Cathedral vs flat ceiling

[Ethan Winer]

Originally Posted by FirstLoveStudio

Sure the fact that wood resonates more than concrete makes a measurable difference? If you're recording a band playing on a wooden floor, you can feel a whole lot of energy under your feet, on a concrete floor there is very little.

Yes, but if you read earlier in this thread you'll see that the wood would be on top of solid concrete and not free to vibrate as if on joists. So all that's being discussed is pure surface reflectivity.

--Ethan

[Ethan Winer]

Originally Posted by andrebrito

I did answer your questions, this was tested in an impedance tube, no other information is given on the book.

Ah yes, I remember now. Sorry. But still, I cannot accept that a solid slab of wood absorbs 80 to 90 percent around 1 KHz. There must be more going on than pure surface reflectivity. Those numbers are way off from all the lab data I've seen. For example, the data I used in my Reflectivity article shows 6% absorption at 1 KHz for a parquet floor.

--Ethan

[andrebrito]

Yes for 0º incidence.. change the degree of incidence and absorption changes... the figure is perfectly clear

[Trev@Circle]

Originally Posted by Ethan Winer

Y So all that's being discussed is pure surface reflectivity.

--Ethan

That is your assumption which it seems others don't agree with. Perhaps if you are going to post bald statements like thatit may be fairer to the discussion if you prefixed it with "my assumption is...".

From what I've read the problem with that assumption is that it doesn't take account of at least 3 factors (though perhaps more):

1. the sound that is not reflected (does the absorbed energy resonate differently within the wood/concrete and does that affect the 'sound' of the room?)

It also assumes that the energy that is reflected does so in an identical way (and thereore not at (2) a different angle or (3) a different speed vis-a-vis the surfaces).

My assumption therefore is that in real life if any of these factors change due to the material that must affect the sound of the room as the reflections will then interact differently and reach your ears/the microphone at different times.

[Ethan Winer]

Originally Posted by andrebrito

Yes for 0º incidence.. change the degree of incidence and absorption changes... the figure is perfectly clear

Andre, I just know you're not saying that a thick slab of wood bonded to concrete absorbs 80 to 90 percent at 1 KHz when sound arrives at a 90 degree angle. So what exactly are you saying?

Two more points need to be made about the graph you posted, but I'll make only one and leave the second to you (and others) to puzzle over.

You say this data was measured in an impedance tube, but all the impedance tubes I've seen are long cement "chimneys" two feet by two feet and 20 feet long or even longer. The longer the tube, the lower the frequency that can be measured accurately. When material is tested in an impedance tube it is placed at one end, and sound is sent from the other end far away. Clue #1: Therefore, measuring different angles means the sample itself must have been rotated.

Clue #2: Now here's the challenge to anyone who like to consider themselves knowledgeable about acoustics: Look at the graph again, especially the big dip in absorption around 3 KHz. What does that tell you about the wood sample that was measured?

--Ethan

[Glenn Kuras]

Ethan if you and I are ever pulled over for speeding, YOU ARE DOING THE talking. lol lol

[mplancke]

Originally Posted by Ethan Winer

There's no difference in sound between concrete and wood, or at least not enough to worry about. Both reflect sound.

--Ethan

Sorry Ethan,

I call bullshit. Especially egregious coming from an acoustic treatment guy.

Yes, they both reflect sound; differently.

Been there, done that, many times over the years.

You can throw "data" around until the cows come home, but it's not gonna change what I've experienced and heard in the four rooms I've built over the years. Each material used in a room will impact the overall sound of the room. Flooring because of it's overall mass will do so substantially.

When I've gone with hardwood flooring in my room, I have never regretted how it looked or how it sounded.

Mark
Sharktank Productions

[Trev@Circle]

Just so I am clear Ethan, are you saying you disagree with my assumption or any of the 3 factors it contains and if so, which one do you disagree with and on what basis?

Originally Posted by rimskidog

That is your assumption which it seems others don't agree with. Perhaps if you are going to post bald statements like thatit may be fairer to the discussion if you prefixed it with "my assumption is...".

From what I've read the problem with that assumption is that it doesn't take account of at least 3 factors (though perhaps more):

1. the sound that is not reflected (does the absorbed energy resonate differently within the wood/concrete and does that affect the 'sound' of the room?)

It also assumes that the energy that is reflected does so in an identical way (and thereore not at (2) a different angle or (3) a different speed vis-a-vis the surfaces).

My assumption therefore is that in real life if any of these factors change due to the material that must affect the sound of the room as the reflections will then interact differently and reach your ears/the microphone at different times.

[Ethan Winer]

Originally Posted by mplancke

You can throw "data" around until the cows come home, but it's not gonna change what I've experienced and heard

That's exactly what the guys who buy $1,000 AC power cords say.

Yeah, we don't need no steenkin' science. Power amp specs? Who needs 'em? I know what I hear and that's all that matters.

--Ethan

[Ethan Winer]

Originally Posted by rimskidog

That [pure surface reflectivity] is your assumption which it seems others don't agree with.

There's nothing to agree or disagree with! The context of the original question in Post #4 that I answered was wood over a solid concrete slab. That's all I addressed. I appreciate that everyone doesn't want to be bothered to actually read this thread from the beginning, but it's pointless to challenge me on something I never actually said.

1. the sound that is not reflected (does the absorbed energy resonate differently within the wood/concrete and does that affect the 'sound' of the room?)

Not sure what you're asking but all materials absorb, reflect, and pass through, in some proportion. In the case of wood bonded to a solid cement base, passing through is removed from the equation at all but very low frequencies.

It also assumes that the energy that is reflected does so in an identical way (and thereore not at (2) a different angle or (3) a different speed vis-a-vis the surfaces).

The lab data for absorption which I used to calculate reflectivity is an average of all angles. The technical term is random incidence in the ASTM C423 docs that define the absorption tests.

--Ethan

[Ethan Winer]

Originally Posted by Glenn Kuras

Ethan if you and I are ever pulled over for speeding, YOU ARE DOING THE talking. lol lol

You got it pal. Maybe I should start a correspondence course to teach fast talking skills.

[Trev@Circle]

Originally Posted by Ethan Winer

There's nothing to agree or disagree with! The context of the original question in Post #4 that I answered was wood over a solid concrete slab. That's all I addressed. I appreciate that everyone doesn't want to be bothered to actually read this thread from the beginning, but it's pointless to challenge me on something I never actually said.--Ethan

Oh I've been following it avidly. Unfortunately I'm no acoustician but I can read and have been known to enjoy a bit of a debate and it's not entirely right tp say that the whole discussion has been about reflectivty because you've rubbished a number of people's points that talk about the effect of the difference on sound.

While much of the time you take the narrow approach (particularly when you are talking about testing) of reflectivity, in a number of places you are clearly talking about a comparison of the affect of the sound in a room rather than pure reflectivity. In post 51 you say:

The use of wood versus cement in a typical basement studio comes up almost daily in the forums

and in post 54:

"I have a basement / garage studio and I'm thinking of covering the cement floor with wood because someone told me it will sound much better and warmer."

The above is typical, and is by far the most common application of this question that I see in forums.

Surely you are not suggesting that the posters are asking about pure reflectivity of material? It must be pretty obvious that they are asking how the different materials will affect the sound of their room. While your narrow answer to them may arguably be right in terms of pure reflectivity the very fact that you are resiling from that in this argument (by saying you are only talking about reflectivity rather than the effect on the sound in a room) implies you accept that you there is more to consider in respect of the affect on a room. Similarly, if you read the posts of most other members they are talking about the affect a wooden surface has on the sound of the room (because that's what the real world discussion is about). Perhaps this entire debate has simply been a miscommunication because you were talking about pure reflectivity (even though that was not clear a t all times) while others were talking about real world 'affect'? Other posts in which you refer to the sound rather than the reflectiity include 33, 35, 42, 51 and 77.

Not sure what you're asking but all materials absorb, reflect, and pass through, in some proportion. In the case of wood bonded to a solid cement base, passing through is removed from the equation at all but very low frequencies.

What I'm asking is do you accept that the factors I refer to could have an effect on the sound of the room? The point being that they may not absorb, reflect and pass through equally in the different materials which takes us back to the other points I refer to. Unless we can also measure the impact those factors have on 'sound' or tonality (whether by resonance or otherwise) the argument simply doesn't stack up.

Almost as an aside I also find it quite confusing that you continually refer to dong things scientifically. Good science, as I understand it, is about taking all of the factors into account which might impact on the result not narrowing the parameters of the test so potential factors which might impact on real world outcomes are ignored.

[Ethan Winer]

Originally Posted by rimskidog

Surely you are not suggesting that the posters are asking about pure reflectivity of material?

Yes, that is the entire issue. At least when talking about bare cement versus wood laid on top of bare cement. Which is all I've ever addressed, and which was the OP's question.

saying you are only talking about reflectivity rather than the effect on the sound in a room

For wood on cement, what else do you think there is beside surface reflectivity?

--Ethan

[Trev@Circle]

Originally Posted by Ethan Winer

Yes, that is the entire issue. At least when talking about bare cement versus wood laid on top of bare cement. Which is all I've ever addressed, and which was the OP's question.

I think you and I know that isn't the question the quotes you gave earlier [for the avoidance of doubt: "I have a basement / garage studio and I'm thinking of covering the cement floor with wood because someone told me it will sound much better and warmer." ] were asking. If that is what you are answering then, at best, there's a fairly fundamental disconnect there.

Originally Posted by Ethan Winer

For wood on cement, what else do you think there is beside surface reflectivity?
--Ethan

I refer you to my earlier post:

Originally Posted by rimskidog

From what I've read the problem with [your reflectivity is the be all and end all] assumption is that it doesn't take account of at least 3 factors (though perhaps more):

1. the sound that is not reflected (does the absorbed energy resonate differently within the wood/concrete and does that affect the 'sound' of the room?)

It also assumes that the energy that is reflected does so in an identical way (and thereore not at (2) a different angle or (3) a different speed vis-a-vis the surfaces).

My assumption therefore is that in real life if any of these factors change due to the material that must affect the sound of the room as the reflections will then interact differently and reach your ears/the microphone at different times.

[johndykstra]

Originally Posted by Ethan Winer

In the case of wood bonded to a solid cement base, passing through is removed from the equation at all but very low frequencies.

It's been brought up multiple times that this is never done. There is always another layer.

Even for a floor as simple as cheap laminate, you need a minimum of a foam vapor barrier.

[mplancke]

You said...

There's no difference in sound between concrete and wood, or at least not enough to worry about.

--Ethan

Reminds me of a university student who just graduated; with all of their school experience to guide them.

That's exactly what the guys who buy $1,000 AC power cords say.

Yeah, we don't need no steenkin' science. Power amp specs? Who needs 'em? I know what I hear and that's all that matters.

--Ethan

Thankfully all my power cords came with the gear, total cost less than $1 per unit.

We don't need no steenkin' ears, we've got science!

Mark

[gn87berner]

E Why not address the issue presented of different woods sound different in guitar making? I was waiting for your response, but right after the post, you choose to regurgitate the same reterct. Even woods "sound" different. A lot of variables will change the absorption and reflection of given wood floor. How thick, surface finish, how porous the surface, what type of wood, laminate or real hardwood ect. Show some strength and admit your errors. When one knows everything nothing else can fit. I used to really heed advice you have given others. I have lost respect for what you say.

[andrebrito]

They only say those measurements where done in an impedance tube... these has been published somewhere I'm sure.

[FirstLoveStudio]

Originally Posted by Ethan Winer

Yes, that is the entire issue. At least when talking about bare cement versus wood laid on top of bare cement. Which is all I've ever addressed, and which was the OP's question.



For wood on cement, what else do you think there is beside surface reflectivity?

--Ethan

So wood attached to concrete has no resonance? It has no impact on the reflections at all?

How about wooden panelling/cladding in top of a stud walling? No impact at all? Laying a wooden floor on top of my concrete floor is going to have no impact on the sound of my room at all? So i can do a take 1 with a full band on concrete, then lay down a solid wood floor on top, and all other things being equal I won't be able to hear any difference on take 2? Wow.

That is odd becuase I can hear the difference between my guitar amp flat on the concrete compared to my amp on a solid wooden table top (without legs), flat on the floor. Maybe I should test whether the difference is real

[Ethan Winer]

Originally Posted by rimskidog

I refer you to my earlier post:

I saw that the first time but it says nothing useful. Again I ask, what more do you think there is besides surface reflectivity in the context of wood on concrete? Please be very specific. If you can't answer that, perhaps you should change your opinion.

--Ethan

[Ethan Winer]

Originally Posted by dykstraster@gmai

Even for a floor as simple as cheap laminate, you need a minimum of a foam vapor barrier.

Then let's see some data showing how much more wood absorbs versus frequency when a thin layer of foam is glued underneath. Don't just theorize - prove your case!

--Ethan

[Ethan Winer]

Originally Posted by gn87berner

I have lost respect for what you say.

Nice first post. Welcome to the forum.

Why not address the issue presented of different woods sound different in guitar making?

I really wish you nay-sayers would read what I write. This is from my article Surface Reflectivity:

I've seen people argue that wood adds a pleasing quality to a room in the same way wood affects the tone of a fine violin. But that's a false analogy because the thin, resonant wood in a violin is meant to vibrate and add pleasing overtones. Versus wood on a floor or wall that is much thicker, and is anchored solidly to the wall or floor backing. Indeed, resonances in a musical instrument are desirable and necessary, but good listening rooms must aim to avoid all resonances as much as possible.

[Trev@Circle]

Originally Posted by Ethan Winer

I saw that the first time but it says nothing useful. Again I ask, what more do you think there is besides surface reflectivity in the context of wood on concrete? Please be very specific. If you can't answer that, perhaps you should change your opinion.

--Ethan

Sorry Ethan but that's unbelievably arrogant (even in the context we've seen above). I've been very clear and not said or done anything to obfuscate or miscommunicate. I'm going to incredible lengths to be clear in all of my communications. Can you say the same (for the avoidance of doubt this is a rhetorical question)?

I've been very clear that I'm not an acoustician. I put the question, as actually has a fairly renowned acoustician whom you've referred a number of people to (including me) in the past (for the avoidance of doubt Max Hodges) of what you say happens to the sound that is not immediately reflected?" Your implication that there is no (or even negligible if I'm being generous to you) difference between the sound of concrete alone and wood on concrete could only make any sense if there is only the thinnest veneer of wood on the concrete. Simple physics are against you. What if the wood is an inch thick, or two, or even six? Are you saying there can be no resonance? Something happens to that energy that is not immediately reflected back. Your thesis takes no account of that.

It also takes no account of whether the manner in which the sound is reflected by the different media makes a difference, perhaps by changing the angle or velocity of the reflections and the way they react in the room.

Now don't get me wrong. I am not saying that you are wrong in the outcome. You may (contrary to the ears of pretty much everyone else who has joined the thread) be entirely right. I'm saying that your methodology may not take all of the factors into account and your refusal to accept this, in your terminology, is unscientific. Your refusal to accept that there may be other factors at play is your downfall and that's why, being blunt, you are losing respect from people around here (and for the avoidance of doubt this is not my first post and I did hold you in fairly high esteem for the good advice I've often seen you give, for free, in the past).

[Trev@Circle]

Originally Posted by Ethan Winer

Don't just theorize - prove your case!
--Ethan

Er, that's a bit rich. Why don't you prove to us that other factors shouldn't be taken into account instead of dogmatically repeating your position. It's you that is stating your thesis as objective fact.

[Ethan Winer]

Originally Posted by rimskidog

Sorry Ethan but that's unbelievably arrogant

WTF? I'm sticking to facts and using hard data, and you're tossing insults? Again, WTF? If you want to discuss the science that's fine. But cut the crap, okay?

I've been very clear that I'm not an acoustician.

I can tell.

Your implication that there is no (or even negligible if I'm being generous to you) difference between the sound of concrete alone and wood on concrete

And your evidence with hard data to the contrary is?

What if the wood is an inch thick, or two, or even six? Are you saying there can be no resonance?

This is where it becomes clear you are not an acoustician. I say that not to insult you. It was your own words.

Something happens to that energy that is not immediately reflected back.

Oh? And what would that be? Again, please be very specific. If you have any numbers or graphs, that can only help.

I am not saying that you are wrong in the outcome.

Then why are you arguing so vehemently?

More to the point, where is your data? I'm the only one here who has posted anything "concrete," excluding Andre's graph that is not useful because details of the material are not known.

Why don't you prove to us that other factors shouldn't be taken into account instead of dogmatically repeating your position. It's you that is stating your thesis as objective fact.

I find this unbelievable! I am the only person here showing hard data, while you toss silly theories about how wood that's six inches thick does "Something happens to that energy that is not immediately reflected back." What is that "something?" What exactly are you arguing, and why?

Dood, if you believe that wood on concrete sounds substantially different from concrete alone,why don't you prove your case with hard evidence? This is not the first time I suggested that to you.

--Ethan

[Ethan Winer]

Originally Posted by rimskidog

What if the wood is an inch thick, or two, or even six? Are you saying there can be no resonance?

Here's another point I'm sure I made earlier, but obviously needs to be repeated:

In a studio live room or control room the goal is to avoid room resonance. Always. So by that logic the surface that resonates less will also be the surface that measures better and also sounds better.

Okay, can we now put this to rest? Dan, you were right after all!

--Ethan

[Trev@Circle]

Unbelievable. You clearly haven't actually taken in a word. Blind arrogance or blind ignorance? I'm not sure but I do hope this thread is locked and your approach to polite questioning of your methodology is left here for all eternity for the world to see.

[johndykstra]

Originally Posted by Ethan Winer

Here's another point I'm sure I made earlier, but obviously needs to be repeated:

In a studio live room or control room the goal is to avoid room resonance. Always. So by that logic the surface that resonates less will also be the surface that measures better and also sounds better.

Okay, can we now put this to rest? Dan, you were right after all!

--Ethan

Ok, that makes sense. However, the discussion is not whether or not a wood floor sounds better but different.

[gn87berner]

2nd post.Thanks for the welcome. If you know it all nothing else can fit and you act like you know it all. How can you make such a blanket statement, then pick and choose which parts to respond to? A true scientist would know even changing the type of wood, especially the surface of the wood changes the equation. All wood reflect the same? Laminate reflects the same as a real hardwood? I guess you know it all. Now pick and choose what you want to respond to. How about laminate reflecting the same as a softer wood. Take your piece of OSB plywood and do your test on the shiny smooth side then on the rough side. You see, there HAS to be a difference because you have changed the equation. IT CAN"T BE THE SAME. I'm not the only one finding you irrational and arrogant. I skip over your posts now. Probably doesn't mean much to you, I'm probably not the only newb that just stumbled on this thread. I'll be quiet now.

[djgizmo]

Forgive me, as I know I'm going to get beaten for bringing this topic back up. I'm not trying to prove any one right or wrong, I just want to have some solid facts as I want to be able to tell my wife and children one day I built my home studio with a design purpose.

I took the time to re-read the entire thing 3x over to make sure I wasn't missing much.

• I see there was a lot of name calling back and forth. I'm a nobody special here and even I know that it's one thing to disagree with someone, its another to start calling someone names.
• The wife and I are buying a house and I've have the go ahead to floor my studio room anyway I choose (within budget reason). I'm willing to rip up the carpet in area (should be a 19'x11'x9' area) and stain the concrete. Once stained, I'm willing to run whatever tests that have been determined valid on the stained concrete room. Once finished, I'll start the process of laying down some kind of wood laminate flooring (which WILL include foam vapor barrier) and I'll run the exact test again. I'll post video/pictures of the entire process. I'll get myself a Nady CM100 and whatever test software that would be needed. My room would be treated with broadband absorbers to help eliminate room defect issues.
• One thing I've read about, and I'm not sure it applies. Doesn't refraction play a role in acoustics at this level? Like others has pointed out, concrete/cement is usually physically colder than wood. This usually causes the air just right above the concrete to be colder, therefore slightly denser. Sound has the tendency to want to stay near denser medium. Wouldn't that affect the speed / bend of the sound which in turn would give it a different RT60. If that is true, then just measuring absorption coefficient response would not be enough as it doesn't measure the speed of the sound.
• I guess since most wood flooring isn't rigidly mounted, wouldn't that cause an issue with difference of sound vs cement. Maybe causing a resonance somewhere?

Thanks for being patient with me.