I didn't say that it was (necessarily)... If a problem is created acoustically then it can be fixed acoustically. This defines the standard.
Not completely off topic , but, IIRC, there is a thread on ASR where Kimmosto shows amazingly clean measurements of a cardioid system in a bathroom.
Kimmosto's relevant posts..
https://audiosciencereview.com/foru...dspeakers-are-they-worth-it.21942/post-753582
https://www.diyaudio.com/community/threads/pattern-control-below-400hz.332057/post-5700769
and finally the bathroom post.. 🙂
https://audiosciencereview.com/foru...dspeakers-are-they-worth-it.21942/post-752932
Those links show just spl response, not RT, decay or wavelet... Long gated response with smoothing is too easy to make look good!
It looks like Kimmsoto used the KS1804 speaker for this. Here are details of that speaker..
https://web.archive.org/web/20170906120623/http://kimmosaunisto.net/KS-1804/KS-1804.html#Sound
I just wish that Kimmosto hadn't removed the old website.. 🙁
It had a lot of very useful information..
In a Finnish forum tmuikku asked kimmosto about room analysis, and regarding REW kimmosto says EDT (Early Decay Time, check REW Help) is most important (but he prefers ARTA's Oct.TI over REW). And this fits my observations too. He has collected data from many friends and showed an overlay of those, huge variations!
K says also that acoustic treatment of the room is absolutely the only working way to improve clarity, definition of transients etc. which are important aspects of hifi sound at home. Speaker directivity can do something, but high DI easily leads to unbalanced too "dull" or too "involving" sound - medium directivity with good acoustics and positioning will give universally best sound.
Attached my EDT measurements in different rooms, same as earlier plus Ainos in a difficult room. Red is my bedroom, black is the bunker with concrete walls. Green and blue are monopole vs. dipole in living room.
K says also that acoustic treatment of the room is absolutely the only working way to improve clarity, definition of transients etc. which are important aspects of hifi sound at home. Speaker directivity can do something, but high DI easily leads to unbalanced too "dull" or too "involving" sound - medium directivity with good acoustics and positioning will give universally best sound.
Attached my EDT measurements in different rooms, same as earlier plus Ainos in a difficult room. Red is my bedroom, black is the bunker with concrete walls. Green and blue are monopole vs. dipole in living room.
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Thanks a lot @Juhazi for all this information 🙂
I am in the process of rearranging my living room.. 😀 (trying to get those speakers along the longer wall) and also trying to make/buy some acoustic panels. After rearranging and before buying the panels, I will try to take some measurements and see the status of the room first.. 🙂
I am in the process of rearranging my living room.. 😀 (trying to get those speakers along the longer wall) and also trying to make/buy some acoustic panels. After rearranging and before buying the panels, I will try to take some measurements and see the status of the room first.. 🙂
Out of curiosity, I went and checked in the Finnish hififorum from VituixCAD website. 😀
https://foorumi.hifiharrastajat.org/index.php?threads/vituixcad.121510/post-2442994
Saw a lot of interesting discussions here from Kimmosto and tmuikku using google translate.
I may have understood only half of it, though, mainly because of the translator..
I could not view the STI graphs since I am not a forum member.. Tried to join but the application got rejected since the language used in the forum is Finnish.. 😀
Anyway, lot more to learn about the room now.. 🙂
https://foorumi.hifiharrastajat.org/index.php?threads/vituixcad.121510/post-2442994
Saw a lot of interesting discussions here from Kimmosto and tmuikku using google translate.
I may have understood only half of it, though, mainly because of the translator..
I could not view the STI graphs since I am not a forum member.. Tried to join but the application got rejected since the language used in the forum is Finnish.. 😀
Anyway, lot more to learn about the room now.. 🙂
I'm not a member there anymore... K specially and others use terrible gibberish slang, I dont' understand all myself either!
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Hahaa, yeah there is some eastern Finland dialect thrown in so can be tough for translator 🙂
In short the late discussion there was about flutter echo, which can be measured with EDT and with Octave Transmission Index which STI calculations are based on. Can be measured with ARTA.
Kimmosto shared some data he has collected over the years and some information with it, most of it he has written in ASR and htguide lately as well I think. Its about balanced mid - high frequency directivity and absorption in room, balanced low EDT which is about the same as smooth Oct.TI. Basically too much flutter echo is bad for perceived sound quality. So, its something that is usually missing in discussion here on the forum, something between first reflections and late reverberation and very audible in empty rooms with hard walls, clap your hands and hear it, robot sound. EDT and Oct.TI spectrum are something that can quantify it and indicate needs for acoustic treatment.
There is also notion that line arrays would strongly excite flutter echo as they blast out to walls above furniture line, while low standing speakers that output at furniture level would excite them less as there is some absorption and perhaps diffusion. So, for a room where there is no possibility to add acoustic treatment in it would probably better to avoid putting speakers high up, where they are surrounded by naked walls.
In short the late discussion there was about flutter echo, which can be measured with EDT and with Octave Transmission Index which STI calculations are based on. Can be measured with ARTA.
Kimmosto shared some data he has collected over the years and some information with it, most of it he has written in ASR and htguide lately as well I think. Its about balanced mid - high frequency directivity and absorption in room, balanced low EDT which is about the same as smooth Oct.TI. Basically too much flutter echo is bad for perceived sound quality. So, its something that is usually missing in discussion here on the forum, something between first reflections and late reverberation and very audible in empty rooms with hard walls, clap your hands and hear it, robot sound. EDT and Oct.TI spectrum are something that can quantify it and indicate needs for acoustic treatment.
There is also notion that line arrays would strongly excite flutter echo as they blast out to walls above furniture line, while low standing speakers that output at furniture level would excite them less as there is some absorption and perhaps diffusion. So, for a room where there is no possibility to add acoustic treatment in it would probably better to avoid putting speakers high up, where they are surrounded by naked walls.
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Vineeth - you should try learning the Finnish language... I heard that it is quite easy 😵
My wife uses vihta in sauna, but I use vasta! (I'm from eastern Finland, Savo)
ps. wearing swimsuit or a towel is not allowed!
ps. wearing swimsuit or a towel is not allowed!
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These sort of "Notions" aren't very helpful, I really wish that people would stop imagining how sound travels and study what actually happens. It is complicated but it does follow rules, they are very unintuitive though so most of what you think will happen does not, or at least not quite.
A true line array will contain almost all the sound within it's length and will not "blast sound at bare walls". An average speaker construction with no attention paid to vertical directivity will spray sound all over the place.
It's a shame that good information on desirable room characteristics gets mixed up with nonsense likely causing incorrect conclusions to be drawn.
Hi fluid,
this is phenomenon one don't need imagination, or simulation, at all and there is high possibility you can do an empirical experiment right now as you read this. Anyone can.
While seated on your listening position, clap your hands together loudly above your head. If you heard flutter echo now clap your hands loudly at your knees, below furniture level, and the flutter echo is probably gone. If you heard it there is high possibility your listening setup would benefit from acoustic treatment, or position the loudspeakers lower, where the furnishing reduces the flutter, increases clarity.
Its not just tall line sources that have output above furniture level but all other speakers positioned above furniture level, like the hand clap. By furniture level I mean above sofas and tables and such, where there is lots of parallel wall surface area without much obstructions in between. If you position a line source below furniture level it would have less issues with flutter echo, similarly as any other sound source like hand clap. Or add acoustic treatment to parallel walls if measurements show there is not enough clarity, too much early reflections.
Sound propagates spherically to all directions from a point source, like hand clap, and it is quite easy to imagine how it propagates especially without obstructions between hard boundaries, a flutter echo. What is hard to imagine how it travels after bouncing from all the furniture attenuating and diffusing before hitting the boundaries but there is no need to.
There is no need to downplay line sources or anything else here, just promote acoustic treatment and awareness how to get better sound with any source, by acoustic treatment.
this is phenomenon one don't need imagination, or simulation, at all and there is high possibility you can do an empirical experiment right now as you read this. Anyone can.
While seated on your listening position, clap your hands together loudly above your head. If you heard flutter echo now clap your hands loudly at your knees, below furniture level, and the flutter echo is probably gone. If you heard it there is high possibility your listening setup would benefit from acoustic treatment, or position the loudspeakers lower, where the furnishing reduces the flutter, increases clarity.
Its not just tall line sources that have output above furniture level but all other speakers positioned above furniture level, like the hand clap. By furniture level I mean above sofas and tables and such, where there is lots of parallel wall surface area without much obstructions in between. If you position a line source below furniture level it would have less issues with flutter echo, similarly as any other sound source like hand clap. Or add acoustic treatment to parallel walls if measurements show there is not enough clarity, too much early reflections.
Sound propagates spherically to all directions from a point source, like hand clap, and it is quite easy to imagine how it propagates especially without obstructions between hard boundaries, a flutter echo. What is hard to imagine how it travels after bouncing from all the furniture attenuating and diffusing before hitting the boundaries but there is no need to.
There is no need to downplay line sources or anything else here, just promote acoustic treatment and awareness how to get better sound with any source, by acoustic treatment.
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When you clap above your head you are placing the source closest to the most reflective boundary the ceiling, as the handclap is quite omnidirectional you hear the reflections most loudly, no surprise. When you put your hands below, there is your body, the seat and maybe the carpet blocking a number of paths so you don't hear a problem.
I don't have an issue with saying don't put omnidirectional sources high up in an untreated room, but if the source has very high vertical directivity the biggest offender is taken away or at least significantly subdued.
Most of the panels I use myself to reduce specular reflection and as broadband absorption are full height free standing, because absolutely leaving large sections of bare walls above and below a smaller panel isn't going to be as effective at combating this sort of issue.
I don't disagree with the problem, but I do with the conclusion.
PS It is how the sound radiates from the speaker that needs the effort to work out.