The Advantages of Floor Coupled Up-Firing Speakers - Page 35 - 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 1st February 2010, 02:57 PM   #341
graaf is offline graaf  Poland
diyAudio Member
 
graaf's Avatar
 
Join Date: Jun 2007
Quote:
Originally Posted by markus76 View Post
Another drawback is the wrong timbre of instruments mixed to the center because they are EQed for compatibility with stereo playback.
certainly not EVERY stereo recording sums into mono well

BUT it just "happens" sometimes - not as a rule

in such a case I prefer stereo headphones
  Reply With Quote
Old 2nd February 2010, 11:20 AM   #342
el`Ol is offline el`Ol  Germany
diyAudio Member
 
Join Date: May 2005
Location: Bavarian Forest
I covered the foam with hard fiber boards to do an A-B comparison with or without absorption. Covering the horizontal absorber resulted in a strong reduction of hight, covering the vertical in a slight reduction of depth, just as expected. I hope I won't have to replace the foam due to cleaning issues.
  Reply With Quote
Old 2nd February 2010, 01:17 PM   #343
el`Ol is offline el`Ol  Germany
diyAudio Member
 
Join Date: May 2005
Location: Bavarian Forest
Quote:
Originally Posted by el`Ol View Post
With synth acoustic I neither have the feeling of being there nor of they are here because it differs much from the natural impression. Just some kind of "envelopment", audible stereo panorama and inaudible speaker positions.
Interestingly I came closer to something like an imaging with a crossed dipole, like a Blumlein microphone.
Stereolith Loudspeakers Question
  Reply With Quote
Old 2nd February 2010, 04:52 PM   #344
diyAudio Member
 
dantheman's Avatar
 
Join Date: May 2008
Location: Mountain View, CA
Quote:
Originally Posted by graaf View Post
certainly not EVERY stereo recording sums into mono well

BUT it just "happens" sometimes - not as a rule

in such a case I prefer stereo headphones
I too have had VERY good luck with recording summing well to mono. I can't recall any that don't specifically. Maybe someone has an example of one that won't? I'd like to hear it--well actually probably not.

You can get some sense of spaciousness from mono. Just aim the speaker to where it's axis passes a few feet in front of you and fires into the wall opposite the speaker. If you sitting within a few feet of that wall, the reflection will be significant enough to provide your ear with some reverb. So if the speaker is on your left, it should fire into the wall on your right. You should sit a few ft from that wall on your right. I like this arrangement for mono.

Dan
__________________
My Blog
My Music Recordings
  Reply With Quote
Old 2nd February 2010, 05:09 PM   #345
graaf is offline graaf  Poland
diyAudio Member
 
graaf's Avatar
 
Join Date: Jun 2007
Quote:
Originally Posted by dantheman View Post
Just aim the speaker to where it's axis passes a few feet in front of you and fires into the wall opposite the speaker. If you sitting within a few feet of that wall, the reflection will be significant enough to provide your ear with some reverb. So if the speaker is on your left, it should fire into the wall on your right. You should sit a few ft from that wall on your right.
yes indeed, and omnidirectional mono is even much better IMHO
  Reply With Quote
Old 2nd February 2010, 07:41 PM   #346
diyAudio Member
 
dantheman's Avatar
 
Join Date: May 2008
Location: Mountain View, CA
Quote:
Originally Posted by graaf View Post
yes indeed, and omnidirectional mono is even much better IMHO
Interesting. I'll have to try that someday.

Dan
__________________
My Blog
My Music Recordings
  Reply With Quote
Old 8th February 2010, 09:59 AM   #347
graaf is offline graaf  Poland
diyAudio Member
 
graaf's Avatar
 
Join Date: Jun 2007
interesting essay:
http://home.provide.net/~djcarlst/SLCBI.htm

very scientific "Auditory scene analysis" approach to the questions of spatial reproduction of sound, a lot of very insightful observations much in agreement with may own experience
some of them seem to indirectly confirm the validity of speaker/room arrangement approach for stereo I have proposed in this thread and also the validity of CFS mono

Quote:
(...) factor that I have observed to aid naturalness of directional localization, but at some sacrifice to distance localization, is a strong diffuse sound field in the listening room.
(...)
Adding the diffuse room reflections transforms spaciousness heard as originating in front of the listener to having a more enveloping quality. The spaciousness hierarchy of perception is as follows: 1. Mono reverberation defines size of recorded space and allows distance localization. 2. Stereo anechoic reverberation adds spaciousness. 3. Stereo with diffuse listening room reverberation adds envelopment.
therefore in a typical listening room the more diffuse sound the more natural sound

Quote:
stereo (...) addresses perceptual requirements by substituting physically practical mechanisms rather than attempting point for point recreation of the original sound field. "Recreation of the Auditory Scene" is a phrase that captures successful stereo. Physical acoustic accuracy is impractical and unnecessary.
yes, no "wavefield synthesis" is needed

Quote:
Stereo (or even monophonic) reproduction is capable of rendering a plausible or accurate AS if certain conditions are met (The Existence test). Subjectively, they are:
1. The speakers do not seem to be the source of sound
2. The listening room acoustics are not audible as such
3. Record/reproduction chain artifacts are sufficiently low
4. Recording captures timbre and direction of instruments and acoustic effect of the space
5. There is defocusing of critical centerline listening at playback
quasi-omni CFS stereo that I have proposed meets the first and the fifth requirements perfectly
the second requirement is in fact a nonissue in a normal listening room of typical size (see below "simple dereverberation experiment")
the third and forth requirements are not questions of speaker/room but quality of hardware and software
as regards loudspeakers themselves I wonder though wheter we should consider transient and waveform distortions as harmful "reproduction chain artifacts"

Quote:
I define “auditory dereverberation” as the psychoacoustic acclimatization process of suppression of reverberation.
(...)
Reverberation makes the sound louder even though it is suppressed as such and the ability to localize distance is greatly improved. We may hear the images as less compact, but we can still identify the exact direction. We also experience envelopment of sound, but not of image directions.
(...)
I have observed two extremes of stereo reproduction from systems using competent components; dominance of direct sound and dominance of room reverberated sound.
(...)
The other extreme is typically found with wide directivity speakers on the other side of a large reverberant room. Dominance of playback reverberation leads to imprecision of imaging in azimuth and depth, in my experience. Also, the room cannot be dereverberated such that the recorded acoustics come through.
Between these extremes, there is a range of personal taste for a more “in your face” experience or a more relaxed and distant perspective. Within this central range, it is my opinion that the Auditory Scene should be dictated far more by the recording than by the playback acoustics.
I agree completely that the second - "extreme reverberant method" - fails in a "too large reverberant room" that "cannot cannot be dereverberated"
but I argue that very rarely a real listening room can be regarded as "too large" in that sense, typical living room RT60 is perfectly suitable for succesful sound reproduction

Quote:
Simple Dereverberation Experiment
Last Summer, I visited Michigan State professor William Hartmann who is a well known psychoacoustics researcher.
(...)
He suggested we do a little experiment right there.
(...)
Experiment’s conclusion: recorded reverberation is far more audible than live reverberation, at least for a simple recording technique.
once again - in a typical listening room the more diffuse sound (more room reverb) the more natural sound

Quote:
A monophonic audio chain (...) On playback, a speaker reproduces this pressure variation where it interacts with the acoustics of the listening room and eventually creates two slightly differing pressure variations at the eardrums. The result can be pleasant: instruments can be identified and their individual melodic lines followed. The size of the acoustic space can be identified and a sense of distance for each instrument can be conveyed.
and quasi-omni "ceiling flooder" is clearly best at that because it "interacts with the acoustics of the listening room" more than any any other mono loudspeaker and that results in the most diffuse sound with the speaker itself (direct sound) being completely drowned in room reverb and as such acoustically "invisible"
  Reply With Quote
Old 8th February 2010, 11:57 AM   #348
Banned
 
Join Date: May 2008
Location: Switzerland
A lot of questionable conclusions. The sound field in acoustically small rooms is NOT diffuse (homogeneous and isotropic) and it will never be. There's more to the story. Psychoacoustics is currently stuck in two competing models (virtual source vs. phantom source, see p. 30 http://hauptmikrofon.de/HW/Wittek_thesis_201207.pdf). My hope is that neuroscience will reveal more about how our perception works.

Here's a link to Bregman's work: http://webpages.mcgill.ca/staff/Group2/abregm1/web/

Best, Markus
  Reply With Quote
Old 8th February 2010, 12:44 PM   #349
gedlee is offline gedlee  United States
diyAudio Member
 
Join Date: Dec 2004
Location: Novi, Michigan
Quote:
Originally Posted by markus76 View Post
A lot of questionable conclusions. The sound field in acoustically small rooms is NOT diffuse (homogeneous and isotropic) and it will never be. There's more to the story. Psychoacoustics is currently stuck in two competing models (virtual source vs. phantom source, see p. 30 http://hauptmikrofon.de/HW/Wittek_thesis_201207.pdf). My hope is that neuroscience will reveal more about how our perception works.

Here's a link to Bregman's work: Al Bregman's Website

Best, Markus
Markus

I know Dave - the author well - and he is well intentioned. HE would readily admit the comments as being "his opinions", but admitedely his "group" tends far too much IMO towards the "opinions are facts - if they are mine". There were the ones to develop the ABX box, but then seemed to loose it somewhere along the line. Sound fields in small room certainly can be diffuse - above some frequency. Thats the problem with statements like yours and his that they are not sufficiently descriptive to define the differences, so they are both correct - in a limited scope - and incorrect as well.
  Reply With Quote
Old 8th February 2010, 01:02 PM   #350
Banned
 
Join Date: May 2008
Location: Switzerland
Earl,

I have to disagree. The sound field in an acoustically small room is never diffuse (even a concert hall shows only an approximation). There are strong directional first reflections and a dimished quasi-diffuse sound field.
One can certainly make a sound field more diffuse but then we'll end up where we always do: how diffuse is diffuse enough and how to measure? Nobody knows because we don't have enough data on that.
  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
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 12:25 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