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Post by rock on Jul 8, 2016 23:47:55 GMT
Hi Adam, we must have been typing at the same time. Sounds like you're building a double wall. Good idea. Read Rod's book. There's this concept of M-A-M. A good wall will have 3 and only 3 components. Mass, Air (or fluffy insulation) and Mass. Your mass layers can be as thick as needed like 3 or 4 layers of drywall but just one composite on each side of the Air or insulation in the middle. Use mineral wool compressed under (and over) the partition's floor and ceiling plates.
Cheers, Rock
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Post by rock on Jul 8, 2016 23:37:01 GMT
Adjacent ceiling, walls and floor are also involved in conducting vibrations into and through the wall/door in question. When addressing the issue of acoustic isolation, a holistic approach needs to be considered. Ethan mentioned "flanking paths" and that's the big problem... With "beefing up" the obvious or primary weak link only to find all the other "weak links" that will emerge. I also hope John chimes in since isolation is a completely separate issue from acoustic treatment. I like to recommend Rod Gervais' book on studio building like the pros.
When the band comes over to practice at my house, the entire house is filled with noise (yeah, we play too loud) and there is nowhere for my wife to escape... so she puts up with it (she's a saint!). To solve the isolation problem, I know I'd have to tear all the walls an ceiling bare and start from the studs/joists. Not gonna do it.
Cheers, Rock
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Post by rock on Jul 5, 2016 17:01:21 GMT
Thanks Ethan, you're right, I saw that report. I should have been more specific. I was referring to film used on superchunk as opposed to 4" panels.
To completely rephrase the question: In using film to increase LF performance, are the increases proportional regardless of the panel thickness (say 4" vs 6" vs superchunk) or is the "return improvement" diminishing with increased thickness?
Thanks, Rock
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Post by rock on Jul 4, 2016 13:43:57 GMT
Thank You for sharing the details! Yes, I can see how a hole punch is much easier to use than a drill but I'm sure your right that if you had a vice or place to clamp the bead and a scrap of wood to back up the metal, drilling might not have been quite as difficult either. To remove pop rivets, if you need to, simply drill them out with a sharp, 1/8" bit.
Thanks again, Rock
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Post by rock on Jul 3, 2016 15:12:27 GMT
I just want to mention I like your use of the metal corner bead. Great idea! Do you have details or a video of how you made your panels?
Cheers, Rock
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Post by rock on Jul 1, 2016 23:48:33 GMT
Yes, very nice. My question: would paper or plastic film glued to the front of the superchunk improve LF performance (of course at the expense of less mid/high absorption) ?
Cheers, Rock
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Post by rock on Jun 29, 2016 23:22:15 GMT
I would not use mineral wool or fiberglass if I was gonna' lounge or get cozy in it... even if I covered it with cotton fabric. Cotton batts like Ethan describes or the ultratouch should work fine. Other than Ethan's test, I don't know of test's comparing the fabric store cotton batts to ultratouch or similar "people friendly" products. I sense we're on the verge of "overthinking the material selection" here. I'm sure one product may perform slightly better or worse than another so go for reasonably dense and thick (2" should be fine) but as Ethan says "thick as possible". If you have any soft cotton comforters laying around, do some experimenting and see what works better.
Cheers, Rock
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Post by rock on Jun 29, 2016 18:55:51 GMT
Thanks. Actually, if one was so inclined, I believe a superior bass trap could be made to resemble a functional sofa or over stuffed chair using traditional upholstery methods with ultratouch and other acoustic materials like Guilfords of Maine fabric etc. I think something like this would be a perfect solution for wall/floor corners where typical panel traps seem to only take up floor space. The idea is the "traps" would normally be empty (not sat upon) mainly because they would be well out of the sweet spot but could accommodate the occasional sitter, and it wouldn't look like you just leaned some panels against the wall. The ultimate wife friendly absorber!
Cheers, Rock
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Post by rock on Jun 29, 2016 15:52:40 GMT
I you measure it, use pink noise instead of white. Pink noise is equal energy per octave so you'll get a flat response with a typical log display in the x axis. White noise is equal energy per frequency so it would be flat too if you displayed the frequency linearly which would loose detail in the lower freqs. forum.blu-ray.com/showthread.php?t=95710Cheers, Rock
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Post by rock on Jun 29, 2016 13:45:01 GMT
I'm going with a simple approach: If you have a fluffy cotton bed comforter, try folding it in half and see if that helps. You probably only need to eliminate mid/high reflections and don't need to address LF trapping. They make a denim product if you want to make something custom yourself www.homedepot.com/b/Building-Materials-Insulation-Denim-Insulation/N-5yc1vZbvev but for med/high freqs, you should only need 2 inches thick or so. Cover the denim with soft cotton, maybe flannel. Cheers, Rock
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Post by rock on Jun 27, 2016 13:23:55 GMT
Hi 90s I don't know anything specific about sound blasters or AWE64 or Soundfont BUT... I simply searched (awe64 soundfont filter specs) and found this: freepats.zenvoid.org/sf2/sfspec24.pdfOn page 46 it says the slope is 6dB/oct but the graphic below shows that it's 12dB/oct??? If this is what is confusing you, I completely understand. I have no idea if this is exactly what you're looking for but it's my best guess. I'm wondering, what did your google searches turn up? I did get a fair number of hits although I only looked at the pdf I posted above. Thanks, Rock
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Post by rock on Jun 26, 2016 1:32:42 GMT
Ha Ha! But yeah, in general, the commercial "acoustic foam" is far inferior to Real Traps or their DIY counter parts.
Cheers, Rock
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Post by rock on Jun 25, 2016 14:07:06 GMT
Once again casa, I did not answer your question: "So ultimately would foam corner pieces be best or actual panels?"
The foam corner pieces are usually too small (12" x 12" x 24 high" will have a diagonal face of only 17" across the corner) to be very effective. 2' x 4' x 4" thick rigid (dense) fiberglass or mineral wool panels straddling the corners are a better choice.
Ultimately it comes down to thickness and area of coverage. The greater the thickness, the lower the frequencies absorbed (spacing away from the wall or ceiling counts). The more area covered, the greater total absorption. You need both. Absorbers not at reflection points (in all 12 corners) should have foil, paper or plastic film facing the room for improved LF absorption.
Cheers, Rock
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Post by rock on Jun 25, 2016 1:28:22 GMT
Right, I was not clear but yeah, foam, fiberglass, mineral wool, cotton batts are all porous absorbers and generally absorb a wide band of frequencies, the thicker the lower and if un-faced with paper, foil or plastic extend to the upper audible frequencies. In contrast, resonant panel absorbers only cover about an octave or so and depend on the resonant frequency of the panel.
Yes, I agree, you can get better performance than sculpted foam from either Real Traps or homemade ones from OC703 or mineral.
Cheers, Rock
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Post by rock on Jun 23, 2016 13:24:17 GMT
Hi, As you know a cube is just about the worst shape next to a sphere. Ethan has a room mode calculator but it is not for Macs so I found this on line calculator: amroc.andymel.eu/?l=8.2&w=8.1&h=8&ft=true&r60=0.6In the link above, I input dimensions for a room almost 8 feet cubed. I offset the dimensions slightly to show how the modes "pile up" at the same (almost the same) frequency and that's what's so bad about the cube. It will make your modal peaks and nulls that much higher and deeper. If you want to eliminate (you can actually only reduce) those modes you need lots of absorption at those frequencies especially the lower ones. I know, and you will read that Ethan has used resonant panel absorbers in the past, but now, I understand that he generally recommends porous absorbers for small rooms. I wonder if the small cubic room might be a candidate for the resonant panel? If porous is still the best approach, you need lots of 4 -6 inch thick panels, straddling all 12 corners and more spaced off the ceiling and walls. Cheers, Rock
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