Don't know if this is possible, but I thought with source, rifle fire, etc would have a different sound given where you were -- if you were in a closed room, it would sound muffled, in an open street, more echo-ey --- is that true? If so, how do you set it up in a map or is it automatically done by the engine? special texture -- ambient_generic -- some kind of sound entity/environment?

To clarify with an example, think it would be neat to have gunfire echoing off the buildings in a street firefight --- similar to how the gunfire sounded in the movie "Heat" when the bad guys were in a big gunfight in downtown LA....

I think thats automatically detected by the size of your room,anyway there were entities on HL1 to set a dsp when going through a trigger,might work on HL2 too..