|
Post by spock999 on Oct 24, 2020 6:58:10 GMT
I wanna treat the Front of the Studio (Back of the monitors) and looking at some info about sound refflection I see that I will get some refflection between the monitor on the wall but also direct sound directly from the back of the monitors a little further left and right. So back to my question, already having Floor to ceiling Bass trap on Both side corners , can I use Absorber behind the monitor and diffusion between them at the reflection point ?
Follow up question
Should I use 6'' or 3'' Absorber with a 1'' Aire Gap behind the monitor ?
Should I use Square Quadratic or Skyline Diffusor ?
|
|
|
Post by Hexspa on Oct 25, 2020 0:26:18 GMT
I don't have direct experience with diffusers. My understanding is that Ethan prefers treatment, including diffusion, on the rear and side walls first. Reason being that less sound radiates to the rear - particularly in the frequency range that diffusion is desirable.
In any case, thicker absorbers are generally better as long as coverage is equal. Skyline diffusers are for the ceiling since they radiate in three dimensions whereas well-QRD radiate laterally only. Diffusing vertically is counter-productive for vertical walls.
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Oct 26, 2020 19:53:04 GMT
Hexspa Many designers still use 2D QRD diffusion(skyline) on rear walls too.
|
|
|
Post by Hexspa on Oct 26, 2020 21:38:48 GMT
Hexspa Many designers still use 2D QRD diffusion(skyline) on rear walls too. That may be so but my main source of acoustics knowledge is from Ethan. If I understand him correctly, directing diffuse reflections toward the ceiling and floor is a waste of purpose. I've heard him say this several times.
Besides this, we can't assume that every skyline diffuser on a rear wall is put there by A.) a professional acoustician or B.) wasn't specifically chosen for other than aesthetic reasons or to bump up the cost of installation.
Regardless of the authority, there must be pros and cons to each. What are they? I found some references:
Understanding Audio; Daniel Thompson "Diffusion is generally most effective at the back of a listening room."
Absorbers and Diffusers; Cox, D'Antonio Emphasizes rear wall diffusion. You should be in the far field where a coherent wavefront is developed. Small rooms disallow this distance. Diffusion should be heard - directed at listener though diffuse. Lots of pics emphasizing 1D diffusers in mastering rooms, live rooms, and rehearsal rooms with 2D toward or on the ceiling.
They do say, however, that 2D diffusers are the least coherent in the far field. The last thing I'll mention about this book is they go into great length about the difficulty of predicting the final result of diffusion - particularly 1D diffusion. Maybe this has changed since the edition I'm reading (2004).
Less emphasis seems to be placed on what kind of diffuser as where. It seems to me that you want the diffusion distributed along the ear plane. What's clear is that, for something as expensive and labor-intensive as a diffuser, it makes less sense to put it behind the speakers - especially when the EBU spec only calls for increased decay between 4-8kHz. That's definitely outside the omnidirectional low frequency radiation of most studio monitors.
My takeaway is that, though the design of diffusers is scientific their application is often heavily dependent on taste. Problem solving aside, such as decorrelating strong echoes in a performance hall, usually people put in diffusion because they don't want a dead-sounding room. This is despite a dead-sounding room potentially being more accurate.
Fun fact: you don't need diffusers to create a diffuse space. All you need is a clever array of reflectors to bounce the sound around all the walls before it hits the listener.
TL;DR - The safe bet is well-type diffusion on the rear wall and skylines on the ceiling.
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Oct 27, 2020 13:31:51 GMT
Hexspa Many designers still use 2D QRD diffusion(skyline) on rear walls too.
Fun fact: you don't need diffusers to create a diffuse space. All you need is a clever array of reflectors to bounce the sound around all the walls before it hits the listener.
Yeah, basically. Its not actually what would qualify as true diffusion. But i've had great results just doing "random" and bad results. They're always unpredictable.
|
|
|
Post by Hexspa on Oct 27, 2020 23:15:32 GMT
Cox and D'Antonio disagree. Acoustic Absorbers and Diffusers p.344 says: If the overall room shape and sizes and orientations of surfaces are such that they will cause reflections to be well mixed for purely geometrical reasons, a diffuse field may be created even if no rough or scattering surfaces are used.Earlier in the work, they define 'diffuse field' as:
A diffuse field is one where there is uniform reflected energy density across the whole room, and all directions of propagation are equally probable.That sounds like 'true diffusion' to me.
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Oct 28, 2020 14:51:53 GMT
Well, thats probably in a large space. I had in mind more like small spaces..
|
|
|
Post by Hexspa on Oct 28, 2020 21:13:00 GMT
It definitely seems impractical - especially for small spaces, like you say. I just thought it was neat that it's possible.
|
|