Interesting article on Room Effects

Very important point that. From my experience, once people head down the acoustic treatment route, they tend to put too much absorption in the room. Your will definately hear a difference doing that but don't loose sight of the fact that a highly diffuse sound field (within limits) is really better for music than an overly "dead" acoustic environment.

Home cinema is an exception where a low reverberation time is preferred as the soundtrack is mixed with that type of playback environment in mind (i.e. cinema).

 

IME rooms with high ceilings sound best.

 

like a catherdral, devil

 

No, just rooms with relatively high ceilings.

 

Higher ceiling = greater room volume.

Greater room volume allows a higher reverberation time and better chance to develope a highly diffuse sound field and that's a good thing.

 

I used to have three 4 ft x 2 ft rockwool absorbers on the wall behind my speakers. They worked very well until I put diffusers behind the listening position. The absorbers had to go as the room then sounded too dead.

My diffusers can be found here: Diffusers

 

Diffusers are supposed to make the room more airy sounding surely? I thought it was too much Absorbtion that made a room dead.

 

Diffusors only offer a small amount of absorption...

Book shelves make good diffusors if they are full of reflective material (like CD cases and books) arranged in a random fashion, fill it with teddies and the like and it becomes more absorbtive. A properly designed diffusor is always going to work better than a bookcase though

 

:lol: I originally put in the absorbers to kill echoes - the sort that go 'booooiiiing' long after a hand clap has ceased. It worked.
For whatever reason, adding the bookcases made the system lack air. Removing the absorbers brought it back and the echoes are still gone, presumably because they are now being diffused rather than absorbed.

The bookcases have one advantage over any of the diffusers I've seen so far. They look good in my living room

 

You just need to frame a perfect square of it in oak, then present it as an arty gift. How could she possibly refuse?

 

With a flying stilletto

:lol:

 

You know my wife???

 

Hi,

The article makes a few major and key points:

1) To sort out LF in the modal range there are few alternatives to equalisation that actually work outside the Marketing departments.

2) To deal with reflections in the diffuse field range you have two options, on one side you may utilise speakers designed with controlled and quite narrow directivity, which simply does not have such problems, the other option is to place SUBSTANTIAL THICKNESS (2"+ foam et al) and large surface foam or other absorbent materials.

Of course, it is funny that I have been tub-thumping and welkin ringing on about the same issues for ages, completely independently from REG (I don't read TAS).

Ciao T

 

i agree

i used to tell my bosses at rayleigh that the dem rooms sounded like shite cos they had no diffraction and no absorbtion so only linn kans sounded good which obviously suited them down to the ground.
it was just when you put a decent speaker in there it went tits up.
oh well now they just make home cinema sound shite.

 

Thats an interesting comment,and bears out exactly what I found when I went for a Linn Keltik demo there some yrs ago....speakers which I knew sounded superb in the right environment flattened by the room reflections.

 

Are you suggesting I put my underwear collection on display?

 

Only if you want your system to be pants

 

the thicker absorbtive material will absorb over a wider bandwidth, thicker foam is not necessarily the best way forward, thinner solutions spaced away from walls also work and have better absorption in some instances over equivelant depth foam

*badaBoom-Tish!*
Thanks very much laadeez and gents, im here all week, and please, try the Chicken Wings....

 

50mm foam or mineral wool absorber surface mounted to walls gives greatest absorption at freq. around 400Hz and above.

100mm absorber gives greatest absorption at freq. around 200Hz and above.

50mm absorber SPACED 50mm from wall gives essetnially the same performance as 100mm surface mounted absorber.