How U determine first and second reflection points

so if you where to hit my instrument and stand in front of it .Lets say you line all 4 walls with humans ,line all the ceiling and floor as well.when you hit the triangle(example)no other person will hear it but you becaue you block it ..right....life is 3d friends.......

I'm not sure what you are trying to say, but if you are saying that you need all of the reflections from the walls, ceiling, and floors to get 3d effect, you are overlooking the fact that on well recorded software that information is already there. To not treat the critical reflection points will distort the original signals and you will lose the value inherrent in making recordings using minimal mic'ing with realistic spatial information. In other words, there goes your depth of field everyone seems to think is so important.

First of all to treat, means kill in hi-fi.You or we (hi-fi)claim or describe sound as a staight line.We give examples of the beam of flash light or a cue ball off of a pool table deflection.

The earth is round...sphere. when we throw a pebble in a still lake.The ripples are round.This is a 2d picture of what happens.If you can imagine 3d of this then you will get sphere.When you take a bath and fart under water the bubbles are ......spheres and smelly(bonus).When you watch under water explosions in movies example,the sound is the shape of a sphere.When the radio tower of a tv station emits a signal it is in a radius(miles traveled) sphere...

No lines....if we change the way we think and get back to what really happens instead of what we think or we read . Hi-fi would be even better than just swapping brands etc...

I want you guys to just think about this.I'm not interested in fights...cool

Not saying that at all - sound reflects in staight lines (many, many, many straight lines - it does not zoom around corners, honest), and when the waves bounce back they cancel each other out at a certain place (standing waves). The way to stop that is to not allow them to reflect back.
Oh never mind, everyone else seems to understand just fine...Yes the earth is flat, and intelligent design is a science - happy now?

Ok.....so now if the speheres collide and bounce off the walls ,and off of each other.We get a problem with standing waves or /nodes.By killing some of the frequencies or musical notes.....All you have accomplished is the death of your music.The spheres will continue to collide.Only now you chopped away most of the vital info in your room by killing it.When you move your speakers around all you do is move the pressure zones about.Big spheres ,small spheres,all your rooms are individual as your are.So you cannot tell what a pressure zone is doing to your friends system. Controlling the waves and nodes.When you learn not to kill ,but to control and use the full energy of your room and system.Live music is never killed....You are trying to remove the walls out of the whole equation.Your little nearfield triangles do a very good job of this ,but then your stuck on hearing the character of your gear.At low volumes.....