Room Treatments in the Real World

[FeddyLost]

nothing but concrete and dry wall when finished. Instead of covering the surfaces with soft material, I am considering just apply treatment as is.

I hope your constructor have good understanding of proper acoustic treatment and drywall building, because in ordinary empty rectangular room of such size typical RT in lows can easily reach 2000 msec. With nasty vibration of drywall and modal issues simultaneously.
In theory, if your room is made according to RFZ concept, you can use zero open porous absorption, but your picture don't look like standard RFZ...

 

[MarnixM]

The good news is you can get an idea quickly with a UMIK and REW. Run a sweep and check your RT60 decay times. If they are 300-400 ms, you are about ideal. Longer than that and you need absorption, less you need some hard diffusion to liven it back up.

Although many try to produce an acoustic “dry room”, Linkwitz states (1): ”For my open baffle speaker designs a room becomes too dead when its RT60 falls below 500mS”.

• S. Linkwitz, “Room acoustics” (2014), http://www.linkwitzlab.com/rooms.htm

 

[Hexspa]

you seem to have perfectly understood everything.

Unfortunately REW doesn't offer any sort of frequency specific cycles so I can't pick one cycle for 20KHz but 10 for 100Hz so you kind of have to experiment a bit with your room and your hearing and trial and error what works (pink noise is incredibly discerning).

However a cycle is one frequency length so in that way it's frequency specific, but 10 cycles for 20Khz for a space as big as a room is way too much.

Thanks for that. You don't apply any smoothing to your graphs prior to EQ do you? I know that REW recommends using Variable smoothing for signals to be equalized. My main concern was if you apply VAR when viewing and interpreting Excess Group Delay. Also, how "far out" do you allow EGD to be before you say, "I can't EQ here,"? For example, subwoofers are often delayed by some amount (and increasing EGD inversely to frequency) yet they can generally be EQed pretty well. Is it just spikey areas you avoid or are a few bumps ok? Thanks.

 

[CDMC]

Although many try to produce an acoustic “dry room”, Linkwitz states (1): ”For my open baffle speaker designs a room becomes too dead when its RT60 falls below 500mS”.

• S. Linkwitz, “Room acoustics” (2014), http://www.linkwitzlab.com/rooms.htm

Keeping in mind, open baffle speakers function differently and a good part of their sound is based on the rear wall reflections. There is also the matter of personal preference.

 

[FeddyLost]

Linkwitz states (1): ”For my open baffle speaker designs a room becomes too dead when its RT60 falls below 500mS

I need to add that I've never seen studio with open baffle speakers.
So it's very questionable solution if one needs correct reproduction of "original sound field" in typical control room with all consequences regarding "common standards" of room for these speakers.

 

[dasdoing]

Unfortunately REW doesn't offer any sort of frequency specific cycles so I can't pick one cycle for 20KHz but 10 for 100Hz

it is possible with the "merge B to A" function

a fast conceptual example:

1fdw and 15fdw of same measurement

merged at 1894Hz

 

[NIN]

Although many try to produce an acoustic “dry room”, Linkwitz states (1): ”For my open baffle speaker designs a room becomes too dead when its RT60 falls below 500mS”.

• S. Linkwitz, “Room acoustics” (2014), http://www.linkwitzlab.com/rooms.htm

Dead, comparing to what? Unless the RT60 is so low that one get problem with comb filtering and if the room don't have good enough with "positive reflection", I would say it is just personal preference.
I like "dry" room because I see the high RT-60 as a coloration that will be on every recording one listen to. For me a good dry room will show and reproduce the music with a bigger difference between the recordings because a "high" RT-60 would somewhat smear the difference between a dry recording and a recording with more air/reverbaration/wet sound. That is my preference.

 

[NIN]

I also think that many that talk about to "dead rooms" are talking about rooms with unbalanced treatment. One need not only to think about absortion and diffussion, one also need to have a good balance between absortion, diffussion and "right" reflections in the room.

 

[dasdoing]

I also think that many that talk about to "dead rooms" are talking about rooms with unbalanced treatment.

yes, when they say "dead room" most of the time they mean "too much hf absorbtion". I reduced my reflection free zone by removing the huge ceiling panel I had before, and I like it much more. on the sides all first reflection points are treated. floor is reflective, too. But this might work for me only because I have speakers with a very controlled (small) vertical

 

[NIN]

yes, when they say "dead room" most of the time they mean "too much hf absorbtion".

I agree. My absorbtion is rather straight down to around 30Hz, with around 200ms between 200Hz-15kHz and 200ms from 200Hz to a peak of 470ms at 33Hz.

 

[Sokel]

You probably need to take a look at this thread,it's dense but gives a lots of answers (and raises a lot of questions too)

How NOT to set up speakers and room treatment ( Goldensound)

if the mods think this isn’t appropriate please remove. it just irks me that this guy is 24 years old , this is his FIRST room with speakers and he made a video on it. and it’s a bunch of BS. his room has an RT60 of 250ms. its a room NOT headphones. he shows an impulse response and...

www.audiosciencereview.com

 

[NIN]

You probably need to take a look at this thread,it's dense but gives a lots of answers (and raises a lot of questions too)

How NOT to set up speakers and room treatment ( Goldensound)

if the mods think this isn’t appropriate please remove. it just irks me that this guy is 24 years old , this is his FIRST room with speakers and he made a video on it. and it’s a bunch of BS. his room has an RT60 of 250ms. its a room NOT headphones. he shows an impulse response and...

www.audiosciencereview.com

Who?

 

[Sokel]

Who?

Amir and others,people who actually know what they're talking about.
Eye opening thread!

 

[NIN]

Amir and others,people who actually know what they're talking about.
Eye opening thread!

Ahh, a superior comment. Good to know that your comments will be ignored in the future.

 

[dasdoing]

haven't read that thread, but appears to be ego-fueled debate among supporters of two valid yet distinct approaches to acoustic room arrangement.
It all depends on how you listen. If you aim to transport yourself out of your room and into the recording room, exclude your room from the equation. If you desire your room to be filled with sound and vibrating bass, leave it mostly untreated. Both approaches are acceptable.

 

[NIN]

haven't read that thread, but appears to be ego-fueled debate among supporters of two valid yet distinct approaches to acoustic room arrangement.
It all depends on how you listen. If you aim to transport yourself out of your room and into the recording room, exclude your room from the equation. If you desire your room to be filled with sound and vibrating bass, leave it mostly untreated. Both approaches are acceptable.

Correct, there are different approaches how to listen and fix the room acoustics.
These "X said Y and because of this all other views are not valid" comments are not fruitful and just unscienctific. Science are very seldom just one perspective and almost never stagnated in time.

 

[FeddyLost]

If you desire your room to be filled with sound and vibrating bass, leave it mostly untreated.

Actually, if you want to have "effectively anechoic" room without room-specific issues, but with reflections and spatial impression, such goal is even more difficult than damping everything. Good reflecting room with proper ITD gap is a tough project.
At least, you'll need bigger room at start.

 

[Sokel]

haven't read that thread, but appears to be ego-fueled debate among supporters of two valid yet distinct approaches to acoustic room arrangement.
It all depends on how you listen. If you aim to transport yourself out of your room and into the recording room, exclude your room from the equation. If you desire your room to be filled with sound and vibrating bass, leave it mostly untreated. Both approaches are acceptable.

It's one of these threads that one can find a massive volume of research (scientific,published) gathered in one place.
Ok,it's a forum thread,there are opinions and strong debate too but one can filter out himself and get a good view.

 

[dasdoing]

Actually, if you want to have "effectively anechoic" room without room-specific issues, but with reflections and spatial impression, such goal is even more difficult than damping everything. Good reflecting room with proper ITD gap is a tough project.
At least, you'll need bigger room at start.

It's kind of an abandoned concept, right? Since engineers mostly monitor in the very near field anyway. Though I obviously see the application for audiophiles.

Never heard a room like that, but they say it becomes bigger? But one thing I can say to you is that for spatial impression, you don't need diffusion.
And yeah, diffusion doesn't work in small rooms anyways

 

[NIN]

Unless you have a dedicated listening room, the audio system will have to co-exist with the living area. Room treatments like bass traps have no place in the living room. At best, we can do something about placements and that's about it.

Use RoomPerfect or Dirac Live to fix room issues. They are really pretty good.

Well, may be in many cases but if one can build the backwall to incl bass traps it can work in a living room. The back of my living room with around 7,5m3 bass traps (both sides + floor riser) and I think it works great as a living room.
But I do understand that a room that adds bass traps not built in could have problem looking like a normal living room.

A couple of years old picture of my room.