Finding Freq absorption specs on material

[Mickstape]

Hi, im re-working my mix room and planning on utilising my sunroom as a live room. I've posted my query on John Sayers forum, but i'm impatient and just wanted to ask the heads here about some acoustic panelling i have in my possession.

I've tried googling but can't find any specific info on this stuff (unless i'm blind or stupid, whichever comes first. I have a feeling someone will jump all over that statement but i have a sense of humour so i can deal with it.) The image is below and my post on JS forum is here http://www.johnlsayers.com/phpBB2/viewt ... 72#p101072




cheers.

[rick]

nice post mick pretty pictures
whats the question ?

[Mickstape]

oh sarcasm. i like it.

the question is in the post header rick. What are the specs for dB absorption and what frequencies does it have the most effect on. For the pics of the stuff i posted. And i think i'll forget about that other place, too many ego's in there. i spent two hours trolling through there and noticed that it was filled with a lot of people who liked to use big words to bag people out and boast about how cool their studio is going to be.

For me this is a temp situation for a live room/mix room Rick, i'm not sure wether you read the post at the link i put up but i'm re-shuffling to make room for some new stuff and re-treating the existing mix room and creating a new "live" room.

Anyway i'm thinking about just staggering the panels ie:panel,rockwool bag,panel etc on the windows and then hanging a combo bag (rockwool on the top two thirds with the panel at the back) in the corners for a bass trap. I have heaps of closed cell foam as well that i've hoarded and schemed over the last two years so i can use that as the initial backing layer on the glass and frame before i screw the panels and bags on. I'm not going to be pumping mass spl's in either room and there isnt really enough room for a full kit setup so it's just a matter of keeping sound from spilling in/out. which where i am atm isnt really a problem.

This is going to be a fiddle with it till its right job i reckon. It's all good, i have to do this sooner or later, hopefully the radio shack app on the iphone will come in handy.

[rick]

ok mick
i dont recognize the stuff to be able to spit out the numbers
but here is the thing , in a small room it doesnt matter past what your ears and eyes tell you !
dont worry about those numbers unless you are a acoustic genius or a total internet troll

stick to the rule of thirds , a third reflection, a third diffusion and a a third absorbsion

by just eye sight alone and in a small room you will be 80 % in the right place following that rule ,

that stuff looks like its an mid to high band absorber to me so you should just treat it as an absorber.
if you really need the numbers just swap in rockwool or strammit and you wont be far off.

all those numbers and coffecients DO really matter in big rooms.. halls etc when your heading for a known result and your spending a shitload of money getting there and its got to be right first time ( err it never is )

all the maths on the internet for little rooms is funny... is like watching a bunch of armchair captains playing battleship
except they are SO serious about their game ... then they post up their converted bedroom and i can tell just by looking at it what they did wrong and how it sounds ...


rooms for making music in are the easy to make .. dont stress just get on with it me thinks

[Chinagraf]

Haa...you sunk my battleship....

[Ausrock]

And i think i'll forget about that other place, too many ego's in there. i spent two hours trolling through there and noticed that it was filled with a lot of people who liked to use big words to bag people out and boast about how cool their studio is going to be.

Mick,

Like Rick, I'm not familiar with the stuff you've shown, so it's unlikely that you'd get a sensible response at John's forum as 99% of the knowledeable people there are from o/seas.........unless of course JS himself happened upon your post.

As for your "impression" of his forum..........well that sounds like 99% of the forums on the www .............Rurtletock is a rare exception.

[Ausrock]

BTW...................WTF can't I edit my post here?

[Chris H]

BTW...................WTF can't I edit my post here?

....been like it for ages....i think it's one of rick's subliminal messages .......like don't worry about the sloppy take, we'll fix it in the mix........don't worry about the hit and miss mix, we'll fix it in the mastering...........

.....well then, don't make a bloody mistake posting on my forum cause your not going to get a chance to edit it!...... and while i'm at it, i'm sick of hearing sloppy protoolized edits on my new high rez monitoring system, and no the weiss/myer thingy isn't going to fix it!! ( or something like that?)

[rick]

you know i put that edit rule in years ago so people could not rewrite history months after the fact
which allows people to be really rude little pricks and then erase it when they grow up ...

i would prefer they put their mark in stone

but i thought we had a 3 or 4 day allowable editing window time ..?

but something happened to the site over the last couple of weeks where it was off the air at the server end for no good reason .
maybe the preferences have changed - i dunno .

mark if you see this can you unlock the editing feature for a short period of time to edit only ?

[rick]

ph by the way mick that "closed cell" foam have been hoarding is near on acoustically useless!
you should have been hoarding "open cell" foam

whoops !

[Mark Bassett]

What are the specs for dB absorption..

I think you're after absorption coefficients. They're not measured in decibels, they don't have any units, they're percentages. Finding these will answer

...what frequencies does it have the most effect on.

BTW...................WTF can't I edit my post here?

You should be able to edit your post, as long as no one has posted after you. This ensures that what they're actually responding to is still there.

[Mark Bassett]

mark if you see this can you unlock the editing feature for a short period of time to edit only ?

Yes and no. Editing has been re-enabled, but it's either on or off. It's now on.

[Mark Bassett]

What are the specs for dB absorption and what frequencies does it have the most effect on.

Your answer is here: http://www.eltomation.com/Eng/Publicati ... eaflet.pdf

and here: http://www.eltomation.com/PDF/Grafiek%2 ... Engels.pdf

Three cheers for Google.

[Mickstape]

Three cheers for Mark A Bassett and his beautiful shiny dome! Cheers man, i could'nt find that stuff so mega thanks to you dude. Even if it does'nt work in this situation those charts and info will come in handy when the shed is up.

@Rick, yeah as it's a temp thing i'm probably going a little too in-depth, BUT, i am making some of those panels that a bloke off GS posted, a cool DIY way to make absorbers and the like, went to bunnings yesterday and regretted ever closing my trade account. Thanks for your input though.

@Chris'O. were you being subtle and saying stfu mick? Or agreeing with me? And yes Rurtle rock is the ONLY exception. It's why i like to lurk around in here. Thanks for your post anyways dude.


Now that i know how to post pics i may just bore you with a step by step guide of how i stapled my fingers to the panels. I actually did a rough track in there last night when i got home, at least i know what that neve "warmth" sounds like now, i dialed up the gain and yep there it was. I wonder if i like it that much.....Just kidding, combined with the DI track and the ribbon mic once i balanced the 2 out it actually added that something that wasn't really there before which is super extra kewl.

Now i must get back to the diy, i neeeed to combat that RT60. which by the way is .38ms atm.

[rick]

your rt 60 is .38 ms and you going to combat it with absorbtion ..?

me thinks you might be holding the wrong end of the snake
are your measurements correct..?
what figure do you want it to be?

[Ausrock]

@Chris'O. were you being subtle and saying stfu mick? Or agreeing with me? And yes Rurtle rock is the ONLY exception. It's why i like to lurk around in here. Thanks for your post anyways dude.

Mick,

Mate I was kinda agreeing with you, I guess I just developed the habit of trying to ignore the "white noise" on forums and just work out (regardless of egos) who's worth "listening to". Unfortunately, the more people on a forum, the more "white noise" you have to contend with :-)

[Mickstape]

your rt 60 is .38 ms and you going to combat it with absorbtion ..?

what figure do you want it to be ?

well i want it like almost dead dude. is that dead enough already you think? To be truthful i think that it may be way more than the figure i got, i followed JS's calculator instructions but he doesn't have a section that deals with big bloody holes in the wall. I figure with the room adjacent to the "live" room having the hole in wall it will add more life to it if the figure i have is correct. I dunno i'm still wayyyy too novice in regards to acoustics and the like, all i know is there are three bloody great windows in the room and when you clap there is definite slapback. hence me trying to deaden the room as much as possible.

[Mickstape]

oh btw Rick, thanks for shattering my hopes of the foam doing any good, the wife saw that post and said i want it gone. now. like right now.

[rick]

slapback...? echo...flutter echo ..?
ok then i think your measurement numbers are wrong
get test box or a i phone app or whatever and measure it properly

or in fact if what you really want to do is just kill the echo , your on the right path
and if you want a really dead room go for it i guess

but i bet you dont want a really dead room - you just dont want flutter echos

so maybe its time to read up on diffusion !

[rick]

oh btw Rick, thanks for shattering my hopes of the foam doing any good, the wife saw that post and said i want it gone. now. like right now.

glad my efforts have cleaned up somebodies life

with the studio move .....you should see mine right now ( urrghhh!)

[Mickstape]

slapback...? echo...flutter echo ..?
ok then i think your measurement numbers are wrong
get test box or a i phone app or whatever and measure it properly

or in fact if what you really want to do is just kill the echo , your on the right path
and if you want a really dead room go for it i guess

but i bet you dont want a really dead room - you just dont want flutter echos

so maybe its time to read up on diffusion !

Yeah i don't want a totally dead room. And i guess if i was to call it an echo it would be more of the flutter and not a definite "slapback" like some venues i encounter on the coast here, doylo anyone?

and yep diffusion is the next read up for me.

[Chris H]

I must say the studio moves rick has had to do in recent times would really test my anger management strategies...... hats off to rick for perseverance:)

[Mark Bassett]

i neeeed to combat that RT60. which by the way is .38ms atm.

Your RT60 is 0.00038s???

Perhaps you mean 0.38s instead of 0.38ms?

[Mickstape]

i neeeed to combat that RT60. which by the way is .38ms atm.

Your RT60 is 0.00038s???

Perhaps you mean 0.38s instead of 0.38ms?

yep thats what i meant. Thats why you get paid the big bucks Mark and i have to make do. Damn this non editable forum!

And damn Dominos discounts & online ordering, grumble grumble there goes that 6 kilos i lost in two weeks!

My wife still loves me, hey Nick maybe you can talk her into buying that Mike-E for me, she sez i'm mediocre in bed but good all the same LOL