Does the first reflection point actually matter??

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.

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

Success on Audiogon means one thing:

When people follow you from thread to thread and post the first knee-jerk reaction they can think of.

Worship me, A’goners, for I have achieved the highest level of satus among Audiophiles, and my evolution among many many lifetimes can stop. I have become perfect among the dissatisfied ne’er do wells who frequent these halls and where I shine my light they must attend.

Dance upon my threads of enlightenment, sing for my enjoyment, and never cease looking to me for approval, you jerkers of the knee,  you mighty mighty spleen venters and I will acknowledge you in time.

Let me alter my thesis, because the original was so hard to transmit, even by those who really know their stuff. In fact let me reword it ENTIRELY.


"In a modest, average home listening environment, you can’t do much for the acoustics with just 4 panels, no matter how ideally placed they are."
There.

And that is what I was sold, long ago, as something useful. Get 4 panels, put them on the reflection points and imaging and detail will get better. I’ve done this. It does not. You can’t do anything with these 4 by themselves.

Part II:

" The overall decay rate of the energy in the room will probably so obscure the original and early reflected signals requiring a minimum critical mass of room treatment, or minimum sound field quality that must be achieved before those original 4 panels mean anything. Control the reverberation time first, and with 4 panels you are barely getting started."


Part III:

"Once the overall sound field is treated, the _exact_ placement of the original 4 panels. becomes moot. You can move around the room and everything sounds good, no matter where you are, and no matter if the current reflection points (which change based on your position) are covered or not.

Part IV:

"While the overall idea of our ears seeing / hearing mid-treble frequencies as light beams is attractive, it is my experience that even then we hear not photonically but statistically. Covering up that magic reflection point to 1 ideal seated location is a trivial if not imperceptible change. Treat early reflections statistically, not precisely. "
Of course, much here in part IV can probably be informed by Head Related Transfer Function research, which I have not looked into.

I'm clearly not saying not to treat the wall behind the speakers or to the sides, or the floor or ceiling.  I'm saying that the original messaging, that there are 4 magical places you must put panels on and that alone will provide noticeable improvement oversells the benefits.


Best,
E

Keep in mind that bass traps can go in more places than behind the speakers. Every corner, including wall to ceiling, and wall to floor can be a good place for them. The GIK soffit traps for instance are meant to be mounted along the soffits, or the line where the wall and ceiling meet.

Yes, overdamping is always possible, which you can prevent by carefully picking the products used as well as making sure to include diffusion.

One trick I often suggest listeners missing bass is to add mid-to-high frequency absorbing panels. They will act like an equalizer, and lower the overall mid-treble energy, and boom, like a ship emerging from the water at low tide, here is the basss!! It’s amazing how you can do this with small speakers.


Best,

Erik

ADMINISTRATIVE ALERTS

murphythecat has been ignored due to the use of word salads to belittle others. 

Please ignore it without fear of being impolite.

This concludes this alert of common sense and good manners.

There really is no issue in my mind to be fixed. 

It's more of a theoretical discussion. 

Maybe another way to word it is this:

You can't do much with room acoustics until you reach a critical mass. 4 2' x 4' panels in a modest living room are probably not going to do anything by themselves no matter how well placed.

Imo "best acoustic principles" in a small room includes correct PLACEMENT of acoustic treatments.

And that unless you are in a small home recording studio, where you can touch the left and right walls at the same time, the correct placement being off 6" here won’t matter.

You could easily circumnavigate the laser point and it would be much much better than merely putting panels on that point.

If I understand correctly, you are still looking at small rooms as if they were large ones, where 20% wall coverage has the same effect no matter where that 20% is located.

My gods we are being so literal.  I'm saying that if best acoustic principles call for 20% absorption on a wall surface near the speakers, whether those panels EXACTLY cover a reflection point which works for exactly one seated position is irrelevant.

You can be off that singular, zero size point by a couple of feet and it will still sound good.

Conversly, ONLY covering that zero area point with a 1'x1' panel will be negligible.

My reservations about using absorption on the entire surface,

Also not what I meant, sorry.  I meant treating the surface appropriately.  That rarely means covering the entire surface but considering the entire surface.

You have this 1" by 1" reflection point.  That is irrelevant. What matters is that portion of the wall, and the overall, average results.  For instance, covering 20% of the wall with absorption and 5% of it with diffusion, as needed. 

Maybe the only real problem is how I interpreted this information early on.  Maybe it was never meant to be a point thing but a starting place?

Let me try this another way. Imagine a highly reflective room with a pair of traditional 2 way speakers and 1 listening chair in a fixed location. The room is 20’x20’x15’ tall.

There are at least six (eight if we include the ceiling) first reflection points. Being points, they are infinitely small. The audio legend is that these specific points are more important, by far, than any other place in the room. In this room we may place 1’x1’ absorptive panels.

My argument is that the legend/myth is wrong. The first six reflection points are not going to be noticeably better than any other place to put an absorber or diffusor.

Lets go through a bit of a mental exercise. We’ll consider two sides to this.

First, the very sparse case in which we treat six points and only those. At six absorbers the room remains too lively to make much of a difference.

Let’s consider the opposite situation. We have 40 panels of the same 1’x1’ dimension. Now we can make enough of a difference in the reverberant field to affect the sound quality. We put 20 or uniformly spread across the wall behind the speaker, and 10 on each side on the speaker end.

Let’s say by chance, four of these panels (2 on the rear, and 1 on each side) are exactly on the first reflection points in terms of the listening chair. In this case, removing those four panels and randomly relocating them will make a very small, if any, noticeable difference.

And this illustrates my point. Treating the initial reflection points is actually not as important as treating the room. The audiophile using a mirror to place a panel exactly on that spot is wasting his/her time.  What is more important, by far, is getting a critical mass of room treatment so that the reverberant field becomes well controlled.

So if I understand correctly, you are saying that treating the relatively small area where a reflection occurs is "practically useless"

Yes, in that I believe most audiophiles would be unable to tell if those treatments were at the reflection points or not, and that in many cases 4 panels of 2'x2', no matter how well placed, would be unable to effect an audible improvement.

And, just so we’re on the same page as much as possible, can you describe what you mean by "treat"?

By this I mean to alter the surfaces by increasing the absorption and decreasing the ability of those surfaces to throw a coherent reflection by both absorption and diffusion.



Best,

Erik

Floors are a different thing, but we don't spot treat floors.  We treat the entire area in front of a speaker. I've never seen anyone put down a 2'x2' carpet exactly in the first reflection point, and this is kind of what i mean.

Audiophiles at some point were encouraged to use a flashlight and mirror to find first reflection points and center acoustic panels there. I call that particular practice bunk. 

We shouldn't spot treat surfaces.  We should treat the surface.  That is, putting 2'x2' panels in exactly the side, rear and even floor reflection points is practically useless. What does work is to treat the floor, side and rear.

Get a carpet to put in front of the speaker, treat the side walls and rear wall and wall behind the listener. Where the mirror points are won't matter.

Best,

E

Early lateral reflections contribute to spaciousness and expand the "apparent source width", according to Floyd Toole.

When "presence" is lacking the earliest reflections are the most responsible, according to David Griesinger.

Which I agree with, but is subtly, different than what I am arguing about. :)

I don't think the laser line matters so much as having the area in general treated.

Brad,

The one issue missing from this discussion is your impression of acoustic treatment at first reflection points completely depends on how wide a dispersion speaker you actually use.

For the purposes of this argument, alone, I want to argue that first reflection points don't matter, ever.

Again, I don't mean that room treatment doesn't matter.  I just argue that the idea that the first reflection points are some sort of magical acupressure point for speakers seems wishful thinking to me.

What does matter, a lot, is the overall acoustic field. An even decay rate and proper balance of diffusion and absorption.  But if you take a dozen panels placed around evenly in a room, I don't think you could tell that the 1st reflection points do anything more special than the rest.

And I am also _not_ making the argument that speaker to room acoustic matching doesn't matter, it does a great deal.

Best,

E

You don’t match acoustic treatments to the operating range of the speakers. You match them to the reverberation of the room.

Anyone who says "well, my speakers work from x to y Hz and therefore so should my panels" is selling you bs. See practically any reference on room acoustics.

Quote me.


Best,


E

The GIK 242s are rated from 250, and the 244s from 80. He specifically wanted to match the 35hz +/- 3db point of the Harbeth for smoother results

Um, that's not how this works, but OK then!

Hope it comes out well.

Best,

E

I love measurements. I spend my day job measuring things. I have 3 calibrated microphones right next to me, and yet, when it comes to the question of:

"How do you help the average audiophile?"

I have really come to be against measurements. I worry that those advocating for measurement software for acoustics and sub configuration (including me in the past) forget just how difficult calibrating a room is.

People think of this software like you are buying a spell checker. You just high light all the red words and check the spelling. They are nothing like that.

For this reason I’ve totally turned around. Now I advise others to find trusted acoustics consultants to help with the room, and good room correction to integrate a sub.

It may seem hypocritical, since I would never do either... but then, I have spent a lifetime learning about what I’m doing and would rather tweak it myself. If a new audiophile shows up and wants to get to done, I don’t recommend my path.

I don't want to ever discourage anyone from learning, I enjoy learning and applying tools, speakers and room acoustics a great deal, but how do I serve the audiophile asking for advice best?  That's the question I have wrestled with a great deal, and no longer answer like I used to.

Now, an audiophile who wants to learn how to make speakers, or is really interested in acoustics, of course to them I answer differently.

My point is, I don't think tools and software serve everyone the same way, and I think we should be more adaptive at least.


Best,

E

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.

@aj523

This is why I always recommend GIK acoustics. Very effective products at reasonable prices. I don’t know of any of them that weigh 150 lbs either. :)

As an alternative, consider the GIK panels with soffit traps, which are cheaper, lighter weight, and also go down to low frequencies. They also do free room consultation.

Truthfully, you may NOT need any bass treatment, so panels that go down to 40 Hz may be serious overkill. Tame the mid/treble range, and this may re-balance your room well enough. If that doesn't make your speakers sound larger and more powerful, then pull out the bass traps (GIK soffit). 

Also, might want to try using excess toe-in. Have the tweeter line cross in front of your head. This may sufficiently improve reflections off the sides. Of course, heavy curtains would also help.



Best,

E

Wow, @lemonhaze you misread my original post and misread my "preaching to the choir" post and now are all mad about both. 

Let's just agree to disagree and move on.

Sorry @lemonhaze but I am not responsible for whatever tangent you misread into my post or my follow ups.

Erik

The software, apart from showing you waterfall plots which identify the most troublesome frequencies, will also help you position your speakers and subs.

You are preaching to the choir.  What I wonder about is how to be helpful with the least amount of trouble for an audiophile, or better yet, a music-phile, who just wants to get excellent results.

I wonder how many really want to learn what the software does, measure and adjust, and also, without a lot of reading and research, come to the right answers. Having the tools doesn't mean you have the skills.

And I don't want to discourage anyone from learning.  What my narrow question here is, for an audiophile who is new to the idea of room acoustics, and wants excellent results, am I doing them a service by suggesting they get a mic and REW or OmniMic, or am I better off suggesting they get a consultant like GIK to help them?

Seems like the only alternative to avoid all this is to buy acoustic measurement software like from Dayton audio and figure out your room. Then treat it accordingly.

Sigh, I don't know.  I mean, honestly, I know speakers more than acoustics, and I think that for the average audiophile, this is a steep learning curve.  I mean, if you want to learn about acoustics, then YES, get yourself a mic and some software young lady/young man and go west with the wagon train...

Fun stuff.

But when I think of how to be helpful, what can I say which helps audiophiles enjoy their systems longer, better, asking the pros for help is a better way to go, along with some experimentation here and there.

Sorry, Toole, not tool.

Typing too fast. My apologies to the good gentleman.

I was only talking in relative terms, on a scale.

Anechoic room  <================> Drywall and concrete

If tool is in the middle I'm a little to the left of him.  The rest, the importance of reflections is important, too many overuse absorption and don't use enough diffusion.

That is all.

Erik

I’m sorry @mahgister but I feel that you misread my points in too many ways to count, so I'm going to let that drop there.  It's too hard to answer all that.



Best,

E

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

@tuberollin


You are clearly wrong .... :)  I'm joking, making fun of so many people here who can't see past their agenda.  Your experiment seems to be exactly the kind of thing I'm asking.

Seriously though, what speakers are you using?? and exactly how do you feel the difference is?? 

@aj523

To my experience, as others here have noted, diffusion at the 1st reflection points are a better idea.  They enhance imaging.

Best,

E

Now your post makes me question which panels are the most critical.

And that’s all I’m trying to do. Imagine you place 8 vertical panels around the room, with 4 of them at reflection points. If you then rotate them all, say 15 degrees from the listener's line of site, so they are no longer exactly on the mirror line, does it do anything all that critical? I do not think so.

The most important part is getting to critical mass in absorption, and adding diffusion in the right areas. The laser-line, first reflection points, in my mind, have never born fruit.

This brings up a great topic, diffusion is better for imaging than absorption. :) 

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

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

Hey @mapman

I'm curiuos if you have attempted to move those absorbers just off the mirror point?  Leave them nearby, just not exactly where they were.

Is the difference stark??

@kenjit,

1 - The proper way to discuss this is not to hijack a poster’s threads with questions and false innuendo that are not relevant to the discussion.

2 - I don’t owe you a discussion.

Best,


Erik

@kenjit

You make 4 suppositions which are not in evidence, so as usual I am ignoring you. 

E

Put this another way, if your room is well treated, and speakers well placed, then you can move off axis and you won’t hear a dramatic shift in clarity when those panels are no longer in a mirror’s line of sight of the speaker.

If that statement is true (and for me it has been) then the 1st reflection points are myths.

By your question you seem to assume that 1st reflection points are correctly treated by using panels etc.

Oh, no, I'm questioning the ENTIRE canon which believes 1st reflection points even matter. In my experience, these points are not actually more important than other nearby points.   That is, treating the room well matters, and treating the 1st point does not.