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Does the first reflection point actually matter??

Hello my friends,

So please read the whole post before commenting. The question is nuanced.

First, as you probably know I’m a huge fan of the well treated room, and a fan boy of GIK acoustics as a result, so what I am _not_ arguing is against proper room treatment. I remember many years ago, perhaps in Audio magazine (dating myself?) the concept of treating the first reflection points came up, and it seems really logical, and quickly adopted. Mirrors, flashlights and lasers and paying the neighbor’s kid (because we don’t have real friends) to come and hold them while marking the wall became common.

However!! In my experience, I have not actually been able to tell the difference between panels on and off that first reflection point. Of course, I can hear the difference between panels and not, but after all these years, I want to ask if any of you personally know that the first reflection point really matters more than other similar locations. Were we scammed? By knowing I mean, did you experiment? Did you find it the night and day difference that was uttered, or was it a subtle thing, and if those panels were moved 6" off, would you hear it?


Best,


Erik
erik_squires
erik_squires OP
16,879 posts
 
Hi @photon,

Well, I didn’t have just one system in one room. I’ve had several systems across multiple apartments.

Never a dedicated, music only room. I’ve had Monitor Audio, Focal, and now my own custom speakers. In placing the GIK Acoustic panels I never had a big "Oh wow" moment with 1st reflection points.

What mattered more, MUCH more, was having enough room treatment.

Best,

E
mapman's avatar
mapman
22,929 posts
 
No need to do that with the Omni Ohms. I can just listen from other spots nearby where the pads are not at first reflection and compare again. Will do that when I get a chance and report back.
erik_squires OP
16,879 posts
 
Thanks @mapman!!

So the other area which to me is more important is the floor between and behind the speakers.   It seems that treble harshness always lives there.

Definitely not first reflection points.

Best,

Erik
Post removed 
brownsfan
1,508 posts
 
@erik_squires, It has been my experience that treating the first reflection points from the sidewalls in a narrow (14') room makes an enormous difference in imaging.   But I didn't get this using "normal" absorbing panels such as GIK monster traps.  What actually worked really well was a pair of 5' tall CD racks, positioned so that the front edge of the rack is angled out from the wall.  The front edge of the rack is positioned slightly to the rear of the first reflection point.  Apparently, the front edge of the racks are reflecting the higher frequencies from the tweeter and midrange back towards the front of the room.  Thus, reflected frequencies higher than 1500 Hz are blocked from a direct path to the listening position.  They are either directed behind the rack or directed back to the front of the room, thus delaying their arrival at the listening position enough that they do not compromise imaging.  

When the CD racks are removed from the room and I attempt to treat that same sidewall area with GIK products, the image collapses.  If I move the speakers enough to change the sidewall first reflection point, the image collapses unless the CD racks are removed a similar amount.  I've also noticed that depth and width of image is somewhat eroded by using GIK 242 or 244 type panels on the side walls forward of the CD racks.    

Note that this is not another ill advised attempt to use a partially filled CD rack as some sort of diffusor. 

My son did something similar in his room using bookcases, and he reported a huge improvement in imaging. 

Folks who have wider rooms will probably benefit less than those of use who listen in narrow rooms. 
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