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Sidhu
 
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Hi,
ive just moved into this small place with the intention of making it
into as much of a workable project room as possible. There are two
rooms. One 10*10 and another 14*10 (yet to measure the ceiling. The
14*10 is where i have the DAW and i got the other room carpeted, this
is where i record.

I need to get some acoustic work done here.... the smaller (record)
room has a lotta flutter to it. soon i wud putting up thick drapes on
the rear (and one side) wall.. that i think wud help till some extent.

But mainly i want the monitoring room to sound good. (i have as of
yet to pik up monitors, hard as i might try i cant seem to kook up a
budget beyong the Behringers). This room is ver boomy.. and there are
section where ther is this sudden boom at bout 60-120. I can pik up a
measurement microphone and the software (?) and then insert an EQ.

I need a solution that does not cost much, is not permanent (cause i
might need to get out, my lease expires in 9 months.) Something that i
can throw on the walls and remove it when needed.

could some of you help me out with some links on DIY acoustics.... ???
i was thinking on perhaps to get a few 3feet by 6feet frames made...
bout two inches deep. stuff it with glasswool and cover it with
perforated gipsum of fibreboard. suspend em bout and inch and a half
off the wall. But will it work.
Basstraps... ???


We do not get Auralex in India.

thanks a ton.

Sidhu
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EganMedia
 
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Check out realtraps.com. Ethan has some really good, budget sensitive ideas
and products. EQing the monitors will merely make the audio as wrong as the
room. Basstrapping, broadband absorption and diffusion are the ways to make a
room sound good.



Joe Egan
EMP
Colchester, VT
www.eganmedia.com
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Chris Whealy
 
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Sidhu wrote:
I need to get some acoustic work done here.... the smaller (record)
room has a lotta flutter to it. soon i wud putting up thick drapes on
the rear (and one side) wall.. that i think wud help till some extent.


Flutter echoes are caused by the reverberation time along one axis of
the room being significantly higher then along the other axes. This is
easily fixed by doing as you suggest, and applying absorption to one, or
both faces of the axis in question.

But mainly i want the monitoring room to sound good. (i have as of
yet to pik up monitors, hard as i might try i cant seem to kook up a
budget beyong the Behringers). This room is ver boomy.. and there are
section where ther is this sudden boom at bout 60-120. I can pik up a
measurement microphone and the software (?) and then insert an EQ.


Fix the room! Don't EQ your music to compensate for a bad listening
environment. If you notch out frequencies created by the resonance of
your room, anyone listening to that music in another room will hear
holes in the EQ, because their room will have a different set of
resonant frequencies.

I need a solution that does not cost much, is not permanent (cause i
might need to get out, my lease expires in 9 months.) Something that i
can throw on the walls and remove it when needed.


A good (and reasonably cheap) solution is to copy the BBC's modular
treatment approach. They produce standard 2' by 4' units that have a 2"
absorbent layer (rockwool usually) over top of a 6" air space. The air
space is subdivided into 4" square box sections using strips of
hardboard. The front face of each unit is covered with an open weave
cloth. These units can then be screwed to the walls.

This approach will probably cost you more in construction time than money.

could some of you help me out with some links on DIY acoustics.... ???


I have written a couple of spreadsheets that will calculate the basic
acoustic properties of a rectilinear room, and also the absorption
curves of slotted and perforated panel (Helmholtz) absorbers. You can
download these free from he

http://www.rmmpnet.org/members/ChrisW/

All the instructions on how to use these spreadsheets are on the
download pages.

You will probably find the control room calculator of most interest.
Here, you enter the ratios of your room dimensions and then the height.
After this, you can fiddle around with different wall, floor and
ceiling surfaces, and it will calculate the reverberation time of the
room using a variety of formulae. You should look at the values
produced by the Fitzroy equations.

i was thinking on perhaps to get a few 3feet by 6feet frames made...
bout two inches deep. stuff it with glasswool and cover it with
perforated gipsum of fibreboard. suspend em bout and inch and a half
off the wall. But will it work.


One thing that you must always be aware of is that for a porous absorber
to have the maximum benefit, it must be placed at a location where the
air particle velocity is greatest. In other words, not flat against the
wall! If you're talking about having a porous absorber 2" deep
positioned 1.5" from the wall, then you should expect maximum absorption
to occur between approximately 700Hz and 2.8KHz.

As you move the absorber farther away from the wall, the frequency at
which maximal absorption occurs drops. E.G. If you increase the air gap
to 4", then the frequency range drops to between 200Hz and 1.4KHz

If you hear stories that all you need to do is place absorptive panels
in the corners of rooms, then please be careful - the information is
often presented in a way that would make you think the performance is
better than can actually be acheived. A porous absorber placed flat
against, or close to, a wall will have significantly reduced bass
absorption capability.

It is true that these panels will have a damping effect on the resonance
of the room, but you must remember that porous absorbers work best where
air particle velocity is highest. This in turn will occur at a quarter
wavelength from a reflective surface. Therefore, in order to absorb the
frequencies at the bass end (200Hz), you will have to move the porous
absorber farther and farther away from the wall. To absorb maximally at
200Hz, you would need a 17" air gap between the absorber and the wall.

There is obviously a practical limit to how much of your room space you
can afford to loose...

Basstraps... ???


Glad you mentioned them. If you have the vertical height in your room,
you can construct a bass trap in the ceiling space above you. I have
done this in the past by attaching rockwool to 4' by 2' sheets of
hardboard, then hanging these from the ceiling at 8" intervals. A
wooden frame was then constructed on the underside and cloth streched
over it.

Alternatively, bass traps can be made by using panel resonators. These
are resonant panels over a layer of porous absorber, but unfortunately,
their performance as bass traps is very difficult to predict due to the
thousands of different ways the panels can be mounted to the walls.

We do not get Auralex in India.


Nonetheless, try contacting Jeff Szymanski ) at
Auralex in the US. He is their chief acoustic engineer, and he should
be able to point you in the direction of practical advice on the
construction and effective placement of acoustic panels.

Hope that helps

Chris W

--
The voice of ignorance speaks loud and long,
but the words of the wise are quiet and few.
--
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Ethan Winer
 
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Joe,

EQing the monitors will merely make the audio as wrong as the room.


That's a great one-sentence summary!

I hope it's okay to quote you. :-)

--Ethan


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Ethan Winer
 
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Sidhu,

This room is ver boomy


That's very typical, especially in such small rooms. Thanks to Joe for
mentioning my company's products, but I assume you're too far away for that
to be practical. The next best thing is to read the Acoustics FAQ, second in
the list on my Articles page:

www.ethanwiner.com/articles.html

It explains all of these issue clearly, and tells what works and what
doesn't.

--Ethan




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Myles
 
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Hi-

"Michael Lauengco" wrote in message
m...
(Sidhu) wrote in message

. com...
Hi,
ive just moved into this small place with the intention of making it
into as much of a workable project room as possible. There are two
rooms. One 10*10 and another 14*10 (yet to measure the ceiling. The
14*10 is where i have the DAW and i got the other room carpeted, this
is where i record.

The 10x10 dimensions (assuming they are in feet) are going to make the
room quite difficult to treat. Not only is the room very small, the
same dimension is repeated, thus intensifying the modes in that
dimension. I would suggest building a closet, say 1.5' deep, to
reduce one of the dimensions to 8.5' so they won't be the same. You
didn't mention the height. That's an important consideration, too.
Then you will need lots of absorption in this room especially on the
corners. Hop over to the following site, click on Acoustic Forums,
then Treatment, then Studio Tips Super Chunk, and check out this very
effective DIY broadband absorber:

http://www.studiotips.com

Take the time to read the introductory articles, too. There's so much
you need to know to be able to treat a room properly, especially a
room that small!

As for availability of materials, I hope you have rock wool or any
rigid fiberglass with a density of around 2.8 lbs/cu-ft in India.

Good luck!

--Michael


I second Michael's post. I think you'll find the Studiotips forum to be a
great source of DIY acoustics knowledge and suggestions, without a
commercial agenda.

Spend some time there reading and you'll learn a lot about what you can (and
cannot) do.

Regards,

Myles


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