Room layout - acoustical assistance needed - Home Theater Forum and Systems - HomeTheaterShack.com
Reply
 
Thread Tools
post #1 of 29 Old 02-28-14, 03:32 PM Thread Starter
wd3
Shackster
 
Join Date: Feb 2014
Location: Indianapolis
Posts: 35
My System
Room layout - acoustical assistance needed

I have attached a drawing of my AV/Living Room, and I was wondering if anyone has some simple suggestions for making the acoustical characteristics any better. I suppose the only thing I have in my room that might adjust acoustics a bit would be the carpeting, furniture, and a heavy curtain in the rear of the room. I'm currently waiting for a UMIK-1 to arrive to measure the room and see how that goes. Also, after looking around on various threads, it looks like typically the biggest issue is bass. I use to have some bass nulls around my room. I haven't checked it recently since I just got new taller bigger couches, and I now have end tables in the corners. I also have a new storage cabinet in another corner. I'm not sure if there is anything simple that would make sense and meet WAF guidelines. Also, my room is about 2300 cubic feet not considering the openings leading to upstairs, kitchen, and foyer. Anyway, any assistance would be greatly appreciated.
Attached Thumbnails
Room layout - acoustical assistance needed-livingroom.jpg  

wd3 is offline  
Sponsored Links
Advertisement
 
post #2 of 29 Old 03-01-14, 08:41 AM
Shackster
Babak
 
Join Date: Mar 2009
Location: Vienna
Posts: 59
Re: Room layout - acoustical assistance needed

Hi

First of all don't worry about nulls.
Also reading threads about other rooms does not really give a picture about issues that are specific to your room.

It is always difficult to make an analysis from the distance.
Measurements will help for sure.
Do a RT30 or RT60 measurement and a waterfall diagram.

--------------

By looking at your drawing I see three points.

One is the asymmetry of the room.
You've got a wall at the right and the open room on the left.

I cannot say whether moving around the furniture is feasible for you.
You should toe in the speakers so they point to your listening position.

--------------

The second point is the wall behind your listening position.
Your are close to that wall and there is a heavy curtain that dampens the reflections.

This makes the reproduction rather flat, you will miss the depth of the recording.
Scattering the reflected sound from the back with diffusors is better than dampening.

I don't know whether there is a window behind the curtain or not.

If it is a wall, you could place a bookshelf there.
Place the books irregularly, then the bookshelf acts as a diffusor.
Align them more to the front edge of the shelves and leave some room between the books and the next shelf above (about 4 inches).
Then it will also act as a an absorber because the sound can enter between the books and the shelves and gets absorbed behind the books.

If it is a window, you need another solution to scatter the sound.
I am using a vertical blind in my living room.


You should also move away the listening position from the back wall.

---------------

That takes me to the third point.

Your listening distance is too far.

Ideally you should listen in an equilateral triangle with the front speakers, with the speakers toed in so they are directed right towards the listening position.

One rather easy solution would be to put a listening chair closer to the speakers, so the distance between the listening position and the speakers is the same as the distance between the speakers.
This would roughly be a little farther away than the ceiling fan.

If the chair can be turned is is easy to turn around if you want to sit and talk with other people on the couches.

And it would also increase the distance to the rear wall.

--------------

Maybe a fourth point.
Your rear surround speakers should be a little behind the seat.

All speakers should ideally be placed on a circle around the listening position.

The centre speaker should be right in front, on 0°.
The left speaker on 30° left.
The right speaker on 30° right.
The left surround speaker on 110 to 120° left.
The right surround speaker on 110 to 120° right.

------------

I hope that helps a little until you have some measurements.

Cheers
Babak
Babak is offline  
post #3 of 29 Old 03-03-14, 12:40 AM Thread Starter
wd3
Shackster
 
Join Date: Feb 2014
Location: Indianapolis
Posts: 35
My System
Re: Room layout - acoustical assistance needed

I suppose I should have been more specific. They layout of the room (i.e. the furniture and curtains) has to remain. I realize from an acoustical perspective it might not be ideal, but I'm sure lots of people use their living room as their home theater area. Because of this, it probably means that the space has to be livable and aesthetics plays an important part of things as well. So, I couldn't move the couch to the middle of the room or anything like that. Then it would be in front of and blocking the fireplace. Due to things like the fireplace, that does place limits on the space utilization. I do realize that having more space behind the couch would be better. In fact, having perhaps more space between the front wall and the speakers would be better. It's just not feasible from a usability perspective. Perhaps the next house I build will have some additional space for behind the couch and front speakers, but for now this is what I have to work with. I also can't make the room look like it is a science fiction movie set. I do plan on taking some measurements on the room. I have an UMIK-1 on order, but the only thing I have ever noticed is perhaps some nulls with bass. The room isn't boomy including the main seating locations for watching movies. In short, I'm just looking for some reasonable suggestions for possible improvements that I can look into. Although, I have to say I have been quite confused as to any reasonable approaches and whether anything should be done at all. For instance, I have read various conversations discussing bass traps, and the fact they may need to be quite large to accomplish anything and some have reported little to no differences in their room after deployment. Also, from various conversations you can do too much as well (i.e. make the room too dead). Perhaps the best thing for me to do since I don't ever plan to have a dedicated home theater area is to just use some EQ and call it a day.
wd3 is offline  
 
post #4 of 29 Old 03-03-14, 01:48 PM
Shackster
Babak
 
Join Date: Mar 2009
Location: Vienna
Posts: 59
Quote:
wd3 wrote: View Post
I suppose I should have been more specific. They layout of the room (i.e. the furniture and curtains) has to remain. I realize from an acoustical perspective it might not be ideal, but I'm sure lots of people use their living room as their home theater area. Because of this, it probably means that the space has to be livable and aesthetics plays an important part of things as well. So, I couldn't move the couch to the middle of the room or anything like that. Then it would be in front of and blocking the fireplace. Due to things like the fireplace, that does place limits on the space utilization. I do realize that having more space behind the couch would be better. In fact, having perhaps more space between the front wall and the speakers would be better. It's just not feasible from a usability perspective. Perhaps the next house I build will have some additional space for behind the couch and front speakers, but for now this is what I have to work with. I also can't make the room look like it is a science fiction movie set. I do plan on taking some measurements on the room. I have an UMIK-1 on order, but the only thing I have ever noticed is perhaps some nulls with bass. The room isn't boomy including the main seating locations for watching movies. In short, I'm just looking for some reasonable suggestions for possible improvements that I can look into. Although, I have to say I have been quite confused as to any reasonable approaches and whether anything should be done at all. For instance, I have read various conversations discussing bass traps, and the fact they may need to be quite large to accomplish anything and some have reported little to no differences in their room after deployment. Also, from various conversations you can do too much as well (i.e. make the room too dead). Perhaps the best thing for me to do since I don't ever plan to have a dedicated home theater area is to just use some EQ and call it a day.
Hi


I must admit that it is difficult to give advice
- Without knowing the room
- Without having any measurements
- Without knowing which changes are feasible for you and which are not
- Without knowing whether anything is wrong with the sound and if yes, what is wrong.

Just because others do something (adding panels, adding bass traps, etc) is not a reason to do the same.
Each room is different and needs different treatment.

And yes, some people add too much absorption and deaden the room and the sound.

Adding bass traps is also a difficult task. They must be made of the right material, have the right dimensions and be on the right positions in the room.

----------

So what is wrong with the sound in your room?

Nulls in the bass?
That's a tricky topic.

First, the human ear can does not perceive dips in the frequency range very well - if at all.
It perceives peakes much better.

I often observe that people think that bass is there if it is boomy.
The other way around, if the bass is dry and fast, they think bass is missing.


----------

There is also another possibility.

Your subwoofer is at the front wall.
There it excites all longitudinal room modes very well.
Your listening position is at the back wall, where all the longitudinal modes have the strongest effect.
So you get a maximum exaggeration of those bass frequencies.

The "nulls" that you hear could be frequencies other than those of the room modes.
They are weaker than the frequencies of the room modes.


So is it really a null or is it that several bass frequencies are over represented due to room modes being excited and others appearing to be weaker in comparison?

I think it's the latter.
But without knowing the room an hearing it, and without measurements to transfer data about the room characteristics over the Internet, nobody can tell for sure.

----------

Only having the drawing of your room I can only stick to basics.



Listening in an equilateral triangle with the speakers toed in (listening on the acoustical axis of the speakers) is one of the basic principles of listening in stereo and multichannel (front speakers).

In your current setting the opening angle between the listener and the speakers is less than the 60° of an equilateral triangle.
That results in a too narrow sound stage and in some coloration due to wrong HRTFs.


You can resolve that by simply adding one chair.
That would also leave spa)ce behind the listener (next issue solved) and if you choose the right chair, it won't look like in a science fiction movie, it can look like in a baroque palace of you like. ;-).

This would most probably result in a better imaging, precision and soundstage.

----------


Nobody suggested rearranging the whole room.


One of my suggestions was putting a chair closer to the speakers so you get an equilateral triangle.
That would leave the existing furniture where it is.

Only add one chair, that's it.


That would improve the following :
1. More precision
2. Better soundstage
3. Better depth ( due to bigger distance to back wall)
4. Probably better bass performance (moving the listening position away from mode maxima)

That's the easiest thing you can do and that would not change your interior design too much.


Cheers
Babak
Babak is offline  
post #5 of 29 Old 03-03-14, 04:05 PM Thread Starter
wd3
Shackster
 
Join Date: Feb 2014
Location: Indianapolis
Posts: 35
My System
Re: Room layout - acoustical assistance needed

So, the the recommendation is to place a chair in the middle of the room. I did state that the furniture has to remain, and I will not be able to add any additional furniture either as a point of further clarification. I just don't have any really good options due to the fact that first reflections would put absorption material in the middle of my fireplace and/or above my ceiling fan. I could place some behind the front speakers, but I'm not sure that would be very effective. So, that just leaves perhaps the rear corners where I might place some absorption material, and I might be able to do the same in the front right corner. Nonetheless, does anyone else have some suggestions other than Babak? At this point, I'm just looking for some recommendations or some guidance. For instance, once I get my UMIK-1 in, if the RT60 is X, you should add some additional absorption material, and based on your room layout you should look at placing them at X location. I'm looking for something along those lines to assist on what I should be looking for in my future measurements, and some typical things that people have done. All the while I realize that my layout is suboptimal perhaps, but it has generally always sounded good to me. I have just heard that room treatments add so much more refinement to the music/experience versus EQ or equipment alone. So, this is my first foray into trying to potentially address that if that is possible.

Last edited by wd3; 03-03-14 at 04:19 PM.
wd3 is offline  
post #6 of 29 Old 03-03-14, 04:33 PM
Shackster
Babak
 
Join Date: Mar 2009
Location: Vienna
Posts: 59
Re: Room layout - acoustical assistance needed

Hi

well, you somehow used the short versio of my recommendation.

The recommendation is to sit in an equilateral triangle with your fron speaker.

----------

This is one of the fundamental basics of listening with stereo/multichannel.
No acoustical treatment will improve what gies wrong when not listening in that configuration.

And without that configuration it also would not making sense to invest in better equipment later.

----------

If you leave the listening position as ist is now, it is surely good enough for leisure listening and watching movies.
It won't bee optimal for listening to music sriously or critically.

Putting an additional chair was only one suggestions.
You will also find other options to get an equilateral triangle.

----------


I don't see te point why you want to add acoustic absorption material anywhere.
Besides the fact that it does not work well in the room corners ...

Without having measurements that show what your room needs, I would not add any absorbers.

----------

You can also think about getting good headphones with a good headphone am for listening to musik and leave the existing system for watching movies or for playing musik more as a background (parties, etc).


Cheers
Babak
Babak is offline  
post #7 of 29 Old 03-03-14, 04:50 PM Thread Starter
wd3
Shackster
 
Join Date: Feb 2014
Location: Indianapolis
Posts: 35
My System
Re: Room layout - acoustical assistance needed

No offense babak, but I would like to hear someone else's opinion on this topic.
wd3 is offline  
post #8 of 29 Old 03-03-14, 06:38 PM
HTS Senior Moderator
 
bpape's Avatar
Bryan Pape
 
Join Date: Sep 2006
Location: Wildwood, MO (St. Loui
Posts: 5,288
Send a message via AIM to bpape Send a message via Skype™ to bpape
Re: Room layout - acoustical assistance needed

If things must remain as they are, then you must address the fact that you are too close to a boundary by trying to get rid of some of the boominess there with treatments behind you. Curtains won't do it so not sure there is anything you can do there.

Before the end tables we could have helped by treating those corners.

So what is left that we can address is the asymmetry in the room where the 2 speakers will have different responses due to phase issues between direct and reflected sound. That would be treating the front right corner with broadband treatment and the right wall with thicker reflection panels to minimize the reinforcement/cancellations from that wall that are not happening off the other wall.

You do not need to be in an equilateral triangle which is the border between nearfield and farfield. I have been in a lot of rooms that are far outside or far inside that triangle that had great sound. It's the sitting by the wall that is the big issue.

You are also getting more reinforcement from the right side back by your seating than from the partial wall at your left.

The fireplace cavity can be a source of resonances. If not in use, fill with insulation and cover with a nice decorative thin screen.

Placing the sub along the side wall between the rack and the fireplace may also help smooth things out a bit.

I'll not comment on the rest of the above as much of it is based on how one would set up a studio for nearfield listening. Even good mastering houses sit outside the equilateral triangle many times. Nearfield gives you more direct vs reflected sound. That's good when you can't control the room. It also trades imaging outside the speakers for better depth of imaging - good or bad pending your preference.

Blinds, etc can be OK for upper mid and high frequencies but will do little to nothing for voice range and down.

I am serious... and don't call me Shirley.

Bryan Pape
Lead Acoustician/Owner
Sensible Sound Solutions
bpape is offline  
post #9 of 29 Old 03-03-14, 08:55 PM
Shackster
Babak
 
Join Date: Mar 2009
Location: Vienna
Posts: 59
Hi

Just one comment.

I think there has been a mix up between the equilateral triangle and the listening distance.

An equilateral triangle has nothing to do with nearfield vs far field or medium field listening.

It is just a triangle with the same length of all sides.
No matter whether it is near field (eg 5 feet), mid field (eg 8 feet) or far field (eg 12 feet)

The crucial factor is the opening angle of 60°.

That's how stereo has been specified.
And that's how all the good Studios are set up (with different distances).
Anything else is a deviation from that standard leading to changes in imaging and coloration (different HRTFs).

The shorter the distance, the less influence from the room.
But then the speaker must be constructed for midfield or nearfield listening.

For usual HiFi speakers the distance (that's the sides of the triangle) should not be nearer than 7 to 8 feet.
Babak is offline  
post #10 of 29 Old 03-03-14, 11:19 PM
HTS Senior Moderator
 
bpape's Avatar
Bryan Pape
 
Join Date: Sep 2006
Location: Wildwood, MO (St. Loui
Posts: 5,288
Send a message via AIM to bpape Send a message via Skype™ to bpape
Re: Room layout - acoustical assistance needed

Correct - but a 5' equilateral and a 10' equliateral are both at the border of nearfield. Inside the triangle is technically nearfield. Outside is mid to farfield. I can sit 2' outside a 4' equilateral triangle and the the benefits of farfield even though I am close to the speakers.

And you agree with what I said. That's how all good STUDIOS are set up. Not how all good LISTENING ROOMS or all good HOME THEATERS are set up. This is not a studio and you're not listening for the same things. If you want to set it up like all good studios, you'd have MUCH more damping in the room than most yet you say you want to use furniture and blinds? Never seen a good studio do that.

I am serious... and don't call me Shirley.

Bryan Pape
Lead Acoustician/Owner
Sensible Sound Solutions
bpape is offline  
Reply

Bookmarks

Tags
acoustical , assistance , layout , needed , room

Quick Reply
Message:
Options

Register Now




PLEASE COMPLETE ALL REQUIRED FIELDS BELOW... THANKS!

REQUIRED FIELDS ON THIS PAGE
YOU MUST COMPLETE ALL OF THESE

Username
Password
Confirm Password
Email Address
Confirm Email Address
Random Question
Random Question #2




User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
PLEASE READ BELOW PRIOR TO ENTERING AN EMAIL ADDRESS!

ATTENTION!

YOU MUST ACTIVATE YOUR ACCOUNT!

Activation requires you reply to an email we will send you after you register... if you do not reply to this email, you will not be able to view certain areas of the forum or certain images... nor will you be able download software.

AN INVALID EMAIL ADDRESS WILL CAUSE YOUR ACCOUNT TO BE DELETED!

See our banned email list here: Banned Email List

We DO NOT respond to spamcop, boxtrapper and spamblocker emails... please add @hometheatershack DOT com to your whitelist prior to registering or you will get nowhere on your registration.


Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page



Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML is not allowed!
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

 


For the best viewing experience please update your browser to Google Chrome