carvahull Posted March 13, 2007 Posted March 13, 2007 I have been looking high and low for affordable and effective broadband acoustic treatment, and came across many websites stating that rockwool/fibreglass like Owens Corning 703 and 705 are the best like Ethan Winers' http://www.ethanwiner.com/density/density.html. Locally, I found http://www.bestofire.com.sg/ who supply rockwool acoustic boards manufactured in Malaysia for sound insulation with the following specs: Type: Rockwool, bare boards (no covers). Area: 600mm X 1200mm Thickness: 25, 50 (in stock), 100 or 150mm (the rest must order) Density: 40kg/m3, 60 kg/m3, and up to 150 kg/m3. Pricing: according to thickness and density. for example, 50mm thickness with density 40kg/m3) cost $13.00. same thickness with higher density 60 kg/m3) costs $18.00 per piece. Minimum purchase quantity: 6pcs (1pack) Since they are bare, they need to be wrapped up cause the fibres are exposed and can cause problems. Corning 703 and 705: Area: 24" X 48" (609mm X 1219mm) Thickness: 2" (51mm), 4" (102mm) Density: 703 is 3 lbs per cubic feet (45 kg/m3) , 705 is 6lbs per cubic feet (70 kg/m3?) Bestfire salesgirl couldn't confirm if they have 703/705, but were pushing for the rockwool instead. Only problem left is a proper cloth to cover the board, which I only managed to find http://www.readyacoustics.com. Any comments? I'm thinking of ordering the readybags and the rockwool boards and then DIY everything myself. oh yes, even this is not enough. The boards only seem to effectively smooth out freq > 100 Hz. Below that, bass traps apparently are still needed to kill off the standing waves with freq < 100 Hz.
Ready Acoustics Posted May 24, 2007 Posted May 24, 2007 Hey there, I think you'll be able to make a huge difference in your room if you can find the right absorption materials locally. Rockwool (6-8 pcf) or OC703 are the way to go. Don't for a second waste your time or money on 705 as this will diminish your ability to absorb lower frequencies in the same effective way that Rock Wool or 703 can. With regard to density reports, the only one you really need to pay attention to are those where the site you are on is not selling something. I prefer Bob Golds coefficient page as this is one of the only ones to re-publish data taken DIRECTLY from the manufacturer's website, and where the tests were derived from measurements in an acoustical laboratory. http://www.bobgolds.com/AbsorptionCoefficients.htm Density reports and subsequent absorption curves derived from tests in a spare bedroom will not give you an accurate description of how the acoustic medium works. Some of the information reported from small rooms can be used as a "guide", but in NO way replace real absorption data from an accredited lab. Know that all you really need to treat your room is a good acoustical medium such as 703 or rockwool, and some fabric to wrap it in. I say; grab up some fabric that you personally like. Visit some fabric stores locally and see what they have. If you notice even a small amount of resistence when blowing through the fabric, it will likely contain fibers from the medium and allow sound waves (at all frequencies/ broadband) to penetrate the acoustical insulation. Our Ready Bags are great, and people buy them buy the dozen (or hundred), but you do not need them to treat your room, and you can save even more money by doing everything yourself. It is certainly more hassle, but it can be done. Here is a video tutorial I created on how to build your own bass traps using locally sourced materials: The bass trap design was put together by the folks at StudioTips some years ago, and I compiled it into video. I hope this helps. Cheers, Joel DuBay www.readyacoustics.com
wolverex Posted May 24, 2007 Posted May 24, 2007 Hey there, real nice of Ready Acoustics to drop by and give us a hand. ;D Anyway i am about to embark on my own room acoustics treatment project too.. I was wondering about the fabrics used to wrap the Rockwool, you'd want sound to penetrate it or at least absorb it right? So a thin rough fabric should be ideal ? if my physics serves me right haha. Another thing is i have a couple of oil paintings in my room, i think they'd make good reflectors which is a bad sign. Any ideas on how to reduce this without removing them? should i place absorbers behind them? Finally about low frequencies, do i have to deal with them separately? should bass traps in the corners of my room suffice? thanks a lot
Ready Acoustics Posted May 24, 2007 Posted May 24, 2007 Hey there, real nice of Ready Acoustics to drop by and give us a hand. ;D Anyway i am about to embark on my own room acoustics treatment project too.. I was wondering about the fabrics used to wrap the Rockwool, you'd want sound to penetrate it or at least absorb it right? So a thin rough fabric should be ideal ? if my physics serves me right haha. Another thing is i have a couple of oil paintings in my room, i think they'd make good reflectors which is a bad sign. Any ideas on how to reduce this without removing them? should i place absorbers behind them? Finally about low frequencies, do i have to deal with them separately? should bass traps in the corners of my room suffice? thanks a lot Hey there, Frankly speaking, many people over-treat their rooms, and do so because some manufacturer told them that they "can never have enough". I think using a broadband approach to treatment is key for smaller rooms. If the absorption material you use is 4"-6" and a medium density as described above and in the tutorial, you'll be well on your way to a better sounding room. In terms of fabric, use something you like and that offers moderate resisitence when blowing through it. (lips against one layer of the fabric) Treat vertical corners first (floor to ceiling if possible) with 4" acoustical medium. If you have a ceiling height less than 8ft, consider using 6" of acoustical medium and perhaps a nested panel approach like the one shown here: We offer brackets that makes this easy, but the concept works whether you use our brackets on not. Our DIY products are work savers, not voodoo... and they don’t cost an arm and a leg. Cheers, Joel DuBay www.readyacoustic.com
deepakvali Posted May 25, 2007 Posted May 25, 2007 can we use these material to stuff up the "L-Boxes" where we have Downlights or even in the False ceilings? Will these method work??
Ready Acoustics Posted May 25, 2007 Posted May 25, 2007 can we use these material to stuff up the "L-Boxes" where we have Downlights or even in the False ceilings? Will these method work?? Yes. However, to know exactly what you mean, can you post some pics of the area you mean? Cheers, Joel DuBay www.readyacoustics.com
sdds Posted May 25, 2007 Posted May 25, 2007 hi wolverex ,i also interested to do a diy bass trap ,count me in if u r doing yr bass trap thks.
wolverex Posted May 27, 2007 Posted May 27, 2007 hi wolverex ,i also interested to do a diy bass trap ,count me in if u r doing yr bass trap thks. i'd be glad to help and post pics of my work when i actually get started but i don't foresee that to be very soon. still doing my research and reading up. By the way where in Singapore can we find a supplier/shop who will be willing to cut to size wood to create the frame for the rockwool? Do you think if art friend would provide such services? from what i know a lot of suppliers are unwilling to do small scale jobs like this and DIY shops here don't do such things.
wolverex Posted May 27, 2007 Posted May 27, 2007 Also i believe most of us here are building panels that not only serve their purpose well but are aesthetically pleasing. We could share our ideas on how to build beautiful panels. For me i'm keen on wrapping the rockwool in fabric to eventually look like paintings/drawings/prints. i thought maybe i could print on the fabric / draw with fabric markers / paint (but very unlikely cos i suck at painting) Another option would be to put panels that are spaced out with gaps on top of the wrapped rockwool so that it eventually looks a bit like oriental window blinds. I thought this may serve a dual purpose of diffusing the sound and at the same time absorb. I'm not sure if this theory is practical. But i do imagine them to look really good if done tastefully. anyone else with ideas?
synthesis1624705793 Posted May 27, 2007 Posted May 27, 2007 .. By the way where in Singapore can we find a supplier/shop who will be willing to cut to size wood to create the frame for the rockwool? ... You can always ask a frame shop to do. ;) You also can consider Ecophon panel. http://www.db.com.sg/ceiling/ceiling.htm
Ready Acoustics Posted May 27, 2007 Posted May 27, 2007 The wood for my tutorial can be cut by hand. And, you can use whatever wood you like just so long as it is 2x2 inches or around there. You can even use 1x3 or something like that. It does not need to be precise. If you build this bass trap (tutorial), you will be amazed at how easy it is, and how cost effective it is too. Any place with wood pieces should be able to cut it for you, no problem. They might even nail it together for you. I hope this helps? ~ Joel www.readyacoustics.com DIY Acoustic Treatment Pros
wolverex Posted May 28, 2007 Posted May 28, 2007 You can always ask a frame shop to do. ;) You also can consider Ecophon panel. http://www.db.com.sg/ceiling/ceiling.htm thanks ok. Think i'll check out art friend cos i know they have ready made pieces like this, i'll just cut them and nail them myself. By the way is that a Dynaudio speaker in your avatar? Excited to make these because i think my room will look really neat after i'm done.
wolverex Posted May 28, 2007 Posted May 28, 2007 The wood for my tutorial can be cut by hand. And, you can use whatever wood you like just so long as it is 2x2 inches or around there. You can even use 1x3 or something like that. It does not need to be precise. If you build this bass trap (tutorial), you will be amazed at how easy it is, and how cost effective it is too. Any place with wood pieces should be able to cut it for you, no problem. They might even nail it together for you. I hope this helps? ~ Joel www.readyacoustics.com DIY Acoustic Treatment Pros Your guide has helped a lot, especially the video tutoria., c'mon with the video tutorial even a dumbass can build a uber bass trap now.
Ready Acoustics Posted May 28, 2007 Posted May 28, 2007 Your guide has helped a lot, especially the video tutoria., c'mon with the video tutorial even a dumbass can build a uber bass trap now. That is exactly what I am hoping to accomplish: make is easy to do, and let the results speak for themself. The finished bass trap (acoustic panel) in my tutorial will absorb well into the sub bass architecture, and absorb a bit of early reflections so it can be used everywhere in a room. If anyone needs placement advice, just post some photos of your room, and I will let you know where to put your bass traps/ acoustic panels. Please also remember that when making this DIY bass trap, it is important to use a fabric YOU like and that appeals to you. perhaps we can ask for this tutorial to become a "sticky" in this forum? Cheers! ~ Joel DuBay Acoustics Frames @ www.readyacoustics.com
wolverex Posted May 28, 2007 Posted May 28, 2007 Ok here's my room: (i'm sorry i'm not good with taking photos and the room's too small ) Rough sketch to show the layout done in Paint: Photographs of my room This is a view of the entrance from inside the room. This corridor is quite narrow and a perfect hallway for reflections (a nightmare for me) This is the view upon entering the room. You are looking at the designated Hi-Fi area! A snapshot of the toilet. Quite insignificant to the topic. This is a view of the bed and oil painting. You can see my desk and my computer at the right of the picture. A window is also visible. This shows the Glass window looking INTO my bathroom. This thing reflects sound as much as it does my silhouette (Hey that's me) Designated Hi-Fi area is TIGHT with one side bordered by the wardrobe and the other side extending into the narrow entrance. Finally this shot shows the desks and windows. 1 of the blinds has been lowered to show how it looks like. It's rough and a bit fluffy on the other end. i would give it a 3/10 in terms of noise absorption. Thanks for reading hopefully you guys could give your 2cents worth on where i could place the panels.
wolverex Posted May 28, 2007 Posted May 28, 2007 oh ya in case you're wondering, i have yet to get my components, i just sold most of my old stuff and planning to upgrade, hence the seriousness about room acoustics and all..
synthesis1624705793 Posted May 28, 2007 Posted May 28, 2007 ... By the way is that a Dynaudio speaker in your avatar? ... No, it's not Dynaudio. ;) It's my DIY speaker with Scanspeak midbass driver and tweeter.
Genesis Posted May 28, 2007 Posted May 28, 2007 That is exactly what I am hoping to accomplish: make is easy to do, and let the results speak for themself. The finished bass trap (acoustic panel) in my tutorial will absorb well into the sub bass architecture, and absorb a bit of early reflections so it can be used everywhere in a room. Joel, I think it's great that you're providing advice on a topic that's tricky to implement and essentiall for proper sound. However, from what you've said above, how would a bass trap absorb early reflections? There's no such thing AFAIK since early reflections do not occur in low frequencies with long wavelengths. Upwards of 1000hz and higher yes, but please explain about the lower frequencies. If anyone needs placement advice, just post some photos of your room, and I will let you know where to put your bass traps/ acoustic panels. Ok but unless you're in the room taking measurements with the actual users equipment based on speaker placement via test tones and SPL meters/microphones, how could you be able to tell from photos and floorplans? I dunno, maybe I'm missing something here, in my experience it's just not that easy :)
Ready Acoustics Posted May 28, 2007 Posted May 28, 2007 Joel, I think it's great that you're providing advice on a topic that's tricky to implement and essentiall for proper sound. However, from what you've said above, how would a bass trap absorb early reflections? There's no such thing AFAIK since early reflections do not occur in low frequencies with long wavelengths. Upwards of 1000hz and higher yes, but please explain about the lower frequencies. Ok but unless you're in the room taking measurements with the actual users equipment based on speaker placement via test tones and SPL meters/microphones, how could you be able to tell from photos and floorplans? I dunno, maybe I'm missing something here, in my experience it's just not that easy :) Very good questions. I hope this might help my approach: Early reflections are typically shorter wavelengths. If your acoustical absorber is broadband (not a tuned absorber or that which features a scrim or membrane) and the covering (typically breathable to some extent) is acoustically transparent, sound waves regardless of length will penetrate. If your acoustical absorber is 1" thick, or more than 10" thick, short wave lengths (higher frequencies) will still be able to penetrate and be "absorbed" if the absorber is: Broadband (not scrimmed, tuned or fitted with a membrane) Utilizes an Acoustically transparent covering (breathable cloth) Utilizes an acoustical absorbent material like OC700 series insulation (or equivalent), rock wool, specific open cell foam, acoustical cotton, hemp, etc.. The added advantage is that 4" or more thickness can not only absorb higher frequencies, but absorb bass frequencies such as those lower in the band. Placement: I agree that some acoustical software can help and may assist in understanding a little of what a particular room needs, and that an SPL meter can assist with the same, however I believe there are some things to consider before ruling out a treatment plan and advice that is not necessarily based on SPL Readings or acoustical software graphs: 1. Small Rooms typically require more absorption at low frequencies. 2. Bass Trapping across vertical corners is widely accepted as the best place to control modes. Thus placement of bass traps across corners is where most treatment plans begin and where many acousticians as well as manufacturer's will advise you to start (in most rooms) 3. Using broadband absorption in smaller rooms is more efficient and effective (in most cases) 4. Placement of broadband absorbers at early reflection points may not only help control things like the Haas Effect, but help with additional bass control and room resonances that are the Bain of small room treatment. 5. SPL Meters and Acoustic software can help, (I think), but consider the following: When testing of acoustical devices such as Ready Traps or any other brand is done in an Acoustical Laboratory like RiverBank Acoustical Labs (the birthplace of architectural acoustics) and others (not some guys bedroom), a full report on everything that has happened in that reverb chamber is delivered. The acoustical device (bass trap, etc) is measured some 80 times (or more) in sweeps around the room and ALL data is delivered to very specific, acoustical data gathering componentry. Whist the reports are very good at delivering accurate readings for certain frequencies, there is one caveat. (This is what bass trap and acoustic panel manufacturers and acoustical software makers don't tell you) The report (All Acoustical Data reports from Acoustics Labs) includes a "Percentage of Uncertainty". What is this? Well, the "percentage of uncertainty" is a "number" based on how accurate the measurement at that frequency should be. When you get lower in the band (even at 80hz), the percentage uncertainty can increase dramatically. When you get to measurements at 60hz-40hz, the percentage uncertainty can be as much as 500%. That's not very "certain". Now, consider that this is a multimillion-dollar facility where manufacturers of all types take their products to be tested. Consider the reputation of such facilities and the integrity. There is almost NO chance, they want to deliver information to any client that isn't correct, even if that information (data gathered from acoustical testing) is not promising. Now, juxtapose this with a cheap SPL meter, some software and a mic used to take “measurements in someone’s bedroom. What might the "percentage uncertainty" be when using these simple, (comparatively cheap) tools that typically take a measurement 1-5 times in a room? Again, I think these tools can help, but they by no means (if you trust what a multi-million acoustical lab tells you) can they be seen as overtly accurate. Best practice (in my view) is to consider some tried and true placement advice that can be had from most reputable companies. They (we) have treated hundreds/ thousands of rooms and have tweaked such spaces (with the end users help) to fine tune the rooms acoustical requirements. Funny, a top acoustician you've likely heard of went into an acoustical space, and had the owner send back 14 of the 20 "bass traps" the owner purchased from a manufacturer. The manufacturer told the client that "more bass trapping" was better. What they didn't tell the client was that there is a point of diminished returns and did not offer practical acoustical placement advice. :oThey just told him to "spread them around". :-\ In large halls and churches (etc), this might be good advice, but for small rooms, I like to rely on what I KNOW the device can do and where experience has told me to place it. In many cases, I end up telling people to buy LESS than they think they need. :) I hope some of this helps? :) Cheers, Joel DuBay www.readyacoustics.com
Ready Acoustics Posted May 29, 2007 Posted May 29, 2007 Thanks for your patience. Here is a treatment plan for your room. This is based on placement of the major furnishings, your audio devices and the room in general. I’d suggest something like the attached… either make your own or use the Chameleon frame, etc. Add a couple of ceiling/wall panels to the rear wall and perhaps another to the front wall. Please let me know how I might assist further, or if you need further explanation on the treatment. Cheers, Joel DuBay Ready Acoustics LLC Bass Traps
Genesis Posted May 29, 2007 Posted May 29, 2007 Thanks for the detailed response Joel, nicely explained. My comment on using SPL meters is perhaps a bit simplistic, but in my room I've found it challenging to manage low frequencies because the room is small (only 17.5' by 11.5' with an inverted V ceiling). And as you stated, this means I'll need absorption. When I first setup the room, I noticed low frequency "shakes" in the light fixtures in the ceiling at the back of the room. So I broke out my trusty SPL meter and used a test tone CD to chart the low end. Sure enough, massive peaks at both 60hz and 100hz, off the range of the meter! I moved my sub around, but that's not the problem. The issue is with the mains since their location is fixed due to the room size. Aside from the usual furniture, carpets and fixtures to disperse and absorb sound waves, I added a bass trap to a vertical corner, but more treatment is needed. Looks like I'll be joining the other bro's in this thread to build some broadband absorbers :) PS, sorry wolverex, not trying to hijack your thread here!
Ready Acoustics Posted May 29, 2007 Posted May 29, 2007 Graciously done my friend. I want to be clear that I do think SPL meters and acoustics software can be useful. But I think you already knew (based on your ears and eyes) that there were low end issues. If I can help in any way, please let me know. I just want to get the word out that acoustic treatment should go hand in hand with just about any audio setup if the full potential of your sound experience is to be realized. Cheers! Joel
Ethan Winer Posted May 30, 2007 Posted May 30, 2007 Hi folks. A friend told me about this thread and suggested I could offer some useful advice. Hopefully I'll be able to help! ;) hopefully you guys could give your 2cents worth on where i could place the panels. All rooms need both bass traps and mid / high frequency absorption. Larger rooms will also benefit from diffusion, but absorption is the staple of acoustic treatment in rooms the size you'll find in most homes. I consider the "crossover" point from bass to mid / high frequencies at around 300 Hz. Broadband (not tuned) bass traps are best placed straddling corners. This includes wall-ceiling corners if possible, not just where two walls meet. Bass traps on the rear wall behind the listener will help even more. Even corners where walls meet the floor are useful for bass traps. Of course, visual concerns are a factor too unless you have the luxury of a dedicated room. It's important to understand that you simply cannot have too much bass trapping. It's impossible to make any small room perfectly flat, and with no ringing. So you add as many traps as you can manage, and accept whatever peaks and nulls remain. Mid / high frequency absorption is used at the first reflection points on the side walls and ceiling. Some additional amount of mid / high absorption is useful on any large areas of bare parallel surfaces, such as opposing walls or the ceiling if the floor is reflective. There's much more information and advice in my Acoustics FAQ. I also need to clarify some misinformation I see in this thread. ETF tests such as shown in my Density Report linked in the first post are not only perfectly valid for comparison purposes, they are much more accurate than standard lab tests, especially below 100 Hz. Acoustic labs and the absorption tests they do were developed for high-volume products such as ceiling tiles and automobile interiors. Most of the products that labs test are meant for use at speech frequencies, and the test methods fail at bass frequencies. For example, at 125 Hz the results can be off as much as 50 percent. If you test the same bass trap materials three times in a row in a standard acoustics lab, you'll get three different sets of data. I've even seen labs return negative numbers at very low frequencies! Music rooms and home theaters have very different absorption requirements than the ceiling tiles used in office buildings. Although ETF and similar programs do not yield data in sabins (the raw unit of absorption acoustic labs report), ETF is extremely reliable - and repeatable - all the way down to 20 Hz. I have done many tests in the RealTraps lab using ETF, and just the other day I tested a product for Cathedral Sound at their request because they didn't know how to do such testing themselves. I hope this helps, and please follow up with any questions if needed. Ethan Winer RealTraps
Ready Acoustics Posted May 30, 2007 Posted May 30, 2007 There goes the neighborhood. ;D Sorry folks, acoustical testing in acoustical labs like Riverbank Acoustical Labs or IBM yields far, far more reliable results than cheap software. ::)Fuzzy reports that are not in keeping with manufacturer's analysis of their own products derived from tests in an mult-million dollar acoustics laboratory are not science. These "tests" and subsequent "reports" are controlled by the person who reaps the benefits of such "report" and are NOT controlled by an impartial body like a real acoustician with a degree in acoustics. It's silly to think that someone can test acoustic treatments in a small room with a relatively inexpensive mic and some simple software, and believe that this is "science". ::) It isn't. It never has been, and it never will be for the near future. Beware of "reports" that aid in selling products and that try to deviate harshly from manufacturer's reports like those from Owens Corning. I'll trust Owens Corning and Riverbank Acoustical Labs to give me the real information on their products or the independant analysis of acoustical devices. Good Luck everyone, Joel DuBay Ready Acoustics LLC www.readyacoustics.com
Genesis Posted May 30, 2007 Posted May 30, 2007 Well I'm not about to take sides on this professional debate, I'm just an informed hobbiest :P That said, I'm looking at two divergent recommendations. One is to minimize bass trap deployment by placing properly constructed traps at optimal points in the room to control reflections and add absorbtion, the other is to maximize the number of bass traps since "it's impossible to have too many bass traps." Eh? The visual impact of adding traps and panels to my HT is fine...it's a dedicated HT after all, not a room for spending time serving coffee to guests and talking about the weather ;D Yet, I want to achieve a balanced soundstage that doesn't cause any peaks and nulls. Some rooms will be impossible to control sonically and small rooms are the worst, I think my HT falls into that category unfortunately. Ok, so do I need to go bass trap crazy, or find the optimal locations? Or both? What do the bro's on the ground here think about this?
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