for curiosities sake - density of absorbers

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for curiosities sake - density of absorbers

Postby Brian Dayton » Wed Aug 04, 2004 12:05 pm

i was intrigued by the great density of absorbers debate, so i took it upon myself to tinker with the data on Bob's web site (bob can insert the url if he wishes)

if you are curious, i've attached the graphs, this is not a pretty file, so be warned. i didn't double-check, so error is possible.

NEW FILE in different thread, thanks :)
Last edited by Brian Dayton on Thu Aug 05, 2004 1:49 am, edited 3 times in total.
Content posted by me is copyright 2004, 2005, 2006  Brian Ravnaas, but may be reproduced without permission for any non-commercial purpose so long as the intent is preserved.  NRC Canada data is copyright them and used with permission, www.nrc.ca
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Postby Eric.Desart » Wed Aug 04, 2004 12:14 pm

Brian,

Just saw this related PM message, which I overlooked
1000 times sorry

Eric
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Postby Brian Dayton » Wed Aug 04, 2004 12:24 pm

no big deal, i'm sure you get a mob of pm's

in any case, that is literally just the pics i made to humor myself, and there is chance of omission and what not. the interpretations of trends was Brian's Eyeball.

still, i think that it is clear from this probably tens or hundreds of thousands of dollars in data that no clear trend exists.
Content posted by me is copyright 2004, 2005, 2006  Brian Ravnaas, but may be reproduced without permission for any non-commercial purpose so long as the intent is preserved.  NRC Canada data is copyright them and used with permission, www.nrc.ca
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Postby Eric.Desart » Wed Aug 04, 2004 12:26 pm

Hello Brian,

My poor brain wasn't very sure what it was looking at.
Maybe you can better describe what you did on the first page?

As such I went to the last page.
The conclusions I understood and are very nice you made them.
So the following is your's not mine:

    Conclusions by Brian Dayton

    based on the absorption data included in Bob Golds' page:
    http://www.bobgolds.com/AbsorptionCoefficients.htm

    Description Graphs
    Absorption coefficient at 125hz with density increasing from left to right. each line in each graph is same maker/product line with increasing density, there is probably not correlation with each vertical data point and density in the absolute sense

    - Marginally more trends down with density
    - Most dense is highest in marginally more cases than it s lowest
    - Lowest density is best far more often than it is worst

    Frankly, I don t think that a rational argument could be made based on this data set for ANY
    correlation between density and low frequency performance, either denser=better or less
    dense=better.

The problem to find a better relation is that you don't find those gasflow resistance data published.
Anyhow, it once more dismantles some unsubstanciated believes and absolutes..

Many thanks
Last edited by Eric.Desart on Wed Aug 04, 2004 12:43 pm, edited 5 times in total.
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Postby Eric.Desart » Wed Aug 04, 2004 12:50 pm

Can somebody help to formulate those conclusions a bit better.
It's still a bit confusing to read.

Just enter message(s), I will clean this thread afterwards.
Brian if you want to get a try. It should be clear for anyone not knowing what you know or did.

The idea:
A clear summary of the conclusions of your experiment, which can not be misunderstood.

Thanks
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Postby avare » Wed Aug 04, 2004 6:10 pm

Brian:

I have been trying to d/l the file for what seems like an hour. Could you email the file to me?

From what little I have been able to glean from this thread, it sounds like a fantastic job you did.

One of the complaints that Eric and I have is how often people look for a certain characteristic in a product without understanding why that characteirstic is, or is not important.


Thanks
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Postby avare » Wed Aug 04, 2004 6:12 pm

Brian:

I have been trying to d/l the file for what seems like an hour. Could you email the file to me?

From what little I have been able to glean from this thread, it sounds like a fantastic job you did.

One of the complaints that Eric and I have is how often people look for a certain characteristic in a product without understanding why that characteirstic is, or is not important.


Thanks
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Postby Brian Dayton » Wed Aug 04, 2004 7:12 pm

right click the download button and hit save target as

that worked for me

it's not a great write-up, avare, just a humble offering if anyone is interested, but thanks :)
Content posted by me is copyright 2004, 2005, 2006  Brian Ravnaas, but may be reproduced without permission for any non-commercial purpose so long as the intent is preserved.  NRC Canada data is copyright them and used with permission, www.nrc.ca
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Postby Eric.Desart » Wed Aug 04, 2004 7:27 pm

Andre,

Follow Brians advice,

Right click >> Save Target as......

For me it doesn't work either.
I notice phenomena with the Acoustic Forum and my CPU which I don't have trouble with via other sites.
So it's finding a workaround.

DAN,

If you read this, is it possible tu upload .mht files?
This are the archive versions of htm or html files.
The difference is that in the .mht files the pictures are directly stored in the main file, so no seperate folder is needed for the pictures.
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Postby Brian Dayton » Wed Aug 04, 2004 7:33 pm

hi Eric,

i can spend an hour this eve and re-do the thing, perhaps i shouldn't have thrown up my chicken scratch...

regarding your request for a clearer summary, i will try here:

i plotted on graphs and in tables the trends for absorption at 125hz for similar materials for the data seen here
http://www.bobgolds.com/AbsorptionCoefficients.htm

ALL LINES IN THE GRAPHS ARE FOR SAME-PRODUCT, SAME-MAKER. for example, the graph for

on second-look, i will re-post the whole thing when time allows. take care all



from this i visually assessed the trends, breaking the data into
Content posted by me is copyright 2004, 2005, 2006  Brian Ravnaas, but may be reproduced without permission for any non-commercial purpose so long as the intent is preserved.  NRC Canada data is copyright them and used with permission, www.nrc.ca
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Postby avare » Wed Aug 04, 2004 7:41 pm

Thanks Brian and Eric. That did it!
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Postby Eric.Desart » Wed Aug 04, 2004 7:50 pm

Brian Dayton wrote:hi Eric,

i can spend an hour this eve and re-do the thing, perhaps i shouldn't have thrown up my chicken scratch...

regarding your request for a clearer summary, i will try here


Brian I'm glad you did.
Please do not understand my question as critisisme.

It's because I find it important what you did that I should like to have a nice summary, easy understandable for people less technical.
And your file then can be downloaded by the maniacs :-) wanting details.

I'll give it a try. It's because I'm not English that others can formulate things better than I do

Please I'm grateful for your work. Don't let my questions stop you.
AND IT'S YOUR'S AND REMAIN YOUR'S however presented.

You're a lab guy, a scientist, numbers live for you.
Others understand it better in words.
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Postby Brian Dayton » Wed Aug 04, 2004 9:15 pm

no, no Eric, in this case it was productive.

my original file was PISS-POOR

new file above, spreadsheet will be posted later.
Content posted by me is copyright 2004, 2005, 2006  Brian Ravnaas, but may be reproduced without permission for any non-commercial purpose so long as the intent is preserved.  NRC Canada data is copyright them and used with permission, www.nrc.ca
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