sound wave reflections

Ok i thought i would start a topic on how sound reflects off objects and how this effects a speaker cab with unwanted distortion feel free to discuss.....

For those that don't no much about this subject i will fill you in with the basics. The reflection of sound follows the rule that the angle of incidence equals the angle of reflection, This is called the law of reflection. Sound waves can reflect off objects, Waves hitting an acoustically reflective surface bounce off it in another direction. The direction of reflection is equal to the angle at which it hits, the angle of incidence equals the angle of reflection. Meaning if a sound wave hit a piece of wood at an angle of +45 degrees, the reflection will also be at -45 degrees



The angles of incidence and reflection is measured to the surface normal. Surface normal is the line perpendicular to the reflective surface.



Below is another pic of parallel sound waves reflecting off an object, the black lines is the angle of incidance, and the grey lines is the reflected wave.



The reflected waves can interfere with the incident waves, this produces constructive and destructive resonances in a speaker cabinet. The same also applies to the room the speaker cabinet is in.

so how does this effect the way speaker boxes are made, weather it a reflex box or a folded horn......

feel free to discuss.......

pt 2 coming soon.............