Concerning speaker room interaction i regard
distributed mode loudspeakers highly interesting.
The following paper is in german language unfortunately,
but on page 14 ff there are some diagrams which show
the influence of reflection in comparison to conventional
speakers.
http://www.wvier.de/texte/NXT_Tonmeistertagung.pdf
As i am experimenting with that technology, a can underline
from personal experience, that DML behave extraordinarily
benign concerning deficient acoustics in small rooms.
As the common living room cannot be modified into a perfect
listening room, a more benign speaker techology is the key
point in my view.
Kind Regards
distributed mode loudspeakers highly interesting.
The following paper is in german language unfortunately,
but on page 14 ff there are some diagrams which show
the influence of reflection in comparison to conventional
speakers.
http://www.wvier.de/texte/NXT_Tonmeistertagung.pdf
As i am experimenting with that technology, a can underline
from personal experience, that DML behave extraordinarily
benign concerning deficient acoustics in small rooms.
As the common living room cannot be modified into a perfect
listening room, a more benign speaker techology is the key
point in my view.
Kind Regards
in fact DMLs are similar to cone-driver-based omni speakers in one feature that is crucial from the the perspective of room-speaker interface - they have very broad dispersion and thus maximum interaction with the room
Here are some polar plots and of axis measurements.
http://www.soundcontrol.tudelft.nl/Personnel/Rinus Boone_files/RB_AES2000.pdf
I cannot agree in so far, as DML directivity can be shaped by
the housing similar as with conventional speakers too.
The well known monopole-kardioid-dipol shaping of the
dispersion is possible similar as with conventional speakers.
But the CHANGE in directivity due to driver dimensions related
to wavelength does not occur as pronounced.
Have you seen the plots in the first paper ?
The diffuse radiation especially towards larger off axis angles
minimizes comb filtering to an extent, which cannot be achieved
with a piston acting speaker.
When listening to DML, the speaker "disappears" and cannot
be localized as sharp like conventional speakers.
For a conventional speaker it takes many conditions to be met
before disappearing itself: Listening room, recording everything has to
fit before music is released from the speakers.
Using a DML this is more something like the "normal mode of operation".
Kind Regards
http://www.soundcontrol.tudelft.nl/Personnel/Rinus Boone_files/RB_AES2000.pdf
I cannot agree in so far, as DML directivity can be shaped by
the housing similar as with conventional speakers too.
The well known monopole-kardioid-dipol shaping of the
dispersion is possible similar as with conventional speakers.
But the CHANGE in directivity due to driver dimensions related
to wavelength does not occur as pronounced.
Have you seen the plots in the first paper ?
The diffuse radiation especially towards larger off axis angles
minimizes comb filtering to an extent, which cannot be achieved
with a piston acting speaker.
When listening to DML, the speaker "disappears" and cannot
be localized as sharp like conventional speakers.
For a conventional speaker it takes many conditions to be met
before disappearing itself: Listening room, recording everything has to
fit before music is released from the speakers.
Using a DML this is more something like the "normal mode of operation".
Kind Regards
I've found this to be true within the envelope that people seem to agree matters the most 1ms-6ms. It's a bit tricky though because above or below that envelope it seems to change. And really the whole thing is kind of counter intuitive to me. I would have thought that the earlier reflections would need to be softer to be innocuous. But you can really push a reflection way up in volume around the 1-2ms region compared to the 5-7ms region. The later the reflection in that envelope it seems the softer it will need to be to blend in with the direct sound. But if you make the reflection really short it doesn't seem like an echo but just sort of a 3-D effect that is hard to even notice unless you can turn it off.
it is not that difficult, all unorthodox setups described in this thread - CFS, SLS and Carlsson - excel at disapearing act
as to DMLs I am no expert, I rely on what I have found:
http://dspace.upv.es/xmlui/bitstrea...d=27DA9794EFADFFAF1B1FB4471E010D0D?sequence=6
best,
graaf
What's unorthodox about Carlsson speakers? I read the "Ortho- Acoustic Loudspeaker" paper (http://www.carlssonplanet.com/downloads/uploads/carlsson_ortho.pdf). The OA5x tries to mimic a flush mounted speaker and comes with some built-in absorber panels to kill first reflections.
I'm sure lots of people have noticed this. I'm not fooling myself into thinking that what I am experimenting with is cutting edge or anything. It's not exactly new but maybe the specifics and just putting all the pieces together in a way that actually works that might be somewhat new.
o yeah, 40 years ago...
and yet...
"Blauert wrote" yet we still do not know
yet somehow we know that "that cannot work, this is nonsense" etc. etc.
I think that is basically what i said. It describes a highly
useful property of that kind of speakers with respect to minimize
loudspeaker room interaction.
Realistic (though exemplaric) data concerning directivity you can
find e.g. in Fig. 5 of the second paper.
Polar plots of DML look very different according to size, panel material
and mounting conditions.
To think about: The strong desire for directivity in piston acting
Loudspeakers when minimizing room interaction comes from
strong interference of conventional (non diffuse) loudspeakers
with room boundaries ...
Although you can shape DML directional too, this is not neccessary to
the extent you have to do it when minimizing boundary interference
for conventional speakers.
This in turn gives a very wide listening area of nearly constant
quality. It is simply "amazing" ...
Kind Regards
I'm sure lots of people have noticed this. I'm not fooling myself into thinking that what I am experimenting with is cutting edge or anything. It's not exactly new but maybe the specifics and just putting all the pieces together in a way that actually works that might be somewhat new.
I agree that own experience has always a different value than theoretical
knowledge. Although i know the mentioned book from Jens Blauert
- it is in fact one of my favourites -
i am experimenting sometimes, even though it is not leading edge.
Kind Regards
have You ever anywhere seen anything similar?
there are much simpler ways to "mimic a flush mounted speaker" than making a very short speaker with drivers firing diagonally up to the ceiling
the Carlsson way means also effective handling of early reflections from the side-walls, floor and ceiling, much more than "to mimic a flush mounted speaker"
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I've seen a couple of "unorthodox" speakers, yes, but the interesting thing is the design principle of a speaker. The Carlson looks not "unorthodox" to me.
there are much simpler ways to "mimic a flush mounted speaker" then making a short speaker with drivers firing diagonally up to the ceiling
the Carlsson way means also effective handling of early reflections from the side-walls, floor and ceiling, much more than "to mimic a flush mounted speaker"
Did you read the Carlson paper? It exactly describes the same principles that led to flush mounting or constant (high) directivity concepts.
ok, great!
What kind of a question is this?
Let me answer accordingly with similar questions:
Did you read my first post in this thread? Did You read Harold Beveridge's paper on room-speaker interface? Or Moulton's? Or Linkwitz's presentations?
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Yes. Do you realize that these names and their concepts stand for very different sound fields?
Now tell me what is wrong with my proposition? What calculation is wrong? What asumptions are mistaken?
Surely there are VERs <1 ms from the adjacent wall but I cannot hear anything bad that could be attributed to them.
I can hear no mucking up of the image, nothing unnatural that "sounds like nonlinear distortion", and certainly no audible unnatural image shift nor widening nor blowing up - which in that case is quite expected because those VERs are coming from the same direction as the first wavefront within just +/- couple of degrees
Surely there are VERs <1 ms from the adjacent wall but I cannot hear anything bad that could be attributed to them.
I can hear no mucking up of the image, nothing unnatural that "sounds like nonlinear distortion", and certainly no audible unnatural image shift nor widening nor blowing up - which in that case is quite expected because those VERs are coming from the same direction as the first wavefront within just +/- couple of degrees
what do You mean by "very different sound fields"?
Yes I realize that in each case there is very different sequence of room reflections, that is for sure BUT question is - how does it translate into audible sensations?
Can we tell from the perspective of audibility which of those "sequences of room reflections" is optimal or at least better than other or at the very least audibly "very different" from other? Can we?
This is the question - how those "very different sound fields" translate into what we hear?
Because each of those "very different sound fields" room reflections differ in direction, timing, intensity and spectral content whether (and to what effect) reflections are audible or not is a function of timing and intensity, and direction and spectral content and so on and so on
perhaps from the psychoacoustical perspective of audiblity and of detrimental effect the differences are not that huge as from the physical perspective of "very different sound fields"?
What do You think?