaker of claim 1 , wherein said electro dynamic transducer is a spider-less transducer.
3 . The loudspeaker of claim 1 , wherein said bass reflex enclosure comprises a port with a cross-section and a length that is determined according to:
L
R
=
S
R
·
c
2
4
·
V
B
·
π
2
·
f
rock
2
wherein c is the sound velocity in air, f rock is said rocking frequency, S R is said cross-section of said port and V B is the volume of said enclosure.
4 . A loudspeaker, comprising:
an electro dynamic transducer whose diaphragm, when driven, vibrates with a resonance frequency f res in free air; and
a bass reflex enclosure, in which said electro dynamic transducer is mounted; said bass reflex enclosure being tuned to a frequency that equals 1.5 times said resonance frequency f res in free air.
5 . The transducer of claim 4 , wherein said electro dynamic transducer is a spider-less transducer.
6 . The loudspeaker of claim 4 , wherein said bass reflex enclosure comprises a port with a cross-section and a length which is determined according to:
L
R
=
S
R
·
c
2
9
·
V
B
·
π
2
·
f
res
2
wherein c is the sound velocity in air, f res is said resonance frequency in free air, S R is said cross-section of said port and V B is the volume of said enclosure.
7 . A mobile device, comprising a loudspeaker according to claim 1 .
8 . The mobile device of claim 7 , being one of a mobile phone, a PDA, a mobile computer, or a toy.