EP21 - Single Stereo Loudspeakers - diyAudio
Go Back   Home > Forums > Loudspeakers > Multi-Way

Multi-Way Conventional loudspeakers with crossovers

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 2nd November 2012, 04:37 AM   #1
diyAudio Member
 
gainphile's Avatar
 
Join Date: Dec 2007
Location: Melbourne the sunny city!
Default EP21 - Single Stereo Loudspeakers

For my 21st loudspeaker build, I would like to implement Elias Pekonen's SSS.

Quote:
Originally Posted by Elias View Post
2 speaker stereo is dead
The concept is very unique and interesting.
dl.dropbox.com/u/2400456/html/Elias_Pekonen/SingleSpeakerStereo.html

I have ordered 3x HiVi B3N / B3S for this endeavour !

I will compare it with my personal reference:
gainphile.blogspot.com.au/2012/03/s19-4-way-dipole-radiator.html

Fun times ahead
__________________
http://gainphile.blogspot.com
  Reply With Quote
Old 2nd November 2012, 06:54 AM   #2
diyAudio Member
 
Moondog55's Avatar
 
Join Date: Jun 2007
Location: Norlane; Geelong: Victoria: Australia
Can I say "Hmmmm" ??
Interested to hear your impressions

Perhaps "Wide-field single speaker box" would be a better name
__________________
QUOTE" The more I know, the more I know, I know (insert maniacal laugh >here<) NOTHING"
  Reply With Quote
Old 2nd November 2012, 10:46 AM   #3
lolo is offline lolo  France
diyAudio Member
 
lolo's Avatar
 
Join Date: May 2010
Location: somewhere by the border..
Please do keep us posted!
  Reply With Quote
Old 3rd November 2012, 03:59 PM   #4
Elias is offline Elias  Finland
diyAudio Member
 
Elias's Avatar
 
Join Date: May 2003
Location: Where you live
Quote:
Originally Posted by gainphile View Post
For my 21st loudspeaker build
21 is a popular number nowadays


If you got any experience of matrix stereo, you'll already have a hint what to expect. Single speaker stereo is a simulation of three speaker matrix stereo. The room side walls are an essential part of the system:
Click the image to open in full size.


See also my FDTD soundfield simulations of SSS. They'll serve as a proof of it's achieved intended functionality.
Elias Pekonen Home Page - FDTD simulations on Single Speaker Stereo SSS


Yes, fun you'll not be lacking


- Elias
__________________
Liberate yourself from the illusion of two speaker stereo triangle
Dipole Bass vs Monopole Bass Stereophonic Sound from a Single Loudspeaker 3 Speaker Linear Stereo Matrix Wavelets
  Reply With Quote
Old 3rd November 2012, 04:58 PM   #5
dewardh is offline dewardh  United States
diyAudio Member
 
Join Date: Dec 2005
Location: Berkeley, CA
Quote:
Originally Posted by Elias View Post
Single speaker stereo is a simulation of three speaker matrix stereo.
It is a simulation, however, that depends on a directivity of the L and R speakers that is not clearly in evidence, and which is also dependent on a high degree of symmetry in sidewall reflections. An alternate scheme (which would be easy to implement and test) is suggested by your "M/S" example (at you web site). A pair of Magnaplanar MMG dipoles could easily provide a M/S source of well defined directivity . . .
  Reply With Quote
Old 3rd November 2012, 06:45 PM   #6
Elias is offline Elias  Finland
diyAudio Member
 
Elias's Avatar
 
Join Date: May 2003
Location: Where you live
Quote:
Originally Posted by dewardh View Post
An alternate scheme (which would be easy to implement and test) is suggested by your "M/S" example (at you web site). A pair of Magnaplanar MMG dipoles could easily provide a M/S source of well defined directivity . . .
I found an old figure of mine from the Stereolith thread describind MS stereo playback of two crossed dipoles:
Click the image to open in full size.

What matters is the response to the 45 angle direction to generate the side wall reflections towards listening position. We need angle independent summation from the two dipoles. I don't think wide ESL is any good in this regard due to their beaming nature at high freqs.

Anyway, as you know the matrix coefficient of 0.5 is the optimal one, so MS stereo is then.. suboptimal


- Elias
__________________
Liberate yourself from the illusion of two speaker stereo triangle
Dipole Bass vs Monopole Bass Stereophonic Sound from a Single Loudspeaker 3 Speaker Linear Stereo Matrix Wavelets

Last edited by Elias; 3rd November 2012 at 06:48 PM.
  Reply With Quote
Old 5th November 2012, 10:37 AM   #7
graaf is offline graaf  Poland
diyAudio Member
 
graaf's Avatar
 
Join Date: Jun 2007
Quote:
Originally Posted by Moondog55 View Post
Perhaps "Wide-field single speaker box" would be a better name
why? if it produces stereo imaging - and it does - then it is stereo
  Reply With Quote
Old 6th November 2012, 01:02 AM   #8
diyAudio Member
 
Join Date: Sep 2012
Location: Maine, Bangor-area
In the two different systems of Elias' post #4, an essential difference is that with the single speaker stereo system, the (L-0.5R) and (R-0.5L) signals are time-delayed in arriving to the listener, relative to the (0.5L + 0.5R) signal. That is, for single speaker stereo set-up, the summed signal has precedence over the difference signals. If the time delay is several milliseconds, then the listener recognizes the sound reflected off of the side walls as non-direct ambient sound and there is no stereo imaging.

It would be great if this really did work, but I don't think so.

Possibly a solution would be to use signal processing to delay the summed signal so that all three signals arrive to the listener simultaneously....

Regards,
Pete

Last edited by cT equals piD; 6th November 2012 at 01:05 AM. Reason: additional idea
  Reply With Quote
Old 6th November 2012, 09:22 AM   #9
Elias is offline Elias  Finland
diyAudio Member
 
Elias's Avatar
 
Join Date: May 2003
Location: Where you live
Quote:
Originally Posted by cT equals piD View Post
It would be great if this really did work, but I don't think so.
Why don't you try it and you will change your mind.


There are several aspects you neglect.

First the precedence is not simply an one dimensional phenomena but it includes both time and amplitude, and usually known as time intensity trading. For this reason there is a psychoacoustic filter involved in the speaker which steers the high freq energy from the center to the sides.

More shocking aspect is that precedence effect (Haas) is only valid with one reflection. In a small room acoustic space a cluster of reflections eminating from about the same lateral angle will override Haas effect completely.

There are issues with current psychoacoustic theories within small rooms that need some rethinking. There would be a good opportunity for someone research minded to write a couple of academic papers on these issues (hint)


- Elias
__________________
Liberate yourself from the illusion of two speaker stereo triangle
Dipole Bass vs Monopole Bass Stereophonic Sound from a Single Loudspeaker 3 Speaker Linear Stereo Matrix Wavelets
  Reply With Quote
Old 7th November 2012, 01:24 AM   #10
diyAudio Member
 
Join Date: Sep 2012
Location: Maine, Bangor-area
Elias, your post #9,

Colloms cites precedence only of the direct sound in allowing the listener to hear a stereo image (in his book High Performance Loudspeakers). He says that if the listener is 3 to 5 meters distant from stereo speakers, then "most of the sound energy heard is reverberant". The arrival time of the direct "focused" sound ahead of the "diffused" reflected sound he claims is the only thing that allows for the perception of stereo.

I don't understand why the precedence effect should be valid for only a relatively focused reflection where all of it arrives to the listener at about the same time. Even if the arrival times of reflections from a side wall are spread out over a fairly large time interval, still the direct sound of the summation signal arrives prior to any of the reflections off of the side wall.

In the patent literature I've seen a proposal at least similar to your SSS from some time ago. Certainly the fact that your SSS will only work in some listening rooms reduces its commercial viability. But as far as I know a system like your SSS has never been commercialized, suggesting that it is lacking as a method of stereo reproduction.

One other critique that I can make is that reflectivity of the walls of the room would need to be taken into account. That is, I think that the level of the directly radiated summation signal should be reduced relative to the level of the difference signals reflected off of the side walls.

Regards,
Pete
  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


Similar Threads
Thread Thread Starter Forum Replies Last Post
Stereo Buffer with a single twin triode Brit01 Tubes / Valves 43 29th July 2009 03:32 PM
Can single PCM56P act as stereo? terranigma Digital Source 1 27th February 2007 10:29 PM
Single or stereo speaker evaluation Salas Multi-Way 23 16th August 2006 10:13 PM
Stereo Single 4780 traw Chip Amps 3 16th February 2006 12:39 PM
Meet belle lab, a new manufacturer of single driver fullrange loudspeakers cdwitmer Full Range 14 11th September 2005 07:23 AM


New To Site? Need Help?

All times are GMT. The time now is 10:08 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