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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
optimize
164 posts
 
We can clearly say it is more than "some".
More exactly half of all reflections is good and the other half is harmful for stereo image.

Experiment: 
Put a wall of panels from your face in sweet spot that extends right in the middle to your front wall between the speakers.

The sound stage is incredibly and will never be better than this.. ..yes it looks stupid and is impractical but just as a experiment.

In short we have one room for left and another for right and the reflections from each speaker is there BUT they are totally separated.

That shows us how "harmful" to the sound stage perception, the first reflection point from the right speaker in the left wall that reach the left ear.. that were intended for the other ear.. and vice versa.

So half of all reflections (when we can see the experiment as we have two separate rooms left and right) is not good or is just destroying the sound quality. And if you have done the experiment then you will most likely agree.
aj523
385 posts
 
I just had my free phone consultation with Mr. Foley and after reviewing my room through photos (see link), he recommended the following:

1. No diffusion anywhere to begin with. That will worsen the problem he perceives given all the windows.

2. Treat the walls closest to the speakers first so that’s the front wall behind the speakers first and the side walls with as much absorption as possible.

3. No need to buy software to measure the room since the problems are obvious and better spent on product.

4. The treatment of corners with bass traps etc is a common fallacy and not a priority.

5. Tame from "40 cycles - 7000 cycles" as he calls it with eight (8) carbon panel CPs at $750 per panel. And since each panel weighs 150lbs, its about $1,000 for shipping. So all in $7,000.

6. He did some calculation where he said I would see 65 percent improvement. I pressed him on what that is measured against but forgot his reply.

7. Then we can talk about diffusion after a period of time of listening to the results.

THOUGHTS?

https://photos.app.goo.gl/BFAQLGEo4UmknMZm6
audiokinesis
2,798 posts
 
Aj523 wrote: 

" 5. Tame from "40 cycles - 7000 cycles" as he calls it with eight (8) carbon panel CPs at $750 per panel. And since each panel weighs 150lbs, its about $1,000 for shipping. So all in $7,000." 

I agree with the frequency region he focuses on.

We see that serious acoustic treatment is expensive. That seven thousand dollar figure is an argument for taking loudspeaker/room interaction into account from the beginning, as imo there are more cost-effective solutions.

Duke

mahgister's avatar
mahgister
15,048 posts
 
A dedicated audio room is way much cheaper to treat and controls....Mine with 2 windows relatively small with irregular geometry, cost peanuts and the results are astounding, superior to many upgrading of my gear...

But a living room, being a common room ask for more esthetical solutions, then costly indeed....

My own room look like the seat of an arachneid that will use his many "fingers" to connect all with his silk cables.... :)

i could not do that without divorcing in a common room....

And like usual people never speak about active room controls of acoustics, only about passive materials treatment.... I begin to think that i had invented the concept..... It seems nobody has ever hear about it all...But active controls cannot be done in a common room anyway...
aj523
385 posts
 
@audiokinesis

Thanks Duke. Your feedback is ALWAYS appreciated. As you know I seriously took the room into consideration when make the speaker decision, turning down several planars /dipoles that i was really interested in. The Harbeths, 3 feet out from the front wall and almost 7 feet from the side walls, with their large front baffle seemed to be the best choice and quite frankly they sound absolutely amazing, BUT Foley tells me the Harbeth midrange and the speaker overall will sound like a different speaker altogether to the extreme.

Soooo... now I’m deciding on putting 1200 lbs of treatment in our main living room but save multiple x $$$$ on the cost of a wedding next June since my fiancee will surely leave me. Not an easy one indeed. 🤔
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