Well, I am perfectly aware that it doesn't help that I am so hopelessly old school...
What's the point of gated measurement?
It would be a step towards finding some relation of the direct sound at your listening seat and the room's contribution in early and later reflections ...
Probably the most important reflections could be identified using the impulse response and a sketch/photo of the setup.
Then it is at least possible to relate some basic properties of your setup to more "conventional" ones, to find out the differences.
Those differences - if occcuring - seem to be "improvements" in your view or they meet your taste at least ...
To correlate your personal impressions with some data seems worth the effort, since the effort is rather low for making some quick measurements at least.
Maybe it turns out, your setup being behaved quite "common". That seems improbable but who knows.
At least "advantages" of certain setups reported just verbally in terms of subjective impressions are worth nothing in audio. I mean, some guy's are writng on the sound of cables etc.
Maybe "FCUFS" sound can also be achieved by using a certain kind of tube amplifier or cable ?
To sort that out, we have to move into the acoustics and see, what's going on in your room at least on a "brief overview" kind of scale.
Probably the most important reflections could be identified using the impulse response and a sketch/photo of the setup.
Then it is at least possible to relate some basic properties of your setup to more "conventional" ones, to find out the differences.
Those differences - if occcuring - seem to be "improvements" in your view or they meet your taste at least ...
To correlate your personal impressions with some data seems worth the effort, since the effort is rather low for making some quick measurements at least.
Maybe it turns out, your setup being behaved quite "common". That seems improbable but who knows.
At least "advantages" of certain setups reported just verbally in terms of subjective impressions are worth nothing in audio. I mean, some guy's are writng on the sound of cables etc.
Maybe "FCUFS" sound can also be achieved by using a certain kind of tube amplifier or cable ?
To sort that out, we have to move into the acoustics and see, what's going on in your room at least on a "brief overview" kind of scale.
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Measurements of various "flooder"/FCUFS implementations were done and posted in this and other threads by Elias IIRC, Radugazon and others, "basic properties" have been revealed. Stop kidding please
oh yeah surely
Am I to understand that we are done talking seriously?
graaf said:
Do you feel we were talking seriously about "FCUFS" aproach ever before ? Mabe it is time to start with.
However there are different types of home listeners ... e.g.
- some are more "sweet spot addicted", sometimes forced by radiation pattern and setup of the loudspeakers
- some are more the recreational "i listen where i like to be" type of listener
However when using e.g. a wideband driver, directing it at the ceiling under some angle and placing it low, this will in most rooms be simply the way to "make the most" out of the highs radiated by the driver, when just looking at the reverberant field.
This is because the ceiling is most likely to be the "least absorbing wall" in a living room. Placing the driver low contributes in "collecting" what the driver radiates to the sides while using also the mostly more "smooth walled" upper areas of the side walls for reflection. Bookshelves, sideboards, pictures etc. are mostly placed more close to the ground where the inhabitants move around, try to store and find their items, look at pictures etc.
Multiple reflections - depending on setup - like
"upper side wall > ceiling > listener", "ceiling > upper front wall > bottom > listener", "upper front wall > ceiling > listener", ...
also contribute to diffusivity (decorrelation), given the radiation pattern in highs is still wide enough.
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Some people were talking seriously.
Looks like talking seriously. Is it?
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This should be the case with most coaxial designs, representing a "short and wide" waveguide for the tweeter, as well as with flat coaxial drivers like e.g. from Thiel.
In most rooms rather late but also rather decorrelated reflections will occur in highs when using "FCUFS", which gives direct sound - which will have a response considerably reduced in highs - "lead enough" to make up a stereo image allowing for phantom localization.
Unfortunately the tonal balance cannot rely on a flat frequency response "on axis" (in direction to the listening seat), which makes the approach pretty dependent from room and setup.
Highs may tend to a "faint" impression, but lifting the highs to meet "flat on axis response" will lead to "overbright" impression, without really resolving that "faintness".
I can imagine a slight lift in the presence region being "a cure" in tonality, also balancing that potential "faint" character without sounding too bright in upper highs.
Tonal balance e.g. of sonab models points in the same direction:
Sonab OA5 mkII
http://www.troelsgravesen.dk/sonab_files/sonab-AO5-II_1mtfb_-22.2dB.jpg
http://www.troelsgravesen.dk/sonab_files/sonab-AO5-II_1mtfb_side_-22.2dB.jpg
BTW i made some experience in having too much highs radiated indirectly at earlier versions of my bending wave transducer, which is a "derorrelated quasi omni radiator" at larger of axis angles in highs.
Also i know well about the temptation in reducing some "perceived faintness" by tonal balance. In my bending wave transducer i finally decided to reduce the rear, rear-side and rear-upward radiating components by an appropriate absorber, which gives a higher D/R ratio, meeting that of midrange better than without the absorber. Of course, here that kind of "curing the cause" was technically achievable.
Plase compare e.g. the "Sonab OA5" responses with "the new kind of presence filter" proposed by Blauert in 1970:
http://www.sengpielaudio.com/Blauert-Filter.pdf
which gives a rise around 300Hz and 3Khz to make up the "present" impression. (See Page 4: "Präsent Einstellung").
There is an astonishing correlation, suggesting that Sonab speaker has been tuned by experimental listening to large extent, which resulted in an on axis response simulating higher presence of the sound stage than really possible with the given low D/R ratio in highs otherwise.
Of course such "sounding tricks" in an FCUFS point towards a remaining problem. The inherent tendency to "dull" (also influenced by crossover frequencies) character of dynamic 2-3way loudspeakers in the reverberant field due to beaming in highs may be mitigated a lot, but the price to pay is a falling on axis response now.
The "sounding trick" may work if not overdone, but is unfortunately dependent from preferred program material, even if a "balanced" tuning due to the individual room setup has been found.
The desirable tuning of the direct response - which cannot be made independently from the energy response as a whole - depends on the kind of instruments to be reproduced and the recording as well.
Sounds like "close human speaker" or solo instruments in a jazz ensemble (more dominated by transients and tones of shorter duration) need by far more "artificial presence" now than e.g. orchestral strings or organ music, as a high reverberant share of sound is already intended with most recordings.
Low D/R ratio speakers lack "universality" and do not excel in prodividing "reliable tonal balance" across a larger repertoire of genres and recordings.
When preferring a certain genre or being ready to change the tuning in a genre specific way (every time when needed), also "low D/R ratio" speakers can provide enjoyful listening without doubt:
The rest is habituation.
Given the sonic results with many "common" multiway loudspeakers in mostly untreated living rooms, i pretty much understand there being a niche for loudspeakers making use of lower D/R ratio especially in highs and making also use of decorrelating the rooms reflections in the early reverb by encouraging multiple reflections in the "mostly smooth walled upper zones" of living rooms (as found in "FCUFS").
However this is not my preferred method ...
In most rooms rather late but also rather decorrelated reflections will occur in highs when using "FCUFS", which gives direct sound - which will have a response considerably reduced in highs - "lead enough" to make up a stereo image allowing for phantom localization.
Unfortunately the tonal balance cannot rely on a flat frequency response "on axis" (in direction to the listening seat), which makes the approach pretty dependent from room and setup.
Highs may tend to a "faint" impression, but lifting the highs to meet "flat on axis response" will lead to "overbright" impression, without really resolving that "faintness".
I can imagine a slight lift in the presence region being "a cure" in tonality, also balancing that potential "faint" character without sounding too bright in upper highs.
Tonal balance e.g. of sonab models points in the same direction:
Sonab OA5 mkII
http://www.troelsgravesen.dk/sonab_files/sonab-AO5-II_1mtfb_-22.2dB.jpg
http://www.troelsgravesen.dk/sonab_files/sonab-AO5-II_1mtfb_side_-22.2dB.jpg
BTW i made some experience in having too much highs radiated indirectly at earlier versions of my bending wave transducer, which is a "derorrelated quasi omni radiator" at larger of axis angles in highs.
Also i know well about the temptation in reducing some "perceived faintness" by tonal balance. In my bending wave transducer i finally decided to reduce the rear, rear-side and rear-upward radiating components by an appropriate absorber, which gives a higher D/R ratio, meeting that of midrange better than without the absorber. Of course, here that kind of "curing the cause" was technically achievable.
Plase compare e.g. the "Sonab OA5" responses with "the new kind of presence filter" proposed by Blauert in 1970:
http://www.sengpielaudio.com/Blauert-Filter.pdf
which gives a rise around 300Hz and 3Khz to make up the "present" impression. (See Page 4: "Präsent Einstellung").
There is an astonishing correlation, suggesting that Sonab speaker has been tuned by experimental listening to large extent, which resulted in an on axis response simulating higher presence of the sound stage than really possible with the given low D/R ratio in highs otherwise.
Of course such "sounding tricks" in an FCUFS point towards a remaining problem. The inherent tendency to "dull" (also influenced by crossover frequencies) character of dynamic 2-3way loudspeakers in the reverberant field due to beaming in highs may be mitigated a lot, but the price to pay is a falling on axis response now.
The "sounding trick" may work if not overdone, but is unfortunately dependent from preferred program material, even if a "balanced" tuning due to the individual room setup has been found.
The desirable tuning of the direct response - which cannot be made independently from the energy response as a whole - depends on the kind of instruments to be reproduced and the recording as well.
Sounds like "close human speaker" or solo instruments in a jazz ensemble (more dominated by transients and tones of shorter duration) need by far more "artificial presence" now than e.g. orchestral strings or organ music, as a high reverberant share of sound is already intended with most recordings.
Low D/R ratio speakers lack "universality" and do not excel in prodividing "reliable tonal balance" across a larger repertoire of genres and recordings.
When preferring a certain genre or being ready to change the tuning in a genre specific way (every time when needed), also "low D/R ratio" speakers can provide enjoyful listening without doubt:
The rest is habituation.
Given the sonic results with many "common" multiway loudspeakers in mostly untreated living rooms, i pretty much understand there being a niche for loudspeakers making use of lower D/R ratio especially in highs and making also use of decorrelating the rooms reflections in the early reverb by encouraging multiple reflections in the "mostly smooth walled upper zones" of living rooms (as found in "FCUFS").
However this is not my preferred method ...
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Perhaps it is (though opinios vary). But is it more dependent than most loudspeakers?
Why do Yo think "a falling on axis response" is a problem in itself? After all we don't perceive the direct sound frequency response as such at all.
Dependent on the type of recorded instrument? Why?
As to the type of recording - perhaps but I haven't noticed anything like problems with "presence".
Jazz ensemble can have great in-your-face presence and an orchestra can have a nice wide and deep perspective. It all depends on recording and there is no kind of sameness or any distortions in reproduced spatiality. I always use headphones as reference.
As to the "reliable tonal balance" - I always use (after SL's recommendation) some ruler-flat frequency response earphones as reference.
As to "universality" I don't know what You mean precisely.
interesting theory, thanks Oliver!
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Low D/R ratio loudspakers, especially if not providing flat on axis response, are more dependent on room setup clearly.
E.g. refer to Toole's studies on listener's preference. The "song of priorities" in listener preference - aka sound quality of a loudpeaker in a room - goes:
- on axis flatness
- on axis smoothness
- off axis flatness
- off axis smoothness
and not vice versa ... i am sorry.
Especially transients - we have resently talked about, what transients are - in the higher ranges are underrepresented in the direct sound of the loudspeaker, when on axis resonse is falling with frequency. Tonal balance in highs is then a "subjectively tuned artificial balance" relying on the room's contribution to large extend.
Such loudspeakers are "less robust" due to tonality and alternative acoustic "perspective" of different recordings, even if the energy response as a whole may be quite balanced.
That is one of the reasons, why a considerably flat on axis frequency response is most important.
Ruler flat earphones ? You mean diffuse field equalized ?
If you want to compare something
- compare a set loudspeakers just to a different set of loudspeakers "known as being good" and set up well (verified by measurement) in your room
- compare a headphone to a different headphone
(unless you being Siegfried Linkwitz, he may do otherwise and also listen to binaural recordings using his stereo loudspeakers, concluding frequency response of the speakers has to be changed ...)
...maybe all i said before in a kind of summary.
Regarding "FCUFS" that is my "analysis" so far, why it "can work well" from an esthetical point of view, given the conditions are "well matching". It is certainly not a way to make up a "tonally robust and universal reproduction chain". But for individual enjoyful listening, who am i to give instructions ?
I prefer a way IMO better meeeting both: Some "correctness aspects" and also the "enjoyment" apects. If both spheres of aspects go together naturally, than its "subjectively perfect" to me.
It is also, what gives me the "largest repertoire of recordings, that can be listened to enjoyfully", being it listening "critical enjoyfully" or "just enjoyfully"
. Kind Regards
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graaf,
we seem to share something, that in my view is independent from approaches currently preferred or discussed:
There are certain typical artifacts introduced by common loudspeakers especially in untreated living rooms, that may "loudspeaker reproduction" or "loudspeaker sound" indentifyable as such.
Unfortunately you can IMO not "buy yourself out of that" even when paying high amounts for speakers, as being ready for thoughtful setup and also some room treatment if necessary is part of a successful installation.
Even fighting a (too) compromised setup's drawbacks using "DRC" is a rather fruitless business ...
Listeners that like to experience "realistic" reverb - like intended and partly captured on well made recordings of acoustic instruments - are thus looking for alternatives, that might help in "overcoming the room".
The art is here IMO, using the room's reflections just for "revision" of the stereo reproduction's inherent drawbacks - like e.g. "inter channel interference" - but keep the listening room's reflections reluctant in a way not to get audible themselves or even contributing to the loudspeakers being localized themselves as sound sources.
This is prefereably achieved with the reverberant field in the listening room having
- first reflections not too early arriving at the listening seat
- having side reflections from (e.g. say around) 60 degrees from the "median plane" arriving at the listener
- balancing ipsilateral and contralateral reflections: Ipsilaterals should not be dominant (> leads to preferred radiation pattern of loudspeakers, as this is impossible without matching directivity ...)
- the more early reflections are the more a diffused (decorrelated) manner is preferred in the "early reverb" (breaking up single reflections into "more" and lower levelled ones)
- single reflections, even the "good ones", not too high in level
- reflections of the early reverb, averaged over eligible time and direction representing a spectrum similar to the direct sound arriving at the listening seat (similar does not imply perfect match, but overall spectral balance)
Some implementations of that "FCUFS" appproach treated in this thread are able to meet some or even most of the criteria, if the room setup is well matched.
The weak point is the missing neutrality in direct sound but this may for many listeners be "outweighed" by getting rid of some typical artifacts in loudspeaker/room interaction.
In my preferred concept i managed to achieve that "unobtrusive but useful" integration of a (living) room's ineviteable reflections without compromising the neutrality and coherence of the direct sound. Of course, this is why i prefer it ...
But we seem to agree about the artifacts, we want to get rid of: We do not want to listen like "listening to loudspeakers".
Kind Regards
we seem to share something, that in my view is independent from approaches currently preferred or discussed:
There are certain typical artifacts introduced by common loudspeakers especially in untreated living rooms, that may "loudspeaker reproduction" or "loudspeaker sound" indentifyable as such.
Unfortunately you can IMO not "buy yourself out of that" even when paying high amounts for speakers, as being ready for thoughtful setup and also some room treatment if necessary is part of a successful installation.
Even fighting a (too) compromised setup's drawbacks using "DRC" is a rather fruitless business ...
Listeners that like to experience "realistic" reverb - like intended and partly captured on well made recordings of acoustic instruments - are thus looking for alternatives, that might help in "overcoming the room".
The art is here IMO, using the room's reflections just for "revision" of the stereo reproduction's inherent drawbacks - like e.g. "inter channel interference" - but keep the listening room's reflections reluctant in a way not to get audible themselves or even contributing to the loudspeakers being localized themselves as sound sources.
This is prefereably achieved with the reverberant field in the listening room having
- first reflections not too early arriving at the listening seat
- having side reflections from (e.g. say around) 60 degrees from the "median plane" arriving at the listener
- balancing ipsilateral and contralateral reflections: Ipsilaterals should not be dominant (> leads to preferred radiation pattern of loudspeakers, as this is impossible without matching directivity ...)
- the more early reflections are the more a diffused (decorrelated) manner is preferred in the "early reverb" (breaking up single reflections into "more" and lower levelled ones)
- single reflections, even the "good ones", not too high in level
- reflections of the early reverb, averaged over eligible time and direction representing a spectrum similar to the direct sound arriving at the listening seat (similar does not imply perfect match, but overall spectral balance)
Some implementations of that "FCUFS" appproach treated in this thread are able to meet some or even most of the criteria, if the room setup is well matched.
The weak point is the missing neutrality in direct sound but this may for many listeners be "outweighed" by getting rid of some typical artifacts in loudspeaker/room interaction.
In my preferred concept i managed to achieve that "unobtrusive but useful" integration of a (living) room's ineviteable reflections without compromising the neutrality and coherence of the direct sound. Of course, this is why i prefer it ...
But we seem to agree about the artifacts, we want to get rid of: We do not want to listen like "listening to loudspeakers".
Kind Regards
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Ok. Then what do You think about a solution like in eg. Gradient Helsinki that is about tilting the speaker back by as much as 45 degrees?
In such a situation the listener at a typical distance and height is within 30 degrees off-axis. UniQ's response is not so much tilting down at 30 degrees, even if we take manufacturer's graphs with a due grain of salt.
Measurements (taken by Jacek Zagaja who is also a user of this forum) looked close to the "combined (ideal) field" (except the top octave).
What for? Such comparisons?
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Yes, so it seems.
I am glad to hear that. OTOH opinions vary as to the question whether low D/R speakers ("omni"/"poly" whatever their manufacturers name them) are more or less room and placement sensitive.
You obviously aim at a hi-end, state-of-the-art type of things, which is very commendable in itself, such aspiration.
Whereas my goals are much more modest
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Meanwhile I did some tests of a new concept with cardboard and plasterboard test baffles and enclosures.
The tests were inspired by the results of some earlier tests:
Now the proper speaker is under construction. I will look a bit like AudioPro Qube but the top baffle will be tilted at 45 degrees and the driver will be Kef CI200QR.
The final prototypes were raised on stands and the tweeter was at about 75 cm.
Experimentally this 45 degrees and the tweeter position at 75 cm appeared to be sufficient to achieve the desired type of presentation with the complete disappearing act and even the hard-panned L and R acoustically dry images completely untied from the speakers and of realistic 3D quality.
…but clearly with this tilt and at the height of 75 cm it is not FCUFS in the original meaning anymore. No more than the Gradients for example.
So, perhaps then there is no need to completely remove the floor reflection... as in the original "flooder" or in Snell Type 1. Perhaps it suffices to lower its level and to establish an asymmetry of strength between the floor and the ceiling reflections.
The tests were inspired by the results of some earlier tests:
Now the proper speaker is under construction. I will look a bit like AudioPro Qube but the top baffle will be tilted at 45 degrees and the driver will be Kef CI200QR.
The final prototypes were raised on stands and the tweeter was at about 75 cm.
Experimentally this 45 degrees and the tweeter position at 75 cm appeared to be sufficient to achieve the desired type of presentation with the complete disappearing act and even the hard-panned L and R acoustically dry images completely untied from the speakers and of realistic 3D quality.
…but clearly with this tilt and at the height of 75 cm it is not FCUFS in the original meaning anymore. No more than the Gradients for example.
So, perhaps then there is no need to completely remove the floor reflection... as in the original "flooder" or in Snell Type 1. Perhaps it suffices to lower its level and to establish an asymmetry of strength between the floor and the ceiling reflections.
graaf said:
Floor bounce is with most setups an issue predominantly influencing upper bass and lower midrange.
https://www.hifi-selbstbau.de/images/stories/Messraum/Bodenreflexion1.png
In a multiway using e.g. a 2nd woofer at considerably different height is a common and well working strategy of "filling the notches" in a single woofer's response due to floor bounce.
Anyhow you should not worry about it too much ...
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It's not just about the bounce. Take a look at Snell Type One. There the tweeter - which have nothing to do with floor bounce whatsoever - is effectively integrated into the floor. Apparently with a coaxial there is no need for this.
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Well, let's put it like this:
- either you manage to get "fullrange corner (or edge) load" (which is difficult in highs using a coax ...),
- or you put the drivers away from the room's edges/bottom so far, that direct sound will not be affected too much within 1-2ms delay ....
Using that - experimentally found by yourself - height above the floor, goes towards the second kind of setup.
I do not know at which distance to the side walls you will place your speakers and how the side walls - e.g. near ear height - are furnitured in your room.
Some photos would help imagination ...
What "Snell Type 1" does, looks like "rather consequent edge loading" even for the tweeter.
http://www.snell.no/images/Snell_type_one.jpg
This is not viable using the coax IMO, because there will always be considerable distance to the corner for the tweeter, with distance being in range of wavelenghs radiated by the tweeter ... that wouldn't be wise IMO.
So it seems to me, you are on a good way finally ... not too radical, but practical and still within "your preferred approach".
This approach seems probably - as we puzzled out so far - based on making use of not too early and hopefully somewhat diffuse reflections in the upper area of your room (upper side walls, upper front and back wall, ceiling ...) and thus avoiding reverb being too "dull".
This seems to meet your preferred quality of reverb, while still a driver system is used, that has narrower radiation in highs than from bass to midrange and thus - like most loudspeakers - a falling energy response in tendency.
- either you manage to get "fullrange corner (or edge) load" (which is difficult in highs using a coax ...),
- or you put the drivers away from the room's edges/bottom so far, that direct sound will not be affected too much within 1-2ms delay ....
Using that - experimentally found by yourself - height above the floor, goes towards the second kind of setup.
I do not know at which distance to the side walls you will place your speakers and how the side walls - e.g. near ear height - are furnitured in your room.
Some photos would help imagination ...
What "Snell Type 1" does, looks like "rather consequent edge loading" even for the tweeter.
http://www.snell.no/images/Snell_type_one.jpg
This is not viable using the coax IMO, because there will always be considerable distance to the corner for the tweeter, with distance being in range of wavelenghs radiated by the tweeter ... that wouldn't be wise IMO.
So it seems to me, you are on a good way finally ... not too radical, but practical and still within "your preferred approach".
This approach seems probably - as we puzzled out so far - based on making use of not too early and hopefully somewhat diffuse reflections in the upper area of your room (upper side walls, upper front and back wall, ceiling ...) and thus avoiding reverb being too "dull".
This seems to meet your preferred quality of reverb, while still a driver system is used, that has narrower radiation in highs than from bass to midrange and thus - like most loudspeakers - a falling energy response in tendency.
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This thread is alive
Looks like there is finally a breakthrough
Now we can discuss about UFS and forget about FC. You know, this new discovery opens up quite a lot of options in loudspeaker design when you don't have to place drivers at the floor level anymore
.
This thread is alive
at least it's ...undead
Looks like there is finally a breakthrough
hehe
at least it is still a flooder
you don't have to place drivers at the floor level anymore
But still You CAN!
You only need either greater listening distance or ...three FCUFSs wired in Elias' matrix network
but when those requiremets are not met then yes -