Author Topic: New Room Layout  (Read 1302 times)

Offline KenMasters

New Room Layout
« on: March 11, 2021, 09:28:18 AM »
After hunting around for a new apartment recently, my wife and I have developed a new appreciation for our current place. Calling our search off, we've decided a better investment would be to upgrade our living room area to make the most of the space we have.

To that end, I'm moving my AV setup from in front of the only source of natural light in the room (which I selfishly hogged so my speakers could fire down its length). We're also buying a new modular couch than can be reconfigured for social engagements, but now I'm getting sidetracked...

The apartment is soundproofed with two layers of thick drywall packed with damping material, other than the wall on the right, which is a solid structural wall (other side of which is still our apartment). The oak wood floors are also lying on top of a bed of damping material. To improve the listening experience within the space, I'd like to add some room treatment. As this is the primary living space of the apartment, it's important that the room remain aesthetically pleasing, so bass traps are not going to fly.

Here's the room layout, I've placed a number alongside each treated position so you can see what I plan to place there. Any opinions on the general layout or treatment types and positions appreciated:



1. Absorber and high frequency diffusor (D: 5cm W/H: 60cm x 120cm) - https://gikacoustics.eu/product/impression-series-50mm-acoustic-panel-diffusor-absorber/
2. Quadratic diffusor (D: 135mm W/H 415mm x 430mm) - https://gikacoustics.eu/product/gotham-n23-5-quadratic-diffusor/
3: Absorber (D: 5cm W/H: 150cm x 75cm) - https://akuarthome.dk/home-30-eller-50/home50/

If you care to know, this is the planned "social" configuration:


« Last Edit: March 11, 2021, 09:55:48 AM by KenMasters »

Offline Greyman

Re: New Room Layout
« Reply #1 on: March 14, 2021, 09:26:45 AM »
Start with treating the first reflection points with thick  8" medium density absorption panels, perhaps covered in a nice breathable fabric mounted off the wall. No need for diffusion or broadband absorption with scatter plates in the first reflection zone.

Offline Avian

Re: New Room Layout
« Reply #2 on: May 16, 2021, 08:34:42 PM »
Hi, I'm late to reply, but I've made a study of acoustics to better treat my own space, which now resides in a dedicated home cinema, but wasn't always. My advice is based on the evidence as found by Dr Floyd Toole in his book about Sound Reproduction, Acoustics and Psychoacoustics. They (Harmon) did extensive studies and the results were not always what one would expect., but it is evidence based according to how humans perceive sound, not just blindly according to measurements.

For your space I would say the most important thing to get dialed in would be the RT (reverberation time), basically how fast the sound decays and it would be a measure of how bright / reflective vs dull / absorptive your space is. A nice number to aim for is around 0.5 seconds at 500Hz.

Measuring this isn't too hard, any laptop / pc, free software (Room EQ Wizard) and I think around $39 for a UMIK-1 mic. So you have to spend a little, but then you empower yourself a lot.

Do a sweep and go to the RT tab, check your time at 500Hz and this will give you an idea as to how much absorption you should ad.

Most living areas have plenty of uneven surfaces, plus you have an asymmetrical room, so diffusion would be the finishing touches as there should be plenty al ready.

If you have access to absorption panels that are made with fibreglass, compressed to approx 48kg/m cubed, that is best, 100mm depth also best. It perform optimally across the broadest frequency range that way. You can make them if you want to go through the trouble. Any material that you can easily blow through will work as covering.

I noticed a coffee table between the sound source and seats - if this can get a soft covering it will make a big difference, especially if there is a center speaker in use.

Regarding first reflections, it is almost uniformly accepted that that is the 1st thing you absorb, but the evidence shows that it is optional and may to many sound better / more spacious. Don't just blindly absorb these areas, try leaving it reflective and diffusion and absorption. You may be surprised to like the image more when it's left reflective in many cases. This was one major thing I learned from the research that I had wrong before.

So to summarize :

1. Diffusion should be plenty, leave that for last
2. Don't blindly absorb the 1st reflections, try all the options and decide what your ears like best
3. The "exception' is the coffee table, the side reflections are optional, but center line reflections are always very bad
4. Thick diffusers work broader band, 50mm is the minimum, all other materials are inferior to 48kg/m3 fibreglass. Look at the data of the product you are aiming to get
5. Try to get a UMIK-1 and REW software, it's not too hard to learn the basics, measuring your RT will give you the best idea of which direction to go. Living areas and stereo rooms can be a bit brighter than cinema rooms. 0.2 - 0.5, the higher being domestic living area and the lower dedicated cinema rooms.

Lastly, have fun with it and go with what your ears like, all the while keeping everyone happy regarding cosmetics etc, and I'm sure the end result will be something you'll be satisfied with.

Offline KenMasters

Re: New Room Layout
« Reply #3 on: May 20, 2021, 04:47:15 AM »
Regarding first reflections, it is almost uniformly accepted that that is the 1st thing you absorb, but the evidence shows that it is optional and may to many sound better / more spacious. Don't just blindly absorb these areas, try leaving it reflective and diffusion and absorption. You may be surprised to like the image more when it's left reflective in many cases. This was one major thing I learned from the research that I had wrong before.

Sorry, I only noticed your reply now. I've also been doing my research and came across the same information, especially relevant to the coaxial speakers I use in my setup.

I have a UMIK-1 with REW and RT time is 0.466s at 500Hz untreated at my listening position. I'm currently in the process of putting everything together and ended up with this setup:



1: Absorber and high frequency diffusor (D: 5cm W/H: 60cm x 120cm) - https://gikacoustics.eu/product/impression-series-50mm-acoustic-panel-diffusor-absorber/

2: Freestanding Bass Trap (D: 10cm W/H: 60cm x 1465mm) - https://gikacoustics.eu/product/freestand-bass-trap/

3:Absorber (D: 5cm W/H: 150cm x 100cm) - https://akuarthome.dk/home-30-eller-50/home50/

4: Bass Trap and high frequency diffusor (H:120mm W: 585mm D: 410mm) - https://gikacoustics.eu/product/impression-series-corner-bass-trap/

Rectangle under the couch is wool rug (200cm x 300cm)
« Last Edit: May 20, 2021, 04:50:44 AM by KenMasters »

Offline Agaton Sax

Re: New Room Layout
« Reply #4 on: May 20, 2021, 06:53:25 AM »
A number of posts have now mentioned an ideal room to have an RT60 of 0.5s at 1kHz. This is true but it needs to be pointed out that a single figure RT 60 in small rooms can be misleading:

Firstly let us think about RT 60 and what it is for a minute. It is the time (in seconds) it takes for a sound i.e a pulse of energy to drop by 60db in an acoustic space. Too long and the room will be echoey, too short and it will sound dead. Concert Halls will typically have it at 2 seconds or so and cathedrals at much higher. Voice recording spaces, radio studios etc. will have it extremely short.  Domestic spaces will (should)have it in the sub-1-second area.

 Now let us look at the ambient noise floor of the domestic room. This is called the RC. An RC of 30 dB is usually what we aim for in listening rooms. In truth, the RC in the domestic environment may be closer to 40db. Most RC measurements are made dbA weighted. That is filtered from 1kHz down. That means lots of mid-frequency energy is simply ignored. dbC is much better for these purposes and dbZ , although seldomly used, probably best,

It makes no sense to run RT 60s if the tail end sits in the noise floor. One, therefore, needs quite a noise to be loud enough to shift the 60db to above ambient noise. Many speakers may not like a pulse of above 100db to create the RT 60. Many acousticians use a pistol shot. That is fine for a single freq RT 60 but...

Secondly. Striving for a single figure RT60 has the potential to sonically destroy a room. Much more important is a decay that stays within 20%  between roughly 200Hz and 5 kHz. with an absolute value (for stereo rooms) between 0.4s and 0.6s as said.  If not you will have a skewed response with either a woofle-woffel room or a tizz -tizz room. It is also important that the decay from RT20 and RT30 to RT 60  be smooth

This from Nyal Mellor and Jeff Hedback:

A room that exhibits uneven decay characteristics, where the sound decays much faster at some frequencies than others can at worst sound noticeably unbalanced with a ‘dull’ treble or ‘bloated’ bass. Uneven decay is most often caused by furnishings within the room such as thin drapes and carpets that absorb significantly more energy at treble frequencies (above around 1kHz) than they do at midrange frequencies. Providing the energy follows the criteria in Section B of this document, it is actually preferred to retain upper midrange and high-frequency energy. Our target here is for T20 and T30 to be within +/‐25% across the frequency spectrum. Significant changes in decay time from T20 through T60 are also a good indicator of spectrally unbalanced reflected sounds./i]

« Last Edit: May 20, 2021, 07:07:43 AM by Agaton Sax »

Offline KenMasters

Re: New Room Layout
« Reply #5 on: May 20, 2021, 08:38:35 AM »
A number of posts have now mentioned an ideal room to have an RT60 of 0.5s at 1kHz. This is true but it needs to be pointed out that a single figure RT 60 in small rooms can be misleading...

From what I understand, it's not really applicable to home environments, having been formulated to access much larger venues.

Offline Agaton Sax

Re: New Room Layout
« Reply #6 on: May 20, 2021, 10:13:30 AM »
From what I understand, it's not really applicable to home environments, having been formulated to access much larger venues.

That is as true as it is hilarious.

Any Acoustician will say that RT60 is not applicable in small rooms. Now, a small room would usually be anything  where f<Fc. Fc being the Schroeder frequency. For an Fc to be below 20Hz the room needs to be larger than 20 000 cubic meter. We all live in small rooms.

The  same Acousticians will then carry on and plan their entire planning for a small room  based on RT 60 !

Offline Avian

Re: New Room Layout
« Reply #7 on: May 20, 2021, 12:03:39 PM »
A number of posts have now mentioned an ideal room to have an RT60 of 0.5s at 1kHz. This is true but it needs to be pointed out that a single figure RT 60 in small rooms can be misleading:

Firstly let us think about RT 60 and what it is for a minute. It is the time (in seconds) it takes for a sound i.e a pulse of energy to drop by 60db in an acoustic space. Too long and the room will be echoey, too short and it will sound dead. Concert Halls will typically have it at 2 seconds or so and cathedrals at much higher. Voice recording spaces, radio studios etc. will have it extremely short.  Domestic spaces will (should)have it in the sub-1-second area.

 Now let us look at the ambient noise floor of the domestic room. This is called the RC. An RC of 30 dB is usually what we aim for in listening rooms. In truth, the RC in the domestic environment may be closer to 40db. Most RC measurements are made dbA weighted. That is filtered from 1kHz down. That means lots of mid-frequency energy is simply ignored. dbC is much better for these purposes and dbZ , although seldomly used, probably best,

It makes no sense to run RT 60s if the tail end sits in the noise floor. One, therefore, needs quite a noise to be loud enough to shift the 60db to above ambient noise. Many speakers may not like a pulse of above 100db to create the RT 60. Many acousticians use a pistol shot. That is fine for a single freq RT 60 but...

Secondly. Striving for a single figure RT60 has the potential to sonically destroy a room. Much more important is a decay that stays within 20%  between roughly 200Hz and 5 kHz. with an absolute value (for stereo rooms) between 0.4s and 0.6s as said.  If not you will have a skewed response with either a woofle-woffel room or a tizz -tizz room. It is also important that the decay from RT20 and RT30 to RT 60  be smooth

This from Nyal Mellor and Jeff Hedback:

A room that exhibits uneven decay characteristics, where the sound decays much faster at some frequencies than others can at worst sound noticeably unbalanced with a ‘dull’ treble or ‘bloated’ bass. Uneven decay is most often caused by furnishings within the room such as thin drapes and carpets that absorb significantly more energy at treble frequencies (above around 1kHz) than they do at midrange frequencies. Providing the energy follows the criteria in Section B of this document, it is actually preferred to retain upper midrange and high-frequency energy. Our target here is for T20 and T30 to be within +/‐25% across the frequency spectrum. Significant changes in decay time from T20 through T60 are also a good indicator of spectrally unbalanced reflected sounds./i]

Hi, this one is probably directed towards me I'm guessing!

You're correct, one shouldn't blindly follow just the RT60. And there's lots to it like you said. It's hard to give acoustical advice on the forum, the info / data one teach yourself over time is too much to transfer this way - so trying to help, you try to give a condensed idea of how to improve things.

My take away was just to get a measure other than your ears of whether the space is overly bright, but I should probably not have quoted Dr Toole's numbers out of context like I did, it's part of a comprehensive chapter in his book.

In my own space I measured the whole spectrum with waterfalls and looked at the smoothness etc.

So apologies if I mislead / misinformed someone - there are obviously very technically orientated and training / well self taught people on here. So I appreciate correct and apologize for inaccurate advice - the motive is to help though!

As more people contribute the advice will collective improve, so I welcome the effort of getting involved in the discussion!

Offline Avian

Re: New Room Layout
« Reply #8 on: May 20, 2021, 12:25:47 PM »
I refer to Dr Floyd Toole's book, The Acoustics and Psychoacoustic and Speaker and Rooms :

Page 63 :

4.3.5 Conventional Acoustical Measures in Small
Listening Rooms
A measurement of reverberation time in a domestic-sized room yields a number.
When the number is large, the room sounds live, and when the number is small,
the room sounds dead. The implication is that there should be an optimum
number. In spite of this, many thoughtful people believe that RT is unimportant
or irrelevant (D’Antonio and Eger, 1986; Geddes, 2002; Jones, 2003; Kuttruff,
1998). The numbers measured are small compared to those in performance
spaces, and so the question arises if the late-refl ected sound fi eld in a listening
room is capable of altering what is heard in the reproduction of music. Yet, RT
is routinely included as one of the measures of small listening and control rooms
for international standards, even to the point of specifying allowable variations
with frequency

Page 64 :
In a small listening room, we are in a transitional sound
fi eld that consists of the direct sound, several strong early
refl ections, and a much-diminished late-refl ected sound
fi eld. What we hear is dominated by the directional characteristics of the loudspeakers and the acoustic behavior
of the room boundaries at the locations of the strong early
refl ections. RT reveals nothing of this. As a measure, it is
not incorrect, but it is just not useful as an indicator of
how reproduced music or fi lms will sound. Nevertheless,
excessive refl ected sound is undesirable, and an RT measurement can tell us that we are in the ballpark, but for
that matter, so can our ears or an “acoustically aware”
visual inspection.


All I was trying to say is that last bit, but I agree I could have done it more comprehensively. Like he says, it's not that useful, but not totally irrelevant either.

Offline Timber_MG

Re: New Room Layout
« Reply #9 on: May 20, 2021, 02:40:38 PM »
The  same Acousticians will then carry on and plan their entire planning for a small room  based on RT 60 !

The RT60 is one indicator and below or even an octave above Fshroeder it matters very little. One must look at the trends and how they correlate with the loudspeaker power response much more than hitting a specific target like in a large commercial setting. Taken in isolation it amounts to sales talk imho.

In isolation RT60 is not by a long shot the only measure, one would look at ETC and analyses of them primarily and there one has to look at the loudspeaker and the setup regards reflections at low and high frequencies independently in much more detail. What does it help if only the late field decay is addressed by treatment and there are other reflections that are psychoacoustically far more relevant? These are things of furniture positioning and choosing areas to treat and how (deflect, diffuse, absorb).

That said there are some rooms with issues that a RT60 plot (averaged over multiple measurements please) can highlight. It is almost always just a guideline though and it will miss flutter echos, image destroying uncorrelated reflections and the like completely (same to be said for EQ aiming for a flat/target curve)


Offline windshear

Re: New Room Layout
« Reply #10 on: May 25, 2021, 02:06:47 PM »
Ken I would suggest if possible to take the No1 panels from the front wall and space permitting place them in the same position on the rear wall to get the maximum benefit of the scattering off the rear wall. It is wasted on the front wall for its scattering ability for the mains and center speaker to increase the "sound" bubble. Interestingly they don't provide diffusion values only an absorption graph, hence why I say its more of a scatter/absorber panel. I know its a bit of a reach but what are the chances of putting more of your no2 absorber panels on the ceiling first reflection point to clean up dialog smear. Also any chance of giving a screen shot of the EDT "time" (from 100Hz to 20K) as well as the ETC curve with a 40ms time window to give an idea of whats going on in this critical time with the reflections. These measurements would only be appropriate if the speakers and couches are in the new positions. On a tangent this whole issue of RT60 time is only relevant of done properly with a dodecahedron and not a normal loudspeaker as well as loud enough to ensure head room remains above your noise floor after the decay(if room noise floor is 40dB then you would need minimum a 100dB measured sound to measure it properly).

Offline KenMasters

Re: New Room Layout
« Reply #11 on: May 25, 2021, 02:31:57 PM »
Ken I would suggest if possible to take the No1 panels from the front wall and space permitting place them in the same position on the rear wall to get the maximum benefit of the scattering off the rear wall. It is wasted on the front wall for its scattering ability for the mains and center speaker to increase the "sound" bubble.

Unfortunately this is the living room, so I'm quite limited in the areas I could place certain panels. The large absorber currently on the back wall was only OK'd as it has a print on it.

Saying that though, my wife absolutely loves the look of the wood veneer panels, so there's a possibility I might be able to introduce two more to the back wall at a later date.

Interestingly they don't provide diffusion values only an absorption graph, hence why I say its more of a scatter/absorber panel. I know its a bit of a reach but what are the chances of putting more of your no2 absorber panels on the ceiling first reflection point to clean up dialog smear.

The ceiling in the living room is very low, there is really no space to do that and have it not look obtrusive. Also, I'm using Atmos Enabled speakers, so the ceiling needs to be reflective.

Also any chance of giving a screen shot of the EDT "time" (from 100Hz to 20K) as well as the ETC curve with a 40ms time window to give an idea of whats going on in this critical time with the reflections. These measurements would only be appropriate if the speakers and couches are in the new positions. On a tangent this whole issue of RT60 time is only relevant of done properly with a dodecahedron and not a normal loudspeaker as well as loud enough to ensure head room remains above your noise floor after the decay(if room noise floor is 40dB then you would need minimum a 100dB measured sound to measure it properly).

All I have is a measurement taken with the old setup. Living room is still busy being worked on:

« Last Edit: May 25, 2021, 02:34:42 PM by KenMasters »

Offline KenMasters

Re: New Room Layout
« Reply #12 on: June 08, 2021, 06:48:28 PM »
Posting the "after" - panels made quite a difference: