The Advantages of Floor Coupled Up-Firing Speakers - Page 127 - 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 5th April 2010, 11:28 AM   #1261
Banned
 
Join Date: May 2008
Location: Switzerland
Quote:
Originally Posted by dantheman View Post
If you had narrow and constant directivity speakers in a multichannel set up, would you still want the mains to cross in front of the listener like you recommend for stereo? Or should they be placed to reduce lateral reflections?
You still want the mains to cross in front of the listener because this reduces the level of lateral reflections.
Furthermore multichannel recordings often don't make use of a center channel but rely on a phantom center.

Best, Markus

Last edited by markus76; 5th April 2010 at 11:35 AM.
  Reply With Quote
Old 5th April 2010, 01:34 PM   #1262
gedlee is offline gedlee  United States
diyAudio Member
 
Join Date: Dec 2004
Location: Novi, Michigan
I agree with Markus.

Center channels are great if 1) they are exactly the same as the mains and 2) they are placed dead center at the same level as the mains. This means that they have to be right where the picture is in a HT. This can only be done with an acoustically transparent screen and a projector. Otherwise use phantom mode. I make a custom center channel speaker crossover which is adjusted for axial response as opposed to off axis. I am installing Harpers in my theater as we speak for the surrounds, thats what they were design to do.
  Reply With Quote
Old 5th April 2010, 01:41 PM   #1263
diyAudio Member
 
dantheman's Avatar
 
Join Date: May 2008
Location: Mountain View, CA
Thanks Markus! Perhaps I used the wrong word there. The lateral reflections I was referring to are the ones that hit my left ear from my left wall, but come from the speaker on m right. Perhaps contralateral would be a batter word.

Thanks Dr. Geddes! I was just having this discussion on another board and said the same thing. That's where I'm at then, phantom center.

Dan
__________________
My Blog
My Music Recordings

Last edited by dantheman; 5th April 2010 at 01:45 PM. Reason: inc
  Reply With Quote
Old 7th April 2010, 09:54 AM   #1264
graaf is offline graaf  Poland
diyAudio Member
 
graaf's Avatar
 
Join Date: Jun 2007
Quote:
Originally Posted by poptart View Post
sound coming from the sides contributes much more to his term "spaciousness" than sound from the front/back/ceiling/floor.
are effects of front/back/ceiling/floor eflections discussed in detail?

Quote:
Originally Posted by poptart View Post
Multichannel is his endpoint, but most of the information in the book is about one or two channel testing at harman.
Here some marketing agenda of Harman is to be seen IMHO, this multichannel is good for speaker business

here is something more of a Toole's own view:

Quote:
I am not sure what "the perfect sound" might be. If it is to transport a listener to a concert hall, then we have gone about it the wrong way - we should have focused our efforts on binaural recordings and playback, or long before now moved into multichannel reproduction, using many more than 5.1 channels.
Matrix Surround for Music

best regards!
graaf
__________________
"high phooey and hystereo" - Yascha Heifetz
  Reply With Quote
Old 7th April 2010, 10:11 AM   #1265
graaf is offline graaf  Poland
diyAudio Member
 
graaf's Avatar
 
Join Date: Jun 2007
Quote:
Originally Posted by Rudolf View Post
If you agree to "horizontal directivity should be constant in any case, and vertical dispersion shoul be narrow" - doesn`t that fundamentally contradict your flooder concept? I was under the impression that you were beaming something to the ceiling. That would not be "narrow vertical dispersion" in my vocabulary.
Note that I have said vertical dispersion should be narrow unless something else is done WRT interaction of speakers with floor and ceiling

what is done in the case of the flooder with floor reflection
- it is effectively low-passed because of the directivity of the speaker in an enclosure and because of geometry of such a setup (check angles if incidence and reflection) - it can be said that from perspective of VERs (of how they are defined) there is no early reflection off the floor in case of the flooder

then what is done in the case of the flooder with ceiling reflection
- it is delayed twice as much as in case of conventional setup, by seating on a shorter armchair/sofa and/or by moving a bit closer to the speaker it can be delayed beyond the worst 10 ms, something that cannot be done with conventional setup without ceiling deflectors (certainly not something to be found in a typical listening room)

honestly I don't know what to think of this ceiling reflection
WRT floor reflection its effects are researched and known but this is not the case of ceiling reflection

My hypothesis is that it is ignored by the brain for purposes of sound localization at all, it adds only to the perceived loudness and affects timbre

why? because there was no equivalent of ceiling reflection during millions of years of biological evolution of our sense of hearing

just hypothesis of course

best,
graaf
__________________
"high phooey and hystereo" - Yascha Heifetz
  Reply With Quote
Old 7th April 2010, 10:22 AM   #1266
graaf is offline graaf  Poland
diyAudio Member
 
graaf's Avatar
 
Join Date: Jun 2007
Quote:
Originally Posted by el`Ol View Post
I have read the first 8 chapters (140 pages) of Toole's book and I will post some quotes here, mainly for graaf, who doesn't want to buy it.
BIG thanks el`Ol! it's helpful and very kind of You

interesting quotations, especially those:

Quote:
Originally Posted by el`Ol
“Listeners appeared to prefer the sound from wide-dispersion loudspeakers with somewhat colored off-axis behaviour to the sound from a narrow-dispersion loudspeaker with less colored off-axis behavior.”
(…)
“Perhaps related to this is the acoustical crosstalk associated with the phantom center image. This coloration cannot be ignored in a situation where the direct sound is strong. Early reflections from different directions tend to fill the interference dip, making the spectrum more pleasantly neutral.”
interesting, at last an attempt at some theoretical explanation in favor of wide dispersion, apart from the disputed question of spaciousness

Quote:
Originally Posted by el`Ol
“[Flindell et.al. (1991)] … The natural concern that wide dispersion and the attendant strong early reflections “would lead to degraded stereo imaging was not confirmed by the experienced listeners using rating scales and blind presentations of audio material.” Providing a contrasting point of view, Newell and Holland (1997) present a reasoned discussion of the requirements for control-room acoustical treatment (and, by inference, loudspeaker directivity). They favor the elimination of all lateral and vertical reflections – a near anechoic space, placing listeners in a direct-sound field. They conclude that “spaceousness and the resolution of fine details are *largely mutually exclusive. Spaceousness should… be an aspect of the final reproduction environment.” There is no doubt that, listening to direct sound only, recording engineers may recognize the callously stark special presentation of hard-panned left and right stereo images and be motivated to remedy it, unless this turns out to be another preference associated with the professional side of the industry. Not to be ignored in any situation in which reflected sounds have been removed is the fact that the acoustical crosstalk that plagues stereo phantom images is present in its naked ugliness, without any compensation from reflected sounds.
(...)
“Why do recording and mixing engineers prefer to listen with reduced lateral reflections? Perhaps they need to hear things that recreational listeners don’t. This is a popular explanation, and it sounds reasonable, but experiments reported in Section 6.2 indicate that we humans have a remarkable ability to hear what is in a recording in spite of room reflections – lots of them. But there is an alternative explanation, based on the observation that some listeners can become sensitized to these sounds an hear them in an exaggerated form.
The natural concern that wide dispersion and the attendant strong early reflections “would lead to degraded stereo imaging was not confirmed...

Spaceousness should… be an aspect of the final reproduction environment...

a popular explanation, and it sounds reasonable, but experiments...


How about that!

*I wonder what Newell and Holland meant by largely? And what tests exactly is their conclusion based upon?
And how can they at the same time conclude that "spaceousness should… be an aspect of the final reproduction environment"? Are they denying audiophiles the resolution of fine details?

Tell me please - is there anything in this book that speaks against the flooder idea?
Any statement from Toole that supports all those statements that have been posted here in this thread, about disasters and crazy schemes?

anything at all?

best regards!
graaf
__________________
"high phooey and hystereo" - Yascha Heifetz
  Reply With Quote
Old 7th April 2010, 10:26 AM   #1267
graaf is offline graaf  Poland
diyAudio Member
 
graaf's Avatar
 
Join Date: Jun 2007
Quote:
Originally Posted by markus76 View Post
concepts like omnis or dipoles. The main drawback is that they make each and every recording sound the same
To put it shortly - WRT omnis or dipoles You have heard perhaps it is true but is is absolutely untrue WRT the flooders

somehow consistently different from conventional stereo – yes, but each and every recording sounds the sameabsolutely not, it is rather true in case of conventional stereo where each and every recording sounds more or less flat and 2D

best,
graaf
__________________
"high phooey and hystereo" - Yascha Heifetz

Last edited by graaf; 7th April 2010 at 10:43 AM.
  Reply With Quote
Old 7th April 2010, 10:28 AM   #1268
graaf is offline graaf  Poland
diyAudio Member
 
graaf's Avatar
 
Join Date: Jun 2007
Quote:
Originally Posted by gedlee View Post
Markus
Quite true about the making everything sound the same. The proposals here will definately do that.
well, they are definitely not doing this

The truth is that You have just no idea how it sounds because You haven't heard it

best,
graaf
__________________
"high phooey and hystereo" - Yascha Heifetz
  Reply With Quote
Old 7th April 2010, 01:59 PM   #1269
gedlee is offline gedlee  United States
diyAudio Member
 
Join Date: Dec 2004
Location: Novi, Michigan
Quote:
Originally Posted by graaf View Post
well, they are definitely not doing this

The truth is that You have just no idea how it sounds because You haven't heard it

best,
graaf
And you haven't heard what Marcus and I are talking about either, so that makes it a stalmate on the subjective aspects and all we can do is to talk about the objective ones. There I don't think that there is much of a contest.
  Reply With Quote
Old 7th April 2010, 02:12 PM   #1270
Elias is offline Elias  Finland
diyAudio Member
 
Elias's Avatar
 
Join Date: May 2003
Location: Where you live
Hello,


Quote:
Originally Posted by graaf View Post
why? because there was no equivalent of ceiling reflection during millions of years of biological evolution of our sense of hearing

Well, but then there were no rooms in savannah so we are not evolutioned to hear any wall reflections either In evolutionary sense a human is mainly a direct sound observer, and in case where room reflections are present the brain is confused. But the confusion does not completely prevent interpreting the direct sound. Only requirement for non-fatique listening is to have clear direct sound and long enough time before room reflections come to disturb.





Quote:
Originally Posted by el`Ol View Post
Toole's book and I will post some quotes here, mainly for graaf, who doesn't want to buy it.
A DIY friendly choice is to borrow the book from the city library! For free! Come on guys, why you allways want to pay for a basic human right like accessing information.



Quote:
Originally Posted by gedlee View Post
To me this is a key finding and one I completely concur with. It is key to my disagreements with Floyd on the subject of directivity. The wide directivity will mask to a much greater degeree the poor recordings that I find so common in marketplace. The highly directional speakers are brutally revealing of these flaws. Floyd is dominately a "symphonic music at home" person. I am quite the opposite. I claim that if the recordings of symponic music were improved, then the prference would shift to narrow directivity.
The symphonic situation will not be improved by any recording or loudspeaker directivity issue. It's because the main thing in symphonic (or chamber music) is the sense of the hall! The envelopement. That is not possible with any 2 speaker set up, but one needs extra speakers to create the "surround field".

The wide dispersion speakers help to overcome this fact. BUT in my opinion the diepersion should be wide only at high frequencies above 1kHz or so. Below 1kHz directivity should be as narrow as possible to overcome the room.



Quote:
Originally Posted by gedlee View Post
And the results of Floyd and his lab at JBL were strongly influenced by the need to sell products
LOL And you are not?



Quote:
Originally Posted by el`Ol View Post
…a pair of loudspeakers deployed at +/-30° or less is not an optimum arrangement for generating strong perceptions of envelopment… Perhaps this is why audiophiles have for decades experimented with different loudspeaker directivities (to excite more listening room reflections), with electronic add-ons and more loudspeakers (to generate delayed sounds arriving from the sides and rear), and with other trinkets that seem capable only of exciting the imagination. All have been intended to contribute more of “something that was missing” from stereo reproduction experience. The solution to this is more channels.”
I agree with this, but I'll rise an issue with "channels" since not necessarily more media channels are needed, but just more loudspeakers and some signal processing therein.


- Elias
  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 03:27 AM.


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