Advance acoustic EL-250 Mode D'emploi page 7

BSW: THE SOLUTION
At Advance Acoustic, we worked hard on a most important problem for the loudspeakers: the tremendous internal air pressu-
res generated by the subwoofer, in vented-box or sealed cabinet, with unwanted vibrations and colorations.
Despite the use of new absorbant materials inside the cabinet, several standing waves are present in some precise areas in
the cabinet, with unwanted and colored sound radiations.
Several solutions are used by the speakers developers : shell-like enclosures, internal bracing, new materials (carbon fiber).
At Advance Acoustic, we know and use some of these solutions (specially selected and very thick wood panels, internal rein-
forcements), but hey are yet no sufficient.
One of a radical solution is to use moving panels, but it's not possible because one of the most important thing is to get uns-
hakeable and very rigid cabinet, for a maximum delibvery in bass, with minimum vibration...
To eliminate radically this problem, Advance Acoustic ha developped BSW : the Breaking Stationary Wave.
It's a thin steel rod, working as a spring, at the end of which is set an « ove » (a kind of egg), in semi-reflecting rubber.
AVANTAGES :
1. The « ove » and his axis are a totally no noise and vibration-free system.
2. This Breaking Stationary Wave system act as a real acoustic servo-controler and regulator.
3. Dramatically improved bass (speed and stiffness).
4. Medium and treble frequencies are more natural, with sound coloration drastically reduced.
Figure A.
Standing (or stationary) waves formation
Figure B.
« Ove » movements, with continuing changes of the pressure waves propagation and areas.
Figure C.
No new formation of standing waves, because the changes of the « ove » position.
A, B & C are air pressure waves
D, E & F are reflecting waves