Does the first reflection point actually matter??

If I ask someone with Floyd Toole level knowledge of loudspeaker-in-room acoustics (which I can with Billy Woodman at ATC),  he would tell me that consistent spectral content of direct vs reflections is the key to imaging.  If the reflections look very similar in spectral content to the direct sound it will image well.  That's why he builds wide dispersion loudspeakers. Narrow dispersion loudspeakers, having different spectral content off axis than on axis, sends spectral energy that does NOT sound like the direct sound on reflection "zones" (love this word Duke, well done).  Its all about the sum of these two complex sources of (direct vs reflected) energy at your ears, because when they combine with each other they partially cancel or completely cancel each other.   Longer path = longer time= phase shift.   This is the idea of nearfeild monitoring in studios, reduce the amount of reflected energy by sitting closer and moving the speakers further from the walls (smaller triangle).   Now you can hear more of your monitor and less of the room.  Engineers use this idea to help them get a more consistent sound in the different rooms they work in without changing speakers, using EQ or DSP (all of which adds another "veil" to the direct sound).  I remember seeing Kevin Shirley mixing about 2 feet from his speakers which were about 2 feet apart.   Not so much "room sound" in such a set up.

Brad    

Hi Brad,
Yep, that's one reason I often recommend audiophiles listen to their speakers from 2' away.  The difference in clarity and resolution and tonal balance between that and the normal listening position is mostly the room.  Once they understand that, they can better decide if treating the room would be wroth it.

Best,
Erik

If I ask someone with Floyd Toole level knowledge of loudspeaker-in-room acoustics (which I can with Billy Woodman at ATC), he would tell me that consistent spectral content of direct vs reflections is the key to imaging. If the reflections look very similar in spectral content to the direct sound it will image well. That’s why he builds wide dispersion loudspeakers. Narrow dispersion loudspeakers, having different spectral content off axis than on axis, sends spectral energy that does NOT sound like the direct sound on reflection "zones" (love this word Duke, well done). Its all about the sum of these two complex sources of (direct vs reflected) energy at your ears, because when they combine with each other they partially cancel or completely cancel each other. Longer path = longer time= phase shift. This is the idea of nearfeild monitoring in studios, reduce the amount of reflected energy by sitting closer and moving the speakers further from the walls (smaller triangle). Now you can hear more of your monitor and less of the room. Engineers use this idea to help them get a more consistent sound in the different rooms they work in without changing speakers, using EQ or DSP (all of which adds another "veil" to the direct sound). I remember seeing Kevin Shirley mixing about 2 feet from his speakers which were about 2 feet apart. Not so much "room sound" in such a set up.

Thanks very much for this informative very important post for me....

That help me to understand the way my controls devices work....And damn ! they work amazingly but i was not being able to understand why.... Your post is the first step for me to understand....The concept of the "spectral content" was lacking in my ignorant and rudimentary acoustical knowledge.... I created my acoustic controls by listenings experiments and intuition without being able to understand why my results at the end were so totally transformative, even if they are unorthodox to say the least....I will not go further here about that tough....

My best to you....

I think many of the mysteries discussed in this thread make it difficult to grasp the unifying issue.  Different rooms and different speakers, its extremely complex behavior.  ( I swear acoustics is a black art) Is it the speaker or the room?  Erik talks about how he doesn't hear much difference with absorption at first reflection zones.  Another poster says absorption at first reflection zones is HUGE, big difference.  How could they both be true?    

I am suspecting the common issue between these two ideas is the speaker dispersion: the wide dispersion having a stronger effect on first reflections, the narrower having less impact on reflection points.  It is quite possible we do not know what the mid and/or tweeter dispersion of our speakers really is.  If we don't know, we could attribute a lot of audible results to things that may be unrelated.  The specs we are given don't come close to revealing this super important info. 

Brad  

Erik talks about how he doesn't hear much difference with absorption at first reflection zones.

I have not actually said this.  I've taken like 2 dozen posts to explain this.