[Guy 13]

Hi all Audio Circle members.
For some time I've looking to get as much as possible information
on room acoustic to help me for the acoustic treatment of my
newly renovated listening room also called : My penthouse.
The best suggestion I found is as per the following sketch.



My listening room dimensions are as per sketch below:



Waiting for suggestions.

Guy 13

[AKLegal]

I think the room is a little too narrow for diffusion on the side walls.  My room is about 16 feet wide and diffusion on my side walls at the reflection point had a negative impact.  I think absorption would be better at those spots.  You also might be too close to the rear wall for diffusion behind the listening position.   

[Guy 13]

I think the room is a little too narrow for diffusion on the side walls.  My room is about 16 feet wide and diffsusion on my side walls at the reflection point had a negative impact.  I think absorption would be better at those spots.  The wall behind the listening position is perfect, that's a great place for diffusion.

Hi AKLegal and all Audio Circle members.
Thanks for your comments, useful and make sense.

Guy 13

[WireNut]

Your 12' and 13' dimensions indicate that your sofa and loudspeakers are right up against the walls

[JLM]

Cheap method:

Check out Floyd Toole's book "Sound Reproduction."  Toole worked at the Canadian National Research Council where much acoustical testing/development occurred.  He would have you buy multiple subwoofers and roughly follow what you've got for absorption/diffusion (we are used to listening in "typical" room environments, so no need to go crazy with treatments).  For residential sized rooms diffusion is only effective for midrange/treble frequencies due to the size of bass frequency sound waves.

Also check out the Cardas website for setup/room dimensional advice:  http://www.cardas.com/room_setup_main.php.  Cardas would have you use a nearfield setup, moving speaker and couch closer to the middle of the room.

Expensive method:

Hire a consultant (no guarantee of satisfaction).

What's the ceiling height?

[Hipper]

I read somewhere 'absorption at first reflection points (side walls, rear walls, maybe ceiling), diffusors at second or higher reflection points'. Books are not considered by experts as particularly useful for diffusing.

I had reflection on my sidewall panels and it really muddied the sound if not made it harsh in some instances. My room is 14' x 13'.

You can't have too many bass traps.

I suggest you buy as many bass traps as you can afford (they can go in all corners - wall/wall, ceiling/wall and wall/floor).

Then buy just a pair of panels and a pair of diffusers and experiment in their positioning. Budget for perhaps another pair of panels.

Diffusers, especially QRD are strange pieces which if you are not familiar with them take some understanding.

My advice is second hand and based on my limited experience. I'm sure the real experts will pop in soon.

[Guy 13]

I read somewhere 'absorption at first reflection points (side walls, rear walls, maybe ceiling), diffusors at second or higher reflection points'. Books are not considered by experts as particularly useful for diffusing.

I had reflection on my sidewall panels and it really muddied the sound if not made it harsh in some instances. My room is 14' x 13'.

You can't have too many bass traps.

I suggest you buy as many bass traps as you can afford (they can go in all corners - wall/wall, ceiling/wall and wall/floor).

Then buy just a pair of panels and a pair of diffusers and experiment in their positioning. Budget for perhaps another pair of panels.

Diffusers, especially QRD are strange pieces which if you are not familiar with them take some understanding.

My advice is second hand and based on my limited experience. I'm sure the real experts will pop in soon.

Hi Hipper and all Audio Circle members.
Thanks for posting your limited experience, it's appreciated.
My biggest problem is my microscopic budget, very small budget
in the range of 200 USD to a very maximum 500 USD.
Therefore, I have to buy the raw material and find some inexpensive substitute and do everything myself.
I will post some pictures of my listening room soon,
so everyone that want to jump in have a better idea
of what has to be done
before they can make real recommendations according
to my actual listening room.
Thanks.

Guy 13

[JLM]

I use bookcases for poor man diffusion on my side walls, just vary the sizes/gaps.  (My room is a combo listen room/office, I even have CDs, LPs, pillows, etc. in the bookcases.  Season to taste.)

For absorption look for wide spectrum performance (sheets of densely packed fiberglass).  Some on the really cheap have just piled un-opened rolls of fiberglass insulation batts in the corners.  You could even try attaching sheets of gauge metal to the room facing sides of the rolls (like some vendors of absorption corner tubes do.  But don't leave open fiberglass batts laying around (not good for the lungs if inhaled).

But don't kid yourself with plastic egg cartons or the like (at best they 'might' absorb a little bit of the highs).


Honestly a well shaped (proportioned) room with near-field setup will eliminate much of the need for any treatments.

[ebag4]

Hi Guy13,
I have a room of similar dimensions (actually a little smaller), this is what I have done to good effect:




I have 4 Pi Audio diffusors that I am going to put in place of the parabolic diffuser as soon as I get them painted.

Best,
Ed

[Guy 13]

Hi Ed (ebag4) and all Audio Circle members.
Thanks for sharing your listening room layout.
Shortly I will take some pictures of my listening room
which will give all the Audio Circle members that want to help me
more details and they will see (More clearly) what can be done
with a mini budget.

Guy 13

[Guy 13]

I use bookcases for poor man diffusion on my side walls, just vary the sizes/gaps.  (My room is a combo listen room/office, I even have CDs, LPs, pillows, etc. in the bookcases.  Season to taste.)

For absorption look for wide spectrum performance (sheets of densely packed fiberglass).  Some on the really cheap have just piled un-opened rolls of fiberglass insulation batts in the corners.  You could even try attaching sheets of gauge metal to the room facing sides of the rolls (like some vendors of absorption corner tubes do.  But don't leave open fiberglass batts laying around (not good for the lungs if inhaled).

But don't kid yourself with plastic egg cartons or the like (at best they 'might' absorb a little bit of the highs).

Honestly a well shaped (proportioned) room with near-field setup will eliminate much of the need for any treatments.

Hi JLM and all Audio Circle members.
I have already down sized my listening room
to improve the sound and eliminating some acoustic problems.
I would never kid myself with Egg cartons,
I know it's useless
and anyway, they don't have that here in Vietnam.
Another thing that is (Almost) impossible to find here in Vietnam
it's fiberglass (Sheets or rolls) or equivalent.
That's a big draw back in trying to acoustically threat my listening room.
Importing from the US is quite expensive.
As soon as I have finish breakfast (Here on planet Vietnam it's 8am)
I will post pictures and then I will continue my quest for the (Near)
perfect listening room or at a minimum a place where I can retreat from everything that is Vietnamese.
Thanks for your comments.
Stay tuned, more soon.

Guy 13

[Guy 13]

Hi (Again) eBag4 and all Audio Circle members.
Would it be too much to ask you to post a picture of your diffusor(s)
or give me a link to see what your diffusor look like.
Thanks.

Guy 13

[ebag4]

Hi (Again) eBag4 and all Audio Circle members.
Would it be too much to ask you to post a picture of your diffusor(s)
or give me a link to see what your diffusor look like.
Thanks.

Guy 13

This is similar to the units I need to paint before installing:








This is a bad pic of my DIY parabolic diffuser:

[Guy 13]

Hi ebag4 and all Audio Circle members.
What's your diffuser made of?
Look like foam?
That type of diffuser would be expensive for me to get it shipped to Vietnam,
even if it is light weight.
On one of your pictures I saw your Bottlehead Paramour 2A3,
according to the picture,
you made some improvement(s) by covering the transformers.
Nice, too bad I can't see it more clearly.
I am posting something about my listening room.

Guy 13

[Guy 13]

Hi all Audio Circle members.
Since I will be staying in Vietnam longer than expected,
might as well be as comfortable as possible,
at least in my listening room,
this is also my office,
where I spend many hours because retirement at 65
it’s not for me.
Yes, I know, my introductions are always too long,
sorry about that.
My listening room is 12.5’ wide at the front and 14’ wide at the back,
13’ long and 10’ high.
The whole room is armored concrete with a ceramic tiles floor.
My first improvement was to install curtains in the window behind the OB speakers; it acts as absorber and maybe diffuser, since it as ripple in them.
The curtains on each sides is at the first reflection point, again they act as absorber and diffuser, well maybe not very efficient, but better than nothing for the time being.
The back wall, well, there is not back wall, only curtain that again act as diffuser and absorber and at the same time, a separation between the listening room and my office, it also makes my listening room smaller for near field listening.
The ceiling is naked and the floor is covered with a rug, later on I will buy a thick under rug , when I can find a store that sell them, because I have found many stores that sell rugs, but no one offer the under rug (Undercushion)…
Now, bass traps.
I know I need one in each corner, but I only have two real corners,
the other two corners are small and large openings.
Maybe I could block the small opening with an absorber
and partially block the large opening with another absorber.
For the ceiling I will need a minimum of two absorbers 2’ X 4’,
I will have to hang them, which means drilling in armored concrete, I hate that…
The two front bass traps will be 4” to 6” thick by 24” wide by 8’ high.
The back bass traps (Or absorbers, whatever you want to call them) will be 2” to 4” by 24” X 6’ self standing.
I am not sure about the diffuser on the front and back walls.
I would like to do them myself, factory built diffusers are expensive to purchase and costly to ship because I am on the other side of the planet.
I found an audio store that sell Styrofoam diffusers, but they are expensive
at 25 USD each for 24” X 24” tile.
Can I get away without diffusers?
According to what I read, you can get away with diffusers
if your room is small, is my room consider small?

Now, my budget is no more than 500 USD.
Cannot do much with only five Benjamin, even if I do it myself.
I was wondering if the pieces of foam shown in the pictures are of any use?
I could use them for the wall – ceiling junction.
I want to buy Roxul bat (2x4’) at 36 USD for 6pk, but I will have to inquire
about the cost of air cargo or sea cargo.
I have calculate that I would need 4 boxes of 6 bat each for a total of 144 USD + transport which will cost as much as the product themselves.
That’s where I am now.
Any (Inexpensive) ideas ? ? ?

Guy 13

4455


4456

 
4457


4458

 
4459


4460


4450


4451

 
4452


 

[Guy 13]

Hi all Audio Circle members.
WHAT ? No comments, suggestions, advices...
O.K. then, if you post something about your problem,
I wont comment your post. 
Just joking.

Guy 13
But I am serious about getting some comments on my post,
I spent some time writting this post.

[JLM]

Forget about styrofoam, foam rubber, or the curtains (all are acoustically useless).  Besides unless your room is a really awkward shape (cube for instance) the bigger the room the better.

Are you able to measure the in-room frequency response of your system?  (To solve a problem you must define it first.)  Do you have a microphone?  (I'm sure you can find test tones.)  How do you know how much ceiling absorption you need?

Nearfield setup will eliminate much of the room issues and it's free to try.

Search the net my friend.  The GIK website would be a good place to start to learn about absorption.

Find out what materials absorb at lower frequencies so you can get a balanced effect.  The best absorber is high density fiberglass (1 - 4 inch thick sheets).  Owens-Corning 703 I believe is the material, but being in Vietnam you'll have to find an equivalent.  Roxul looks OK, but not as good as 703 at lower frequencies and weighs only slightly less.  I'd mentioned tightly packed rolls of fiberglass insulation, it that's not available what else is that could be similar?

Diffusors that are sized for room use are only effective down to about 1,000 Hz and must be made of sonically impenetrable material (like wood) in order to work.  DIY recipes exist based on the math involved for the frequencies of concern (again what frequencies are a problem?).

I wouldn't sweat this too much.  The human ear is conditioned to listen in rooms that are 'typically' furnished (what's typical for you?).

BTW, what's 'armored concrete'?

[bpape]

JLM is right on the money. Even 'good' foam isn't worth much. The foam you're showing is likely closed-cell which as pretty much zero acoustic value. Only open-cell foam has some benefit, though not much.

3lb rigid fiberglass board is what you want or as close as you can get.  Mineral wool is another option that works well and can be slightly less expensive. I just don't know what is used there for building insulation.

Bryan

[WireNut]

Diffusors that are sized for room use are only effective down to about 1,000 Hz and must be made of sonically impenetrable material (like wood) in order to work.  DIY recipes exist based on the math involved for the frequencies of concern (again what frequencies are a problem?).

Hmm, I've always wondered why diffusors are made out of wood  always seemed odd to me since I've only used foam products for wall treatment.
So basically diffusors work based on overall size, width and depth of the gaps/valley's rather then absorbing like foam?   
Make's me think that a diffusor must be at least 4" thick in order to work properly, sound about right?

   


 

[Guy 13]

Hi bpape, JLM and Audio Circle members.
Thanks for your comments.
Living here in Vietnam for 18 years,
I know where to go to buy all kind of stuff,
but mineral wool, still looking for it.
By the way, most of the building are not insulated.
Armored concrete is concrete with re-bar inside.
Importing fiberglass to Vietnam is too expensive for my budget
Well I guess I will have to live with what I have now.
Thanks anyway.

Guy 13
My purchase of the HD-650 and Crack amplifier,
might be more useful than initially thought.