Svanå's acoustics philosophy

Bjørn ("Orso") · 30.05.2011

This is a contiunation of a discussion in another thread and it will be in english to avoid misunderstanding (swedish/norwegian acoustic terminology). Please write everything in english.

I'm starting this thread to have discussion around the acoustic philosophy that Svanå uses. I believe Performance Acoustics Labs (PAL) are their branch in the states with similar type of treatment and principle.
http://www.performanceacousticslabs.com/PAL/Home-Acoustics_Listening_Rooms.html
http://www.diffusor.com/

The treatment that Svanå/PAL are utilizing to treat a room differs from the more traditional LEDE concept. Research on psychoacoustics isn't something new. It's been around for many years and the matter has been well studied.

My questions to Svanå are:
- Why not use the LEDE concept?
- How is ISD gap provided with diffusers alone and especially in rooms only treated with some diffusion like level 1? Or is RFZ and ISD gap something Svanå don't see the importance of?

Here's a link with graphs to a room Svanå has treated:
http://www.diffusor.com/bildersvana/bilder.html

The ETC of the Svanå room shows that alomst all reflections until 10 ms are below -20 dB. Which implies that there has been created a more or less anechoic zone of the first reflections. It doesn't say how the room is treated.

Hope the founder of Svanå, Mats, will contribute and explain the thoughts behind their concept.

Henrik Salvesen · 30.05.2011

Svanå's acoustic philosophy

differs from the more traditional LEDE concept. Research on psychoacoustics isn't something new.

The "live end/dead end" concept (lede) was developed by Peter D`Antonio in 1984, it uses broadband absorption in the front of the room and diffusore on the back wall, it has since evolved into the RFZ concept (but lede is still being used), in a rfz room reflections within a time window is treated (this is reflections from the front of the room), these are treated with both diffusors and absorbers, but one try to avoid to much absorption in order too keep some reflections in the room. Diffusors can be used in 1 reflection points in order to keep the sonic image wide (if absorbers are used, the soundstage can appear narrower, and to the extreme as if the sound comes from one point in space).

P:S reflections actually reach the listener within the rfz time window ,when diffusors are used at 1 reflections, but these reflections are temporarly dispersed, and has less sound energy so they are below the loudness threshold for when reflections impacts the direct sound from the speakers negatively.

This concept use Schroeder diffusors (based on mathematics)

The back wall is treated with schroeder diffusors in both cases (often qrd).

Svanå design rooms has some similarities with the rfz concept.

Henrik Salvesen · 30.05.2011

redigert, off topic

Bjørn ("Orso") · 30.05.2011

Svanå's acoustic philosophy

Henrik Salvesen skrev:
differs from the more traditional LEDE concept. Research on psychoacoustics isn't something new.

Klikk for å utvide...

The "live end/dead end" concept (lede) was developed by Peter D`Antonio in 1984, it uses broadband absorption in the front of the room and diffusore on the back wall, it has since evolved into the RFZ concept (but lede is still being used), in a rfz room reflections within a time window is treated (this is reflections from the front of the room), these are treated with both diffusors and absorbers, but one try to avoid to much absorption in order too keep some reflections in the room. Diffusors can be used in 1 reflection points in order to keep the sonic image wide (if absorbers are used, the soundstage can appear narrower, and to the extreme as if the sound comes from one point in space).

This concept use Schroeder diffusors (mathematical based), because it has better temporal diffusion than geometrical, and thus creates less combfiltering.

The back wall is treated with schroeder diffusors (often qrd) in both cases .

Svanå design has some similarities with a rfz room.

Well, this is a bit off topic but some of what your'e saying is incorrect. LEDE was developed by Don and Carolyn Davis in the mid 70's. The RFZ model (D'Antonio) is just a continuation and refinement of the original LEDE concept. The ETC and room response are the same for both from what I've read.

Henrik Salvesen · 30.05.2011

The ETC and room response are the same for both from what I've read.

Links?

p.s it is correct that D`antonio did not invent lede, he evolved it as you said.

edit. thank you for the pm

Skink_123 · 30.05.2011

Hvor mange forskjellige filosofier er der ute som blir brukt?

Nordenstam · 30.05.2011

On the general development in acoustics for small rooms: http://www.rpginc.com/news/seminars/Diffuse_Seminar_2007_iRoom.pdf

Some AES articles on LEDE: http://www.aes.org/e-lib/browse.cfm?elib=2852 http://www.aes.org/e-lib/browse.cfm?elib=3965 http://www.aes.org/e-lib/browse.cfm?elib=11805

Excerpt from LEDE inventor Don Davis' Sound System Engineering: http://books.google.no/books?id=l1ul2d2jh0QC&pg=PA183

Page 54 and so on in this book: http://www.sensusdesigngroup.com/auxiliary_files/Research_Studio_Acoustics.pdf

Measurement centric history: http://www.tvtechnology.com/article/93738

Edit, for freshness, another new school room idea somewhat similar to SMT: http://www.bozoel.com/hosted/myroom-acoustics/MyRoom_Design-white_paper.pdf

... beklager til de som ikke har fått svar på forumposter og epost.. er litt for travelt om dagen! kommer tilbake til det..

Bjørn ("Orso") · 30.05.2011

kjoenik skrev:
Hvorfor skriver dere på engelsk???
Et forsøk på å få litt internasjonal shwung over sentralen??

If you had read this thread http://www.hifisentralen.no/forum/index.php/topic,58061.20.html, you would know.

I want to hear Svanå's thoughts and ask questions to them. And this is actually way easier for me to discuss in english oppose to getting answers in swedish. Reading acoustic terminology in swedish isn't my strong point.

Bjørn ("Orso") · 30.05.2011

Nordenstam skrev:
Edit, for freshness, another new school room idea somewhat similar to SMT: http://www.bozoel.com/hosted/myroom-acoustics/MyRoom_Design-white_paper.pdf

Maybe I'm missing out on something her. But it's like they're giving an impression of only using diffusion at first reflection areas while can see you at the pictures they are in reality using foam at first reflections points on sidewalls and ceiling. :

So I don't understand the conclusion they come to:

The principle of having all of the surfaces, except the floor, air transparent and
diffusive, and good low frequency absorption is definitely the right approach for the
rooms in which surround monitoring is expected.

We also concluded that diffuse early reflections in control rooms are extremely
important for quality, and more precise (hence more objective) assessment of sound
image, and thus faster decision making during the production. This assumes a
hypothesis that the presence of diffuse room reflections above 1 kHz causes better
mix translation, even during the trial attempts, and also causes less work fatigue and a
more relaxed approach to work. Also, the already mentioned phenomenon of the
diffusers causing a psychoacoustics feeling of a larger space than it in physical reality
is helps to reduce the feeling of discomfort caused by smaller spaces.

To use diffusion at other surfaces is really nothing special or new. They have just done it in a large capacity for a small room and combined it with slats for bass treatment.

But correct me If I have overlooked something.

Bjørn ("Orso") · 30.05.2011

Sometimes you want to delete what you have written. ;D

The absorption they are using in the room I just commented are in the back of the room around the surround speakers. So forget what I said.

EngelholmAudio · 31.05.2011

Matts comes with an answer.

BurntIsland · 31.05.2011

kjoenik skrev:
orso skrev:

kjoenik skrev:

Hvorfor skriver dere på engelsk???
Et forsøk på å få litt internasjonal shwung over sentralen??

Klikk for å utvide...

If you had read this thread http://www.hifisentralen.no/forum/index.php/topic,58061.20.html, you would know.

I want to hear Svanå's thoughts and ask questions to them. And this is actually way easier for me to discuss in english oppose to getting answers in swedish. Reading acoustic terminology in swedish isn't my strong point.

Klikk for å utvide...

Alright, greit å nevne i starten på tråden at det er en fortsettelse av en annen tråd og at det skrives på engelsk for å forstå hverandre.

orso skrev:
This is a contiunation of a discussion in another thread and it will be in english to avoid misunderstanding (swedish/norwegian acoustic terminology). Please write everything in english.

edit: og det var tydeligvis ikke redigert inn før i dag... ouch

Sorzy · 02.06.2011

Looking at the graphs from the link you posted Orso, there was a reference to "Audio Concept" which leads me to believe that these are measurements from Audio Concept's level 3 room in Stockholm. If you look at pictures from this room you will see that it has diffusion on front wall, side walls, back wall and in the roof. If memory serves me right, there are golden horn type diffusion in the roof and more broadband diffusion on the walls. In addition there are a few Helmholz boxes around the room which you will see in most if not all SMT designed rooms. The floor is plain wood but even hard tiles would be ok I think. I'm sure Matts can explain more on this but the floor should not have carpet or any other absorption.

The way I understand the concept is that he doesn't use direct absorption (exept from HH for low frequencies) but uses all the diffusors to absorb without losing the energy like normal absorption would do. I'm no expert so don't kill me if I got this wrong, but it is an extremely interesting topic and I hope Matts will chime in here with some comments.

Henrik Salvesen · 06.06.2011

The way I understand the concept is that he doesn't use direct absorption (exept from HH for low frequencies) but uses all the diffusors to absorb without losing the energy like normal absorption would do

Diffusors are designed to diffuse sound, you do not "keep" energy by absorbing sound (with one exception, when bass modes are treated with basstraps it can strengthen the energy at some frequensies which was canceled due to the room mode).

I think the main discussion point here is that early reflections within approximaely 18 ms is stronger in a svanå room than in a rfz room/lede room ,and that svanå use geometrical based diffusors instead of mathematical diffusors /porous absorbers at side walls.

As far as golden horn, to me it looks like a 2d qrd diffusor (based on mathematics).

Sorzy · 06.06.2011

Henrik Salvesen skrev:
The way I understand the concept is that he doesn't use direct absorption (exept from HH for low frequencies) but uses all the diffusors to absorb without losing the energy like normal absorption would do

Klikk for å utvide...

Diffusors are designed to diffuse sound, you do not "keep" energy by absorbing sound (with one exception, when bass modes are treated with basstraps it can strengthen the energy at some frequensies which was canceled due to the room mode).

I think the main discussion point here is that early reflections within approximaely 18 ms is stronger in a svanå room than in a rfz room/lede room ,and that svanå use geometrical based diffusors instead of mathematical diffusors /porous absorbers at side walls.

As far as golden horn, to me it looks like a 2d qrd diffusor (based on mathematics).

My main point from what you quoted was that diffusors also absorb energy but to a lesser degree than pure absorbers. With a lot of diffusors I would expect the absorption to be significant.

From "Acoustic absorbers and diffusers: theory, design and application": "In 1983 D'Antonio made the first absorption measurements of a commercial QRD... The average absorption coefficient was 0.24 ..."

I agree with you on what is the main point for further discussions. On a side note, have any of you been to a Svanå level 2/3 room?

Henrik Salvesen · 06.06.2011

My main point from what you quoted was that diffusors also absorb energy but to a lesser degree than pure absorbers. With a lot of diffusors I would expect the absorption to be significant.

wood paneling has an absorption coefficient of between 0.15-0.30 from 2000hz and down to 125hz(probably deeper aswell, but it is hard to get correct measurements below 125 hz),
in a lede room the absorption coefficient of a large part of the room is 1.0 at many frequensies

absorption is not the goal of diffusion, the design criteria in most cases is to have as low absorption as possible.

Svanå has stronger early reflections than rfz and lede rooms , you do not get stronger reflections from absorption.

As you said this is off topic

Henrik Salvesen · 07.06.2011

On a side note, have any of you been to a Svanå level 2/3 room?

Hey, I have not been to a svanå room.

Svanå makes quality products,however the philosophy is quite unconventional compared to lede room/rfz room when it comes to treatment of early reflections, especially treating surfaces close to the listener that is not first reflections with diffusors, thus having more reflections reaching the listener a short time after the direct signal than would be the case if these areas had no acoustic treatment.

Personally I have not made a judgement on this approach, but it is an interesting discussion.

The discussion is mainly between Matts and Orso.

Bjørn ("Orso") · 07.06.2011

Everyone can participate. Just hoping Matts will show up here.

A quick word about LEDE/RFZ and ISD gap. 20 ms is what is normal in a larger room (concert halls etc.). In a small room like a living room, it's really fine to have ISD gap shorter. As low 12-10 ms is considered fine. The advantage of having a larger gap, is larger sound. And also the system will be able to reproduce recordings done in larger spaces with greater reality. To have a small room reproduce a recording done in a large concert hall with a good illusion/reality is probably impossible with two speakers.

I haven't been to a Svanå room but would like to visit one. I think one should always be open to new ideas, though I admit I'm sceptical. The main reason is because it seems to go against psychoacoustics studies, which have also led to the foundation of LEDE/RFZ. It also seems like people have misinterpreted Floyd Toole when they are saying reflections from sidewalls are pleasing. Yes, there are indications that they can be good if they arriving late enough. Are they arriving early, they will be detrimental to intelligibility and clarity.

smt · 10.06.2011

The Svanå Concept for acoustic treatment rests on two foundations:
- Control of Bass Modal Frequencies
- Provision of Sound Field Spaciousness

Bass Modal Frequencies
Axial modal frequency peaks are selectively absorbed using Svanå's proven tunable Helmholtz-type bass traps.
Transverse and oblique resonances are treated using a combination of the Helmholtz-type traps for lower frequencies and diffusion modules for the higher frequencies.

Sound Field Spaciousness
Reflections are controlled using Svanå's new Wing diffuser. The unique "bottomless" construction of the Wing allows for the first time the creation of a broad-banded diffuse field in the musical, 5 to 15 ms time zone

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
Record and replay lifelike sounding tracks in the Spaciousness Soundfield

Matts Odemalm
CEO
Svanå Miljöteknik AB

Bjørn ("Orso") · 11.06.2011

Matts,
I can't see you've answered any questions with that posting. The ETC with high levels of early reflections looks really bad with specular reflections. Does this imply that you see early reflections as beneficial and that you don't see the importance of attenuating them? If that's the case, how can you say that your goal is to "transform the listening room into the recording room by removing listening room colorations"? You seem to be doing the exact opposite.

smt · 17.06.2011

Hi Orso
My ambition the last 15 years have been to came up with a acoustic concept that is transparent enough to give a illusion that feels lifelike and were you think the music event is happening in front of you To accomplish that I had to ignor most of the traditionally acoustically conclusions you refere to Instead I was earley inspired of Stig Carlssons ortoacoustic theories (www.carlssonplanet.com/) and the ancient Greek amphitheatres

My belief why we have total opposite opinions is that you refere to physcho acoustics from the mikes point of view ,when I relyed on my testgroup of wellknown musicians and audiophiles There conclusions trough the years have been very important and and the result can you see in my ETC diagram (its dense diffused early reflections not specular as you mentioned )

Its now well known that many broadbanded diffused early reflections enhanced speech and acoustic music, when the mike see the same ´information as acoustic distortion
If you chose to absorb the reflections you take away information from the slow brain(100-1000 slower then the earsystem) The absorbers ruin the " second chans" the brain need to have and you sit with a dead and fatigue sound

A example from a danish acoustican about the RFZ concept
manufacturers of diffusors) around 1984 as a logical step further. Based on a purely geometrical basis, the idea was to form the front part of the walls and the ceiling, in a way that all reflections were passing round the mixing area, thus letting the direct sound of the loudspeakers radiate unaffected. The approach is only valid for rather high frequencies, but as the goal was to maintain a stable stereo image, which is related to a frequency range from approximately 500 to 5000 Hz, the idea seems to be justified.
Interesting enough, thinking back, a large number of international top hits of that time were produced in studios and control rooms designed by Hidley, and suddenly a new control room design based on more or less complete opposite ideas was the only appropriate way. The situation was more or less triggered by the new TDS measuring technique, though interesting enough this was not connected to human sound perception. To the authors knowledge no listening tests were made, except of the type where the designer and his client walk into the new control room making their judgment regarding the sound quality.
Documentation was typically made by means of a measuring technique able to reveal variations in the spectrum, which may or may not be perceived by the listener. As one critic puts it, the actual measuring situation corresponded to a listener with one ear without the pinna, deaf on the other ear, and lying on one side! The real situation is, of course, a little bit different, nameley: a listener with two ears with pinnae on either side of the head, and with a head and a body. A dummy head measuring system would come much closer to the real listening situation, but proper analysis methods and more psycho-acoustic understanding is needed."

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

Energy in the direct sound squeezes out early in time so the listening room colorations dont interact with the recording room It also create maximum conditions for the brain to hear all the ambience, timbre and details in the music.

.The last piece to complete the Svanå Acoustic Concept was to invent a geometric diffusor for broadband diffuse the early reflections
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
My level 3 rooms (spread all over the world) have no acoustic footprint so they are perfect for
listening rooms
mixing rooms
tracking rooms
alternative to fatiguing and dead sounding rooms
evulating different machine noice for the industry
class rooms for people with hearing loss (the Wings are just now manufactured for a reference classroom )

Some late references :

40mm GH in front of the mix room

Hope to have a drum demo up soon for downloading from Mikaels now world famous level 3 room
Wing diffusors close surrounded both drums and mike in the demo

Startkit for mixrooms that explain my concept

NR oslo Bus with nearfield diffusion by Golden Horn

Henrik Salvesen · 19.06.2011

Interesting info and impressive client list

Just a couple of qeustions that it would be nice to get some more in debth info on:

Is golden horn a mathematical diffusor?
it has all the characteristics of a reflective phase grating design (albeit not the same sequense as f.eks omniffusor)
RPG omniffusor:

what aspects of acoustics from ancient greece do you use principles from?

A example from a danish acoustican about the RFZ concept

here is a link to the full article you reffered to:
http://www.akustikjav.dk/assets/PDF/50-years-of-control-room-design.pdf

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

Depending on the frequency range of the diffusor, this required distance is normaly between 2-3meters, many small rooms have 2-3 meters distance between listener and boundaries.

it is generally adviced to have a some distance to all types of reflective surface.

mathematical diffusors have better temporal dispersion while geometrical (at least polys) have better spatial dispersion.

Broadband diffused early reflections (5-15ms ) increase the
intelligibility and timbre in acoustic music and speech
Broadband diffused late reflections mask the intelligibility and timbre in acoustic music and speech

many rfz rooms have appr 18ms time gap,very close to 15ms

thanks

Sorzy · 19.06.2011

Lots of interesting reading here, thanks. I've been to the Svanå room at Audio Concept store in Stockholm, but would also like to visit Marten's room in Gothenburg. Orso and Henrik, wanna join me?

Bjørn ("Orso") · 19.06.2011

smt skrev:
Its now well known that many broadbanded diffused early reflections enhanced speech and acoustic music, when the mike see the same ´information as acoustic distortion
If you chose to absorb the reflections you take away information from the slow brain(100-1000 slower then the earsystem) The absorbers ruin the " second chans" the brain need to have and you sit with a dead and fatigue sound

Thanks for participating.
I'm wondering if you have understood the modern RFZ/LEDE concept. A good RFZ treated room is far from dead and fatiguing sounding. You seem to refer more to anechoic or semianechoic room.

First of all, you don't necessarly absorp early reflections with the RFZ concept. You can also redirect them to the rear of the room. This is done in many rooms.
Secondly, you use absorption with precision at those surfaces that causes early reflections. RFZ is not about dampening all of the front part of the room.
Thirdly, a high termination of ISD gap will cause the sound to be lively.
The rear of the room has diffusion and reflections

A well designed RFZ room will not sound dead at all. Far from it!

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

Energy in the direct sound squeezes out early in time so the listening room colorations dont interact with the recording room It also create maximum conditions for the brain to hear all the ambience, timbre and details in the music.

.The last piece to complete the Svanå Acoustic Concept was to invent a geometric diffusor for broadband diffuse the early reflections
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
My level 3 rooms (spread all over the world) have no acoustic footprint so they are perfect for
listening rooms
mixing rooms
tracking rooms
alternative to fatiguing and dead sounding rooms
evulating different machine noice for the industry
class rooms for people with hearing loss (the Wings are just now manufactured for a reference classroom )

What you're implying about diffusion of early reflections and late diffuse soundfield seem to be a direct contratiction to well studied psychoacoustics. We need to remember that RFZ was not only based on a development for control rooms, but on human perception. Why would it then be different for a listening room? I can see that adding something may be pleasing to some, similar to audiophiles prefering tube with high distortion, but this is not an obejctive fact based on verified studies. Perhaps we need more psychoacoustics studies and also to see if in a listening condition people would prefer something less accurate, but then we are also moving away from the goal of true fidelity.

A high reflective termination of the ISD gap will avoid later locational cues and lock the listener to the direct sound. A diffuse soundfield must gradually decay to avoid tonality issues. If this is done, late diffuse energy will not have a negative effect.

I would be interesting to know what you compared your principal with when you had testgroups of musicians and audiophiles.

Bjørn ("Orso") · 20.06.2011

smt skrev:
A example from a danish acoustican about the RFZ concept
manufacturers of diffusors) around 1984 as a logical step further. Based on a purely geometrical basis, the idea was to form the front part of the walls and the ceiling, in a way that all reflections were passing round the mixing area, thus letting the direct sound of the loudspeakers radiate unaffected. The approach is only valid for rather high frequencies, but as the goal was to maintain a stable stereo image, which is related to a frequency range from approximately 500 to 5000 Hz, the idea seems to be justified.
Interesting enough, thinking back, a large number of international top hits of that time were produced in studios and control rooms designed by Hidley, and suddenly a new control room design based on more or less complete opposite ideas was the only appropriate way. The situation was more or less triggered by the new TDS measuring technique, though interesting enough this was not connected to human sound perception. To the authors knowledge no listening tests were made, except of the type where the designer and his client walk into the new control room making their judgment regarding the sound quality.
Documentation was typically made by means of a measuring technique able to reveal variations in the spectrum, which may or may not be perceived by the listener. As one critic puts it, the actual measuring situation corresponded to a listener with one ear without the pinna, deaf on the other ear, and lying on one side! The real situation is, of course, a little bit different, nameley: a listener with two ears with pinnae on either side of the head, and with a head and a body. A dummy head measuring system would come much closer to the real listening situation, but proper analysis methods and more psycho-acoustic understanding is needed."

I had to check some sources before I commented this one. This is absolutely wrong. LEDE and the later incorparation of RFZ was based on extensive psycho acoustical testing. Both before and with more research later for validation.
Extensive interaural cross corrrelation studies were done by the same people to my knowledge (D'Antonio and others).

You said that the benefit of a Svanå concept was "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. Record and replay lifelike sounding tracks in the Spaciousness Soundfield"
If you are going to hear fully what's on the recording the ISD gap needs to be larger in the listening room then what it was in the recorded room. How do you accomplish that with high levels of early "reflections" from diffusors placed on close surfaces? It will add coloration and its own sound to the recording. You could do this by creating a ambechoic room, but then you need more space to the surfaces and much deeper diffusors.

I don't understand how your goal of removing the listening room and transporting the listener to the recording room can be accomplished by your method. To me it seems that you rather are creating a colored or footprint sound to the music.

I think it would be fair to ask to see more measurements and a more accurate explanation of your approach. What about relative levels at the various arrival time? Do the Svanå rooms have a similar result?

smt · 21.06.2011

Henrik Salvesen skrev:
Interesting info and impressive client list

Thanks ,but you havent seen nothing yet 8)

Just a couple of qeustions that it would be nice to get some more in debth info on:

Is golden horn a mathematical diffusor?
it has all the characteristics of a reflective phase grating design (albeit not the same sequense as f.eks omniffusor)
RPG omniffusor:

GH have fractal qualitys and have solved the problem of construction surfaces that behaves uniformity in 2 dimensions and at the same time and are so irrugular that they create a phase clean diffusion
This is not the case with ordinary diffusors since current number theory usually works with infinite sequences in one or two dimensions
another great benefit is the almost 2000small compartments /m2 that solve the problem with specular reflections up to 16000hz
(The omnifuser have 192/m2)
Thay are also std in Swedish Broadcasting mix and OB busses

what aspects of acoustics from ancient greece do you use principles from?

The ancient Greeks and Romans embedded large wine bottles in the walls of their theaters, where only the holes of the wine bottles were visible, and they used sand to change the air volume of the bottles to tune the acoustic behaviors of the rooms based on the anticipated number of people in the audience, type of performance,
I train Roomtuners all over the world with my adjustable basstrapps

They also used big pots and resonators to get more reflections to the outside theatres

A example from a danish acoustican about the RFZ concept

Klikk for å utvide...

here is a link to the full article you reffered to:
http://www.akustikjav.dk/assets/PDF/50-years-of-control-room-design.pdf
Thanks !

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

Klikk for å utvide...

Depending on the frequency range of the diffusor, this required distance is normaly between 2-3meters, many small rooms have 2-3 meters distance between listener and boundaries.
Broadband (250Hz -)math diffusors need at least 3.5m meters distance
so they kickin after the 5-15ms musical time zone

it is generally adviced to have a some distance to all types of reflective surface.
mathematical diffusors have better temporal dispersion while geometrical (at least polys) have better spatial dispersion.
Yes thats why I had to invent a new Wing family !

Broadband diffused early reflections (5-15ms ) increase the
intelligibility and timbre in acoustic music and speech
Broadband diffused late reflections mask the intelligibility and timbre in acoustic music and speech

Klikk for å utvide...

many rfz rooms have appr 18ms time gap,very close to 15ms

Yes they come in when the musical fun is over
Best
Matts

thanks

Henrik Salvesen · 21.06.2011

The ancient Greeks and Romans embedded large wine bottles in the walls of their theaters, where only the holes of the wine bottles were visible, and they used sand to change the air volume of the bottles to tune the acoustic behaviors of the rooms based on the anticipated number of people in the audience, type of performance,
I train Roomtuners all over the world with my adjustable basstrapps

I don`t see how one could use these principles as an argument for early reflections in small room acoustics, if you mentioned the positioning of vases under the seats (greeaks called them echea) then I could possibly see a pararell, but it is still used in a large venue and the device is different from the ones you produce.

The varitune devices absorb low frequency sound, the Echea will add ambience due to the reflective walls of the Helmholtz design, the ambience is largely in the mid frequensies

Broadband (250Hz -)math diffusors need at least 3.5m meters distance
so they kickin after the 5-15ms musical time zone

Which diffusors are you reffering to here?

Normally the diffusors have a higher design frequency, it is most important to scatter frequensies in the mids from a psychoacoustic perspective.

Your argument is based upon claiming something unusual to be the norm.

The 18ms timegap used in rfz rooms is not a result of design limitations of mathematical diffusors, rather an effort to avoid the isd gap being smaller than on the recorded sound.

Personally I am not locked to a room design philosophy, I think there are many roads to Rome

another great benefit is the almost 2000small compartments /m2 that solve the problem with specular reflections up to 16000hz
(The omnifuser have 192/m2)

you are isolating one aspect when you talk about number of compartments/m2, because there is one drawback to this design, and that is the number of sharp edges pr m2, edges cause absorption due to diffraction, more sharp edges equals more absorption, and this absorption will not be evenly distributed.

This is the reason that 1d diffusors have lower absorption than 2d difusors when using same sequence and build debth/width.

There are several types of diffusors, each has their strength/weakness

it is generally adviced to have a some distance to all types of reflective surface.
mathematical diffusors have better temporal dispersion while geometrical (at least polys) have better spatial dispersion.
Yes thats why I had to invent a new Wing family !

From my understanding temporal scattering has often been mentioned as important in small room acoustics due to it lowering combfiltering.

p.s I am also a maker of acoustic treatments (we are both biased

)

edited

Bjørn ("Orso") · 21.06.2011

I have some diffusors that are quite effective down to about 600 Hz (around 0,6 coffiecient). They are 23 cm deep. A diffusor that's broadband or effective down to 250 Hz needs to be deeper.

Mr-T · 22.06.2011

Most diffusors tend to be fairly effective an octave or more below its theoretical limit, at least that's my experience. My rear wall diffractal diffusor is about 1.2 meter deep. The theoretical limit is about 140 Hz, but its effect on the room response can be measured as low as 40 Hz. That's almost 2 octaves below the "limit". But of course the effectiveness decreases at low frequencies.

Henrik Salvesen · 22.06.2011

Most diffusors tend to be fairly effective an octave or more below its theoretical limit

In this area the scattering coefficient is lower, the point of having a distance is to avoid hearing single wells or group of wells better than the rest, this is from what I understand mainly due to the reflective phase grating design, golden horn use a reflective phase grating design, so should require the same distance as Omniffusor (which was mentioned in comparison to golden horn), omniffusor starts to scatter sound at appr the same frequensy as golden horn (800hz)

smt · 24.06.2011

I don`t see how one could use these principles as an argument for early reflections in small room acoustics, if you mentioned the positioning of vases under the seats (greeaks called them echea) then I could possibly see a pararell, but it is still used in a large venue and the device is different from the ones you produce.
The varitune devices absorb low frequency sound, the Echea will add ambience due to the reflective walls of the Helmholtz design, the ambience is largely in the mid frequensies

I said I was inspired of there impressive feeling for acoustics (seems they know at least as much as most acousticans nowdays )
Its also interesting that I have reintroduced a 2000years old proffession as Roomtuner
While they tuned the basstrapps with different volyme of sand I adjust a hatch on my V-6 and V-4 HH trapps
The Echea is one of the names I have considerd to add for my Wing family

Which diffusors are you reffering to here?

Normally the diffusors have a higher design frequency, it is most important to scatter frequensies in the mids from a psychoacoustic perspective.

Your argument is based upon claiming something unusual to be the norm.

Its very important to diffuse broadbanded 250-300 up to atleast 8000hz If not, you miss to unmask the full dynamic and timbre in many instruments and voices
Ordinary built diffusors (schröder etc) need a time distance around 15-20ms distance from sweetspot

you are isolating one aspect when you talk about number of compartments/m2, because there is one drawback to this design, and that is the number of sharp edges pr m2, edges cause absorption due to diffraction, more sharp edges equals more absorption, and this absorption will not be evenly distributed.

Evidence how 50 GH mounted on all first reflection points even out the Before decay time broadbanded CIU room

As I said ,Gh is a unique module that produce a phase clean diffusion with even absorbtionkoefficient (around 0,2 ) over the hole bandwith
The effort to avoid manufacturing diffusor modules from a singel mould , is also part of the sucsess (after 15 years we have not delivered one lookalike)

Mikael Wikmans Drumstudio drum demos (plays frequently in Level 3 showrooms and HIFI shows ) is a perfect example of the broadbanded diffusion the Wings togheter with GH deliver
Mikael contacted me becouse he was tired of his dead sounding tracking room
I invited him to my reference room at Audio Concept in Stockholm and asked him to bring a cymbal and kickdrum
I will never forget his kind of jaw dropping smile when hi heard his cymbal under the GH ceiling

When Ian M Dash and Fergus R. Fricke presented this paper at the130 AES convention in May (London ) this year
Whats wrong with scattering theory?
it was very quiet from the experts in the room It seems that they actually dont know whats happening with the scattered and diffused energy ( Measuring the GH with a B&K intensity probe indicated that it is a soft absorber (reflections broadbanded 15dB down ) but the enchance of timbre and ambience is dramatic infront of the module )
Until the scientist will comeup with a standard method to measure the scattering and diffusion coefficient I will go on with my own methods (test them on musicians and audiophiles and fill the room with the modules and use a Bruel &Kjear Reference Sound Source and do before and after measurments My own omnisound source (I needed it for diffusion measurments) soon become a worldstandard for over 10 years ago They were distributed by B&K up to a couple a years ago

From my understanding temporal scattering has often been mentioned as important in small room acoustics due to it lowering combfiltering.

My Wing family builts on different geometric forms and diffuse broadbanded from 250Hz and up with a depth of only 250mm

smt · 26.06.2011

Hi Orso
Absobtion vs diffusion was generally talking
Soft absorbers on first reflection points in a listenngroom colour the sound
The room contribute somewere between 40 -60 % of the total soundexperients, so its important that the listening rooms contribution is a broadbanded copy of the speakers respons
Check whats happening with the higher frequences when you put a 200mm soft absorber on first refelction piont The frequence respons is time seperated from the speaker respons

200mm absorber

The Wooden Wing

Before and after measurments from a Haugeland customer that wanted to transform absorbtion to Svanå diffusion (Wings GH and PC 1200)

Just to make everything clear:
I understand that not all mixers want to unmask the sound to a point my concept go, so I have full respect for acousticans and mixers/listeners that choose other concepts then my own Svanå Acoustic Level 1-3

The bigger part of my buissness is to deliver panels or modules that acousticans (most in Scandinavia ) have suggested for there clients
Over the years have my own concept grown compared to my total turnover ( Proaudio ,Hifi ,HT, commercial cinemas ,musical schools, concert halls etc )

Svanå Acoustic ,Level 1-3, is a upgrade module system and each step gradually remove both Frequence Masking and Time Masking
All levels also fullfill 2.2 EUB Tech 3276 (see below)
(using omnidirectional speakers in level 2-3 rooms activate the diffusors more and as you can see below create dense early reflection just 5 dB down)
ISD is not mentioned in the std

from tech 3276
2.2. Early reflections
Early reflections are defined as reflections from boundary surfaces or other surfaces in the room which
reach the listening area within the first 15 ms after the arrival of the direct sound. The levels of these reflections
should be at least 10 dB below the level of the direct sound for all frequencies in the range 1 kHz to 8 kHz.
The amplitude and frequency responses of individual reflections may be derived from a measurement of
the room impulse response, using Fourier transform methods. The fundamental constraints of time and frequency
will limit the resolutions which can be obtained. It is important that the effective time window and bandwidth of
the measurement are appropriate1. The measurement of early reflections of sounds including components in the
frequency range below about 500 Hz may be difficult.

Musiclovers have no interest in the 10dB line and ISD gap ,instead they ask me if its possible to implement more diffusors to reveal even more details and timbre in the recording ( mobile GH and Wings on the floor is not unusal )

The brain is a amazing computer but togheter with the earsystem it have computing flaws
The musical killer MP3 is a good example
Time and frequencey masking is very complex and create many different problems for the brain .
Strong transients mask sound direct after ( even mask music informations before the transient)

Some examples
A tone of greater intensity masks a broader ranger of tones than a tone of less intensity. This is demonstrated on track 29.

http://www.ece.uvic.ca/~aupward/p/demos/track29.wav
A single tone is played, followed by the same tone and a higher frequency tone. The higher frequency tone is reduced in intensity first by 10 dB, then by steps of 3 dB. The sequence above is repeated twice, the second time increasing the intensity of the single tone by 28 dB.

Brick hits wall
www.sfu.ca/sonic-studio/handbook/Sound/Reverb_Brick.aiff

if we play it backwards you hear what the brain miss to detect

www.sfu.ca/sonic-studio/handbook/Sound/Reverb_Brick_Reverse.aiff

What Svanå Acoustics do is give the brain a "extra chans" ,boosted in the 5-15ms time zone, to detect the missing information
The decay time afer the musical boost now almost acts if its was soft absorbers in the room wich means that the recording rooms acoustic can kick in
Its right that the Wing family add information but without the extra information you will never hear how the acoustic instruments really sound
Over the years its the same reaction from musicians that play or listen to there recorded instruments in my level 3 rooms Amazed how there instrument really sound and how the recording room transforms into the listening room
The Concept is also space saving
The design protection for all Wing modules in EU is hopefully soon ready so I can launch them on my homepage.

Some Svanå Acoustic statements over the years
" .You get one with the instrument when I play in the room and I hear detalis I never experients before The room have no impact (no couloration) of the sound it just deliver a full instrument ambience and timbre, full of details " Tor Forberg - norwegien classic bassist playing in Audio Concepts level 3 room in Stockholm

Mike Chauffe:
David Zucker's demo rooms at Sound Experience Florida essentially disapear. They are so balanced in frequency and time, that it is now possible to optimize equipment and positioning parameters to get closer than ever to the holy grail of unquestioned accuracy.
One of Mikes references : Sound Designer for the large 5.1 Playback System for the Audio Engineering Societys 123rd. Convention in New York City.

MikaelWikman :
Efter flera års sökande efter det optimala trumrummet så föll polletten till slut ned när jag fick provspela mina trummor i ett utav Matts Odemalms referens rum. Den energi, fart och det tryck som uppstod i trummorna i kombination med den mjuka, fina diskanten från cymbalerna var magisk att uppleva i rummet. Vidare så fanns det en tighthet, kontroll och tydlighet i trummorna som jag aldrig upplevt i något studiorum tidigare och som jag eftersökt länge. Detta är något jag hoppas att även andra musiker ska få uppleva med sina instrument. Att det sen lät lika bra på inspelningarna och att rummet även är optimalt för referens lyssning var ytterligare en stor bonus för mig.

Peer Astrom Level 2 room
(Madonna,Celine Dion,Enrique Iglesias,Miley Cyrus,Kelly Clarkson,Cyndi Lauper,Josh Groban, Glee etc)
Matts!
Thank you for your help!
With Your knowledge and products, You managed to exceed my very high demands.
With a less then ideal celing height to start with, the room stil plays straight from 20khz down to a shattering 20hz!
And the amount of detail and resolution in the sound is mindblowing.
By far the best room I've ever worked in!
Thank you!

Stockholm Highend show 2011
Peter McGrath (Wilson Audio)
"-I mean, this guy is an ABSOLUTE WIZARD! He has an understanding of acoustics that is simply very rare on this planet. Other acousticians mess things up with their general idea to absorb sound. Matts fights to keep the energy of the music intact, and REDIRECTS it instead, which is a much more intelligent way of dealing with the problems."

San Diego-based producer Christian Cummings has recorded in the BoomTown studio and is very happy with the acoustics as well as the over all feel of the studio.
"Personally, it's rare that I find a studio as well balanced as BoomTown. It's very neutral yet pleasing, and I believe Svanå Miljöteknik is major factor in that success." Says Christian

Svanå have been involved in more then 300 mix/recording / rooms during the past 15 years
Some worldclass references
http://fenixrecording.com/
http://midasproductions.fi/
http://www.boomtown.nu/boomtown/default/page_18
www.dreamhillstudio.se/
http://www.axxell.fi/sv/enheter/axxell-lappfjaerds-folkhoegskola/aktuellt/nya-studio.html

Best Regards
Matts Odemalm
www.diffusor.com

Bjørn ("Orso") · 27.06.2011

smt skrev:
Its also interesting that I have reintroduced a 2000years old proffession as Roomtuner
While they tuned the basstrapps with different volyme of sand I adjust a hatch on my V-6 and V-4 HH trapps

The Helmholtz resonator has been used by many for years and decades. What do you mean when you're saying you've reintroduced it?

smt skrev:
Its very important to diffuse broadbanded 250-300 up to atleast 8000hz If not, you miss to unmask the full dynamic and timbre in many instruments and voices
Ordinary built diffusors (schröder etc) need a time distance around 15-20ms distance from sweetspot

Most of the diffusors you use/sell are definetly not broadband. I'm not sure any of them are.

You need to be 3 wavelengths away from the diffusor of the diffused frequencies.

smt skrev:
Until the scientist will comeup with a standard method to measure the scattering and diffusion coefficient I will go on with my own methods (test them on musicians and audiophiles and fill the room with the modules and use a Bruel &Kjear Reference Sound Source and do before and after measurments My own omnisound source (I needed it for diffusion measurments) soon become a worldstandard for over 10 years ago They were distributed by B&K up to a couple a years ago

To my knowledge there is method and a standard to measure diffusers.
http://books.google.no/books?id=f19...&resnum=1&ved=0CC4Q6AEwAA#v=onepage&q&f=false

smt skrev:
My Wing family builts on different geometric forms and diffuse broadbanded from 250Hz and up with a depth of only 250mm

That sounds too good to be true. Do you have any simulations with BEM you can post?

Bjørn ("Orso") · 27.06.2011

smt skrev:
Just to make everything clear:
I understand that not all mixers want to unmask the sound to a point my concept go, so I have full respect for acousticans and mixers/listeners that choose other concepts then my own Svanå Acoustic Level 1-3

Accuracy is exactly what a mixer want. And that was also what laid the foundation of LEDE/RFZ.

smt skrev:
Musiclovers have no interest in the 10dB line and ISD gap ,instead they ask me if its possible to implement more diffusors to reveal even more details and timbre in the recording ( mobile GH and Wings on the floor is not unusal )

If you don't have a ISD gap and a termination you have an acoustic environment that's adding something. Perhaps someone wants that and it can enhance some music, but it's absolutely something you don't want in a critical listening environment where the goal is to be close as possible to the source material.
Comb filtering and early reflections will not enhance details and intelligibilty. That's the very opposite of what studies have showed.

Again, I would like to ask you to post several ETC graphs of rooms you have treated. Frequency response and waterfall isn't the question here. I'm wondering if there's any consistency to how you treat a room. How are the levels at the various arrival time?

Henrik Salvesen · 27.06.2011

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

all other reflective phase grating designs I have seen on the market has a somewhat uneven absorption, normally between 0.2 and 0.5 for 2d diffusors like the golden horn, I do not see anything in your design that would lower absorption (it actually has more sharp edges than other designs).

I have not seen any proof that your design is better than phase gratings using the formulas disovered by Mannfred Schroeder (everybody using a phase grating design are in fact somehow implementing his invention that he decided to not patent).

Is it correct that golden horn is not a prd/qrd but anothr form of phase grating , and that the pattern is repeated one time on a smaller scale, making it out to be the start of a fractal structure?

If this is the case then this is somewhat similar to rpg diffractal (albeit it being 1d) and many custom designed 2d diffusors, the essential part is the quality of sequence used (or random pattern), the fractal element
will extend the frequency range for diffusion, but there will be a frequency gap between the design frequency of the bigger structure and the smaller structure inside it.

I am not saying that GH is a bad design, but I point out that I have not seen anything proving your claim that it is superior to other designs.

Positive feedback from a big room full of diffusors and basstraps is not something new.

Ordinary built diffusors (schröder etc) need a time distance around 15-20ms distance from sweetspot

rule of thumb for qrd diffusors are 3 times the wave length of the lowest frequency from where the diffusor is designed to work (if this frequency is for instance 600hz then this distance is 1.5 meters), there are other parameters involved aswell, the general size of the room, ratio of dimensions, polar response of speakers, direction of the diffuse sound e.t.c, I do not think that one can apply strict rule of thumb.

Ethan Whiner has a video where he argues completely opposite to you
(I do not agree 100% with the arguments in the video, but it shows that there are other views out there)

If your claims would be true then these rooms would not be succesfull:
http://www.myroom-acoustics.com/
http://www.blackbirdstudio.com/#/studios/ ( studio c, Georg Massenburg studio)

Its also interesting that I have reintroduced a 2000years old proffession as Roomtuner

There are many good roomtuners around, it is not a profession that is lost and forgotten.

While they tuned the basstrapps with different volyme of sand I adjust a hatch on my V-6 and V-4 HH trapps

I still fail to see the connection to echea when it comes to how it actually sound, the echeas where used to enhance the sound of specific notes, 12-13 vases in each row, and the echeas of each row enhancing notes from a different mode.
Varitune absorbs sound
http://www.arturobarba.com/pdf/Articulos congresos/Paris08 H002320.pdf page 6

Its very important to diffuse broadbanded 250-300 up to atleast 8000hz If not, you miss to unmask the full dynamic and timbre in many instruments and voices

Picture 1 and 4 in your post at the top of page 2 in this thread shows large surfaceses being covered with golden horn, a diffusor with a lower limit of 800hz

Best regards

Henrik Salvesen

Henrik Salvesen · 27.06.2011

Orso, while there are psychoacoustic arguments for rfz rooms, I have not seen any definitive evidence that this room design is superior in every setting, D`antonio has designed rooms that are different, and there are many other designs being implemented out there.

There are many recordings with a larger isd gap than a rfz room, so in a hi-fi setting one has to see it in another light than in a control room setting.

In a studio one can design a rfz control having larger isd gap than the microphones in the live room, in a hi-fi setting the "live room" can be anything from a dry small liveroom to carnegie hall.

Bjørn ("Orso") · 27.06.2011

Henrik Salvesen skrev:
Orso, while there are psychoacoustic arguments for rfz rooms, I have not seen any definitive evidence that this room design is superior in every setting, D`antonio has designed rooms that are different, and there are many other designs being implemented out there.

What's superiour depends on the goal. LEDE/RFZ what developed to be accurate. To give the best clarity, details, tonality, loacalization, etc for stereo. If you desire something else, that can be fine. There are no serious studies that I know of that says there's a better concept for accuracy.

Non-environment is another concept. The early reflections are also reduced in a NER, but it lacks the termination of the ISD gap which is is very important from a psychoacoustic standpoint. With a NER and the missing termination, you will get a anechoic space and the localization will not be very good.

Ambechoic/Masenburg, which D'Antonia was part of creating, is basically a room for surround. It therefore cannot be compared to LEDE. In a surround setup you have surround speakers to give you a return.

Henrik Salvesen skrev:
There are many recordings with a larger isd gap than a rfz room, so in a hi-fi setting one has to see it in another light than in a control room setting.

In a studio one can design a rfz control having larger isd gap than the microphones in the live room, in a hi-fi setting the "live room" can be anything from a dry small liveroom to carnegie hall.

If the recording room has a larger ISD gap then the ISD gap in your listening that means you will not hear everything with that specific source material. Is that a reason to do something complete different? You have to live with a compomise, but it will still sound great. But no doubt that a larger room has the potential of sounding better then a small one.

Sorzy · 27.06.2011

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?

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?

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

Henrik Salvesen · 28.06.2011

Ambechoic/Masenburg, which D'Antonia was part of creating, is basically a room for surround

from blackbird studios website about studio c:

designed for stereo and multichannel mixing

The room also proved to be very good as a live room, and there have been several albums tracked in this room.

but it lacks the termination of the ISD gap which is is very important from a psychoacoustic standpoint

There are different views on this, if you listen to jazz from the 50`s this would often be recorded in a lage room with poly diffusors, and a larger isd gap than a rfz room has, weather you really detect that isd gap and percieve it is as unnatural is another case.

LEDE/RFZ what developed to be accurate. To give the best clarity, details, tonality, loacalization, etc for stereo. If you desire something else, that can be fine. There are no serious studies that I know of that says there's a better concept for accuracy

I have never stated that I desire something else,
I have yet to see any study by D`Antonio that "proves" that the Svanå concept is wrong when it comes to psychoacoustics.

Bjørn ("Orso") · 28.06.2011

Henrik Salvesen skrev:
Ambechoic/Masenburg, which D'Antonia was part of creating, is basically a room for surround

Klikk for å utvide...

from blackbird studios website about studio c:

designed for stereo and multichannel mixing

Klikk for å utvide...

The room also proved to be very good as a live room, and there have been several albums tracked in this room.

Basically means basically and that's what I've been told. The room has early reflections down 30 dB compared to the direct signal. So it will not interfere with localization, imaging and intelligibility. And the diffusion is so dense that it will not be peceived as destructive. How it compares to LEDE in terms of stereo I don't for sure, but it doesn't have the termination which are important to localiazation. Perhaps the extreme use of diffusion and density makes up for it. Somone else would have to answer that. But even if ambechoic is as good for stereo as LEDE, I don't find it very interesting. Why? Because it's unpractical to build. We're talking about meters of diffusion. Not something you could build yourself.

Henrik Salvesen skrev:
but it lacks the termination of the ISD gap which is is very important from a psychoacoustic standpoint

Klikk for å utvide...

There are different views on this, if you listen to jazz from the 50`s this would often be recorded in a lage room with poly diffusors, and a larger isd gap than a rfz room has, weather you really detect that isd gap and percieve it is as unnatural is another case.

I don't understand how this relates to what I was saying about NE room and the lack of termination.

Henrik Salvesen skrev:
LEDE/RFZ what developed to be accurate. To give the best clarity, details, tonality, loacalization, etc for stereo. If you desire something else, that can be fine. There are no serious studies that I know of that says there's a better concept for accuracy

Klikk for å utvide...

I have never stated that I desire something else,
I have yet to see any study by D`Antonio that "proves" that the Svanå concept is wrong when it comes to psychoacoustics.

The Svanå concept is a direct contrast to psychoacoustic studies about early reflections and combfiltering (the Henry Precedence Effect and Haas corollary). When you remain early reflections you will reduce intelligibility, localization and imaging due to polar lobing and combfiltering. From what I know this has also been repeatedly and objectively verified.

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.

The importance of the termination of ISD gap goes back from I've heard to Beranek's documentation and study of the ITD. Studies by Schroeder and Puddie (Carolyn) Rodgers ar also said to be important and it was reinforced by inter-aural cross correlation (IACC) studies. A Svanå room doesn't seem to have any strong termination of a ISD gap.

I don't how much of this information is out there in the open. The researches have been published over many years in papers and books. I trust those who have followed the studies and have read it all.

There have been some new concepts coming forth. Like Svanå and Moulton. But when they have ideas that goes against established psychoacoustic studies one should ask questions. Commercial brochures and some testimonies are not going to convince me that LEDE is now obsolete and this is the new and better thing. What researches and objective measurements have they done? And how have they been able to prove that LEDE is wrong? I can't see any.

Svanå's acoustics philosophy

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