First reflection points & dead front wall - AVS Forum
Forum Jump: 
 
Thread Tools
post #1 of 7 Old 06-10-2012, 07:34 PM - Thread Starter
Senior Member
 
Yzfbossman's Avatar
 
Join Date: Nov 2007
Location: Frisco, TX
Posts: 258
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 50
hey Guys,


I’m just beginning my theater design. I plan to start a planning thread soon. smile.gif

I have a few tweaks to make to this design but I want to make sure I’m figuring out the first reflection points correctly.

I did a mirror image of the speakers and drew lines to the seating positions. As I understand this will give me the point on the wall to place treatment … Q1 did I do that right?

I used this method -> See the last section "FIRST REFLECTIONS: SIDE WALLS" & Figure 4 on this link

http://www.realtraps.com/art_room-setup.htm


The green shaded area is the full treatment area taking into account the front and rear seats.

My room is wide…19’ and it looks like it makes my treatment area soo large.

Q2 with that wide of a treatment area will columns be a problem in that area?


My false wall is 9” deep. I plan to make the front dead…Q3 is 9” deep of acoustic treatment too much for the front?

Thanks
Rick

BTW - The room is 19’9” x 19’9”




464

Here is my build thread:

---->
To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.
<----
Yzfbossman is offline  
Sponsored Links
Advertisement
 
post #2 of 7 Old 06-10-2012, 08:05 PM
AVS Special Member
 
Spaceman's Avatar
 
Join Date: Nov 2009
Location: North Houston
Posts: 1,966
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Liked: 100
Q1-This is how I have seen it done in the past.

Q2-Depending on how you design your columns, they can be incorporated into your acoustic plan. Many are fabric wrapped, so could be treated just like the wall.

Q3- You may have 9" of space behind your false wall but you certainly don't need 9" of acoustic treatments back there. Many get by with just 1" of Linacoustic. Others do 2" (2 layers of 1" material). Others add a layer of 3-6 mil poly sheeting between the 1" layers. I don't think you need anything more than 2". Certainly not 9". One thing that will help are bass traps in the corners. You should look at designing your false wall to accommodate a triangular bass trap in each corner.

A few comments/questions on the plan.
1. I see a line on your plan, between the false wall and front row of seats, that resembles a curved stage. Is that what I'm seeing? If so, why is it so far out into the room? Do you hold neighborhood karaoke contests?
2. Is the entrance to the room in the back left corner? I'm assuming that is why you don't have a 5th seat in the back row.
3. You may need to address some negative acoustics as a result of your room being square. I don't have the experience/knowledge to tell you what needs to be done. I just know square rooms tend to present their own unique set of problems.

Look forward to seeing your planning/build thread. Good luck.

Spaceman Theater Build


To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

Spaceman is offline  
post #3 of 7 Old 06-10-2012, 08:29 PM - Thread Starter
Senior Member
 
Yzfbossman's Avatar
 
Join Date: Nov 2007
Location: Frisco, TX
Posts: 258
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 50
Quote:
Originally Posted by Spaceman View Post

Q1-This is how I have seen it done in the past.
Q2-Depending on how you design your columns, they can be incorporated into your acoustic plan. Many are fabric wrapped, so could be treated just like the wall.
Q3- You may have 9" of space behind your false wall but you certainly don't need 9" of acoustic treatments back there. Many get by with just 1" of Linacoustic. Others do 2" (2 layers of 1" material). Others add a layer of 3-6 mil poly sheeting between the 1" layers. I don't think you need anything more than 2". Certainly not 9".

Thanks Spaceman!

I'm wondering if it's a negative to have 9"...or would it act as an additional bass trapping?
Quote:
Originally Posted by Spaceman 
One thing that will help are bass traps in the corners. You should look at designing your false wall to accommodate a triangular bass trap in each corner.

I do plan to put in corner bass traps in all 4 corners. I also plan to open up the riser with "vents" along the back wall so it can act as a bass trap too.
Quote:
Originally Posted by Spaceman 
1. I see a line on your plan, between the false wall and front row of seats, that resembles a curved stage. Is that what I'm seeing? If so, why is it so far out into the room? Do you hold neighborhood karaoke contests?

yes it's a stage. two things 1) front left is a door to the attic. It will make it easier to conceal with the longer stage. 2) I thought it would be fun for my kids to have a "stage" smile.gif
Quote:
Originally Posted by Spaceman 
2. Is the entrance to the room in the back left corner? I'm assuming that is why you don't have a 5th seat in the back row.

Yes, double doors in the back left corner.

Quote:
Originally Posted by Spaceman 
3. You may need to address some negative acoustics as a result of your room being square. I don't have the experience/knowledge to tell you what needs to be done. I just know square rooms tend to present their own unique set of problems.

Yes, I've heard the same. I'm hopeing the 9" false wall will help a bit... confused.gif
Quote:
Originally Posted by Spaceman 
Look forward to seeing your planning/build thread. Good luck.

Thanks!

Here is my build thread:

---->
To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.
<----
Yzfbossman is offline  
post #4 of 7 Old 06-13-2012, 11:19 AM - Thread Starter
Senior Member
 
Yzfbossman's Avatar
 
Join Date: Nov 2007
Location: Frisco, TX
Posts: 258
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 50
Here is our first run at the design. We are going to make some changes but I like the way it's looking. (it's still missing lighting, AC vents, etc...)

In my first reflections drawing I removed the corner bass traps but they will be in all 4 corners.


Q3 is 9” deep of acoustic treatment too much for the front? or will it help with additional bass trapping? Or should I stick with 2" and put more if I need it after measuring the finished room?

Please comment on any of the design elements, I appreciate feedback.

Thanks


401

401

Here is my build thread:

---->
To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.
<----
Yzfbossman is offline  
post #5 of 7 Old 06-13-2012, 12:17 PM
Senior Member
 
willscam's Avatar
 
Join Date: Aug 2009
Location: Las Vegas
Posts: 364
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 2 Post(s)
Liked: 10
Wow. That looks like a really tall riser. How tall is your ceiling?

Regarding question 1. I don't think there is any problem using 9" of insulation behind the false wall. It can only increase sound absorption, including lower frequencies. You could also use cheaper materials. I used Roxul SafeNSound.

I was going to post a picture of my front wall insulation, but ran into errors....stupid new website.

You can find pictures in my build link in my signature line below.

"Trying is the first step towards failure" - Homer Simpson

 

willscam is offline  
post #6 of 7 Old 06-13-2012, 12:35 PM
AVS Special Member
 
HopefulFred's Avatar
 
Join Date: Mar 2007
Location: Atlanta, GA
Posts: 2,834
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 157 Post(s)
Liked: 205
Not that I'm an expert, but I think there is no down side to having that much depth of absorbers on the front wall in your case - but be prepared to adjust if/when you measure the speaker responses in your room.

It looks like you're preparing with good ideas for reflections, but I would suggest (on a hunch) building them wider by a half wavelength or so - maybe a foot and half or two in each direction, but dealing with the bass will be a challenge. http://www.aes.org/tmpFiles/elib/20120613/13680.pdf How many subwoofers do you think you can squeeze in there?


To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.
HopefulFred is online now  
post #7 of 7 Old 06-13-2012, 03:48 PM
AVS Special Member
 
Mr.Tim's Avatar
 
Join Date: Jul 2004
Location: SC
Posts: 2,095
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 11 Post(s)
Liked: 56
You may want to post in the acoustic treatments master thread regarding the front wall.

I believe the current line of thinking is 4" fluffy fiberglass + 4" air space behind, which you could do very nicely. And inexpensively. But I would ask in the sticky thread.

Also, your lines from the reflection on the left don't connect to the rear seats smile.gif Otherwise it looks like you have used the reflection technique properly.

The 2' high riser is bada$$ imho. I just saw one in another thread and it looked awesome! I think it was a DE design.

Double doors are going to be an acoustical problem. Better to go with a single, solid door.

Tim

ICC Certified.


To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.
||
To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.
||
To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.
||
To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

Mr.Tim is online now  
Reply Dedicated Theater Design & Construction

User Tag List

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


Forum Jump: 

Posting Rules  
You may not post new threads
You may not 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 code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off