Freddi,
The thread has primarily been Graaf continually defending that FCUFS (Floor Coupled Up-Firing Speakers) create some listening advantages, not about the type of speaker used.
Lay a pair of your Karlson's on their back positioned as in post #1's diagram and report back if you have a mystical revelatory listening experience
.Art
here's one higher than I would put - Johnny Cash sounds fab on Karlsons - so does Pavel Lisitsian on my little K12 with SK58 - I like Art's daddy's K8 interpretation too.
Art - - thanks for the clarification
Art - - thanks for the clarification
An externally hosted image should be here but it was not working when we last tested it.
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The drugs probably had something to do with that I suspect. They did for me
(I was listening to Hendrix just the other day, it was on a film track, and I asked my son if he had ever heard him. He said no. I commented that he really should because in his brief life he made an incredible impact. I had seen almost everyone from the 70's live, except Hendrix, and I always regretted that.)
Actually, in this case I was drug and alcohol free, though that all changed later.The drugs probably had something to do with that I suspect. They did for me
(I was listening to Hendrix just the other day, it was on a film track, and I asked my son if he had ever heard him. He said no. I commented that he really should because in his brief life he made an incredible impact. I had seen almost everyone from the 70's live, except Hendrix, and I always regretted that.)
I wished I would have seen him too.
Just finished re-reading "Hendrix-Setting the Record Straight" by John McDemott with Eddie Kramer, really brought back a lot of memories, and excellent detail of the times. Jimi was not only a musical innovator, his business practices changed the way concerts were promoted and presented, he was able to pull far more profit from his shows than any of his contemporary artists.
Amazing to find that Jimi was doing 15,000 seat arena shows with six 15" and 6 HF horns total (Altec A7s), though only the vocals and drums were put through the PA.
I had built a larger PA than that for the band I worked with shortly after his death, although we never played for more than 800 people.
Now, an average "big name" arena show brings in around 200 (or more) transducers.
Art
I resemble that remark! My July 4th, 1970 was a fabulous 'purple haze' day: Jimi Hendrix Concert Setlist at Atlanta International Pop Festival 1970 on July 4, 1970 | setlist.fm
GM
please do not misinform people, ok?
the type of the speaker used matters - I made it clear many times in this thread, also quite recently:
hi graaf - - my apologies for looking at the end of the thread rather than the first.
if I am seeing correctly (?) your FE206 enclosure is sealed, ~0.13 cubic feet, qtc 0.5->.7 (depending upon internal damping material), and top panel about 3.5" thick and extremely inert and rigid.
did you apply eq or did the room position of the enclosure and up-firing nature with 206's rising on-axis response set the tonal balance?
http://www.diyaudio.com/forums/atta...floor-coupled-up-firing-speakers-p6255901.jpg
regarding "floater" with midrange and tweeter section angled upwards, is there a particular angle of tilt which is preferred?
if I am seeing correctly (?) your FE206 enclosure is sealed, ~0.13 cubic feet, qtc 0.5->.7 (depending upon internal damping material), and top panel about 3.5" thick and extremely inert and rigid.
did you apply eq or did the room position of the enclosure and up-firing nature with 206's rising on-axis response set the tonal balance?
http://www.diyaudio.com/forums/atta...floor-coupled-up-firing-speakers-p6255901.jpg
regarding "floater" with midrange and tweeter section angled upwards, is there a particular angle of tilt which is preferred?
Rudolph,
IMO concerning ITDG (Ininial Time Delay Gap) cue
the study MODELING AUDITORY DISTANCE PERCEPTION IN ROOMS
http://webistem.com/acoustics2008/a...-sevilla/forumacusticum/archivos/psy03003.pdf
by A. Bronkhorst, is neither intended nor adequate to
conclude what you say. (Although i subscribe to almost all
you say subsequently in your post.)
In chapter "Method" the author describes, how reflections
in the experimental setting are created artificially:
"
In order to create a reflection, the HRIR for the (approximately)
correct direction was selected and subsequently filtered in 1/3-octaves according to the
calculated frequency spectrum. Finally, based on the reflection’s pathlength, the HRIR was
attenuated and a delay was added.
"
By using this method you will not be able to make any
conclusions about the relevance of the ITDG cue in
isolation and in contrast to any other possible cues.
This is simply, because the ITDG cue is always i n c l u d e d
when choosing that kind of method.
If the goal would be comparison of ITDG cue's relevance for
perception of distance of sound sources in contrast to other
cues, a different experimental setting would have to be chosen.
The author's final conclusion
"
The current findings provide support for the hypothesis that the D/R ratio cue is,
actually, a binaural cue, and that it is based on ITD differences between incoming sounds.
It is, however, clear that this hypothesis is still based on a limited body of data and
that further validation is required."
is in line with his findings, that lateral reflections
-and only those can contribute substantialy to ITD (Interaural Time Delay)-
are of high relevance, when separating reflections from the direct sound,
especially for the more early arrivals.
The study points towards binaural hearing (ITD cues) and thus sidewall reflections
being of high relevance in estimating the distance of sound sources.
Since ITDG cues are included in the set of stimuli used, the study seems able
to refine and complement knowledge about the relevant set of cues, but does not
rule out or even quantify the role of ITDG.
To me the prominent message of the study is: We are in trouble when estimating
the distance of a sound source without any lateral reflections present.
Hopefully here ITDG was the only parameter changed between settings, i don't know:
Intimacy Auralizations
Rudolf,
let's please have a closer look at that "window" kind of analogy to
stereo loudspeakers and see how far the analogy meets reality.
Let's assume my listening room being adjacent to a nice concert hall,
or even being build - virtually - in the thick of it.
I have 2 windows in front of my listening seat - a left one and
a right one - the center spot between the windows being at say 6th row
center of the concert hall, is that OK for you ?
Now we have to build the frames of the windows: Which size ?
Intuitively i would like a rather large pair of windows, not just
keyholes.
Would 1,20m X 0,50m be OK ?
Say my room's front wall is 10cm thick, i would like to have the window
frame rounded by a radius of 5cm, so that edge diffraction is reduced.
Now we have a little anomaly: An instrument from center stage cannot
send direct sound to me, it is shadowed by the piece of wall between my
windows. For large wavelengths, the diffraction through my 0,5m wide
"listening slots" will make up for that, but in the Khz range that direct
sound from center stage will pass through the window but will also just
hit my neighbours, not myself. The best i can get is higher order reflection
starting with a first bounce from the back wall of my listening room.
So the first little refinement would be an acoustic lens fitted into
each windowframe, which shifts the radiation of the windows to the center,
in order to make direct sound from center stage audible at my seat.
Luckily that problem can be solved since the correction needed is not too
large at 6th row.
Now how does these "window frame speakers" behave ?
Very interesting:
- Direct sound from the stage is (for higher frequencies) passed
in a rather directed manner. It is nearly like plane waves emanating
from inside my window frames.
- For Direct sound there would be strong intensity shifts between left
and right window for sound sources located at left or right wing of the stage:
Since wavelengths smaller than the window's width would roughly keep
their original direction, an instrument visible through the left window
would also be just audible through the left window.
The wave coming from that left instrument will also pass through the right
window of course, but only a portion of the low frequency content from the right
window will hit me directly by diffraction, the higher frequencies are directed
at the right sidewall of my listening room.
Now for the reverberant sound in the concert hall ...
- while direct sound passes the windows roughly keeping the original direction,
the same occurs for the reflections in the hall.
- the reverberant sound from inside the "speaker windows" is diffuse and has no
preferred direction: It will be very "wide radiating" in contrast to the
direct sound, which will be nearly plane waves, but keeping the direction of
the original source.
We could make the window frames more narrow now, until we have just two
1,2m x 0,01m "listening slots" at each side. We can omitt the acoustic lens now,
because our "diffraction slots" will both send the sound from a center stage instrument
to our listening seat in the median plane of the listening room, by radiating 180 degree
horizontally each.
But now the directivity (of the inner side of our "speaker windows") of direct and
reverberant sound (coming from the hall) is the same.
Which type of window would you prefer, wide or narrow ?
In fact no conventional speaker can do, what the "wide speaker window" does, in that
- a (single channel/single speaker) conventional loudspeaker's directivity will
never make a difference between direct and reverberant sound to be reproduced.
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Karlson's reflective patent
ACOUSTIC SYSTEM
John E. Karlson et al
Patent number: 2896736
Filing date: Aug 15, 1955
Issue date: Jul 28, 1959
https://www.google.com/patents/US28...&sa=X&ei=VUbgUfrqFPDYyQGd4YAo&ved=0CDYQ6AEwAA
1955 look at the middle picture of the Karlson 12 - this was Karlson's "Aural Optics"
An externally hosted image should be here but it was not working when we last tested it.
ACOUSTIC SYSTEM
John E. Karlson et al
Patent number: 2896736
Filing date: Aug 15, 1955
Issue date: Jul 28, 1959
https://www.google.com/patents/US28...&sa=X&ei=VUbgUfrqFPDYyQGd4YAo&ved=0CDYQ6AEwAA
1955 look at the middle picture of the Karlson 12 - this was Karlson's "Aural Optics"
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Hi Freddi,
at least this is a "floor coupled upfiring speaker" (FCUFS)
approach ... and it uses the front wall to make up a
mirrored sound source of itself in relative proximity.
Also sidewall placement ("Beveridge placement",
like proposed by graaf ) would be possible.
But does this speaker/room arrangement make a difference
between direct and reverberant sound on the recording ?
at least this is a "floor coupled upfiring speaker" (FCUFS)
approach ... and it uses the front wall to make up a
mirrored sound source of itself in relative proximity.
Also sidewall placement ("Beveridge placement",
like proposed by graaf ) would be possible.
But does this speaker/room arrangement make a difference
between direct and reverberant sound on the recording ?
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Oliver,
In small rooms ITDG is just a geometrical concept, but nothing we would hear as an impression in time. Reflections delayed for less than 15 ms would appear as ASW or source displacement, but not as "late".
ITDG is used in sound production to control distance impressions in recordings. But that is another story than the distance impression of the "window" in the listening room.
I have to cite the Bronkhorst paper again (from the conclusions):
What is above "arrival time" other than ITDG?
Rudolf
Sorry, no!
I was speaking of a single window like a loge opening into the opera auditorium. Or like my room with the front wall taken away. The related discussion was not about accurate stereo reproduction, but about the lacking ability of stereo to provide the 360° envelopment and spaciousness of a large recording venue in the back of my "loge".
Rudolf
I see.
Nevertheless comparing 2 speakers and 2 imaginary windows seemed
quite illustrative to me. It seems something completely different.
Even the loge opening and 2 speakers behave completely different, for the
same reasons i was posting. Just the "stage center problem" disappears.
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I think i am aware of that too, but was trying to illustrate the aspects
which to not match within that analogy, when using common speaker
types and recording technology as a base.
If a certain analogy has only few matching aspects, we should be aware
of that and just use the analogy for those aspects explicitly.
But - as we all know and might be tempted to from time to time - even
in this forum there is a tendency of generalizing aspects/facts/analogies
beyond the limits of proven validity or common experience.
Nevertheless a loudspeaker with "window like" behaviour would be
interesting as a concept, wouldn't it ?
I mean without thinking about how it could be implemented yet.
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