Go Back   Home > Forums > >
Home Forums Rules Articles diyAudio Store Blogs Gallery Wiki Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

Multi-Way Conventional loudspeakers with crossovers

The Advantages of Floor Coupled Up-Firing Speakers
The Advantages of Floor Coupled Up-Firing Speakers
Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 9th April 2010, 01:24 PM   #1351
gedlee is offline gedlee  United States
diyAudio Member
 
gedlee's Avatar
 
Join Date: Dec 2004
Location: Novi, Michigan
Quote:
Originally Posted by markus76 View Post
By back wall you mean the wall behind the loudpseaker? I would call that the front wall. Interesting thing that Moulton recommends damping that wall too despite his preference for omnis.
Yes, front - back, left - right, all depends on your perspective. I do mean behind the speakers. Toole recommends this as well.
__________________
Earl Geddes Gedlee Website
  Reply With Quote
Old 9th April 2010, 01:27 PM   #1352
markus76 is offline markus76  Germany
Banned
 
Join Date: May 2008
Location: Switzerland
Quote:
Originally Posted by gedlee View Post
I'm sorry that you feel picked on and that your thread was hyjacked.
The thread topic is "Loudspeakers and room as a system" and not "Ceiling flodder is the best thing since sliced bread", so there's nothing to feel sorry about.
  Reply With Quote
Old 9th April 2010, 04:37 PM   #1353
dantheman is offline dantheman  United States
diyAudio Member
 
dantheman's Avatar
 
Join Date: May 2008
Location: Mountain View, CA
Dr. Geddes,

A couple questions, and my apologies if you've covered this before. Do you have a projector screen or a TV between your speakers?

What do you damp that wall with and how thick? The WHOLE wall or just between the speakers?

To what frequency to you hope to absorb? 500Hz(ish)? Or just as deep as possible? You say it smooths out the bass, but Dr. Toole suggests absorption is not very effective against the walls and corners at damping bass. Do you build a weak wall to resonate and thus damp bass?

Thanks,

Dan
__________________
My Blog
My Music Recordings
  Reply With Quote
Old 9th April 2010, 11:07 PM   #1354
gedlee is offline gedlee  United States
diyAudio Member
 
gedlee's Avatar
 
Join Date: Dec 2004
Location: Novi, Michigan
Quote:
Originally Posted by dantheman View Post
Dr. Geddes,

A couple questions, and my apologies if you've covered this before. Do you have a projector screen or a TV between your speakers?

What do you damp that wall with and how thick? The WHOLE wall or just between the speakers?

To what frequency to you hope to absorb? 500Hz(ish)? Or just as deep as possible? You say it smooths out the bass, but Dr. Toole suggests absorption is not very effective against the walls and corners at damping bass. Do you build a weak wall to resonate and thus damp bass?

Thanks,

Dan
In my case I use foam. Thats because I have a lot of it, from scraps etc. I have used very heavy drapes as well. And yes I do the whole wall - everything from the speakers back. There should not be any sound coming from the direction of the speakers but the speakers themselve. This includes - and this is very important - nearby diffraction. My room has nothing in the front except the speakers and the screen and the screen is very low diffrcation.

My whole room is damped at LF so I don't need LF damping behind the speaker, and yes, there probably isn't much LF damping from the foam, not compared to the CLD walls.
__________________
Earl Geddes Gedlee Website
  Reply With Quote
Old 10th April 2010, 12:38 AM   #1355
dantheman is offline dantheman  United States
diyAudio Member
 
dantheman's Avatar
 
Join Date: May 2008
Location: Mountain View, CA
Thank you. I wish I could build CLD walls. Perhaps my place is flimsy enough to not really need them. Can anyone recommendation a good source (cheap) for a lot open cell foam? Anyone interested in a group buy if we can do cheaper in bulk? Things I've seen will cost quite a bit of money.

Curtains also sound like a good idea as they could be opened and closed easily for people with flat televisions. They could possibly even improve the decor. I'll run that by the wife.

Dan
__________________
My Blog
My Music Recordings
  Reply With Quote
Old 10th April 2010, 12:46 AM   #1356
gedlee is offline gedlee  United States
diyAudio Member
 
gedlee's Avatar
 
Join Date: Dec 2004
Location: Novi, Michigan
Quote:
Originally Posted by dantheman View Post
Thank you. I wish I could build CLD walls. Perhaps my place is flimsy enough to not really need them. Can anyone recommendation a good source (cheap) for a lot open cell foam? Anyone interested in a group buy if we can do cheaper in bulk? Things I've seen will cost quite a bit of money.

Curtains also sound like a good idea as they could be opened and closed easily for people with flat televisions. They could possibly even improve the decor. I'll run that by the wife.

Dan
If I didn't get the foam as scrape, I wouldn't use it. Find an old pair of used drapes - it will be a lot cheaper. Or just buy the material at the craft store. A lot of times they will have an end lot on sale. I prefer Barbie prints myself.
__________________
Earl Geddes Gedlee Website
  Reply With Quote
Old 10th April 2010, 01:06 AM   #1357
dantheman is offline dantheman  United States
diyAudio Member
 
dantheman's Avatar
 
Join Date: May 2008
Location: Mountain View, CA
Sounds like a great idea, but I'm not sure this will fit in with my decor:
Click the image to open in full size.
Maybe something like this would be better:
Click the image to open in full size.
I'm not even going to discuss opening those curtains.

Dan
__________________
My Blog
My Music Recordings
  Reply With Quote
Old 10th April 2010, 01:06 AM   #1358
markus76 is offline markus76  Germany
Banned
 
Join Date: May 2008
Location: Switzerland
Quote:
Originally Posted by dantheman View Post
Thank you. I wish I could build CLD walls. Perhaps my place is flimsy enough to not really need them. Can anyone recommendation a good source (cheap) for a lot open cell foam?
Get 6" thick fiberglass and mount it with a 6" air gap. Cover the front with burlap to hold fibers back. That will give you good absorption down to 200Hz and below.

Play around with this calculator to find out what characteristics to look for: Porous Absorber Calculator V1.56

Here you'll find some more information: Acoustic Treatment and Design for Recording Studios and Listening Rooms

Best, Markus
  Reply With Quote
Old 10th April 2010, 01:52 AM   #1359
dantheman is offline dantheman  United States
diyAudio Member
 
dantheman's Avatar
 
Join Date: May 2008
Location: Mountain View, CA
Thanks Markus! It seems unrealistic for me to think you can get absorption down to 200Hz with just 6 inches, but I'm not betting against you. Does it have to be burlap though? I'm really fond of the MM print. It speaks loud and clear to me.

Thanks,

Dan
__________________
My Blog
My Music Recordings
  Reply With Quote
Old 10th April 2010, 07:53 AM   #1360
StigErik is offline StigErik  Norway
diyAudio Member
 
StigErik's Avatar
 
Join Date: Feb 2008
Move up to 12" (300 mm) and you'll get good absorbtion to 100 Hz!

Data from Rockwool and others making acoustic ceiling tiles show that you can get good absorbtion to 100 Hz with just a 50 mm ceiling tile spaced 300 mm out from the surface behind.
__________________
dipoles dipoles dipoles dipoles dipoles dipoles dipoles dipoles and dipoles
  Reply With Quote

Reply


The Advantages of Floor Coupled Up-Firing SpeakersHide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

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

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Using a diffuser cone for up-firing speakers tspringer99 Multi-Way 19 23rd July 2014 02:04 AM
Floor Standing Speakers. gurpreetsingh Full Range 11 12th June 2012 06:42 AM
side/ rear firing speakers Good/Bad? mcmahon48 Multi-Way 1 6th February 2009 12:28 PM
How far can the driver of a down-firing sub be from the floor? The Paulinator Subwoofers 11 16th May 2007 08:10 PM
Woofer: side firing pair vs front firing? tcpip Multi-Way 13 9th September 2005 02:13 PM


New To Site? Need Help?

All times are GMT. The time now is 08:51 PM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 15.00%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
Copyright ©1999-2017 diyAudio
Wiki