Sorry but you'll have to be a bit more specific and less acronym laden in your posts for me to understand you.
"RFZ believer" ?
"flooder in beveridge placement ?"
Neither means anything to me.
yes, and a flooder in Beveridge placement does it, it only needs killing/diffusing of the very first reflection off the adjacent wall
absorbed/diffusor can be placed just on the wall next to the flooder or can even be integrated as part of it's enclosure
Hi,
This does not help. If I feed uncorrelated noises to the two tweeters simulataneously, I still hear two tweeters separately. What else could I hear in this case?
- Elias
This does not help. If I feed uncorrelated noises to the two tweeters simulataneously, I still hear two tweeters separately. What else could I hear in this case?
- Elias
Sorry but you'll have to be a bit more specific and less acronym laden in your posts for me to understand you.
"RFZ believer" ?
"flooder in beveridge placement ?"
Neither means anything to me.
RFZ believer is a person who believes that for high fidelity sound reproduction at home a sort of early Reflection Free listening Zone is needed that is all early reflections <6 ms (other say <10 ms etc.) should be eliminated
flooder in Beveridge placement is a stereo setup that I have proposed in this thread:
http://www.diyaudio.com/forums/multi-way/121385-loudspeakers-room-system.html
it is very short up-firing speaker with no reflectors above, similar to some old Swedish Carlsson/Sonab speakers, placed in a room in a way recommended by late Harold Beveridge for His electrostatic speakers
ps.
in a small room of 3.5 x 5 m proportions the setup may look basically like this:
Attachments
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If by "flooder" you mean essentially non-directional, then boundary mounting will make that first boundary disappear. So that will help with regard to the first boundary. The other issue though, is that you are forcing a low direct to reflected ratio. This may not be a good thing. Also, if you must damp the opposite wall then you don't have an optimum dispersion speaker, do you? You are forced to take corrective action. A bit like saying dipoles are perfect as long as you absorb the back wall bounce.
David S.
Toole says comb filtering is not audible at all?? A bit of a stretch, especially as he extensively discusses the audibility of various reflections (and the reflections must cause comb filtering). I think the takeaway from Toole is that a live room will wreck havoc on measured frequency response and room impulse response, but much of the later energy is a generally good thing.
Put me in the camp of "RFZ believers", but not to the extent of Don Davis and the early LEDE camp. If every modern study shows that early floor, ceiling and back wall bounces must lead to audible colorations at typical strengths, then I think the goal is to reduce their level. Early lateral reflections lead to a different problem of a "twangy bounce" (listen to the game environmental simulation a few pages back), and are equally undesirable. David Moulton is at odds with all modern research in advocating wide dispersion studio monitors in conjunction with narrow rooms with hard sidewalls.
David S.
great! then no absorber is needed at all because I thought that there will be necessary to absorb exactly the reflection off this boundary next to speaker, at least such was suggestion I got from Dr Geddes
yes, this is it and yes perhaps, it may not be good, but I really like what I can hear (and it is not only me - ask tinitus for example)
misunderstanding - I assumed that it will be necessary to absorb the very early reflections/diffractions from the wall next to te flooder, not the opposite wall
Regarding the Beveredge approach, Yes, to the extent that the speaker is smoothly integrated into the wall the first boundary disappears. The opposite of how a PZM microphone works. But how do you make the leap that this is ideal? If the first reflection disappears, then great, but you have a system that is primarily aiming its energy at the opposite wall. Why is that good?
For Elias, no inventor to blame for stereo, but we can do research and find out if there are good and bad issues associated with the many conventions for stereo playback in the home. That many people have many oppinions on the subject does not mean that some of those oppinions aren't clearly wrong.
Stereo is an incomplete system in that it does not replicate a soundfield. If we can't bring Carnegie hall into our home are we still well served by letting the room play a role in adding reflections to the sound of the speakers?
David S.
For Elias, no inventor to blame for stereo, but we can do research and find out if there are good and bad issues associated with the many conventions for stereo playback in the home. That many people have many oppinions on the subject does not mean that some of those oppinions aren't clearly wrong.
Stereo is an incomplete system in that it does not replicate a soundfield. If we can't bring Carnegie hall into our home are we still well served by letting the room play a role in adding reflections to the sound of the speakers?
David S.
firstly, neither Beveridge nor flooder are primarily aiming their energy at the opposite wall - the horizontal polar patern is perfectly uniform - 180° precisely speaking
secondly, it is good because it gets rid of the floor and ceiling reflection for good (in case of a true line source as in Beveridge) and enables us to have the earliest of the early lateral reflections arrive >8 ms even in a room as narrow as 3.5 m
in a bit larger room it is easy to have delays >10 ms to satisfy even the requirements of Dr Geddes et consortes
it is an advantage over typical stereo where we have very early vertical reflections and even 6 ms of delay is difficult to obtain for lateral reflection (in case of vertical reflections quite impossible to obtain), isn't it?
in case of a flooder the lateral reflections are delayed by the same amount as in Beveridge and first-order floor reflection is eliminated as the speaker is as much integrated into the wall as into the floor - being very short and up-firing
and the ceiling reflection is just as lateral reflections ie. delayed by 8 ms or more (depending on the height of the room and of the listener's seat)
this is why I think it is good from RFZ-fans perspective, wouldn't You agree?
after all even Dr Geddes agrees that reflections delayed by more than 10 ms are beneficial to sound quality
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Hi Oliver,
I see you are afraid of the group delay!
According my understanding up to date, group delay is purely an engineering term and means almost next to nothing in psychoacoustic perception in small room acoustic spaces.
Here (from the data in stereolith thread) is my test box measured at the listening position at 2m in my living room. These are psychoacoustic wavelets at 50ms time frame and betwen 500-10000Hz. Only the right element is playing, left element is mute. Omni mic.
First pic shows the direct sound at 0.007s. Room (wall) reflections come at 0.015s.
How you define group delay from this ? Above 2kHz major energy is at 0.007s but below 2kHz it is at 0.015s. Bad group delay?
Second pic is with the sound absorbing pillow placed betwen the speaker and the listening position to attenuate the direct sound. The sound at 0.007s is almost eliminated.
What is group delay now? It can be seen that major energy arrives at 0.015s at all the frequencies, so one can say group delay has been improved by blocking the direct sound?
- Elias
I see you are afraid of the group delay!
According my understanding up to date, group delay is purely an engineering term and means almost next to nothing in psychoacoustic perception in small room acoustic spaces.
Here (from the data in stereolith thread) is my test box measured at the listening position at 2m in my living room. These are psychoacoustic wavelets at 50ms time frame and betwen 500-10000Hz. Only the right element is playing, left element is mute. Omni mic.
First pic shows the direct sound at 0.007s. Room (wall) reflections come at 0.015s.
How you define group delay from this ? Above 2kHz major energy is at 0.007s but below 2kHz it is at 0.015s. Bad group delay?
An externally hosted image should be here but it was not working when we last tested it.
Second pic is with the sound absorbing pillow placed betwen the speaker and the listening position to attenuate the direct sound. The sound at 0.007s is almost eliminated.
What is group delay now? It can be seen that major energy arrives at 0.015s at all the frequencies, so one can say group delay has been improved by blocking the direct sound?
An externally hosted image should be here but it was not working when we last tested it.
- Elias
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Good question ! 
Are you ready to explore? With open mindset?
Then follow the stereolith thread
- Elias
Are you ready to explore? With open mindset?
Then follow the stereolith thread
- Elias
how does a smeared transient sound to You exactly?
somewhat that is...?
and finally - what are You talking about? certainly not about anything specific in the context of our recent discussions here because You haven't tried it yet
neither Elias' side- nor my ceiling flooder, have You?
so "smeared transient" and "strings sound somewhat colored" etc. are only in Your imagination
luxury items? we are not industry guys here, are we? so I say **** "luxury items"
we are in it for the MUSIC
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e.g. loss of detail in pizzicato passage (contrabass, cello, violin):
The notion of a multitude of strings being plucked but single sounds arrive
with slight offset, which creates a special quality a new whole ...
can be diminished a lot by mediocre systems.
To have a somewhat wider usable listening area, and "involvement"
are items i regard as personal luxury in listening.
The others mentioned like "acceptable transients", "low coloration" are
fundamentals to me.
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Unfortunately neither ceiling- nor side flooder approaches have been
specified sufficiently up to now (or did i miss something) ... preferably
it seems you like others to be definite.
- Whether to use fullrangers or multiway
- Whether to restrict the "indirect only" radiation to a certain
frequency range
- What "blocking" of direct radiation means in terms of (minimum required) level attenuation.
- Which further dispersion characteristrics of the indirect radiator to use
- Whether and how to design the reflective surfaces in order to achieve
controled conditions due to frequency dependent absorption and
stereo symmetry
- Whether and how to compensate for group delay in case a multiway
approach is used (with low frequencies possibly also radiated directly)
- Which dispersion for low and mid frequencies is chosen.
- How is seamless blending between LF and HF achieved (frequency range, DI)?
- How is the room interfaced below schroeder frequency ?
- Which cues for lateralization does the system provide, that are captured in the recording ?
- How is filter function of the pinna in median plane accounted for (esp. in case of a ceiling flooder) ?
...
So at the current state of affairs my own experience with "similar" arrangements
seems more than sufficient to report my impressions, yes.
specified sufficiently up to now (or did i miss something) ... preferably
it seems you like others to be definite.
- Whether to use fullrangers or multiway
- Whether to restrict the "indirect only" radiation to a certain
frequency range
- What "blocking" of direct radiation means in terms of (minimum required) level attenuation.
- Which further dispersion characteristrics of the indirect radiator to use
- Whether and how to design the reflective surfaces in order to achieve
controled conditions due to frequency dependent absorption and
stereo symmetry
- Whether and how to compensate for group delay in case a multiway
approach is used (with low frequencies possibly also radiated directly)
- Which dispersion for low and mid frequencies is chosen.
- How is seamless blending between LF and HF achieved (frequency range, DI)?
- How is the room interfaced below schroeder frequency ?
- Which cues for lateralization does the system provide, that are captured in the recording ?
- How is filter function of the pinna in median plane accounted for (esp. in case of a ceiling flooder) ?
...
So at the current state of affairs my own experience with "similar" arrangements
seems more than sufficient to report my impressions, yes.
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yet it seems that both are specified sufficiently for You to criticize them
You can use advanced search function
great, so, let's summarize: not only You haven't listened to it You even don't know precisely what it is because it hasn't been specified sufficiently up to now (or You missed something)
and yet You feel in a position to criticize it... it must really be a world record of... oh You know what...
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I am bringing to mind aspects that IMO have to be dealt with in any
loudspeaker relying on indirect radiation predominantly, at least at frequencies
above midrange.
The "search functions" you recommended me to use would have to be very
sophisticated (like telepathic pattern completion) to bring those missing
solutions to light.
Since your usual comment to almost every aspect neglected in that "design" is
analogous to "no solution needed".
(System smears enough in conjunction with a room small enough, so it doesn't
matter anyhow. Audio science especially concerning spatial hearing is just
"piecemeal" when applied to real home audio, right ?)
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IMO? so You rely on your opinion in general - I rely on my experience with the specific thing
problems with search function? ok, here it goes, be my guest:
I used fullrangers and coincident two-way but below is a picture of tinitus flooder so limits of this approach in this regard are not fully determined
a flooder doesn't rely on "indirect only" principle, as to the side-firing thing I feel Elias has more experience
a flooder doesn't rely on "blocking", as to the side-firing thing I feel Elias has more experience
What exactly do You mean by "further dispersion characteristrics"?
requirements of symmetry are the same as in case of convetional stereo, no need to design reflective surfaces , great results with standard plasterwork
I used single way fullrange or coincident two-way so I have no experience in that regard but tinitus tested what is pictured below and reported:
in case of a flooder as wide as possible, as to side-firing thing Elias is better expert
in a flooder I used single way fullrange or coincident Uni-Q so I had no problems with blending, as to non-coincident 3-way You can ask tinitus who said that crossover could be tricky
as one wishes - in case of trouble use flooder pair as satellite speakers and whatever subwoofer approach that works for You, small multiple, stereo OB, mono IB, whatever
interesting question
in case of a flooder I can say the same as conventional stereo, as to side-firing - Elias is better expertanother interesting question - how is it accounted for in a conventional speaker?
I don't know
but in case of a flooder it is consistently reported that everything is positioned with the correct height, no sound coming from the floor expected by our dear Markus...
no sound from the ceiling eitherright! audio science dealing with loudspeakers and rooms from perspective of music reproduction at home does much better, and flooder doesn't go against any conclusions/recommendations from Dr Toole's book, does it?
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