kcatthedog
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Post by kcatthedog on Feb 10, 2024 15:48:03 GMT -6
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Post by the other mark williams on Feb 10, 2024 16:07:49 GMT -6
Given the strength of lower bass notes, how does the facing prevent significant transmission? Wouldn’t it act like a mild reflective/ diffusive capacity ? It does reflect/diffuse the higher frequencies. I used damp course barrier sheet for the facing which is commonly used under brickwork. Holes cut in the facing helps the transmission of air in and out of the tube. Two tubes shown here. The left tube is turned to show the fully absorbive side. The right shows the facing which covers half the tube’s radius. Rotate the tubes to expose the facing for a more live/open sound. View AttachmentHow tall are these, rowmat? Six feet or so? |
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Post by the other mark williams on Feb 10, 2024 16:19:12 GMT -6
So am I right in thinking a product like this: www.spi-co.com/1013386/product/n/jm-3mapjmhpu8x3-1-2would have 3.5" of insulation, then an 8" gap, then another 3.5" of insulation - for a total diameter of 15"? Am I thinking correctly here? And that particular one obviously has the ASJ facing on it, but you could get a version with no facing? |
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Post by rowmat on Feb 10, 2024 16:24:10 GMT -6
It does reflect/diffuse the higher frequencies. I used damp course barrier sheet for the facing which is commonly used under brickwork. Holes cut in the facing helps the transmission of air in and out of the tube. Two tubes shown here. The left tube is turned to show the fully absorbive side. The right shows the facing which covers half the tube’s radius. Rotate the tubes to expose the facing for a more live/open sound. View AttachmentHow tall are these, rowmat ? Six feet or so? Yes. Two metres or about 6 1/2 feet. And 400mm in diameter. About 16 inches. |
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Post by rowmat on Feb 10, 2024 16:28:55 GMT -6
Exactly what I was thinking ( and about your pics), the facing protects the insulation and prevents fibre migration. I method could be to cut holes all around or open all of back half and replace with vapour barrier for likely a negligible difference? Cutting holes in rear facing half seems like a good start specially if you did measurements with tubes stock as baseline, then removed say a 1/4 of facing on front and remeasured, repeat as required ? I didn’t rely on the facings to prevent fibre migration. I coverered the tubes with black acoustically transparent fabric. See the tube on the right. Although I did first cover the non reflective side with a layer of 1” polyester insulation See the left side of the middle tube. The white polyester is visible with some poking out of the top prior to trimming. Attachment Deleted |
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Post by domono on Feb 10, 2024 16:30:56 GMT -6
Grainger seems to be the only place I’ve been able to find to get pipe insulation tubes down here in Houston. try these guys -- www.spi-co.com/locationsI always got my 703 from the one in Austin. Looks like they can get pipe wrap too. I was curious if SPI sold to individuals so your report is great to hear. Thanks! |
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Post by the other mark williams on Feb 10, 2024 16:43:49 GMT -6
Exactly what I was thinking ( and about your pics), the facing protects the insulation and prevents fibre migration. I method could be to cut holes all around or open all of back half and replace with vapour barrier for likely a negligible difference? Cutting holes in rear facing half seems like a good start specially if you did measurements with tubes stock as baseline, then removed say a 1/4 of facing on front and remeasured, repeat as required ? I didn’t rely on the facings to prevent fibre migration. I coverered the tubes with black acoustically transparent fabric. See the tube on the right. Although I did first cover the non reflective side with a layer of 1” polyester insulation See the left side of the middle tube. The white polyester is visible with some poking out of the top prior to trimming. View AttachmentWow - really really nice job, man. Those look good. And I'm sure they sound even better. |
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kcatthedog
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Post by kcatthedog on Feb 10, 2024 16:50:12 GMT -6
@row just thinking removing all the facing isn’t really required for the tubes to function well?
If you got material with no facing , for the reflective/diffuser function you’ll just have to add 6ml vapour barrier anyway .
So, at that point, it’s 50/50 covered to uncovered, might as well just remove half the facing ?
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Post by rowmat on Feb 10, 2024 17:06:27 GMT -6
@row just thinking removing all the facing isn’t really required for the tubes to function well? If you got material with no facing , for the reflective/diffuser function you’ll just have to add 6ml vapour barrier anyway . So, at that point, it’s 50/50 covered to uncovered, might as well just remove half the facing ? I believe the original Tube Traps are 50/50 reflective/non reflective. You rotate them as required. Speaking into each side of the tube from six inches away the difference is very obvious. |
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Post by kcatthedog on Feb 10, 2024 17:32:15 GMT -6
Makes sense: thx !
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Post by rowmat on Feb 10, 2024 17:46:55 GMT -6
Refer to the ‘Treble Range Reflector’ which covers half the trap.  |
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Post by domono on Feb 10, 2024 17:53:43 GMT -6
This pdf tube trap build guide is clear and well put together. It’s free but you do have to create an account/get on the mailing list. It’s a slightly more complex build than Eric Valentine’s super simple wrap ‘em or not cap ‘em or not approach. mixland.io/products/diy-tube-trap-build-guideman I really need to get going and actually pull the trigger on some tubes |
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Post by kcatthedog on Feb 10, 2024 18:09:01 GMT -6
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Post by rowmat on Feb 10, 2024 22:49:06 GMT -6
Pretty similar to what I built but I used rockwool glass batts which required an inner and outer wire exoskeleton to hold the batts in place and provide rigidity for the structure. |
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Post by jcgriggs on Feb 11, 2024 8:35:37 GMT -6
If you can get the insulation unfaced (without the cloth or plastic covering) it will be better. I used Roxul Techtron 1200 pipe insulation and I am in Ottawa, Canada (which I believe is also your home town) but I'm afraid the place I purchased from does not sell to consumers (I was able to convince a salesperson who was very interested in my weird application for their product to sell to me on the side but that person has since left the company) If you have to buy it faced, I think you'd want to strip the facing off, at least for the non-diffusive side of the device(s).
The ends MUST be sealed if you want the same behaviour as the ASC product - it depends on having a trapped air mass inside the resistive shell to provide the extra bass absorption...
Regards, John
So this stuff is faced, it would be a chore to get that covering off? I only now noticed the “ASJ Facing” part of the description thanks to your post. previously thought that was just the paper covering. Been looking at those for a while as Grainger seems to be the only place I’ve been able to find to get pipe insulation tubes down here in Houston. The tubes seem easier to come by up north which makes sense. Gotta look harder. www.grainger.com/product/OWENS-CORNING-Pipe-Insulation-Tube-4LFG5 I have always bought the stuff unfaced and never had to remove the facing, so I have no idea how difficult that would be - sorry. I expect that you could also perforate the facing rather than removing it entirely - that might be easier.
Regards, John
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Post by jcgriggs on Feb 11, 2024 8:41:20 GMT -6
Exactly what I was thinking ( and about your pics), the facing protects the insulation and prevents fibre migration. I method could be to cut holes all around or open all of back half and replace with vapour barrier for likely a negligible difference? Cutting holes in rear facing half seems like a good start specially if you did measurements with tubes stock as baseline, then removed say a 1/4 of facing on front and remeasured, repeat as required ? The ASC patents state that the devices have a sheet metal tube that is perforated differently (different hole sizes and spacing) to provide the absorptive and diffusive faces of the device. They also discuss using limp mass barrier in place of the metal (again with varying perforation). The vapour barrier approach is a DIY-friendly alternative - I've been told by people with a better grasp of the physics and math that 6 mil plastic on the absorber surface should reflect above about 500 Hz and pass below that - not sure how to calculate the perforations for similar performance.
Regards, John
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Post by jcgriggs on Feb 11, 2024 8:46:26 GMT -6
BTW, another cheap tip - I used cheese cloth (applied with 3M 77 spray glue) to prevent fibre migration. This is under the 6 mil plastic, 1/4 inch metal mesh (for mechanical robustness) and cloth finish. Regards, John |
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Post by kcatthedog on Feb 11, 2024 10:19:40 GMT -6
All understood and we agree. i used the vapour barrier trick with my two back diffusers, these are also stuffed with roxul, vp on back, and the whole stand is on wheels, so a sort of gobbo hybrid, the side absorbers are two of the knocked down shelving units, stuffed with roxul also on wheels . Attachment Deleted |
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Post by kcatthedog on Feb 11, 2024 14:51:17 GMT -6
A simple build using concrete form tubes.
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Post by jcgriggs on Feb 12, 2024 9:39:30 GMT -6
A simple build using concrete form tubes. I have no idea how effective these would be, but they are definitely not the same as the ASC Tube Trap (TM) design. The key element of the ASC devices is a trapped air mass inside a resistive casing and this design does not provide that trapped air. This looks to me like someone copying the form without considering the actual workings of the ASC design.
Regards, John
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Post by kcatthedog on Feb 12, 2024 9:55:01 GMT -6
A simple build using concrete form tubes. I have no idea how effective these would be, but they are definitely not the same as the ASC Tube Trap (TM) design. The key element of the ASC devices is a trapped air mass inside a resistive casing and this design does not provide that trapped air. This looks to me like someone copying the form without considering the actual workings of the ASC design.
Regards, John
I agree, essentially, they are building a round absorber with inconsistent insulation inside. It would have some effect but nothing like a real tube trap or proper copy! |
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Post by nick8801 on Feb 12, 2024 12:44:33 GMT -6
The ASC traps I got are great. They're huge. I actually can't fit them in any corner because of the way my room is setup. I experimented with moving them around and I notice the biggest change just placing them in the center of the room. Not ideal, but I can leave them there when I'm mixing, and I can move them around for various recording duties. Definitely worth it for the evening out of the sound in the room. One day I'll have a slightly bigger space, and these will go in the corners behind my desk. They even work great as monitor stands if that's what you want to use them for.
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Post by kcatthedog on Feb 12, 2024 12:53:32 GMT -6
Interesting sounds like you have some room modes coalescing in the centre of your room ? Have you ever dropped your room measurements into a mode generator?
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Post by nick8801 on Feb 12, 2024 14:58:51 GMT -6
Interesting sounds like you have some room modes coalescing in the centre of your room ? Have you ever dropped your room measurements into a mode generator? Yeah I did a whole thing with my room when I moved in. Amroc I think it’s called? I took care of most of the stuff. I should have put another cloud up, but I never got to it. |
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Post by OtisGreying on Mar 4, 2024 3:41:32 GMT -6
About to come to the end of this recording area/control room acoustics situation with a layer of 4 inch Caruso Isobond in front of most of my existing treatment. Gonna find a way to prop them up infront of my tubes. After lots of research it appears rockwool/owens corning is too dense for the acoustic effectiveness to do much past 8 inches of depth, everything is sounding great but apparently I may have wasted some space making these denser materials so deep. The low Gas Flow Resitivity (GFR) on the Caruso Isobond panels should make the balance in the room even better to a degree that is apparently unacheivable with just adding more fiberglass/denser materials like rockwool and OC703. We'll see when it gets here, I'll report back. Apparently the material is made of polyster and is signficantly safer than rockwool/oc703 or fluffy insulation which is pretty cool too.
I wonder how recent this information is, I noticed Eric Valentine constructed one of his studios with 2 feet of rockwool on each wall. According to this, that material wouldn't pose much if any benefit past 12 inches of use. Better to use lower GFR/ fluffy insulation at those depths, or materials in similar GFR/lower density to fluffy insulation
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