ACAD is certified compliant to ISO 9001 and ISO 14001

Date: 2011-02-03

ACAD now holds an ISO 9001 certification for quality management systems and an ISO 14001 certification for environmental management systems. We passed our recent audit with flying colors.

The added value for our customers is their assurance that our services is based on a sound and audited platform where the quality of our services is monitored and improved.

Vibration effect on older buildings

Date: 2010-11-15

Vibration effect on older buildings is an enormously complex area. The conception of older buildings’ sensibility differs a lot between Sweden and other countries.  We are currently working intensely with the handling of the issue in connection with the construction of Citybanan and also in planning the new Slussen area.

Swedish newspaper DN recently wrote an article on Riddarholmskyrkan and Citybanan. Read the article here: http://www.dn.se/sthlm/sprangningar-skakar-city-1.1207852

Are you disturbed by your neighbours?

Date: 2010-11-02

Swedish magazine Hem & Hyra has in an article examined the not soundproof houses. In the article, buildings from different eras are classified in respect to soundproofing. According to the article, houses from the so called million projects are the worst. However, we do want to point out that these houses often fulfil, or almost fulfil, demands on construction of new houses (sound class C) regarding air and insulation of footsteps between flats.

Todays’ newly built houses are usually designed for sound class B, which to a much higher degree matches better sound conditions than sound class C.
Read the article here: http://www.hemhyra.se/Sidor/Lyhorda-hus.aspx

DN also writes a short notice on the examination by Hem & Hyra, read it here: http://www.dn.se/ekonomi/lyhort-i-miljonprogrammets-hus-1.1200621

Noise is a highly topical public issue

Date: 2010-10-28

Media continues to pay attention to noise as a topical public issue. Please read some of Swedish newspaper DN’s articles below regarding traffic noise by schools, the evaluation of silent asphalt and noise fees for heavy vehicles.

http://www.dn.se/sthlm/trafikbuller-skadar-barn-pa-skolgardar-1.1193030
http://www.dn.se/sthlm/tyst-asfalt-klarade-inte-vintern-1.1187325
http://www.dn.se/motor/buller-ska-kosta-for-tunga-lastbilar-1.1188449

We are increasing our numbers!

Date: 2010-10-04

We welcome Marja Gustin to us at ACAD. Marja will join our group of acousticians in the beginning of October. She has a Master of Engineering degree in media technology with speciality in sound.

The Art Gallery in the "Marabou Park" now open

Date: 2010-08-31

On August 28, the Art Gallery in the Marabou Park in Sundbyberg was opened. The opening exhibition Park Life is shown between August 28 and November 7. We have designed the acoustics of the Gallery in collaboration with architect Martin Hansson at WGH Architects.

We have previously paid attention to the Marabou Park among our projects: http://www.acad.se/se/hem/projekt/09132-1/

Please visit the Marabou Park home page: http://www.marabouparken.se

It has also been noticed in the media, for example at SvD.se: http://www.svd.se/kulturnoje/nyheter/bunker-som-konsthall_5205925.svd and at DN.se: http://www.dn.se/kultur-noje/nyheter/fran-kakaolabb-till-konsthall-1.1159367

Changes during the Summer

Date: 2010-08-16

We are now in full numbers after the Summer holidays and would like to remind you of some changes that have occurred with us during the Summer.

- Firstly, we would like to welcome Viktor Granbom to us at ACAD. Viktor has a Master of Engineering from Chalmers, where he studied electro technology with a speciality in acoustics.
- Sanna Cramér is on maternity leave and will be away until the beginning of next year. Please contact Anders Schönbeck if you have any questions regarding her projects.
- We have moved to newly refurbished, fresh premises near Sveaplan. You can now visit us at Sveavägen 151, 6th floor.

Our new postal address is
ACAD-International AB
Sveavägen 151
113 46 Stockholm

- In connection with the move, we have switched to a mobile switchboard. Our old network numbers will shortly be discontinued. Please update your contact lists.

- In connection with the move, we have retired our fax machine. Instead, you can scan mail our e-mail addresses. 

Summer holidays

Date: 2010-07-16

During the high summer season, we are partly closed at the office. We will slowly start up again from August 2 and will be back in full swing by August 16.
The easiest way to contact us during Summer is via e-mail.

Summary of BNAM 2010

Date: 2010-06-15

Some time ago we informed about our participation at the upcoming BNAM (Baltic-Nordic Acoustic Meeting). Peter Blom was present has returned with new knowledge and contacts. His and the other conference articles can be found through http://www.bnam2010.com/.

Recruitment in August

Date: 2010-05-26

We welcome Viktor Granbom as our new employee. He will start in mid-August and will arrive in our new offices at Sveavägen 151 as our eleventh co-worker. We are making room there for 15-20 people.

Viktor has a Master of Engineering from Chalmers with a speciality, among other things, in building- room- and electro acoustics. We are complementing our group of co-workers with another knowledge focus.

We are now a group of eleven: our acousticians are engineers and PhDs within F, M, T and V, and now also E, all with focus on sound and vibrations. We possess a co-ordinated wide knowledge and have one of the most extensive experiences that we apply to every project.

Before then, we will make room for Johan Hedekäll, who is studying sound and vibrations at MWL. Johan will help us with miscellaneous jobs during Summer and will be seen doing measuring work etc. We hope to give Johan a good practical experience during a couple of weeks to complete his on-going studies.

Impressions from the new Opera house in Oslo

Date: 2010-05-25

ACAD last weekend went to visit the new Opera house in Oslo. A different building where the ceiling landscape has been made available to the Oslo residents. The house is of a high quality in everything, acoustics included. It is well planned and implemented.

We went to the premiere of “Around the world in 80 days”. This opera was planned for the opening, but was too technically complicated for the staff to execute. Now, a couple of years later, they have learnt the technique so that the performance could be staged. It is an imaginative and striking opera with a lot of humour. Fantastic singers and an excellent orchestra gave us a performance we will not forget.

Acoustically, the Great Hall was well made with only a few misses in the design. The background level was high. The proscenia opening do not give strong enough and scattered enough reflexes. It is this aperture setting which contributes the most of the contact between the stage’s inner parts and the salon. Now you have the effect that in certain places, the contact is good, but somewhat further in the singing voice disappears. The proscenia edges need to be much wider and shaped so that they cast the sound over all the audience.
In the foremost part of the salon, closest to the stage, the side walls are too smooth. They give directed reflexes, echoes into the salon. 

The volume has become somewhat low, but that was a budget issue. They have used the volume that is available.

The chairs are upright in the back and tiresome to sit in. The leg room is bad. Visibility is good. Ventilation is good and lasted the three hour performance with a full house. We sat at the third balcony, which should be among the warmest seats.

On the whole it is a good opera salon, with acoustics beyond the normal.

Impending move

Date: 2010-05-04

After 8 years in Bandhagen, we are moving to new, light premises at Sveavägen 151, near Sveaplan.  The new geographic location brings us closer to our customers and will be a central point of our work, near transportation links for cars and public transport.

The planning is in full swing and we expect the move to take place in early July. More info on the move and the changes it brings will shortly be sent out to our customers and suppliers.

Baltic-Nordic Acoustics Meeting in Bergen

Date: 2010-04-23

We will attend this year's Baltic-Nordic Acoustics Meeting (BNAM) the 10-12 May 2010 in Bergen, Norway. A presentation will be given by Phd. Tech. Acoustics Peter Blom from ACAD on the force generation and structure bourne sound from ventilation fans.

Learn more about BNAM at their website: www.bnam2010.com

The newspaper Stockholm City pays attention to sound

Date: 2010-03-18

In today’s Stockholm City, an article on the sound environments in Stockholm restaurants and the visitor’s experience is published. ACAD has contributed to the article through Lennart Karlén.

Lennart comments on the article thus:
” 'Let every meal be a feast' – an older friend taught me. It is an important approach to assimilate food in a pleasant and healthy way. To eat in the company of good friends is amazing, when the locale allows for social interaction. One invests a good deal of cash and time to enjoy a dinner in good company, where the conversation is an important part of the moment. How often has one not been in a restaurant and only been able to speak to those next to you or possibly across the table? What does one do then? You finish as quickly as the service makes possible to go somewhere else to be together. The locale should be a help to the business, not a hindrance.

In Sweden, the restaurateurs also have the bad habit of playing music at a loud level which drowns the small possibility of conversation. In combination with an acoustically impossible locale, the sound level from the music becomes intolerable.

As guests we have a choice to make. There are many so called high class, posh restaurants I won’t be visiting again. In others I have found some table where the acoustic is a little better and will request that when booking.

But the staff cannot choose! They have to put up with sound levels that are considered harmful to your hearing. This is particularly so for bars and night clubs where the speaker music is ridiculously high. Sound levels above 90-100 dBA regularly every night is not unusual. Some bars are decorated such that the staff is the most exposed. It is not allowed, under the Work Environment Act, to expose your staff to such high sound levels without having an action plan to reduce noise and meanwhile equip the staff with hearing protection.

Noone wants these disturbingly high sound levels so why don’t the restaurateurs listen to reason and change their style before society legislates against it. That will surely be the next process to enhance the restaurant environment for the employees after the smoking ban was introduced.

Imagine the day in the restaurant when you can hear that you are chewing on crisp bread or that your friend smacks his lips with pleasure because the food is good."

The article can be read in today’s Stockholm City and at their web http://www.city.se/, pages 18-19.

Seminar: Noise and acoustics indoors

Date: 2010-03-15

From spring 2010 and onwards, Lennart Karlén will be holding a seminar in noise for BFAB with basic acoustics for architects, municipal officials from Environment and Health services, Building services, Planning offices, technicians from the building materials industry and others.

The seminar is called "Noise and acoustics indoors" and gives a basic understanding of acoustic conditions in society, the building and the room. The demands that the National Board of Housing, Building and Planning have in mind in reference to the Construction Standards SS 25267 and SS 25268 are gone through with applied examples. Noise in the environment according to SNVBs claims are recognised as examples of the content.

Read more on the seminar here: http://www.stf.se/kurser/kurs/Buller-och-akustik-inomhus---Baskurs/

Lennart Karlén has given similar courses since 1974 to SIFU, RK, KTH A, College of Arts, Uppsala University, and other training institutes and colleges.
We offer more courses, go to http://www.acad.se/en/courses/. We would also be pleased to design a course according to your wishes and needs. Contact us for a dialogue.

Silent blowers put wind in the sails

Date: 2010-03-07

The on-going boat show ”Allt för sjön" as usual offers model boat sailing in the C-hall, this year with a plastered pool.

ACAD can as usual be seen in connection with the wind farm by the model boat pool. We have constructed the wind farm to provide a low noise level which will not disturb the exhibition visitors and will provide good sailing conditions at model scale.

Are you too in need of different solutions – perhaps impossible? We will gladly take on such challenges.

Visit the model boat pool at ”Allt för sjön”, March 6-14 at the Stockholm fair.

Acoustics course for the Architect program at LTH

Date: 2010-02-18

ACAD will during 2010 be giving a new education in acoustics for the Architect program at the Faculty of Engineering in Lund. The course is called “Acoustics as a design element” and will be given in two parts. The course members come from A2.

For a number of years, we give courses for the construction engineering education, the design education, and courses in Sound and Light at KTH in Stockholm. There, we offer training in acoustics with the basis in form, material and technology.

The Interior designers at the College of Arts are another group that we have trained in acoustics.

We also provide training for training courses and directly for companies. We design the training to suit the company’s and its co-workers’ needs. Among the ones we have trained are fan manufacturers, ventilation companies, ventilation consultants, architects and municipalities.

Please read more on our courses here at our web page: www.acad.se/se/kurser/ and let us know if you want to talk about designing a course that will suit your company.

Acoustics in Stockholm's concert halls

Date: 2010-01-22

Swedish daily newspaper “Svenska Dagbladet” has assessed the acoustics in Stockholm's concert venues. Assessment has primarily been with regard to electro-acoustic events. Two venues for concert music were commented on. One is the Berwald Hall, where it is noted that “it has been adapted acoustically for a symphonic orchestra, which means that the sound will be of poorer quality for electric.” The other venue is the Stockholm Concert Hall, probably the Great Hall, although this is not specified. Here the assessment is “Very good for acoustic, poorer for electric.”

Their assessments are interesting and probably conducted ambitiously, including many venues. Unfortunately, they provide no information on their method or which criteria they have used in their assessment. Hopefully, all eight persons named in the jury have visited all venues at the same time to ensure a proper comparison between them. If some visited certain venues and others visited others, the comparison loses in quality, as there is no clear norm against which to judge.

They also suggest that there is a conflict between acoustic music and “electric". It is correct that the Berwald Hall has been adapted to a symphonic orchestra, but in such a way that the distinctness of a microphone recording will be adequate for radio broadcasts. The acoustics in the hall for the listeners is moderately rich in tone, with preponderance toward higher frequencies. In addition, diffusivity is low, which means that it is important to choose the right location. The acoustic limitations are really no obstacle to a concert performed by an electrically amplified orchestra.

At The Stockholm Concert Hall, it is correct that The Great Hall and the entire Concert Hall are adapted to the Stockholm Philharmonic Orchestra. It is their building. It is very special and no other venue in the world is probably organised this way. Normally, the orchestra is a tenant among others of a concert hall that is used for several types of events. This means that the acoustics in the Great Hall and the Grünewald Hall are designed to provide the best possible acoustics for an orchestra composed of acoustic instruments. Here it is a question of a good balance between richness of tone, distinctness, brilliance, clarity and other audible acoustic qualities at each listener's position. Diffusivity of the sound in the concert halls is good, which makes for a soft room tone and even quality at most positions.

How then does the Great Hall work for electrically amplified instruments? It is apparent that it is difficult to master the tone of the room if the music is played at a fast tempo. One might imagine playing modern music at a fast tempo in a church. The church hall will in time mix the sound into a mush. This has nothing to do with the amplifier/loudspeaker system, but with the room. Distinctness can be improved by choosing more loudspeakers and shorter distances. It is to some extent possible to design the loudspeaker system such that the room's tone is avoided.

Loudness is no limitation if diffusivity is good. Often, when one feels that the loudspeakers are noisy, this can be due to the fact that they are positioned in such a way that strong aimed reflexes that interfere with the direct sound arise. This is the case with many concert halls, but less so at the Stockholm Concert Hall.

Their comments on Stockholm's various live venues form an interesting summary that provides a clear picture of the fact that there is much more that needs to be done in order for electro-acoustic sound to sound good.

These efforts should be made at the same time that the quality of the rooms for their purpose is improved. Then it will be possible to lower volumes so that audiences can enjoy the music without losing the sensation of intensity.

The article is available in Swedish at: http://www.svd.se/kulturnoje/nyheter/scener-som-hjalper-och-stjalper-svds-kritiker-har-betygsatt-stockholms-konsertlokaler_4120823.svd

Acoustics get media attention

Date: 2010-01-21

We have noticed that good and not so good acoustics are coming more and more to the fore in public debate. Bar staff and guests are bothered by the loud volume in restaurant settings, while it places great and costly demands on construction. It is good that these problems are brought out and aired.

The Svenska Dagbladet newspaper wrote in their Web edition of 21 January about the study that the Swedish Association of Hard of Hearing People (HRF) has conducted. The HRF is conducting a campaign whose aim is to promote conversationally-friendly environments. The “Befria samtalet" (liberate conversation) campaign is a touring campaign “against poor sound environments, for a conversationally-friendly Sweden".

The HRF writes in its press release that “two of three members of the Swedish Teachers' Union and the National Union of Teachers in Sweden consider the sound environment to be a problem every day/every week. More than half of them often/sometimes have difficulty hearing what the pupils say in the classroom. Problems are great in offices too; 57 percent find the sound environment in open plan office spaces a disturbance."

The Svenska Dagbladet newspaper recently assessed Stockholm's concert venues. Their assessments were presented in their Web edition on the evening of 20 January and in the cultural section on 21 January. We will return to this article shortly with comments.

Read the full articles in Swedish:

Disturbances in the office space: http://www.svd.se/nyheter/inrikes/varannan-stors-av-ljud-pa-jobbet_4123459.svd

Stockholm's concert venues: http://www.svd.se/kulturnoje/nyheter/scener-som-hjalper-och-stjalper-svds-kritiker-har-betygsatt-stockholms-konsertlokaler_4120823.svd

Merry Christmas and a Happy New Year

Date: 2009-12-24

We would like to take this opportunity to wish all new and old clients a very Merry Christmas and a Happy New Year.

2009 has been a very exciting and active year for us, in spite of the financial crises and warnings surrounding us. During the year, ACAD has grown by three new employees. We have been given several big, interesting assignments, and we have conducted a change in profile as we celebrate our seventh anniversary. As we leave the 00's behind us, we can look back on excellent development, and we hope to be as strong in the 10's.

New graphic profile

Date: 2009-12-01

ACAD-International has developed rapidly since we started up in December of 2002. Today's ten employees form a tight-knit team of young, clever, communicative acousticians. We strive to make our communications reflect today's company and are launching a new brand and a new graphic profile produced in conjunction with the AGoodId agency.

The change will take place gradually over the coming weeks, and we look forward to working under a new common banner.

Educational trip to Copenhagen

Date: 2009-11-17

On Friday, 20 November, ACAD will travel to Copenhagen for an educational trip. The focus will be on room acoustics and we will be visiting, among other places, Copenhagen's new concert hall and opera house.

On Friday evening, we will experience Denmark Radio's symphony orchestra performing works by Dvorak, Schumann and Hornemann. On Saturday, we will visit the opera house and take a guided tour of the halls and backstage.

We will be back at our posts on Monday, 23 November.

ACAD won the procurement of acousticians for Slussen

Date: 2009-10-16

We are pleased to announce that ACAD-International AB won the Stockholm City Development Administration Office's procurement for ACOUSTICIANS for the SLUSSEN project in Stockholm.

Tengbom wins BEX award

Date: 2009-10-16

We would like to congratulate Tengbom arkitekter, who won The Building Exchange (BEX) award last summer for “Client Commitment" for their House of Culture project in Dar es Salam, Tanzania. The facility, which houses a culture house and the national museum, was built using energy-saving, sustainable, environmentally-friendly technology, especially adapted to a tropical coastal climate.

ACAD is contributing to the project with acoustic solutions and the indoor climate, designed using natural ventilation and passive systems, which also makes for low energy consumption. The systems are characterised, among other things, by being capable of working without electricity, a commodity in short supply in Tanzania.

More on this on the following websites:
http://www.tengbomgruppen.se/home.aspx#/en-US/news/2009-06/75/
http://www.houseofculture.or.tz/
www.b-e-x.com

Henrik Anréus back with ACAD

Date: 2009-10-15

Henrik Anréus is back on our team. Henrik worked previously with ACAD during the period 2004-2007. Henrik chose to dedicate the past two years to his other great interest in acoustics, sound design.

As Lead Sound Designer at the game development company Grin, he worked creating sound and applying sound to their products. His great interest, knowledge and experience in sound design can be applied in several industries, such as game development, Web production, product profiling, post-production of advertising and films, etc.

Now we look forward to working together with Henrik again and also being able to benefit from his added expertise and experience.

The fall with ACAD

Date: 2009-08-10

We are now back from holidays after an eventful summer. We look forward to a fall full of exciting projects and new challenges. Please contact us for a dialogue concerning your own points of interest.

You can find our contact information to our employees here: www.acad.se/en/home/employees/

Summer hours

Date: 2009-07-06

During weeks 28-32 of the summer, we will have reduced staffing. The office will be closed during weeks 29-31. During these weeks, monitoring of telephones and e-mail will be less frequent than usual.

Have a good summer!

Marabou park art exhibition hall, breaking ground

Date: 2009-06-17

Yesterday, TV-news covered the first- shovel ceremony breaking ground in construction of the new art exhibition hall in Marabou Park in Sundbyberg, one of our projects.

Both the Swedish major daily newspapers SvD and DN feature articles today describing the project, with the exhibition hall situated under the park. A high, vaulted ceiling with generous natural light from the park side ensures that the facilities are fresh and airy. ACAD creates the acoustic quality in the art exhibition hall and in entrance/restaurant that are added onto the existing building above ground. This project is a collaboration with the architect offices of WGH Arkitektkontor.

Read more about the project here: www.acad.se/en/home/projects/09132-1/

Visit the Marabou park art exhibition web site: http://www.marabouparken.se/?lang=eng&year=&nav=aktuellt

Generation of forces and vibrations by fans

Date: 2009-04-20

In the April issue of the Swedish construction and technology periodical  "Bygg och Teknik", Tobias Ahlgren (KTH) and Peter Blom (ACAD) presented results from their study on disturbances caused by vibrating fans in their article: "Fläktars kraft- och vibrationsalstring" (Generation of forces and vibrations by fans). The aim was to achieve better precision when dimensioning sound insulation.

The article is available on our website: http://www.acad.se/en/home/articles/generation_of_forces_and_vibrations_by_fans/

Study visit to Vienna - Theme: Room acoustics

Date: 2009-04-02

ACAD travels to Vienna for a study visit April 3-5. The theme is room acoustics and we will also visit concert halls and the city opera during the weekend.

This means that we have limited time for project- related inquiries on Friday. On Monday April 6 we are back and business is as usual.

ACAD is growing

Date: 2009-03-17

ACAD is growing, despite a clear downtrend among many other technology consultants. We can only conclude that the market is demanding acoustics-consultant services with simple and sure-fire solutions created on the basis of sound theoretical understanding. Our extensive experience and high level of training across the board permits flexible and creative project solutions with no concessions on quality. We coordinate projects into complete solutions with the help of feedback and dialog.

Joel Johansson recently joined ACAD and has already earned his stripes during an earlier summer internship. We have recruited yet another rising star and are happy to welcome Henrik Per who also hails from MWL at the Royal Institute of Technology in Stockholm. Henrik will start in April and we're  looking forward to getting to know him.

Precedent- creating decision about 25 dB(A) from nightspot

Date: 2009-02-07

For the first time, a precedent has been created stating that the sound level from i.e. a nightclub may not exceed 25 dB in surrounding residential spaces.

The Supreme Environmental Court has denied an appeal by the establishment "Wallins salonger" in Halmstad after the environmental court ruled that the music may not exceed 25 dB within the apartment of a female tenant in the same building.

The case has been pursued by the Swedish Union of Tenants, as reported by the union's Internet magazine Hem & Hyra (Home & Rent).

A remarkable detail in the case is that "Wallins salonger" has since May 2006 been open for business in an ex- Baptist church. The woman lives in an apartment at the top of a turret- like structure. The noise is at its loudest during the pre- Christmas holiday buffets in November and December and during so-called pay-day weekends.

Initially, "Wallins salonger" received approval from the local health and environmental authorities to play music at a sound level up to 30 dB. A female tenant appealed the decision to the County Administrative Court in Hallands County, which lowered the level by five decibels. "Wallins salonger", in turn, appealed the decision to the Environmental Court and later the Supreme Environmental Court.

The National Board of Health and Welfare has lowered its recommendation from 30 to 25 decibels for disturbances from music, which has been a guide for the courts.

From the daily newspaper DN

ACAD:s nightclub sound-insulation raises eyebrows

Date: 2009-02-02

Recently, Lennart Karlén participated in an interview published in the latest issue of local community papers in Stockholm. The article covers our work with restaurants and night clubs adjacent to living spaces and particularly, the successful facilities we created together with Ahrbom & Partner architects, where the Restaurant "Imperiet" is located.

Local community reporter Emelie Molinder met with Lennart Karlén and Niklas Ahlbom who run the Restaurant "Imperiet" and talked about how restaurants and night-clubs can coexist with living quarters in an urban environment, providing the space is built/adapted thereafter. The earlier in the project we can present our viewpoints, the better.

New employee at ACAD

Date: 2008-12-23

Early next year Joel Johansson will join our forces here at ACAD. Joel is just now finishing his masters degree at MWL KTH and will focus on industrial needs in the field of sound and vibrations.

ACAD is keeping it's pace and has expanded from two employees in 2003 to eight in 2008, of which two has a doctors degree. We plan to continue our expansion by employing one or two persons per year, given we find the right people. That pace seems to be just right to be able to maintain and assure the knowledge and quality in our work.

ACAD strives to be the best educated and most knowledgeable acoustic consultancy in the Nordic countries. Our work is rational and focused. That combined with our high competence and thorough experience enables us to find solutions that are rational and cost effective to our principals.

Kulturhuset is being redesigned

Date: 2008-11-20

Swedish daily newspaper Svenska Dagbladet had recently an article about the redesign of the entrance level at Kulturhuset in Stockholm, a project we are working on with architects Ahrbom & Partner. As acousticians in the project it is nice to see that the redesign i progress already attracts the attention of the media. 

Read the article at Svenska Dagbladet web edition (Swedish only): www.svd.se/kulturnoje/nyheter/artikel_2011485.svd
Our project description: www.acad.se/en/home/projects/08287-1

Master thesis at ACAD

Date: 2008-09-29

During autumn Tobias Ahlgren is working with us on his master thesis for The Royal Institute of Technology in Stockholm, where he is studying electrical engineering with a specialization towards medical applications and sound and vibrations.

The purpose of the master thesis is to experimentally investigate and theoretically model the vibration generating mechanisms of ventilation fans. In order to predict the magnitude of those vibrations a connection between the fan unit’s specifications and the vibrations introduced in to the structure is ultimately sought after.

The research is being performed in ACAD’s laboratories in cooperation with The Marcus Wallenberg laboratory (MWL) at KTH. Supervisor at ACAD is Ph.D. Tech. Acoustics Peter Blom, and at KTH, Associate Professor Leping Feng.

The project is expected to be finished at the turn of the year.

Noise from sport activities

Date: 2008-09-11

Local newspapers has recently printed a series of articles about how residents in apartment buildings close to sports grounds like soccer fields in the vicinity of Stockholm finds the noise from the sport activities to be a nuisance. The sport grounds are many times right next to the apartment buildings. Artificial turf allows for a high rate of use and that combination yields equivalent noise levels that are thought to be high.

We are mapping the noise problems and measures noise levels over a period in time during sports activities. See our project http://www.acad.se/en/home/projects/08204-1/

BNAM2008

Date: 2008-08-29

We are now back in full force after the conference BNAM2008 in Iceland. The conference hosted many interesting presentations and views. The main focus was on room acoustics and concert halls. During the conference we went on an excursion to the famous Blue Lagoon and after swimming in the hot spring we had the conference dinner in the Blue Lagoon Restaurant built partly sunk into the lava field, over all a very pleasant evening.

Now that we are all back we look forward to new challenges this fall.

Stockholm Concert Hall reconstruction

Date: 2008-08-05

The reconstruction of Stockholm Concert Hall is nearing its end for the Main Hall and the Grünewald Hall. The reconstruction main concern is working environment, indoors climate and energy consumption. A new ventilation system with heat exchanger and humidity controlled instrument storage rooms is being installed. While rebuilding we make some changes to improve the room acoustics by changing some surfaces and their properties. Among many other things the stages in both the Main Hall and the Grünewald Hall are being remodelled. Later this year the acoustics in the Aulin Hall will be overhauled.

Last summer a reflecting/diffuse surface was added to the ceiling in the Main Hall and the chairs were complemented to reduce their impact on the room dampening. These changes lead to audible improvements throughout the hall.

We look forward to the reopening of the Main Hall on the 25th of August where both the room acoustics and the indoor climate for the orchestra has been improved.

New Employee

Date: 2008-07-07

We welcome Martin Fraggstedt who joins us after the summer vacation. Martin has recently become a Ph. D. in Technical Acoustics at KTH, Stockholm. His thorough knowledge further increases our analytical capabilities in solving difficult and complex acoustical problems. We find this very stimulating and welcome him gladly!

Opening hours during the holidays

Date: 2008-06-30

During the summer weeks 29, 30 and 31 ACAD will close down the office for holidays. You can reach with us via e-mail, mobile phone or voice mail. 

Summer trainées at ACAD

Date: 2008-06-01

During the summer months ACAD increases the workforce by two trainees. Joakim Dahlborn and Joel Johansson both study sound and vibrations at the Royal Institute of Technology in Stockholm. They will mainly assist in projects such as sound measurements, traffic noise calculations and room acoustic calculations in Odeon.

BNAM2008 in August

Date: 2008-05-20

ACAD will be visiting Joint Baltic-Nordic Acoustics Meeting - BNAM2008 in Reykjavik in August. Some of our employees are preparing papers to be presented during the conference. We look forward to visit Iceland after the vacation.

Read more about BNAM2008 at their website: http://www2.vfi.is/events/BNAM-2008/

New recommendations from The National Board of Housing

Date: 2008-04-14

The National Board of Housing, Building and Planning – Boverket – is the central government authority for planning of the management of land and water resources, urban development, building and housing under the Agency.

For the first time The National Board of Housing, Building and Planning publish an advice about planning new houses exposed to traffic noise.

The advice is not legally compulsory and the purpose is to give guidance how to act in different situations when planning new houses exposed to traffic noise.

The new advice “Allmänna råd 2008:1 Buller i Planeringen“ is valid since the 1st of March 2008 and can be downloaded for free in Swedish at www.boverket.se

Article in Swedish magazine

Date: 2008-04-09

ACAD-International AB's partner Lennart Karlén is the author of an article in the April-issue of the Swedish magazine “Bygg och Teknik”. The article is about acoustics in restaurants and is available for download in Swedish here at our website.

ACAD back from Annecy, France

Date: 2008-03-17

We are now back in Stockholm after having spent a few days in Annecy, France. Annecy is a small town located next to the alps and about an hours drive from the ski-resort Chamonix. We got to soak up some French sun and do a couple of excursions while we where there.

ACAD.se In English

Date: 2008-02-08

Welcome to the English version of ACAD.se.

All content on the Swedish website, with a few exceptions, have been made available in English. With the English version we hope to reach out to our English speaking visitors which have been overlooked until now. There is a lot of nourishing information on acoustics here, make good use of it and raise the level of knowledge and the acoustic quality in your building project.

Articles will only be available in the language they were originally written in. Switch between English and Swedish using the link in the top right corner of the page.

Room acoustic modelling

Date: 2008-02-01

We are starting to get a grip on the possibilities provided by our new room acoustics software Odeon from Bruel & Kjaer.

A snippet from Bruel & Kjaer’s website gives an overview of the program:

“ODEON software simulates the acoustics of buildings. From the geometry and properties of surfaces, the acoustics can be calculated, illustrated and heard.

ODEON's prediction algorithms (image source method and ray tracing) allow reliable predictions at modest calculation times. ODEON is ideal for prediction of acoustics in large rooms such as concert halls, opera halls, auditoria, foyers, underground stations, airport terminals and industrial workrooms. For prediction of noise from large machinery in industrial environments, a special ray-tracing algorithm has been developed allowing modelling of surface and line sources.

ODEON can be used to predict the acoustics of new buildings, as well as to evaluate and recommend improvements in existing buildings. It is straightforward to use and takes care of the bookkeeping involved in stepwise improvement of models.”

Read more on Odeon at B&K: http://www.bksv.com/2154.asp

ACAD augments its inventory of instruments

Date: 2008-01-07

We took delivery of new measuring equipment from Bruel & Kjaer at the New Year. We are augmenting our inventory of instruments with a PULSE model multi-channel system, which enables us to measure and analyse eight channels simultaneously. This entails a more rational working method in some assignments and the possibility for us to take on more assignments where corresponding equipment is required, for example the measurement and analysis of full-body vibrations, machine vibrations and framework sounds.

We also took the opportunity to invest in a new PC-based analysis tool for room acoustics from the same supplier. Odeon is a powerful tool for simulating room acoustics based on a CAD model in 3D, where geometry and the materials of surfaces and their properties are variables. The room’s acoustic properties can be calculated, illustrated and heard in the program. Odeon was developed by DTU, the Technical University of Denmark and uses two algorithms in its image source and ray tracing calculations. There is more information on Odeon on Bruel & Kjaer's website, www.bksv.com.

Swedish Acoustical Society online

Date: 2008-01-01

The Swedish Acoustical Society (SAS) has created a website for persons interested in acoustics and their applications. The annual general meeting will be held on 12 March in Gothenburg. The time and venue will be posted on www.akustiska-sallskapet.org

Manning during the holidays

Date: 2007-12-23

Merry Christmas and a Happy New Year to all of you from all of us at ACAD. We thank you for a year full of exciting projects and many satisfying collaborations and we look forward to more in the year to come.

We would also like to inform you that the office will be unmanned for the most part during the holidays. We can be reached by telephone, so we can turn out as necessary. Otherwise we will be at full speed again 7 January, 2008.

Kind regards // Lennart, Anders, Daniel, Fredrik, Peter and Sanna.

ACAD launches new website

Date: 2007-12-18

Welcome to our new website.

We have made our move and created a completely new website. Our plan is to supply the visitor with the information desired in a structured and easily navigable way. The content is divided and categorised according to work area in order to enable faster navigation. We aim to be clearer, better and faster with regard to updates and the flow of information via the website.

We have chosen to publish several of our co-workers’ articles on the website and more will be posted in time. Articles are only available in the language they were originally written in.

We will publish a small sample of our projects either as current projects or reference projects, as this is often requested by orderers.

In our news, we will publish information concerning the company and/or acoustics in the industry or in society.

The site will be bilingual very soon, accommodating our English-speaking orderers. There are more additions ahead, so keep an eye on www.acad.se.

We recommend the latest version of Internet Explorer or Mozilla Firefox with a resolution of at least 1024x768 pixels and ClearType fonts.

Go-ahead for the Concert Hall

Date: 2007-10-31

It was decided today that Stockholm’s Concert Hall will receive the funding from the Stockholm Country Council enabling the planned refurbishment of the concert hall. For us, this means continued work on one of Stockholm’s signature buildings and a part of Swedish 20th century history.

It remains to be seen whether the building permit for the annexe building over the garage downramp is approved and how that proposal is formulated.

More on this in Swedish at DN.se: www.dn.se/DNet/jsp/polopoly.jsp?d=1298&a=711076