Schroeder Diffusor Installation

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matriachamplification

Wall Thomas
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Joined
Feb 3, 2019
Messages
451
Location
Ontario, Canada
Hello friends,

Full disclosure. It feels good to be back on GDIY! My family and I I hope you are well in these surreal times. This build is a hybrid QRD and Ramped QRD design with low frequency treatments. Acoustic Engineering is more complicated then I can convey and we have been working on the look-book for several years as a starting point for Martin and the team at Pilchner Schoustal, Hopefully this thread can help us decide on some options.

Since this is our first post in some months we should fill GDIY in on our progress. For starters we are still building out cards for our console and still ordering parts. More on that soon.
On a side not, we have had 2 garbage bins dropped/filled with a last bin coming in a few days all in preparation for re-modelling our farmhouse. With lumber long stored in the Barn we are eager to start building and hope to gather insight from GDIY in regards to carpentry, materials, build techniques etc.

We've attached the basic layout of the room we are developing first. A 16.5 x 14.5 x 9-9.5 room. The Schroeder Diffusor or Quadratic Residue Diffuser that we are building is an instillation rather then what we know as a typical QRD Panel. We say installation as the "Walls" will include LF absorption and... well.. it is a 14.5 x 9 foot wall. Its a lot of real estate to cover in timber.

I am going to do my best to be thorough in this thread.

Couple notes on the room.
  • The floor is maple hardwood and slopes from 9 feet to 9 1/2 feet giving us a "natural" offset with the ceiling.
  • There is a 8.25 foot "open concept" nook that leads into the fireplace lounge and kitchen.
  • There is a 9 inch trim around the base walls of room.
  • ?Slat & Plaster? walls (building over)

CARPENTRY

While we are fortunate to have the tools, materials and space to build this installation, there are so many techniques that experienced carpenters can impart we simply will not consider. We hope to implement some clever carpentry into our QRD walls. Storage space being important as well as Sunlight. That said building sliding QRD doors or hidden cupboard styled doors that cover that windows is of importance.

MATERIALS

We are interested to learn more about materials used in Sound Absorption. My partner asked if we can make a couch and is interested in learning about the acoustic properties of furniture foam.

BUILD TECHNIQUES

We have been taking in the many unique QRD builds on youtube. We are hoping to figure out how to create a seamless look for the Ramped QRD on the ceiling and QRD Wall.

Thank you for reading this and please ask any questions you might have,

Be well,

Wall
 

john12ax7

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2,094
Location
California, US
Foam can work good for absorption if it is open cell, you want something that has been tested and verified for acoustics. Regular furniture foam may or may not work. Regular foam can also be very flammable, something to definitely avoid.

Roxul, OC703, and the pink fluffy fiberglass are all common for studio absorption. Can be very irritating to some people though, another thing to keep in mind.

I've been curious to try the Caruso Iso bond, seems like a great option.

Whichever way you go, the deeper the better, as the thickness will be directly proportional to the frequency of absorption. (There is some nuance to this with the material characteristics)
 

matriachamplification

Wall Thomas
GDIY Supporter
Joined
Feb 3, 2019
Messages
451
Location
Ontario, Canada
absorption and diffusion are different, low end management takes volume and mass, diffusion will need to be taylored to the space, start with isolation requirements.
make sure your floor/foundation is built to hold the weight you will be adding

Noted and thank you Shabtek for the clarification as well as thoughtful advice. To re-iterate his first point, Diffusion and Absorption are not the same.

Weight issues. Yes... a major concern. The floor/foundation is solid 'ish'. So, we will be adding several extra support beams as a precaution. When looking in the dirt basement we did make note that the floor in question is uninsulated. To address this we will be adding Roxul 24 (doubled) that "should" help with Low End Absorption as well as the cold winters here in Canada.


Wall
 

matriachamplification

Wall Thomas
GDIY Supporter
Joined
Feb 3, 2019
Messages
451
Location
Ontario, Canada
Foam can work good for absorption if it is open cell, you want something that has been tested and verified for acoustics. Regular furniture foam may or may not work. Regular foam can also be very flammable, something to definitely avoid.

Roxul, OC703, and the pink fluffy fiberglass are all common for studio absorption. Can be very irritating to some people though, another thing to keep in mind.

I've been curious to try the Caruso Iso bond, seems like a great option.

Whichever way you go, the deeper the better, as the thickness will be directly proportional to the frequency of absorption. (There is some nuance to this with the material characteristics)
Thanks! The tip regarding the flammability of furniture foam is something we had not discussed. Caruso ISO Bond looks promising.

Roxul 24 has been our goto. We have built several Roxul M/HF Panels that work wonderfully well in the kids rooms. My wife was not willing to build furniture from Roxul for the same reasons you mention. Caruso ISO Bond looks to be perfect for her vision. Nice find! We are reaching out to Fidelity Audio now.

Wall
 
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