[rockdrummer]

Hi everyone.  I have been on a mission to learn about acoustic treatments.  I have an OB kit from GR research that I will be building when I pick up the servo sub bottom end for them.  Anyway, I read somewhere that OB speakers like diffusers.  I think they should go behind the speakers on the front wall.  I will also put bass traps  somewhere in the front too.  They are going to go into a finished basement that has a really long main room.  I will be able to really only do treatments in the front of the room. 

It seems really overwhelming.  Maybe because when I read so many different ideas, I have trouble sticking to one.  I was planning a skyline diffuser.  I also was wondering how I decide what frequencies to plan to diffuse. 

But anyway, I just really hope to get some direction, at least confirming my knowledge so far about OB needing treatments and what kind.

Thanks so much for your time.

Ben

[-Richard-]

Hi Ben  ~ The idea of room treatments has always seemed to me as a 'trouble-shooting' approach... to something that is disturbing about ones OB configuration assuming one does not want to readily change a device. These days many sophisticated audio enthusiasts use a digital device to alter frequency gamuts to 'correct' how a system sounds in a room... rather than to physically change the room around, but they are expensive and yet another layer of technology to have to deal with.

Why not just listen to your system first before doing anything?

I live in a fairly 'live' space that emphasizes the 'hall' effect to the sound... which I love. I have never heard about OB's needing or liking 'diffusers '(?)

With Warmest Regards ~ Richard

[SteveRB]

I believe that the man 'issue' with OB and room treatments is that the speakers are firing mids and highs at the front wall from very close range. While this can add to the effect of the speakers. It can also take away from other audiophile effects due to the reverse phase reflections being so close behind the main front wave.

In domestic sized listening rooms this can be an issue or a pleasing effect.

Have to say this is probably a trial and error situation. General rules such as 20% surface area absorbers and 25% surface area diffusion would be a good start.

[AJinFLA]

I read somewhere that OB speakers like diffusers.

No, speakers are inanimate objects and don't "like" anything.
What you most likely read, was that some person(s) preferred diffusion, in their room, with their tastes. Tastes and rooms differ.
I prefer diffusion on my rear walls only, but my speakers are 7' from the front wall and 6' from the sides, with toe-in. My room is "treated" with furnishings. My tastes slant towards acoustic/orchestral/jazz music and not as much studio constructs. So YMMV.
As with any of these things, I would suggest starting slowing and doing things in reversible steps, be they diffusion or absorption. Diffusion rear, then front, then....etc.
Each step, trust your ears/tastes, make them non-permanent.
A useful site: http://www.linkwitzlab.com/rooms.htm

cheers,

AJ

[rockdrummer]

Great information. Thanks. I am jonesin to do something. So superchunk and diffusers are going to be my next project.

I am trying out a few plans for calculating and building.
Ben

[InfernoSTi]

Every room is unique and should be treated as such…so take all comments (at least mine) with a grain of salt, please.

I like to treat a room for a couple of different things.   

First, I like to tame room modes below 500 Hz or so with bass traps, etc. The more the better and I like them thick…12" thick is great! 

Second, I like to tame decay so the room gets back to flat sooner (as seen on waterfall graphs).  This seems to aid clarity and detail a lot!

Third, I like to have a diffusion on the sides and front corners and absorption on the front and back walls generally speaking.  So my sides are live and my front and back are dead, if you will.  This is for a medium to large room.  I follow the 1' per 1" of diffusion depth rule (so I need to be at least six feet away from a diffusor that is 6" deep, for example).  This can change things with a small room (significantly). 

I then like to move stuff around and see how things sound.  Diffusion here, there, absorption here, there.  Just listen to see what sounds right to you. 

Finally, I like to treat my corners very much. I cover my corners with bass traps and diffusion and I make sure I have corner triangles in place if my ceiling/wall/wall corner is exposed.  I don't like 90 degree intersections in my room (three way 90 degrees being the worst). 

Most important: space the OB speaker a lot farther from the front wall than ever before…"tune" them to get a clear image.  Think of the front wall reflection as a tuning experiment and move the OB speakers further/closer to the front wall to match the first reflection timing that creates space but not blurry imaging.

Best,
John