Jeg fikk faktura, jeg har betalt, og varene er på vei! Nå er det bare å glede seg til tull med toll og den lange veien fra Gardermoen til Ski.
I got the invoice, I payed, and the package is on its way! I hope the norwegian customs doesn't delay the delivery much.
Viser resultater 21 til 40 av 52
03-12-2010, 23:24 #21
03-22-2010, 19:47 #22
Jeg fikk bagene, og de ser flotte ut. Nå er spørsmålet hva jeg skal putte i dem. Er det sånn som er anbefalt? http://guiden.rockwool.no/media/2143...stikkplate.pdf
Eller andre forslag? Hvor får jeg helst kjøpt slikt?
03-22-2010, 20:29 #23
Jeg vil tippe at Akustikkplater er et ganske trygt sted å begynne. Du må antagelig bestille de i byggesjappa. Hvis butikken må få de tilsendt såpesielt så koster det 1000,- ekstra i transport, men hvis butikken kan få de på neste lass fra Rockwool så slipper du antagelig transportkostnader. En pakke med 6 stk. 50 mm plater koster ca. 600,-.
Ellers driver mor10 her på forumet et firma som selger Akustikkplater men da må du hente de selv. Jeg så også nevnt her et sted at Dynabel selger Glava sine utgaver at akustikkplater.
03-22-2010, 20:42 #24
Takker! Jeg får begynne med å høre med min lokale planke-pusher. :-)
03-22-2010, 23:09 #25
Prøv Rockwool markplater. Er tyngre og har mer "densitet" enn akustikkplater og demper bedre i lavere frekvenser. Har det selv, funker supert
03-23-2010, 08:12 #26
03-24-2010, 00:26 #27
Har du mulighet til å legge ut et par bilder av disse posene? Og hva kom 6 stk på inkludert alt til deg?
03-29-2010, 13:43 #28Opprinnelig postet av b-ill
Akkurat nå holder jeg på med en masse ting fordi det ¤%¤#&%(/&%# rommet ikke liker større bølgelengder, og de blir stående i lytteposisjon (bølgene altså). Skal poste erfaringer med dempingen etter hvert. Bilder av posene også.
03-29-2010, 18:00 #29Opprinnelig postet av hjalmarjalla
Et annet poeng er at et materiale med veldig høy tetthet vil delvis reflektere frekvenser over bassen.
Man må kjøpe materiale etter hva man skal gjøre. Er planen å dempe føsterefleksjonene, så bør man dempe hele veien opp. Og da er rockwool akustikkplatene glimrende egnet med en tetthet på 60kg/m3. Bruker man 10 cm (og gjør helst det!) vil de også dempe noe i bassen.
Akustikkplate :: Byggisolering :: Produkter :: AS Rockwool
03-29-2010, 19:00 #30
Jeg skal bruke 5cm tykke lydplater til å dempe førsterefleksjoner.
Vet ikke helt hva jeg skal gjøre med bassen ennå. Kan bli omfattende. Jeg har tenkt på å flytte frontveggen 50cm ut og dempe der. Vet ikke helt ennå.
03-29-2010, 22:37 #31Opprinnelig postet av orso
http://avforum.no/forum/1231150-post32.html, og som er hentet fra flere fora og hjemmesider til firma som driver med akustiske tiltak. Noe av poenget med høyere massetetthet/densitet er at man ikke nødvendigvis trenger like tykke/store absorbenter for å oppnå bra resultat. Men det er helt rett som du sier at det kommer an på hva man ønsker å oppnå. Forøvrig tror jeg ikke det er fare for at markplater vil reflektere frekvenser over bassen, men at de ikke nødvendigvis demper like mye i de aller høyeste frekvensene som f.eks akustikkplater er nok tilfelle. Så etter min oppfatning vil markplater fungere bedre dersom man har problemer med lave frekvenser i et rom, men gjelder det høye frekvenser så er ikke dette nødvendigvis mest effektivt:
"My own tests in a certified acoustics lab confirm this, showing denser types of rigid fiberglass absorb as much as 40 percent more than less dense types at 125 Hz and below. More recently I performed THIS series of measurements in my company's test lab, which shows the relationship between density and low frequency performance even more conclusively....
...However, it is important to understand that a material's density is but one contributor to its effectiveness as an absorber. Obviously, if the density is made too high the material will reflect more than it absorbs, so it's a mistake to conclude that higher densities are always better...."
Forøvrig så har Grumle testet både akustikkplater og markplater i sin byggetråd og beskrevet sin opplevelse av dette i forbindelse med demping/bassfelle her: http://avforum.no/forum/av-rom-konst...ml#post1402582
03-31-2010, 18:35 #32Opprinnelig postet av hjalmarjalla
May I ask where this quote was taken from? Because there is no 3rd Party, independent acoustical testing that proves higher density glasswool is better at absorbing lower frequencies. In fact, there are many tests that show that the lower the frequencies to be absorbed, the "thicker" and less-dense the absorptive materials should be - (glasswool specifically)
You can see Owens Corning's own test data here:
03-31-2010, 18:54 #33Opprinnelig postet av Ready Acoustics
Acoustic Treatment and Design for Recording Studios and Listening Rooms
Ethan is probably right when it comes to smaller sizes (up to 6"?) and of course up to a certain density. But hjalmarjalla was making a general statement that higher density absorbs bass better which I know from reading is incorrect. It depends on the thickness.
I've yet to see any calculator on this though. Bobgolds' page doesn't give any answers when it comes to anything over 6". I'd love to see more data on different thicknesses and how they absorb low frequencies. I'm in the process of making triangular superchunk basstraps that are 60*60 (on sides) and I choose rock wool material that has a density of 30 kg/m3. But perhaps even lower density would have been better for that thickness?
03-31-2010, 19:18 #34Opprinnelig postet av orso
Hmmm, that is unfortunate. I can't imagine testing my own materials and telling people they perform better than "x", especially if I benefit from whatever information I've decided to published. It is better accepted by the acoustical sciences community (and consumers) when "tests" are performed by an independent, "3rd Party" and without interference or potential embellishments by the party that benefits monetarily by such tests.
That's how I see it anyway.
Acoustic scientists have performed a multitude of testing in real reverb chambers and have concluded that lower density materials are better for low frequency absorption, specifically when the thickness increases in glasswool.
For SuperChunk style corner applications, I've seen the recommendation is usually 45 kg/m3, however I'd love to hear your results with 30 kg/m3.
(specifically when using rockwool) The recommendation for 45 kg/m3 materials may be due to availability of these materials in a specific region however.
03-31-2010, 22:32 #35
03-31-2010, 22:55 #36Opprinnelig postet av pnerbye
Acoustics Forum • View topic - Studiotips SuperChunk
To threat very low frequencies you need either Helmholtz resonators or panel resonators. Something like this:
RPG Diffusor Systems
RPG Diffusor Systems
Modex Corner which is a tuned basstrap cost 2500 kr. Modex Plate which absorbs in a broader range (500-50/35Hz) are more expensive. A tuned Helmholtz resonator shouldn't be too hard to build, but I'm not sure how. It's seldom enough with one. So they take up space which could have been used for broadband basstraps. The bass around 80-120Hz is really more important to treat.
03-31-2010, 23:08 #37Opprinnelig postet av Ready Acoustics
"For a given thickness, 703 is about twice as absorbent as acoustic foam at the lower frequencies, and it generally costs much less. Even better for low frequencies is 705-FRK, which is much more absorbent than 703 at 125 Hz and below. FRK stands for Foil Reinforced Kraft paper. This is similar to the paper that grocery bags are made of, but with a thin layer of metal foil bonded to one side. The FRK paper was not intended for acoustic purposes, but to serve as a vapor barrier in homes. It just happens to be good acoustically too. Be aware that the paper reflects mid and high frequencies when installed with that side facing the room; this may or may not be desirable for a given application. 705 is also available without a paper backing. Top
Although 703 and 705 fiberglass panels are more effective than foam of the same thickness, they are usually covered with fabric for appearance, and to prevent the glass fibers from escaping into the air. This adds to the expense and difficulty of building and installing them. (In practice, fiberglass particles are not likely to escape into the air unless the material is disturbed.) A comparison of 703, 705-FRK with the reflective paper exposed, and typical foam is shown in Table 1 below. Note that foam panels sold as acoustic treatment are often sculpted for appearance, and to better absorb sound arriving at an angle. Removing some of the material reduces foam's effectiveness at low frequencies. If rigid fiberglass was compared to solid foam panels of the same thickness, the disparity in low frequency performance would likely be less. However, not having a sculpted surface would then reduce foam's absorption at higher frequencies.
125 Hz 250 Hz 500 Hz 1000 Hz 2000 Hz 4000 Hz
Owens-Corning 703 0.17 0.86 1.14 1.07 1.02 0.98 1.00
Owens-Corning 705-FRK 0.60 0.50 0.63 0.82 0.45 0.34 0.60
Typical sculpted acoustic foam 0.11 0.30 0.91 1.05 0.99 1.00 0.80
Table 1: Absorption coefficients of 703, 705-FRK, and a popular brand of sculpted acoustic foam at different frequencies. All material is two inches thick and applied directly to a wall. This data was obtained from the respective manufacturer's published literature.
It's not difficult to understand why 705 fiberglass is so much more absorbent than typical sculpted foam at low frequencies. Besides the fact that sculpted foam has about half the mass of solid foam due to material being removed to create the irregular surface, another consideration is density. According to test data published by several manufacturers of rigid fiberglass and rock wool, the denser types absorb more at low frequencies. The data published by Johns-Manville for their line of rigid fiberglass shown below is one example. Acoustic foam has a density of less than 2 pounds per cubic foot (pcf) compared to 705 fiberglass which has a density of 6 pcf.
My own tests in a certified acoustics lab confirm this, showing denser types of rigid fiberglass absorb as much as 40 percent more than less dense types at 125 Hz and below. More recently I performed THIS series of measurements in my company's test lab, which shows the relationship between density and low frequency performance even more conclusively. Regardless of the reason, there is no disputing that for a given panel size and thickness, 705-FRK is substantially more effective at low frequencies than the same thickness of typical acoustic foam. However, it is important to understand that a material's density is but one contributor to its effectiveness as an absorber. Obviously, if the density is made too high the material will reflect more than it absorbs, so it's a mistake to conclude that higher densities are always better. For this reason, test data must be the final arbiter of a product's effectiveness."
Acoustic Treatment and Design for Recording Studios and Listening Rooms
Rigid fiberglass density tests
04-02-2010, 17:44 #38
I've been playing around with the excel sheet found here. By changing the thickness, density and placement of the absorbing material, you will find how the absorbsion of different frequencies changes.
In the spreadsheet the density is adjusted in the "Absorber flow resisitivity"-cell measured in "rayls/m". The Owens Corning 703 has a "rayls" of about 23600, Rockwool Akustikkplate 50 mm is about equal til the 703, maybe a bit higher. Regular rockwool og glasswool insulation is about 5000 rayls/m.
More information here Isolasjonstetthet, amerikanske vs norske utgaver
08-06-2010, 21:05 #39
It took some time, but I had better things to do this summer! :-) The bags are now on the wall and they look really nice. I suspect I need some more treatment to the room, but the bags I have now is definitely an improvement. I will post my experiences after some listening.
08-06-2010, 23:29 #40