[jimdgoulding]

The former.  The latter has dimensions too similar.  Good listening to you.

[Sonny]

I'm proud of ya    But now you have to deal with that window.  Young-Ho has some good ideas for covering it, and you could open it as that will act as a bass trap.  Nice system you have there.

Thanks Max!  Well, the other recommendation of "opening the window" which is a good idea, but only for warm summer/fall months! 

I was thinking of placing some 1.5 inch fiberglass panels, that are 2x4 feet on the ceiling at first reflection.  Also to do so on the side walls and back wall.  I here's a before picture, still in the loan process and won't close until the end of March.

Larger rectangular room:  (taken from the entry to the room)



Squarer room with the 9 feet ceiling: (taken from the corner of the room)

[OzarkTom]

I have always liked tall ceilings the best. One of the very best was a small lake house with a square room and 30 foot high all glass walls. That room made me sick cause all the owner had was some big box speakers and a Revox receier.

But since you have a choice, have a friend over and try both rooms.

[Sonny]

I have always liked tall ceilings the best. One of the very best was a small lake house with a square room and 30 foot high all glass walls. That room made me sick cause all the owner had was some big box speakers and a Revox receier.

But since you have a choice, have a friend over and try both rooms.

I used to have a room with 13' ceilings, 55 long and 20 - 35 wide, it was great, but that was in my loft and when I was single, now, I am married with two kids. 

I think the 1 ft difference may not be that significant, especially with the dampening I plan to do. 

Here's some pictures of the loft:

[bpape]

I would take the longer room.  It gives you a lot more flexibility in seat and speaker position to get the best starting response and keeping the modes spread out more evenly rather than a squarer room.

[Sonny]

I would take the longer room.  It gives you a lot more flexibility in seat and speaker position to get the best starting response and keeping the modes spread out more evenly rather than a squarer room.

Agreed!

Does anyone know of some easy to do DIY diffusions projects out there?

[JLM]

Here's a diffuser good recipe:  http://pmerecords.com/diffusor.cfm

Most diffusors work in one plane, these work in two planes but they're heavy.  Note that diffusor materials must be non-acoustically absorbent, so they're bound to be heavy.

Decware.com has plans, kits, and assembled typical one plane diffusors.  Note that diffusors typically are limited to roughly 3.5 octaves (1,100 - 12,000 Hz) based on geometry of the panels and size of sound waves.

[Sonny]

Here's a diffuser good recipe:  http://pmerecords.com/diffusor.cfm

Most diffusors work in one plane, these work in two planes but they're heavy.  Note that diffusor materials must be non-acoustically absorbent, so they're bound to be heavy.

Decware.com has plans, kits, and assembled typical one plane diffusors.  Note that diffusors typically are limited to roughly 3.5 octaves (1,100 - 12,000 Hz) based on geometry of the panels and size of sound waves.

Thanks...sounds simple enough, but lots of work!  Will need at least two (2x2) just for the back wall perhaps some for the side walls too?

[ACHiPo]

Agreed!

Does anyone know of some easy to do DIY diffusions projects out there?

Sonny,
I have some (4 24"x48") diffusors and will make you a deal.  They are poly and need to be painted or something.

AC

[JLM]

Thanks...sounds simple enough, but lots of work!  Will need at least two (2x2) just for the back wall perhaps some for the side walls too?

How'd you come up with needing only two panels?  8 square feet of coverage seems very small for a room with over 500 square feet of wall surfaces.

ACHiPo, what is "poly"?  If they are hollow plastic I can't believe they'd be acoustically reflective (as needed for diffusors).

[gregfisk]

I would go for the longer room, you are pretty close to the Cardas rule so it should be a much better space than a square.

JLM, I don't know this but it seems like as long as the diffusers can't absorb the sound, it shouldn't matter if they are hollow or what they are made of? Plastic is a hard surface so why wouldn't it work just as well or even better than wood?

[Sonny]

Sonny,
I have some (4 24"x48") diffusors and will make you a deal.  They are poly and need to be painted or something.

AC

Could you send me a PM or email to with pictures, and offer, etc?  I am PMing you.

I am in Washington, zip code 98335.

Thanks
Tuan

[Sonny]

How'd you come up with needing only two panels?  8 square feet of coverage seems very small for a room with over 500 square feet of wall surfaces.

ACHiPo, what is "poly"?  If they are hollow plastic I can't believe they'd be acoustically reflective (as needed for diffusors).

JLM, well, I don't want the room to be covered with diffusors, there needs to be some absorption as well, right?

[ACHiPo]

Could you send me a PM or email to with pictures, and offer, etc?  I am PMing you.

I am in Washington, zip code 98335.

Thanks
Tuan

Got your PM and will respond.

[JLM]

Again, what kind of "poly"?  What exactly is meant by "hard" (stiff, high strength, not easily deformed, non-resonsate, etc.)?  And what is the geometries involved (random depths, to how deep, how thick is the material, what dimensions is it trying to span)? 

Try contacting GIK here at Audio Circle (they sell diffusers and absorption) to see what proportion/locations/materials/geometries they recommend.

Or read "Sound Reproduction" by Floyd Toole.

I've just seen too many variations of open cell foam "absorption" panels and egg crate type of "diffusion" panels that are all useless.

[youngho]

Hi Sonny,

Looks like you can sit a decent distance from the rear wall, which opens up a lot of possibilities, whether it's diffusion or absorption (or some combination of the two). You'd probably want to start with 16-24 sq ft of diffusion for the rear wall (looks like there's a door in the corner, so focus on the middle section), for which you could consider a QRD-style diffuser (http://www.gikacoustics.com/product/gik-acoustics-q7d-diffusor/ or http://realtraps.com/diffusor.htm). There are also polycylindrical "diffusers," though one starts to get into semantics about whether they simply scatter sounds in different directions without changing phase/time as "true diffusion" does.

There's a basic representation of how a little absorption and diffusion might affect your perception of music here: http://www.wghwoodworking.com/audio/LoudspeakersandRoomsPt2.pdf

If possible, consider 3-4" absorption panels over thinner ones like the 1.5" you mentioned, especially for first reflection points.

Young-Ho

[youngho]

You might also consider working with a professional? These guys seem very reasonable:

https://www.gikacoustics.com/diffusion-by-jeff-hedback/
http://www.acousticfrontiers.com/early-reflections-101/