Svanå's acoustics philosophy

[Bjørn ("Orso")]

In addition to LEDE / RFZ control rooms there is quite a lot being written about a third design called ESS (Early Sound Scattering). Would it be correct to say that Svanå concept share some of the same elements as ESS?

I''m not really familar with ESS. I've read the artice at SoundonSound, but since they don't describe RFZ/LEDE correctly and I don't trust it totally.
Initally though, there's seem to be some similarities to Svanå. But due to a lack of a clear roadmap, I still haven't understood the goal of a Svanå room. So I really don't know.

In my view the track record of Matts (and also visiting a level 3 room) has proved his concept is a viable one, although his philosophy is not necessarily in line with other concepts. I think there are still lessons to be learned in acoustics and that room design will continue to evolve. Didn't RFZ evolve because the control room needed windows on front wall to see the artist, thus making it difficult to apply front end absorption?

There's definetly need for more studies on psychoacoustics. I agree.

I don't know whether the need for windows contributed to RFZ, but it was definetly based on researches that indicated that it was early reflections arriving the listener that was detrimental. And it's also much easier to get a strong termination of ISD gap when you don't dampen too much and remain energy.
You can also redirect reflections instead of absorbing them.

Being in the planning stages of a new room, there is almost too much information out there to make qualified decisions on which concept to go for. Threads like this are valuable so please carry on discussing guys

There are many ideas out there. And it's difficult to argue against a subjective experience. Like someone saying they prefer a anechoic room. But you want the best intelligibilty, imaging, tonality and localiazation I don't see any reason to choose anything other then LEDE/RFZ. Just make sure you understand the principle of the room and follow the requirements 100%. There are many who claim they've have built a LEDE, but in reality they haven't. Or you can choose the easy path, and get an acoutician who have understood the principle and has experience building LEDE to do it for you.

If you get the chance, visit LEDE/RFZ rooms when you're also visiting Svanå room. There might be both in Stockholm, but I need to doublecheck. Would be fun to compare. Would like to do that myself one day.

 

[Henrik Salvesen]

I trust those who have followed the studies and have read it all.

You have a thread on another forum where people with a lot of knowledge about acoustics disagree with you (there people on both sides of the fence in that thread).
Some of the things you claim that there are definitive answers to is actually a matter of taste, especially in a hi-fi setting.

The Svanå concept is a direct contrast to psychoacoustic studies about early reflections and combfiltering (the Henry Precedence Effect and Haas corollary).

This is from a rpg, discussing the history and future of control room design, notice that D`Antonio includes the work/theories of Floyd Toole and Dave Moulton.
-We have oscillated from being unaware of the importance of early
reflections
- to emphasizing them in Hidley’s compression ceilings
- to learning of their importance in providing envelopment from Schroeder’s
concert hall research
to removing frontal reflections completely due to comb filtering and image
-shift in Davis’ LEDE, D’Antonio’s RFZ, Hidley and Newell’s non-environment
approaches
- to utilizing rear diffuse reflections for enveloping passive surround sound in
D’Antonio’s RPG rear wall
-to re-evaluating the perceptual importance of specular and diffuse
reflections in the work of Massenburg, Angus, D’Antonio, Toole, Martens
and Moulton

 

[vredensgnag]

+1 ganger Uendelig.

Merk det som står med fet skrift, og merk det godt, orso.

 

[Bjørn ("Orso")]

I trust those who have followed the studies and have read it all.

You have a thread on another forum where people with a lot of knowledge about acoustics disagree with you (there people on both sides of the fence in that thread).
Some of the things you claim that there are definitive answers to is actually a matter of taste, especially in a hi-fi setting.

You don't necessarly have much knowledge about psychoacoustic studies because you have many posts. Most of those guys don't know the basics of a RFZ room or the researches that have been done. They have gone their own ways and some try to defend themselves.

Matter of taste? I don't mean to be rude but I'm not interested in discussion with people who overlook studies that have verified again and again when it comes to our perception. There are many things we know and some areas that still need to be studied. But no reasons to throw everything we've learned overboard. Should we overlook the fact that frequency response and dispersion are the most important factors for a system to sound good, because some audiophile guy says he thinks tube and cables are more important? I'm sticking with objective studies.

Personal taste doesn't make much sense to me when one is talking about human perception. If you look at studies, you see large percentage of people preffering the same. I believe, personal taste, is mostly a result of people not testing under controlled methods. But sure, I you want to go for another principal, there's no one to stop you. Like I said earlier, it's difficult to argue against what people are saying they like. But that doesn't mean objective studies aren't valid.

The Svanå concept is a direct contrast to psychoacoustic studies about early reflections and combfiltering (the Henry Precedence Effect and Haas corollary).

This is from a rpg, discussing the history and future of control room design, notice that D`Antonio includes the work/theories of Floyd Toole and Dave Moulton.
-We have oscillated from being unaware of the importance of early
reflections
- to emphasizing them in Hidley’s compression ceilings
- to learning of their importance in providing envelopment from Schroeder’s
concert hall research
to removing frontal reflections completely due to comb filtering and image
-shift in Davis’ LEDE, D’Antonio’s RFZ, Hidley and Newell’s non-environment
approaches
- to utilizing rear diffuse reflections for enveloping passive surround sound in
D’Antonio’s RPG rear wall
-to re-evaluating the perceptual importance of specular and diffuse
reflections in the work of Massenburg, Angus, D’Antonio, Toole, Martens
and Moulton

The fact that some ideas are mentioned, probably due to politeness, on a webpage doesn't say anything. Where are the researches that tells us something objectively? Floyd Tooles research about diffusion from sidewalls don't really contradict with the RFZ much. The energy was attenuated -15 dB to the direct signal when he used diffusion on sidewalls. His studies are also almost the only kind that support this and that was it's said that there are indications that reflections/diffusion form sidewall can be beneficial since it's add spaciousness. We don't know this for sure. Increased spaciousness will often make things less accurate, so it may depend on the goal. I don't think Floyd Toole ever has intended that early reflections are good. At least those who know him quite well, like Earl Geddes for instance, is saying that.

Moulton hasn't proved anything. But rather then expressing more of my opinion, I'm going to refer to a quote that describes this better then I can do.

And then we get to listen to those who make unsubstantiated assertions of new acoustical models while name dropping without presenting ANY new substantiated objective psycho-acoustical principles; nor do they provide an substantive documentation on how the LEDE fails to meet the old or these 'NEW' psycho-acoustical principles to which they only allude but which are never placed into evidence; nor do they present the new psycho-acoustical concepts and then provide objective verification that the new room model satisfies the 'new' psycho-acoustical principles.

Isn't it amazing how many specifically claim to offer improvements on the LEDE? Gee, it seems that by the mere, almost obligatory reference, is itself a source of status and credibility! And rather than standing on their own with objectively sourced psycho-acoustical principles and objectively measured design criteria, they feel compelled to preface their assertion based upon reference to the LEDE! And what is the objective basis and source of the newly discovered psycho-acoustical response principles? Testimonials?!?!?! And NOT one publishes any objectively verifiable ETCs. In fact, one even literally claims that to publish the ETC would 'reveal too much'! LMAO! I bet!

One can like whatever they like. And conjecture posited as one's supposition is fine. But that does not constitute an objective valuation with standing!

But when the conversation becomes one of a Humean questioning of what can we know, and that there are no objective standards of psycho-acoustics or acoustical physics, the discussion devolves into something outside of acoustics - simply reinforcing the fact that many do not know enough regarding the subject to intelligently discuss it! (And its terrifying to note that only 2-3 folks were brave enough to dare assert that we can know things and that objective standards do indeed exist with regards to many aspects of acoustics and psycho-acoustics!)

And when someone starts making claims posited as fact that models akin to little more than the resurrected Bose direct reflecting model is psycho-acoustically superior and that Q does not matter (noting that it was Bose who claimed not only precisely this, but also claimed a 'larger sweet spot' (sound familiar?) - albeit it uniformly mediocre with no optimal spot with which to notice a comparison! - as well as how so many of the claims made regarding early arriving reflections in many alternative response models are remarkably similar in nature!!!), then start looking for something to stand on. Oh, and BTW, the Bose claims were objectively exploded in the '80s at the University of Illinois fieldhouse for all those curious to know.

So, if folks want to discuss topologies, how about eschewing descriptions limited solely to marketing brochures and please start from basics, such as providing the ACTUAL psycho-acoustic basis for the room design, and then show objective measured verification that such objectively verifiable response characteristics are met - and for that matter, those making claims for their 'new' model predicated on the alleged failure of the LEDE to met psycho-acoustical standards should provide an objective basis that the standard does not meet such requirements. NONE of which has been heretofore done!

I've attached a file about LEDE/Moulton which may be of interest.

 

[Bx]

Orso,

You're a big boy so there's no need to hide behind Moulton. Show us the scientific evidence that you have based your position on instead.

 

[Bjørn ("Orso")]

Orso,

You're a big boy so there's no need to hide behind Moulton. Show us the scientific evidence that you have based your position on instead.

Hiding behind Moulton? Can you see anything that I've said supports Moulton? You need to read again. Moulton has claims without any validation. The RPG powerpoint is simply mentioning him because he has an alternative idea. But there are no psychoacoustic basis to back up what he states. And as the pdf file I attached indicates, he seems to say one thing and does something else in his design.

We're talking about researches that has been conducted over many years that has given us an understanding of psychoacoustics.
You want to look at studies from people like Haas, Leo Beranek, Manfred Schroeder, Don Davis, Peter D'Antonio, Carolyn A. "Puddie" Rodgers, Dick Heyser, Dr. Eugene Patronis, and there are many more.

And here are some books:
http://www.amazon.co.uk/Acoustic-Absorbers-Diffusers-Trevor-Cox/dp/0415471745
http://www.amazon.co.uk/Room-Acoustics-Heinrich-Kuttruff/dp/0419245804
http://www.amazon.com/gp/product/0240803051/ref=olp_product_details?ie=UTF8&me=&seller=
http://www.amazon.com/SOUND-FATAL-A...8838/ref=sr_1_2?ie=UTF8&qid=1308557314&sr=8-2

 

[Bx]

Perhaps I misunderstood your last post. It could easily be read as if you were quoting Moulton. Who were you quoting when you referred to a quote that describes this better then I can do? Anyway it looked to me like you were quoting some authority to prove that you were right. Only that the quote didn't have any substance....

Right now I am not interested in reading the books you quote. I am more interested in learning about what you have learned.

For instance, you have stated that The Svanå concept is a direct contrast to psychoacoustic studies about early reflections and combfiltering (the Henry Precedence Effect and Haas corollary).. My question to this is: In what way?

 

[Henrik Salvesen]

Matter of taste? I don't mean to be rude but I'm not interested in discussion with people who overlook studies that have verified again and again when it comes to our perception

You mention the studies of Haas, I think you are rather meaning an interpretation of these studies, the studies by haas did not have any clear distinction between reflections arriving before and after appr 18ms.

The "haas fusion effect", which is said to appear at apr 20ms is from my understanding not mentioned in the original studies by haas , it`s rather an interpretation.
An interpretation that is debated, Floyd Toole argues that there is no has fusion zone in “Sound Reproduction: The Acoustics and Psychoacoustics of Loudspeakers and Rooms”

Another important aspect is that the haas experiment was made in an anechoic environment, with one single reflection, of course this is a very clinical setting compared to the real world.

There are many things we know and some areas that still need to be studied. But no reasons to throw everything we've learned overboard

This is strawman tactics
My room setup is partly inspired by rfz design, I have a shortert isd gap (around 10ms), I have tried absorption instead of qrd diffusors on the backwall, but I preffer diffusors (I have also tried polys on the backwall, I preffer it over aborption in this specific room)
I have absorption at first reflections.

I have never stated that rfz is obsolete.

The fact that some ideas are mentioned, probably due to politeness, on a webpage doesn't say anything

I don`t think either of us are in a position to make such interpretations.

You list D`Antonio/Cox “acoustic absorbers and diffusors” as a source for studies that undermine the svanå concept,could you list a specific page?
it mentions rfz rooms, and some good points for having mathematical diffusors on the backwall (good temporal scattering, reduction of the regularity of the combfiltering).

What it says about early reflections is that it affects the characteristics of the sound at the listening position, from my understanding, this is a description of specular early reflections, not diffuse (early reflections in a svanå room is diffuse)

There might be more info on this in the new edition (mine is printed in 2006)

it's said that there are indications that reflections/diffusion form sidewall can be beneficial since it's add spaciousness.

I think Floyd Tooles main point is that audible effects of early reflections on a recording are preserved, even though the isd gap in the listening environment is shorter than on the recording(according to his own studies, and interpretation of these studies).
One reason for a large isd gap in the rfz design is the theory that early reflections from the listening environment disturbs the listeners ability to detect the isd gap on the recording.

Personally I think there might be other reasons to treat first reflections than just having a larger isd gap

Best regards

Henrik Salvesen

 

[Bjørn ("Orso")]

You are taking things too literally and misinterpreting. I mentioned Haas together with others. And there many others like for instance Madsen and Rodgers. You have to look at more then just one person and his/hers studies.

I never said that one specific book (Acoustic absorbers and diffusors) undermined the svanå concept. I referred to some books as a good start to learn about psychoacoustics. But you will find something here:
http://books.google.se/books?id=f19...l established that early reflections"&f=false

20 ms ISD gap isn't a requirement for LEDE. It's more general recommendation. There can be span from 10-25 ms. Like stated before the advantage of a larger ISD gap is that the chance to hear all of the direct signal in the recording is greater. There are other requirements of LEDE, but that is for you to find out for yourself.

Moulton doesn't have any objective validation. It's not enough for a person to claim something.

This is a bunny trail and I'm not sure there's any point in continuing. You can read and learn about psychoacoustics for yourself directly from the sources. I do have some papers on LEDE and RFZ, but I'm not aware of any papers that briefly gives a summary of LEDE and all the psychoacoustics that has been established. If I find some, I may post them. Personally I know enough today to know that the Svanå concept violates with some fundamentals about psychoacoustics. I've mentioned briefly a few reasons earlier.

 

[Henrik Salvesen]

Orso:

Svanå is also saying that laterally diffuse energy has a negative effect. And this also a direct contrast to reasearches. Laterally arriving diffuse reflections that arrive outside the Haas region aid localization and tonality. The very opposite.

What do you mean with "outside HAAS region"?

what "haas region" is this?


when it comes to early reflections ,I quoted the text from rpg where Moulton and Toole was mentioned to point out that there is an ongoing discussion on this topic.

Matter of taste? I don't mean to be rude but I'm not interested in discussion with people who overlook studies that have verified again and again when it comes to our perception

taste does matter when it comes to perception, for instance the timing of when the presedence effect occur change with age.

Human perception is different, hence different taste

 

[Sorzy]

Personally I know enough today to know that the Svanå concept violates with some fundamentals about psychoacoustics.

Maybe these fundamentals are not really that fundamental after all? Maybe we don't know enough yet about psychoacoustics? You might be surprised by a visit to a Svanå room. Clearly, his track record and list of references indicate there are alternative room treatment concepts imo.

 

[Mr-T]

I have a question regarding this graph, more precisely the green graph. This high level of early reflections are almost impossible to obtain even in an untreated room, so I wonder how this measurement is made? Is it taken in the diffuse field (far from speakers). It surely cannot be made at a typical listening position, as the reflection level is way too high for that I think.

 

[Bjørn ("Orso")]

Personally I know enough today to know that the Svanå concept violates with some fundamentals about psychoacoustics.

Maybe these fundamentals are not really that fundamental after all? Maybe we don't know enough yet about psychoacoustics? You might be surprised by a visit to a Svanå room. Clearly, his track record and list of references indicate there are alternative room treatment concepts imo.

We do know a lot. If you want accuracy, I can't see the Svanå concept to be the roadmap. If you goal is something else it might be fine. Kind like preferring tube distortion. I don't have a problem with that. But when Svanå says that the benefit of the concept is to "transform the listening room into the recording room by removing listening room colorations", and that diffusion at early reflections increases details, plus stating that lateral diffusion is something negative that is the very opposite to obejective studies over the years. Both are not correct.

And I'm not surprised people get impressed since their reference is mostly rooms with no treatment or rooms with poor treatment. Diffusion at early reflections and removal of modal issues will definetly sound much better then no treatment.

 

[Bjørn ("Orso")]

My experience is
Broadband diffused early reflections (5-15ms ) increase the intelligibility and timbre in acoustic music and speech

Ok. Let's see if we can get back to the topic.

smt: About the statement above. What are you comparing to? If you're comparing with stronger early sparse reflections, you're of course correct. But have you ever compared it with a clean ISD gap (with or without termination)?

Mathematical diffusers need a listening distance of 3 times the wavelength of the lowest diffusion frequents so its not possible to take full advantage of them in small room acoustics

That's only the case if you don't know how to use 1D diffusers correctly.

Benefits of the Svanå Concept
Transforms the listening room into the recording room by removing listening room colorations and providing maximum conditions for the brain to hear all the ambience, timbre and details in the music

That would imply that you have no strong early reflections. But that doesn't seem to to be the case with many Svanå rooms, or Am I wrong?

Soft absorbers on first reflection points in a listening room colour the sound

With the LEDE the early reflections are attunated with at least -20 dB. And a strong termination locks the listener to the direct signal. How can the absorbed reflection spectrum then color the sound?

I understand that not all mixers want to unmask the sound to a point my concept go

Do you have any proof that your concept unmask the sound better then the LEDE concept? Has there been comparisons?

What Svanå Acoustics do is give the brain a "extra chans" ,boosted in the 5-15ms time zone, to detect the missing information

What missing information are you referring to?

As I said ,Gh is a unique module that produce a phase clean diffusion with even absorbtionkoefficient (around 0,2 ) over the hole bandwith

Like earlier mentioned, please post measurements.

 

[smt]

Linkwitz AES report was published 2007 and
Its very interesting to read that his conclusions is spot on Svanå Acoustics 10 years back
This is well known fact for many experients acousticans around the world

SMT is the first company to have tools to eliminate all masking phenomen broadbanded in small rooms acoustics
Level 3 takes care of
Resonance ,Time and Frequence masking



Some conclusions from his report
.
. Reflections generated by the two loudspeakers
should be delayed copies of the direct sound to the
listener.
The delay should be greater than 6 ms.
The high frequency content of the reflections
should not be intentionally attenuated.
. Under these conditions the direct sound from the
loudspeakers dominates perceptually.
The room interferes minimally with the spatial, temporal and
timbral cues embedded in the direct sound and
with the creation of a phantom sound stage
between and behind the loudspeakers.
. Under these conditions the cognitive faculty of the
brain is better able to separate the static listening
room acoustics from the acoustics embedded in the
recording which are presented dynamically by the
two loudspeakers.

For the reflections to be delayed
relative to the direct sound the loudspeakers must be
placed at least 1 m away from adjacent surfaces. Still,
the first arriving floor reflection will have less than 6
ms delay. This does not appear to cause a problem.
After all, almost every source that we hear has a floor
reflection and we seem to use this information
primarily to determine the height of the source above
the floor.
The requirement for full spectral content of the
reflections rules out the use of frequency dependent
absorbers on the room surfaces.
The various commercially available foam or fiberglass panels
absorb predominantly higher frequencies only and
would color the room reflected sound dynamically to
where it no longer can be cognitively separated from
the direct sound. This then argues for relatively live
room acoustics that are determined by the .normal
stuff of life. with which the room is filled and
decorated, acoustics with which we are intimately
familiar as normal.
.

The live-end, dead-end room arrangement practice,
with loudspeakers at the dead-end and the listener at
the live-end, is actually reversed from what the
hypothesis requires. The absorbing end of the room is
usually not broadband attenuating and increasingly
reflects the lower portion of the spectrum. The liveend
is often made diffusive which in reality only
affects the higher frequencies. Thus the room
assumes a peculiar acoustic character through its
reflection pattern which cognitively would be
difficult to separate from the sonic cues of the
recording in the direct loudspeaker signals.

Hopefully this work stimulates further investigation
of the loudspeaker-room-listener interplay, especially
since it points to the limitations of common practices
in loudspeaker design and room setup. It could also
lead to recording techniques that consistently capture
the instruments and the spatial context in which they
are being used. Monitoring during the recording
process could become more accurate and would
match how the audience will hear the recording under
optimal conditions. = Svanå Level3 recordings just wait for distribution rights

Tooles conclusion from almost most 300 science references and a long music life
“Individual reflections, in general, appear to be flattering to both music and speech sounds, and those occurring naturally in small rooms are, if anything, too low in level to have an optimal effect. Indeed, numerous early reflections have a positive cumulative effect on speech intelligibility. From the perspective of sound quality, multiple reflections reduce the effects of comb filtering (good) and enhance our perception of resonances (good for the music, and bad only if the resonances are in the loudspeakers)”. Floyd toole

Interesting that my biggest problem with my early level 3 rooms was to explain for some speaker manufactures that the boxy resonances they heard for the first time come from the construction not the room

Hope to come back with a exlusive statement from a wellknown mixer that travells back and forth between Svanå acoustics and US LEDE rooms tonight

Best
matts
www.diffusor.com

 

[Bjørn ("Orso")]

I have a question regarding this graph, more precisely the green graph. This high level of early reflections are almost impossible to obtain even in an untreated room, so I wonder how this measurement is made? Is it taken in the diffuse field (far from speakers). It surely cannot be made at a typical listening position, as the reflection level is way too high for that I think.

I would also like to know the answer to that. It seems like it's from SynAudCon.

And if this is the way Svanå thinks a ETC graph should look like, I'm wondering why the Svanå room in the link below, where the early reflections are approx below -15 dB, is treated differently. Isn't there a consistency to what Svanå does? And what does smt/Matts think is the better one?
http://www.diffusor.com/bildersvana/bilder.html

 

[Micmac]

A very interesting discussion going on here.

Orso, i have two questions.: I wounder...

1: What do you think about your listening experiences, what kind of room do you think sounds the best?

2: And what kind of room do you have when you listen to music? (Some pictures of your room would be appropriate).


Best regards

//Michael

 

[smt]

One of Svanå acoustics groundstones is broadbanded diffusion(first company with a 2 way crossover) with built in HH resonators
This modules have beeen on my homepage more then 10 years
http://www.diffusor.com/Moduler.htm
The new Wing follow this concept with a depth of just 250mm

No wings

8 wings

I tryed to explain that I reinvented the Roomtuner proffesion not the HH principle
In my level 3 rooms I have around 25 basstrapps with adjustble hatches to work with
The method and result is unique on the market (Just check out my case studies)

I also educate special persons to help me around the world
An example what Martti at Concept Hifi in Finland did in a room in Gothenburg
A frontwall with V-6 and some V-4
Before

room tuner after

The Gh seem to attend alot of intrest
Over 10 years ago Audiodatalab did a 10m2 test I will present the reult asap
Amore interesting result is this room with GH Almost 100 modules and you can see how even the decay time is The benefits of not producing non lookalike is obvius
EDT 0.25s +-0,05 betweeen 250-12000Hz
G GH

2k

4k

8k

presenting a generally ETC graph doesent tell the hole story It would have been very interseting to see more etc slices from Massenburgs room

Best
matts

 

[smt]

I have a question regarding this graph, more precisely the green graph. This high level of early reflections are almost impossible to obtain even in an untreated room, so I wonder how this measurement is made? Is it taken in the diffuse field (far from speakers). It surely cannot be made at a typical listening position, as the reflection level is way too high for that I think.

Hi Mr- T
All my level 3 rooms must have the green graph inside the Spaciousness field As I said before I had to invent a omidirectional speaker that even activate the walls and ceiling More directionalspeakers with even powerrespons will still measure in the S-field but at a lower level

For this customer I used one of his MBL 101 that have a amazing frequence respons
Here is the unique impulse respons

reflections in the S-field must also be a copy of the direct sound or will the soundstage and musicality dissapere
MBL 101 frequence respons valid down to 1200 Hz
(The mike is dropping above 15K)

The 30 wings 5-30ms answer on that

How the Stockholm Concert hall and Big church transforms in this rather small room (25m2) must be heard

The focused 3D soundstage and Timbre in acoustic instruments and voices are pure magic
Dense early reflections is also one of the reasons that high musicality speakers tend to be full range omni or semi omni speakers

Michael Fremer was invited earlier this year to Thomas We all sat there with happy smiles for over 3 hours chosing from over 16000records
His comment in Stereophile July number is spot on what I want to achieve
Musicality, is if a musical instrument sounds like the musical instrument

Best
matts
www.diffusor.com

 

[Mr-T]

Hi Mr- T
All my level 3 rooms must have the green graph inside the Spaciousness field As I said before I had to invent a omidirectional speaker that even activate the walls and ceiling More directionalspeakers with even powerrespons will still measure in the S-field but at a lower level

That makes sense. But - do you think that omni speakers are a requirement in order to satisfy your acoustic philosophy?

 

[Bjørn ("Orso")]

The ETC graph you posted is band limited.
The frequency response is with 1/3 smoothing and someone prompted me saying you don't seem to understand how gating effects the results at low frequencies.

Frequency response or waterfall isn't the matter here anyway. My question has all the time been the ETC since you're using diffusere for early reflections. And then later, asking for measurements for these "super diffusers", whichhasn't been provided yet.

And it's interesting to notice the Svanå room has early reflections at -15 dB and other ones has much higher. No consistency.
The diffusers also seem to absorb quite much, since there's a very low decay and no use of broadband absorbers.
http://www.diffusor.com/bildersvana/bilder.html

I think I've received the answers to my questions.

 

[smt]

The ETC graph you posted is band limited.
The frequency response is with 1/3 smoothing and someone prompted me saying you don't seem to understand how gating effects the results at low frequencies.

Frequency response or waterfall isn't the matter here anyway. My question has all the time been the ETC since you're using diffusere for early reflections. And then later, asking for measurements for these "super diffusers", whichhasn't been provided yet.

And it's interesting to notice the Svanå room has early reflections at -15 dB and other ones has much higher. No consistency.
The diffusers also seem to absorb quite much, since there's a very low decay and no use of broadband absorbers.
http://www.diffusor.com/bildersvana/bilder.html

I think I've received the answers to my questions.

I thought you had learned it by know Orso ,the measuring system say one thing, the brain another
This time Svanå Acoustics rules out Sabins formula in small rooms
With a absorbtion coefficient of 0.2 for the Wing the room calculated with Sabin formula should end up around 0.7s
The calculating system take very little notice to the early reflection and for the brain its just the opposite

A good example : if you talk in a big hall with a 10m ceiling height and a 5s rt60 it will be very difficult for peaple to hear what you are saying
Insted you move to another part of the hall were its 2.5m ceiling height ,your speech will be clear becouse of all early reflections If you then measure at the spot you were standing the answer will be the same 5 s

According to the 15 db down is the simple answer, Robert (owner of Audio Concept ) wanted to keep the reflections in the lower part of the S-field, mainly becouse he dident want the customers experients to big differents ( details timbre etc ) between the shop and home Thats why you can see absorbers , AD 40mix (dacron strip inside ad40) and a thin cloth behind sweetspot News is that the backwall will soon have the new wings in place

Did you mean this graph when I used my building acoustic sub for showing how deep the wing work? Its jus a ordinary arta measurment with a band limited sub 100-1000Hz

Or was it just the 1/3 smoothing
There are three recommendations (EBU-European Broadcast Union, ITU - International Telecommunication Union, AES - Audio Engineering Society) listed above, and all of this papers agree in this one thing, smoothing should be 1/3 octave.



Here you can see the omni speaker I use with the sub on the floor

best
Matts
www.diffusor.com

 

[Roald]

if you talk in a big hall with a 10m ceiling height and a 5s rt60 it will be very difficult for peaple to hear what you are saying
Insted you move to another part of the hall were its 2.5m ceiling height ,your speech will be clear becouse of all early reflections If you then measure at the spot you were standing the answer will be the same 5 s

That was a really god example an probably will many have expired it themselves, but if we take the same scenario but pretend RT60 IS 2, 1, 0,5, 03S, how do you think this will affect the perception?

 

[Henrik Salvesen]

A good example : if you talk in a big hall with a 10m ceiling height and a 5s rt60 it will be very difficult for peaple to hear what you are saying
Insted you move to another part of the hall were its 2.5m ceiling height ,your speech will be clear becouse of all early reflections If you then measure at the spot you were standing the answer will be the same 5 s

5 sec rt 60 is alot , there would be a very uneven timing of the reflections ,and you would recieve reflections from more people speaking under the high ceiling than the low.

Both rfz rooms and Svanå rooms have diffuse refletions arriving a lot sooner than 50ms, speech intelligibility is often measured for sound arriving before and after 50 ms, sound arriving before 50 ms carcterized as “useful” for speech intelligibility and after carecterized as “detrimental” .

sensing these transient sounds is very important when listening to music, to better "get" the micro timing ,personally I get a better sense of the transients with diffusors on the wall behind listening position (rather than flat wall giving specualar reflections or covering very large areas of the room with broadband absorbers).

There are other parameters aswell, coloration of timbre that can occur due to combfiltering from early reflections.

This is the reason that taste matters, for “Art Blakey and the jazz messengers”, the main focus is probably intelligibility of the transients, for the more rubato works by Debussy, it is probably more important to avoid coloration of timbre.

 

[Henrik Salvesen]

I tryed to explain that I reinvented the Roomtuner proffesion not the HH principle
In my level 3 rooms I have around 25 basstrapps with adjustble hatches to work with
The method and result is unique on the market

I think this part of the discussion was lost in semantics, I agree that the varitune concept with a comercially available tunable helmholtz is good and something new on the market (helmholtz resonators used to be custom designed/built).

 

[smt]

[quote
That makes sense. But - do you think that omni speakers are a requirement in order to satisfy your acoustic philosophy?
[/quote]

Hi Mr-T
If the speaker have even powerrespons and you treat all first reflection points with my modules ,you have captured enough early reflections for a very musical listening experients .
Although omnidirectional speakers will activate a Level 3 room more even and give around 3- 5 dB higher energy the first 5-15ms

Svanå Acoustics take advantage of the processing time in the hearingsystem I call it "The Musicalshop" with a opening time until around 30 ms
After the Musicalshop is closed its very important that the listening rooms reflections are lower then in the recording room

If you wait until 15-20ms to treat the reflections you get problems :
time and frequence unmasking effect will decrease
create a fatiguing (sometimes harsch) transient sound
hard to fullfill the important criteria that the reflections in the listening room must be lower in level then in the recording room

A good example is on page 437 Masterhandbook ,4 edition
C-room Mastersound Astoria
After 60 ms the C-rooms reflections is only around 18dB down
Compare that with Svanå acoustics, 60ms = 25dB down

Reading Linkwitz conclusions 2007 was very inspiring and spot on what all music lovers including myself led me to
.
. Reflections generated by the two loudspeakers should be delayed copies of the direct sound to the listener. The delay should be greater than 6 ms. The high frequency content of the reflections should not be intentionally attenuated.
"The high frequency content of the reflections should not be intentionally attenuated. Under these conditions the direct sound from the loudspeakers dominates perceptually.
The room interferes minimally with the spatial, temporal and timbral cues embedded in the direct sound and with the creation of a phantom sound stage between and behind the loudspeakers.
. Under these conditions the cognitive faculty of the brain is better able to separate the static listening room acoustics from the acoustics embedded in therecording which are presented dynamically by the two loudspeakers".



Taking the ISD gap to 5-6 ms , I got the same comments during the last 15 years

Recently from a world famous "first call" mixer Lasse Marten

"Like most engineers I spend a lot of time on my mixes to make them
sound vivid and exciting, I also spend a lot of money on fancy
speakers and great equipment.
With this in mind, working in a dead room where the acoustic treatment
is there to absorb and kill the very sound I work so hard to get,
makes absolutely no sense to me.
I had the pleasure of having Matts Odemalm from SMT involved when I was
building my mix room at Decibel Studios in Stockholm.
I have very specific demands when it comes to acoustics so I explained
my vision of this room to Matts and Johan from acoustic architects Audio Data Lab and they nailed it.
They made my small room sound much bigger and full of life with
unparalleled imaging.
I'm not a theoretical kind of guy but I know a well designed room when I
hear it and this one is well designed.
Not only is it fun to mix in but my mixes also translates flawlessly
to other systems.
I've been working in some of the finest control rooms in the world and
most of them are built using the classic but obsolete LEDE design, even if
these rooms have a frequency response that is flat like a
ruler I think they have a tendency to suck the life out of the music.
This is not the case in the SMT rooms I've been in, they will instead
enhance every note.
Needless to say I'm very happy, so happy I am now building another control room together with SMT and ADL.
/Lasse Mårten, Mixer/Engineer
(Lykke Li, PBJ, Pink, Backstreet Boys, Johnossi)




The unique green graph comes from Thomas Wing room with a GH ceiling His request was that the vinyls and cds must be seen in the room or else he was musicallity lost (he compared it with a library without books ;D ) The only person I can compare Thomas music intrest with is Michael Fremer, so its was a evening to remember when Thomas invited Fremer to his listening roomearlier this year Fremer comments his visit in Sweden in Stereophile july nr


Thomas comments going from absorbing to Svanå Acoustics :

"From music in a normal living room (slanting roof) to a garage, that was turned into a music room.
The dream of a highly qualified music room is within reach
I practice and enjoy active music listening. Baroque style, classical and jazz. Active listening means
full concentration on what’s being played and how, alternative interpretations, observing differen-
ces and creative patterns.

Technically qualified recordings and reproductions of course add value to the joy. As a “consumer
of reproductions” I have to do my part in preparing relevant conditions, to come as far as possible in
this respect.

Previous, insufficient and inadequate acoustics

Over the years I have made significant “investments” in music, and in playback hifi-products and
-systems. The final step in the old order was taken when a living room was covered with absorbing
elements on the walls and in the ceiling, all provided by distinguished and recognized acousticians.
The idea was to muffle and soften, to deaden signal peaks.

During these years I had a dream: Being able to listen to chamber music in my home with a sound
acoustic similar to the concert hall, and to baroque organ music with an acoustic similar to the
church room

However, I came to the conclusion that it would not be possible to get the genuine reproduction
qualities I was hoping for. Those levels of acoustics obviously were not within reach in my home.

Real acoustics. The dream comes true

One day I was introduced to Matts Odemalm, Svanå. He was convinced that he could help me, and
presented me with a completely different kind of acoustics.

We found that the only part of the house that would meet all formal conditons and requirements
was my garage. So he said “Let’s transform your garage to the music room you are dreaming about. I
will diffuse the sound signals in a systematic way, not absorb them, not reduce them”.

And that’s precisely what he did. My garage lost it’s role as family warehouse. It was redesigned and
transformed to a music room, by Matts and two carpenters.

The new music room

The ceiling is now covered by the Svanå Golden Horns. A third of the shelves otherwise containing all
CDs, LPs, Blu-rays etc is (in earheight) occupied with broadband Wing diffusors. Svanå mobile Wing
walls were positioned behind the sweetspot (listener’s seats), to capture early (5-15ms) reflections.

Matts has promised to describe in professional terms exactly what he has done, and why, and how it
therefore was possible to get the results I had dreamed and hoped for, whose potential I previously
was completely unaware of.

So, it was possible to reach an acoustic order that would allow music to play completely undis-
turbed, with all it’s inner dynamics and it’s original richness, after all. I now have a music room
that responds, performs and delivers music qualities the way I have always dreamed about. It is
furnished and equipped with an MBL system, an omni-directional, multi-channel, high end sound
system, supplied by Audio Concept. The role of the MBL system is of course significant in achieving
these results.

The limited size of my garage is now - through Matts’ efficient sound arcitechture - unbelievingly
well overshadowed by an acoustic effect that resembles the one of the concert hall.

Friends being musicians and active music lovers confirm that music now played is pure, dynamic and
genuine. Some of them discover timbre in their own instruments they never heard before.
Music comes alive in all dimensions, with space, intimacy, depth, and with
a real-time feeling never experienced before.

There is no way I can describe in detail all the appreciation and gratitude I feel for the acoustic solution that was put in place, and the distinguished music qualities that are generated in the new
music room every day now. It has to be experienced.

Conclusions

It took - after a warm and promising handshake with Matts - two months to get there. It was a challenging/fascinating and fairly logical project, once it became clear and understandable for me what could be achieved. And practically and financially not intimidating. The only sad thing is that it took me so long to understand that the opportunity was there all these years.
I urge every music lover in possession of a garage of normal standard to consider doing the same. An unlimited music richness - hidden in old and new recordings, and acoustically within reach through the Svanå product line - is waiting to be discovered and enjoyed.


Best
Matts
www.diffusor.com