Multiple Small Subs - Geddes Approach - Page 58 - diyAudio
Go Back   Home > Forums > Loudspeakers > Subwoofers

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 3rd February 2009, 12:13 PM   #571
breez is offline breez  Finland
diyAudio Member
 
Join Date: Jul 2004
Location: Finland
After EQ.
Attached Images
File Type: jpg tonisubam.jpg (94.8 KB, 286 views)
  Reply With Quote
Old 3rd February 2009, 12:31 PM   #572
Banned
 
Join Date: May 2008
Location: Switzerland
Looks like this box is pretty effective if you want to automatically EQ a single listening position. 225 Euros is ok.

Best, Markus
  Reply With Quote
Old 3rd February 2009, 01:56 PM   #573
gedlee is offline gedlee  United States
diyAudio Member
 
Join Date: Dec 2004
Location: Novi, Michigan
Quote:
Originally posted by markus76
Looks like this box is pretty effective if you want to automatically EQ a single listening position. 225 Euros is ok.

Best, Markus

I think that was Todds point earlier. If all you want to do is a single point then its a far easiler problem.
  Reply With Quote
Old 3rd February 2009, 02:01 PM   #574
gedlee is offline gedlee  United States
diyAudio Member
 
Join Date: Dec 2004
Location: Novi, Michigan
Quote:
Originally posted by john k...



I think the problem is the way Morse write the relationship

G(R,Ro) = g(R,Ro) + X(R)

This says X(R) = G(R,Ro) -g(R,Ro) .

Obviously X is a function of Ro. However, X(R) is a solution to (here we go again) the homogeneous wave equation with inhomogeneous boundary conditions (finally got that right). This is were the dependents of X(R) on Ro comes in because the boundary conditions are dependent upon the value of g(R,Ro) evaluated on the bounding surfaces. So while the dependence of X on Ro is not explicit, there is implicit dependence of X on Ro from the BC's. Perhaps it would have been better if Morse had written X(R) is a solution to the homogeneous wave equation with inhomogeneous boundary conditions, BC = F(g(Rb,Ro)) where Rb is the position vector defining the bounding surface. Change the source position and the X changes as well.

I guess I saying that I'm not particularly worried about what Morse says he does or doesn't do. If I have G(R,Ro) and I know g(R,Ro) I can drop in the values of R and Ro and find the value of X (R) for any values of R and Ro in the bounded region. But it's all academic because there is no need to worry about X if we know G(R,Ro).
John

Agreed. I had always viewed this subtraction of the direct field as approximate at the boundaries, never exact. I think that's the part that may be getting lost. You are correct that G(r,r0) is exact and what is needed, it just converges very slow near the source. I suppose that one could use the near field term for points close to the source, but drop it further out. This would work if the source is not too close to a boundary. If the source is close to a boundary then using an image source or sources would work as the combination is always zero at the boundary.
  Reply With Quote
Old 3rd February 2009, 02:15 PM   #575
Banned
 
Join Date: May 2008
Location: Switzerland
Quote:
Originally posted by gedlee
I think that was Todds point earlier. If all you want to do is a single point then its a far easiler problem.
I didn't argue against using an EQ. I just expressed my doubts that ringing can be completely eliminated in a real room by applying an EQ.

Talking about that box, how does it determine the target magnitude?

Best, Markus
  Reply With Quote
Old 3rd February 2009, 03:21 PM   #576
soongsc is offline soongsc  Taiwan
diyAudio Member
 
soongsc's Avatar
 
Join Date: Mar 2005
Location: Taiwan
If the RT60 decay is slower than the real environment, the probably playback fidelity is also effected.
__________________
Hear the real thing!
  Reply With Quote
Old 3rd February 2009, 05:18 PM   #577
Banned
 
Join Date: May 2008
Location: Switzerland
Talking about magic little black boxes:
http://www.krksys.com/ergo/intro.php

Best, Markus
  Reply With Quote
Old 3rd February 2009, 08:04 PM   #578
diyAudio Member
 
Join Date: Jan 2009
Quote:
Originally posted by markus76
Talking about magic little black boxes:
http://www.krksys.com/ergo/intro.php

Best, Markus

I was about to laugh, then I saw that it is "Room Perfect", which was developed by Jan Pedersen, for Lyngdorf. At least there's some science involved.
  Reply With Quote
Old 3rd February 2009, 08:56 PM   #579
Banned
 
Join Date: May 2008
Location: Switzerland
Why laugh? Because it uses FIR?
  Reply With Quote
Old 3rd February 2009, 09:07 PM   #580
gedlee is offline gedlee  United States
diyAudio Member
 
Join Date: Dec 2004
Location: Novi, Michigan
Markus

Because its too simple to do what it says. And its all talk with pretty pictures and no apparent science.
  Reply With Quote

Reply


Hide 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
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



New To Site? Need Help?

All times are GMT. The time now is 02:55 PM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright 1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2