Cathedral vs flat ceiling

[max the mac]

Trev,

re-arrange the following.

Worms,



Can,




Of,.







put down the shovel, step away from the hole , is an appropriate phrase...


but.... as my last comment


Voids i mentioned...

I was talking about concrete surfaces.

For example, a High air content mix, as it sets, results in loads of tiny bubbles in the top surface, many of which will be partially open to the exterior , and possibly linked to others a little further inside the material, of a variety of depths....

the result is a floor surface that's , in essence, actually more like an Aero, or Whisper bar with it's top shaved off.

which displays a more complex mix of small scale absorption and smaller still VHF diffusive properties, than a material such as a high strength , low air, self levelling top screed mix, that's been polished.... and demonstrably sounds different....
or wood.


so to compound the disagreement here still further....

Concrete is not Just Concrete.

or rather, Not all concrete is created equal




as to the resonance component.


as well as the material itself, how a floor is built will determine how it behaves as a resonant structure... and this resonant behaviour has bearing on the actual absorption, reflection and transmission that happens as a result....

(Think about the differences between assorted wooden bodied instruments for 30 seconds, and then scale it up to room size)

and therefore also, the contribution back in to the room . and therefore the sound of the room.


so one COULD say that most of the tabled data available is arguably irrelevant, other than as a general indicator of inherent difference.... as very few of them specify with any great detail, exactly how the floor was built, and what portion of the behaviour might be ascribed to structural resonance patterns as opposed to purely material based behaviors...




anyhoooo.


the bottom line is that different materials DO sound different...


whether on floor , or wall, or ceiling.

or guitar.









,

[max the mac]

in the majority of cases..... on balance, i'd rather not have a flat ceiling if at all practicable....


but sometimes it's the only option....

[Trev@Circle]

Okay. This is making a little more sense to me now. I just couldn't see how only one factor could be relevant. I'm sure I'm very far from being all the way there but I'm a little further down the road.

That's what I love about this forum. Realworld industry experts with years of experience are willing to help ignorant oiks like me get a grip on complicated stuff. Thanks for your help!!

Originally Posted by max the mac

Trev,

re-arrange the following.

Worms,



Can,




Of,.







put down the shovel, step away from the hole , is an appropriate phrase...


but.... as my last comment


Voids i mentioned...

I was talking about concrete surfaces.

For example, a High air content mix, as it sets, results in loads of tiny bubbles in the top surface, many of which will be partially open to the exterior , and possibly linked to others a little further inside the material, of a variety of depths....

the result is a floor surface that's , in essence, actually more like an Aero, or Whisper bar with it's top shaved off.

which displays a more complex mix of small scale absorption and smaller still VHF diffusive properties, than a material such as a high strength , low air, self levelling top screed mix, that's been polished.... and demonstrably sounds different....
or wood.


so to compound the disagreement here still further....

Concrete is not Just Concrete.

or rather, Not all concrete is created equal




as to the resonance component.


as well as the material itself, how a floor is built will determine how it behaves as a resonant structure... and this resonant behaviour has bearing on the actual absorption, reflection and transmission that happens as a result....

(Think about the differences between assorted wooden bodied instruments for 30 seconds, and then scale it up to room size)

and therefore also, the contribution back in to the room . and therefore the sound of the room.


so one COULD say that most of the tabled data available is arguably irrelevant, other than as a general indicator of inherent difference.... as very few of them specify with any great detail, exactly how the floor was built, and what portion of the behaviour might be ascribed to structural resonance patterns as opposed to purely material based behaviors...




anyhoooo.


the bottom line is that different materials DO sound different...


whether on floor , or wall, or ceiling.

or guitar.









,

[andrebrito]

Lou,

Like I said, it starts from the listener. Science can be used to represent and explain sound but you cannot take away the listener's perception.

Also the listener's perception changes over the years. A studio or a concert hall in the 70s is very different from a place currently being build nowadays.And you need to take in account the goal of the room, is this a home theater, a control room, a opera house etc etc

[Weasel9992]

Originally Posted by andrebrito

It is not a question of subjectivity versus science. One thing I have learned about acoustics is that it is much more than just numbers.

What matters first and up most is the perception of sound for the listener or listeners and afterward the numbers we use are the justification for that perception. All the acoustics development starts from the listener: Munson curves, optimal reverberation time in a room etc etc...

Maybe some stuff cannot yet be measured or we are doing the incorrect measurements, who knows ?

So if someone tells me that wood sounds different than gypsum and concrete,I have no hard time accepting this. Even if this just a temporary psychological effect, it does sound different for that listener.

Now we can go into another discussion which is what sounds better etc or if it justifiable to choose one material over another.

Thanks Andre...well put. That is exactly what I was saying.

Frank

[max the mac]

As a side note.... the floor question (which should maybe be a different thread really).

it becomes of particular relevance mostly in Live rooms.... the impact it has on the recording is often far greater than on the response of the room ...

a lot of things are recorded with Mics close to , or on, the floor surface....

at which point the behaviour of the floor surface and material itself becomes more important than it is as an overall factor in the room's general response.

now we're heading in to the realm of "micro acoustics" if you like....

examples, recording acoustic guitar , or cello.

where what the floor surface is, between the Mic and the instrument , makes a huge difference to the recorded result.... (witness the old home recording tricks of sticking a piece of wood on a carpeted floor between the instrument and the mic... or , a rug on a wooden floor between the instrument and the mic.... and endless variations on that theme )



In a control room environment, one designs a floor to behave in a controlled and balanced fashion , and it's integrated in to the room response as a whole, and the response at the mix position , aiming for a balanced neutral result.


in a Live room, you have to consider the actual use of the room, which means considering the contribution of the floor in a real recording situation, NOT just as a contribution to the overall room response.




the same is true for ceilings when one starts looking at high overheads on Drums , and choirs etc...

[andrebrito]

I agree with you 100 % and it goes back to my idea: the listener (in a tracking room the microphone can be seen as a listener) and the function of the room. Acoustics, well room acoustics, does not make sense without these two factors involved.

[Ethan Winer]

Originally Posted by rimskidog

If resonance is one of those variables which might make a wooden room sound different to a concrete room

Yes, but that was never the issue in this thread. Go to the top of this thread, Post #4, where knightrupert asked about putting wood on top of his existing concrete floor. That was all I addressed, and it's pure surface reflectivity. A cement floor on a (presumably) solid foundation will not resonate the way a floor on wood studs resonates.

--Ethan

[Ethan Winer]

Originally Posted by andrebrito

One thing I have learned about acoustics is that it is much more than just numbers.

Yes, it's numbers and also subjective opinion. But we must know when to use each. Nobody can say if diffusion is "better" than absorption for some given situation. I like spaghetti and Joe likes burritos. But comparing surface reflectivity of different materials as discussed here is entirely numbers. Boiling it down to the difference in dB versus frequency is entirely numbers. Now, if you have two surfaces that reflect differently, then we can argue over which "sounds better" 'til the cows come home. But determining whether two surfaces differ enough to be audible is entirely numbers. This is the domain of science, not subjective opinion.

--Ethan

[Ethan Winer]

Originally Posted by max the mac

Beranek "Acoustics" 1986 edition.

I don't have that book, but we can continue anyway because...

those for Wood on Solid substrata are NOT the same as for concrete

What's missing from your post is the actual numbers. In the table of reflectivity I made from the data Andre posted, the difference in reflectivity between concrete and drywall at 1 KHz is 0.09 dB. So while they're "NOT the same" to quote you, at less than 0.1 dB they are so close as to make no audible difference.

So Max, please post the numbers from that book, and I'll plug them into my spreadsheet to find the reflectivity difference in dB. Or you can do that. I enhanced the spreadsheet in my Surface Reflectivity web article so you can add new surfaces to see how much they reflect in each octave band.

--Ethan

[Ethan Winer]

Originally Posted by max the mac

the floor question ... becomes of particular relevance mostly in Live rooms ... a lot of things are recorded with Mics close to, or on, the floor surface.

Yes, exactly. This is why it's so important to separate floor reflectivity from "room structures" and other unrelated issues. In a small home studio "live" room, wall and ceiling reflectivity becomes more important because those too are close to the sound sources and to the microphones.

All I'm trying to do here is apply some science to this subject. With science we can learn what matters and what doesn't, and avoid trial and error.

--Ethan

[Ethan Winer]

Originally Posted by loujudson

I know what I hear and your measurements are not relevant to sound and music in the least ... Measure anything you want, it won't change the sound I experience.

This is exactly what people who buy $2,000 AC power cords say.

--Ethan

[andrebrito]

But determining whether two surfaces differ enough to be audible is entirely numbers.

No, it is not just numbers, it is psychoacoustics. There's a huge difference between them.

[spencerc]

Originally Posted by Ethan Winer

Excellent Andre! That saves me the effort of doing a home-made test that might not be accepted as valid by everyone here.
--Ethan

Well when you post home-made tests such as your diffusion test, its hard to take them seriously.

[spencerc]

Originally Posted by loujudson

Oh my god, Ethan, I will never listen to another thing you say as anything but vapid opinion. You have just become a born-again preaching nonsense to me! I know what I hear and your measurements are not relevant to sound and music in the least.

I do not believe; i have experience and ears! Measure anything you want, it won't change the sound I experience.

And I do not subsribe to expensive powercords so your metaphor is lame...

Bye Ethan. Have fun in your little world!

Lou

haha

It amazes me how many people on this forum just take Ethan's opinion as "God's Word" so to speak. (I'm not just referring to this thread, but to many other threads Ethan posts on...heck, he even has people asking for HIS opinion in their thread titles ).

Going back to the original post (#4)...you also have to consider what the budget is. If you are loaded and have $5000 burning in your pocket to spend on a nice wooden floor, and (as proven by everyone but Ethan) it does sound different, then do it. If your a small project studio owner who's money would be much better spent on better session musicians, instruments, microphones, preamps...(notice the importance of the signal chain)...then spend the money there.

I'm going to side a little bit with Ethan on his first post, however, with the point I THINK he was trying to make:

In a small project studio, your money is probably better spent on other things aside from a wooden floor vs a concrete floor (even though they sound different). Example...If you have $5000, and your best microphones are entry level CAD microphones...you shouldn't even be thinking about spending that money to upgrade your floor. Upgrading your microphones will have a far greater difference on the sound than changing your concrete floor to wood. I THINK that is why Ethan said that there wouldn't be a difference, or none that really mattered. Am I right Ethan?

Keep in mind this is strictly talking about audio differences.... You also have to consider how concrete vs wood sets the mood in your studio. A comfortable musician will perform better than one who feels like he is in a concrete dungeon , and you can't fix an uninspired/poor performance with the best mics/preamps in the world.

-Spencer

[andrebrito]

And my question is that it is invalid to make such assumptions just by using surface reflectivity... it is way too vague not taking in account the listener, the directionality of the sources, the function of the room, etc etc...

[Glenn Kuras]

Dan,
I wish you would have kept your post. YES this thread should just die. There is enough info to confuse most. lol lol

Yes, but that was never the issue in this thread. Go to the top of this thread, Post #4, where knightrupert asked about putting wood on top of his existing concrete floor. That was all I addressed, and it's pure surface reflectivity. A cement floor on a (presumably) solid foundation will not resonate the way a floor on wood studs resonates.

Then Lou comes in - guns a'blazin' to make sure I understand how much respect he lost for me - and confuses what I said about a non-resonant floor surface with the unrelated issue of walls and ceilings. Then Frank shows up and, not reading carefully enough, backs up Lou's mischaracterization of my comment. Then later Max does the same thing, not reading what I said and instead replying to what others claimed I said.

It's no wonder they call Internet arguments like this "religious" arguments!

Here you go buddy!

[DanDan]

Glenn, jeez you are fast, that post was up for only a couple of seconds! You are probably the only other person in the whole universe who knows what I said. Perhaps Curiosity will do the trick :-)
Since we are well off the topic, perhaps entirely off the wall, a songwriter, Jimmy McCarthy, said this to me recently.

'Being angry with someone is like eating poison and expecting them to get sick'


DD

[Glenn Kuras]

Since we are well off the topic, perhaps entirely off the wall, a songwriter, Jimmy McCarthy, said this to me recently.

'Being angry with someone is like eating poison and expecting them to get sick'

I just spit up my coffee from laughing so hard!!!!!!!! YOU ROCK!!

[Ethan Winer]

Originally Posted by andrebrito

No, it is not just numbers, it is psychoacoustics. There's a huge difference between them.

Andre, please explain what will be different in the sound if you have a room with a cement floor and then lay wood parquet tiles on top. Be as specific as you can in your explanation! I'm not talking about how people might respond to the visual change - mood and ambience etc. Only how the sound will change for Stevie Wonder or Jose Feliciano.

Folks, I'm trying hard to keep this on the topic of surface reflectivity. "Corrosive" comments about losing respect and other insults only show that the posters have nothing of substance to contribute. Disagreeing about the science is fine! But keep it to that so we can talk about testing methods, and the frailty and lack of repeatability of human perception. Otherwise you just come off as childish fools.

Now, please let's get back to how the sound will change when different floor materials are replaced with others that reflect very similarly.

--Ethan

[DanDan]

Well my ploy didn't work. I would like to make a formal request to Jay to terminate and if possible delete this whole thread. I believe it is harmful to the forum. If anyone else shares this opinion, please speak up and let's get it done and move on.
Sincerely, Dan

[Ethan Winer]

I agree Dan that this thread has gone in a direction it never should have. But I'd hate to see it deleted because there's a lot of useful info. Maybe just trimmed a bit.

--Ethan

[Glenn Kuras]

Originally Posted by Ethan Winer

I agree Dan that this thread has gone in a direction it never should have. But I'd hate to see it deleted because there's a lot of useful info. Maybe just trimmed a bit.

--Ethan

I can second that and hoping you will do so after we talked on the phone.

[DanDan]

Glenn, are you seconding voluntary trimming or deletion?
I would be happy to delete all my posts in the thread, if you two do likewise. :-)
I believe total deletion would be the fairest to all concerned.
This has hardly been our finest hour.
If there is useful information in there, which is totally arguable, given a bunch of grumpy old nerds, it can easily be put in another thread.

DD

[Ethan Winer]

Why don't I just post a link to my article and we can start again? I edited it this morning to include additional surfaces - specifically, adding wood tiles on concrete and a wood floor on joists. I also found a better example of glass without the added LF absorption from being a large free-standing plate:

Surface Reflectivity

--Ethan

[DanDan]

Ethan, By all means post your hard work again.
Before you do that though, let's have a private chat.
There are extrapolations which ruin your faux science
and they would raise hackles again. There is no good side to that, it obscures your actual point, so I would gladly help with a little diplomatic editing.

I would still like this Thread gone though.

Best DD

[Glenn Kuras]

Originally Posted by DanDan

Glenn, are you seconding voluntary trimming or deletion?
I would be happy to delete all my posts in the thread, if you two do likewise. :-)
I believe total deletion would be the fairest to all concerned.
This has hardly been our finest hour.
If there is useful information in there, which is totally arguable, given a bunch of grumpy old nerds, it can easily be put in another thread.

DD

I would be more then happy to delete what ever should be or for deleting the whole thread. I am not really sure what Ethan is saying what is insulting or just not agreeing with him. Maybe he could take a moment and quote all the things he says is insulting???? Or maybe not???? Which ever is fine with me.

Hey Ethan I am sorry (which I will apologize for anyone) if you found something insulting and hurt your feelings. That is not the aim of good threads like that. Have a beer on me, if it makes you feel better.

All the best.

Glenn

[Ethan Winer]

Originally Posted by DanDan

Before you do that though, let's have a private chat.
There are extrapolations which ruin your faux science and they would raise hackles again.

Hey, I have no ego about this stuff, and I don't need to be right all the time!

If you think the way I converted absorption to reflectivity is wrong, or that 0.30 dB changes in reflectivity are significant, or anything else, please explain what's wrong and why. I'll gladly change my article and acknowledge the error. Or if the underlying data is wrong, let's get better data and I'll update the image and Excel file.

I truly believe this "wood is warm" myth is important to debunk, and I see no reason it can't be discussed in public as long as everyone is civil and sticks to the subject.

--Ethan

[Ethan Winer]

Originally Posted by Glenn Kuras

Hey Ethan I am sorry (which I will apologize for anyone) if you found something insulting and hurt your feelings.

You did nothing to apologize for! I consider you not just a good friend, but a great friend.

--Ethan

[johndykstra]

I'd rather people tell me I'm an idiot than ignore me...

Is there nothing to the effects on air regarding humidity and temperature given of the retention properties of wood vs concrete?

testing one...two...check, check