hook.Add("EmitSoundWave", 1, function(ent)
    local i = 1
    local id = "particle_test" .. ent:EntIndex()

    local emitter = ParticleEmitter(ent:GetPos())

    local function Think()
        if i < 0 or not ent:IsValid() then hook.Remove("Think", id) return end

        local pos = ent:NearestPoint(ent:GetPos() - ent:GetVelocity())

        for i = 1, 50 do

            local particle = emitter:Add("sprites/heatwave", pos)

            -- movement
            particle:SetVelocity(VectorRand() * 1000)
            particle:SetAirResistance(0)

            -- appearance
            particle:SetColor(255, 255, 255)

            particle:SetStartAlpha(255)
            particle:SetEndAlpha(0)

            particle:SetStartSize(ent:BoundingRadius())
            particle:SetEndSize(0)

            particle:SetDieTime(math.random() * 0.3)

        end

        i = i - FrameTime()
    end

    hook.Add("Think", id, Think)
end)

sonic_boom_backup=sonic_boom_backup or backup or physenv.GetPerformanceSettings()

local settings={}
settings.MaxVelocity=50000
settings.MaxAngularVelocity=50000
physenv.SetPerformanceSettings(settings)

local WAVE_CONSTANT=0.001
--size in newtons
function EmitSoundWave(b)
    hook.Run("EmitSoundWave",b)

    local speed=((b:GetVelocity():Length()*3600*0.0000254*0.75)/3600)/1000
    local pos=b:GetPos()
    local pitch=0
    local v = LocalPlayer()

    pitch=255/((speed*(v:GetPos():Distance(pos)*0.01905))/WAVE_CONSTANT)
    if pitch<255 and pitch>0 then
        if v:GetPos():Distance(pos)>512 then
            if math.random(1,2)==1 then
                sound.Play('/ambient/weather/thunder4.wav',pos,0,pitch)
            else
                sound.Play('/ambient/weather/thunder3.wav',pos,0,pitch)
            end
            sound.Play('/fireworks/firework_explosion_3.wav',pos,0,pitch)
            sound.Play('/ambient/arrowlight.wav',pos,0,pitch)
        else
            sound.Play('/ambient/machines/floodgate_stop1',pos,0,128)
        end
    end

end

timer.Create('DSPtest',0.25,0,function()
    for k,v in pairs(ents.GetAll()) do
        if ((v:GetVelocity():Length()*3600*0.01905)/1000)>100 and v:IsPlayer()==false then
            if v.sonicboom==nil then
                v.sonicboom=true
                EmitSoundWave(v)
            end
        else
            v.sonicboom=nil
        end
    end
end)