Geometry
Moderators: Aaronw, kendale, John Sayers
-
Xaos
- Posts: 7
- Joined: Sat Nov 20, 2004 4:49 am
Geometry
HI: I have haunted the site for quite a while and even read newell's book. I am still lost when it comes to geometry. Where I am lost is the side walls and rear walls. I have a 12' x 15' basement room area with 8' to joist (9' to subfloor). I am confused as hell and trying to model the room after one on the SAE site. I have attached a smartdraw file of of what I have come up with. Please have look. Is this design any good, or have I got the geometry wrong? Please excuse how horrible I am with smart draw. The cirles represent support columns. Thanks a million in advance.
-
John Sayers
- Site Admin
- Posts: 5462
- Joined: Mon Jan 27, 2003 12:46 pm
- Location: Australia
- Contact:
what you've drawn is totally correct. It's what I would have drawn 
Also don't forget about the vertical. A rear wall in a small room can be treated by building an agled wall in the vertical plane - so it starts at the wall floor connection and leans forward at 6 degrees so it's around a foot off the wall when it reaches the ceiling.
Take a look at Hello Testing which I built back in the mid 80s in a bedroom. http://johnlsayers.com/Pages/Hello_Testing.htm
every time I revisited that room it blew me away. For a 12 x 9 bedroom it sounded better than some major studio control rooms I'd worked in. Paul produced international award winning radio commercials in that room, he recorded the voices in the control room hence the wrap around console we designed for him. - the hall way outside the control room was covered from floor to ceiling on both sides with awards he won in that room.
The rear wall angles forward and is covered with panels made from soft fiberboard with a layer of fibreglass and then wrapped in cloth.
cheers
john
Also don't forget about the vertical. A rear wall in a small room can be treated by building an agled wall in the vertical plane - so it starts at the wall floor connection and leans forward at 6 degrees so it's around a foot off the wall when it reaches the ceiling.
Take a look at Hello Testing which I built back in the mid 80s in a bedroom. http://johnlsayers.com/Pages/Hello_Testing.htm
every time I revisited that room it blew me away. For a 12 x 9 bedroom it sounded better than some major studio control rooms I'd worked in. Paul produced international award winning radio commercials in that room, he recorded the voices in the control room hence the wrap around console we designed for him. - the hall way outside the control room was covered from floor to ceiling on both sides with awards he won in that room.
The rear wall angles forward and is covered with panels made from soft fiberboard with a layer of fibreglass and then wrapped in cloth.
cheers
john
-
Xaos
- Posts: 7
- Joined: Sat Nov 20, 2004 4:49 am
-
John Sayers
- Site Admin
- Posts: 5462
- Joined: Mon Jan 27, 2003 12:46 pm
- Location: Australia
- Contact:
-
barefoot
- Moderator
- Posts: 554
- Joined: Thu Feb 27, 2003 4:49 am
- Location: Portland Oregon
- Contact:
Hi Matt,
Since you’re not going to soffit mount (offline conversation), I would adjust the room layout like I’ve illustrated below. I did the following:
1. Removed the soffit walls. These are no longer needed. With freestanding monitors they would actually create more early reflection issues. Plus you need the extra walking space to the door.
2. Pulled the side walls out a little. This gives more walking space, reduces early reflections, and reduces the boundary induced low end response rise.
3. Moved the desks and listening position back. Once again, it gives more walking space, reduces early reflections, and reduces the boundary induced low end response rise. It also brings the rear desk closer to the sofa, making a more convenient coffee table for customers.
4. Added an 8” riser under the sofa. This makes customers feel less isolated and more in control of their environment. It’s also a great place for a bass trapping. A perforated mesh floor with carpet and padding makes an outstanding absorber.
5. I’ve also become much less enthusiastic about plain slot absorbers. I personally think they are far more trouble than they are worth. Instead I like the idea of hanging drywall on resilient channels then filling the rear area with hangers or insulation. The pink lines in the drawing represent cloth covered openings. They are located at the corners and first reflection points on the side and rear walls.
6. I’ve also indicated that the door should be covered with a broad band absorber like a suspended 703 panel.
7. Another option is to build Diffusive Slot Resonators ( http://johnlsayers.com/phpBB2/viewtopic ... 3&start=15 ) like I’ve indicated on the left side of the drawing. These will yield lower frequency absorption than plain slot resonators, plus they offer mid band diffusion.
Thomas
Since you’re not going to soffit mount (offline conversation), I would adjust the room layout like I’ve illustrated below. I did the following:
1. Removed the soffit walls. These are no longer needed. With freestanding monitors they would actually create more early reflection issues. Plus you need the extra walking space to the door.
2. Pulled the side walls out a little. This gives more walking space, reduces early reflections, and reduces the boundary induced low end response rise.
3. Moved the desks and listening position back. Once again, it gives more walking space, reduces early reflections, and reduces the boundary induced low end response rise. It also brings the rear desk closer to the sofa, making a more convenient coffee table for customers.
4. Added an 8” riser under the sofa. This makes customers feel less isolated and more in control of their environment. It’s also a great place for a bass trapping. A perforated mesh floor with carpet and padding makes an outstanding absorber.
5. I’ve also become much less enthusiastic about plain slot absorbers. I personally think they are far more trouble than they are worth. Instead I like the idea of hanging drywall on resilient channels then filling the rear area with hangers or insulation. The pink lines in the drawing represent cloth covered openings. They are located at the corners and first reflection points on the side and rear walls.
6. I’ve also indicated that the door should be covered with a broad band absorber like a suspended 703 panel.
7. Another option is to build Diffusive Slot Resonators ( http://johnlsayers.com/phpBB2/viewtopic ... 3&start=15 ) like I’ve indicated on the left side of the drawing. These will yield lower frequency absorption than plain slot resonators, plus they offer mid band diffusion.
Thomas