Does the first reflection point actually matter??

Reflections within listening rooms are real and numerous. Some would argue that they all are problems to be eliminated. Others take a more philosophical view that they just provide information about the room, and the brain can figure it out. I’m somewhere in the middle, but leaning towards the latter. The science that has been done so far seems to be on my side.

article: Room Reflections & Human Adaptation for Small Room Acoustics by Floyd Toole

Dr. Floyd Toole says that in 2019 article has impressive business and academic credentials, having held the postion of Corporate Vice President – Acoustical Engineering at Harman International from 1991 until he retired in 2007 and Senior Research Officer in the Acoustics and Signal Processing Group at the National Research Council of Canada.

He knows perhaps what he is speaking about...

My own experiments with my room acoustic, using reflections instead of killing them, make me think that he is right....I just stumble on this article few days ago, searching for a confirmation of my experiments that contradict many advices given on most audio thread....

It is not new, on many thread people advise to upgrade gear even without having ever embed it rightfully before... 


:)

I have diffusers at first reflection points on side walls and ceilings. Definitely helps !!!

I like Toole, but let's be clear that this is his personal opinion about what he likes.  For some of us, the acoustics of live spaces can take a toll on our brain power. As others have written, filtering out a room all the time can be exhausting, including academic settings.

I personally want my room a little less present.  I like my stereo to be the acoustic equivalent of looking across a mountain range.  That feeling of relaxation you get when suddenly you feel like you can see forever, but with my ears.

How much you are taxed by the space, how much you are willing to filter out is very individualized.  I think it's funny to do the recording experiment, where you tape yourself speaking in a room, and then play it back.  In the recording you become aware of the room acoustics, and then realize that you can hear them, you've just been filtering them out.  Fun stuff.


Best,

Erik

"It pays to keep an open mind, but not so open your brains fall out." - Carl Sagan.

One can also apply that concept to tuning ones' listening area.  It's possible to correct Everything....but you couldn't live in it.

But your significant other will demand that you do...Now.

Erics' 'mountain range concept' has appeal; the space 'gets out of the way' of the audible 'view'.  I like that...+1, at least... ;)

Hi Erik, there is a lot of well meaning advice being offered but most of it ill informed. This whole thing is a science with specific goals. Some posters claim that they adjust the toe-in of their speakers and everything sounds fine. Useless info this.

Correct treatment is truly transformative and if you are not prepared, for less than the cost of a mid-priced interconnect, to buy a suitable microphone and download for free, REW or HolmImpulse (as used by Geddes) then add bass traps and treat first reflection points. Just this will amaze you.

Unless you have your system set up on the long wall where sidewall reflections arrive much later you will need to absorb some of that energy to reduce smearing and congestion. The average room requires about 400ms for the sound to decay evenly across the frequency range by 60dB, known as T60. Tables are available online for different enclosed volumes.

Someone mentioned floor and ceiling reflections which of course is as important as the others. Here though a ceiling 'cloud' works extremely well and a small rug or no rug is fine. The cloud frame needs to be preferably 4" x 6ft x 8ft and hung with a 4" gap below the ceiling. This will act as a broad-band absorber, unlike wall to wall carpet which is narrow-band and harmful to the sound. Consider that your ears are a known, to your brain, fixed distance from the floor so these reflections are not as problematic. We have evolved to allow for this.

Diffusion is good in larger rooms, not so much in small ones. From experience I can confidently state that treating the modal region below the Schroeder frequency is the most effective if you wish to limit the amount of treatment. I'm talking about bass traps, real bass traps and not the silly little scraps of foam that cannot absorb anywhere near bass. They are physically just too small.

GIK do not make 'proper' broad-band absorbers because they will not sell well and would be a nightmare to ship, so they tend to oversell lesser units. I know somebody who returned a few because the room was too dead!

My best advice is to educate yourself as much as possible on this fascinating and immensely rewarding process by reading articles from the right source. Leo Beranek is tough going but the true authority, Foley from acoustic fields not so much.