jezzaboogie Posted September 22, 2022 Posted September 22, 2022 I'd like to sound proof this (laminated) glass door. I'm thinking a heavy duty curtain that I can roll up when not in use. What material is best for this? The glass needs to remain to bring light into the room when light is the priority. Further down the track, we might get a double glazed door (I wished we'd done this in the first place!)
Guest Posted September 22, 2022 Posted September 22, 2022 The heavier the curtain, the better it absorbs. Please have a look at this, scroll down to drapery https://www.acoustic-supplies.com/absorption-coefficient-chart/
Upgrayed Posted September 22, 2022 Posted September 22, 2022 I have used acrylic sheets to insulate wooden windows for sound and heat. One on either side would do the job if you can design something that looks aesthetic. Associated Plastics in Birdwood Ave are great people. 1
wasabijim Posted September 22, 2022 Posted September 22, 2022 don't forget solutions to create a seal between the door and its frame when closed. generally sound leaks where air can. I would also think about taming reflections in that stair well. some (obviously not all) frequencies may be randomly emphasised on the way out or in. eg. a mat on the landing, avoid pictures in glassed frames but consider tapestries or prints using acoustically transparent material and a frame that allows an inch of some absorption stuff behind it or that 9mm pin board from bunnings. an elaborate wood based hanging light fitting. 1
tripitaka Posted September 22, 2022 Posted September 22, 2022 Worry first about the door seals ...and then buy heavier glass, would be my advice. Good luck 2
jezzaboogie Posted September 22, 2022 Author Posted September 22, 2022 All good info and ideas. Thanks!
jezzaboogie Posted September 22, 2022 Author Posted September 22, 2022 7 hours ago, Snoopy8 said: The heavier the curtain, the better it absorbs. Please have a look at this, scroll down to drapery https://www.acoustic-supplies.com/absorption-coefficient-chart/ How do I read the absorption coeffs? Does 0.6 mean a 60% reduction in perceived volume? i.e. a bit over a half? Is that the right way to think about it?
Guest Posted September 22, 2022 Posted September 22, 2022 1 hour ago, jezzaboogie said: How do I read the absorption coeffs? Does 0.6 mean a 60% reduction in perceived volume? i.e. a bit over a half? Is that the right way to think about it? https://commercial-acoustics.com/acoustic-absorption-coefficient/amp/
jezzaboogie Posted September 23, 2022 Author Posted September 23, 2022 A sound absorbing pleated curtain is probably the go. Any pointers for where to obtain from? I'm in Hobart.
jezzaboogie Posted September 23, 2022 Author Posted September 23, 2022 19 hours ago, wasabijim said: don't forget solutions to create a seal between the door and its frame when closed. generally sound leaks where air can. I would also think about taming reflections in that stair well. some (obviously not all) frequencies may be randomly emphasised on the way out or in. eg. a mat on the landing, avoid pictures in glassed frames but consider tapestries or prints using acoustically transparent material and a frame that allows an inch of some absorption stuff behind it or that 9mm pin board from bunnings. an elaborate wood based hanging light fitting. Doing something in the stairwell is also a great suggestion, thanks.
Guest Posted September 23, 2022 Posted September 23, 2022 23 minutes ago, jezzaboogie said: A sound absorbing pleated curtain is probably the go. Any pointers for where to obtain from? I'm in Hobart. Go to any curtain place and get thicker heavier material with pleats and backing. Forget special acoustic fabric. It will cost at least triple and will need to be imported, with minimum quantity.
Guest DrSK Posted September 23, 2022 Posted September 23, 2022 23 hours ago, jezzaboogie said: How do I read the absorption coeffs? Does 0.6 mean a 60% reduction in perceived volume? i.e. a bit over a half? Is that the right way to think about it? Absorption isn't sound proofing. It will do little, if anything to reduce noise going out the door. Absorption is about reducing reflections, not transmission. Absorptive only reduces transmission in wall cavities as it reduces coupling from standing waves. Any perceived noise reduction out the door will be psychological as you can't see the speakers anymore. You need firstly, full perimeter seals that get compressed in the jams, plus a drop down seal to the floor. Then upgraded glazing. I'd double up on 10.5mm Vlam hush, if your hinges and frames can handle it.
jezzaboogie Posted September 24, 2022 Author Posted September 24, 2022 Ah, ok. I take the point about difference between absorption and transmission as well as sealing the gaps around the door - the latter is done but could be improved. I'm open to alternative solutions. What about framing something up that gets attached to the door when sound transmission is a concern using velcro or suction caps? Could that possibly work well if the right material used? I'm guessing not because stopping transmission is going to require a high mass material and for that it needs to built into the door properly.
jezzaboogie Posted September 24, 2022 Author Posted September 24, 2022 (edited) Noted that there seem to be differing opinions (or maybe just different interpretations of the question), it would be great if anyone else with experience speaks up. To clarify: I want to stop sound going through the door. Edited September 24, 2022 by jezzaboogie
Guest DrSK Posted September 25, 2022 Posted September 25, 2022 3 hours ago, jezzaboogie said: Ah, ok. I take the point about difference between absorption and transmission as well as sealing the gaps around the door - the latter is done but could be improved. I'm open to alternative solutions. What about framing something up that gets attached to the door when sound transmission is a concern using velcro or suction caps? Could that possibly work well if the right material used? I'm guessing not because stopping transmission is going to require a high mass material and for that it needs to built into the door properly. The issue with Velcro etc is that it isn't an acoustic seal. It needs to be airtight, otherwise it will just bypass the panel you are attaching. What you can get are magnetic edged perspex panels. But they do rely largely on a 100mm air gap to achieve the stated performance. https://www.magnetite.com.au/magnetite-windows-benefits.html?gclid=Cj0KCQjw1bqZBhDXARIsANTjCPLmNMa0cNcZJgMYQaIUlUUl8NMH9dJMFtw8Zb_3lB6gr-36MoOLszQaAiISEALw_wcB If you tell me what glazing your door currently has, and the maximum gap that can be achieved, I can tell you the maximum noise reduction. I've treated many houses with their system.
wasabijim Posted September 25, 2022 Posted September 25, 2022 I'm by no means anything but a hack... But to me it's mass and air sealing you're after and acceptance on what is achievable. A heavy curtain misses on the sealing side. Would a curtain dividing a room in two isolate each side sonically? I've read of 'plugging' windows n doors with an acrylic sheet that is couple minute job to put up/take down. It needs to sit flush n tight with the door (rubber or felt sealing). Having an air gap to the glass further helps as energy diminishes at each medium boundary.
Guest DrSK Posted September 25, 2022 Posted September 25, 2022 (edited) 30 minutes ago, wasabijim said: I'm by no means anything but a hack... But to me it's mass and air sealing you're after and acceptance on what is achievable. Yes, but remember that creates a resonant system when added to an existing mass. The isolation provided by that resonant system needs to be significant, otherwise there is no point. 30 minutes ago, wasabijim said: A heavy curtain misses on the sealing side. Would a curtain dividing a room in two isolate each side sonically? Nope. Sound goes straight through a 'heavy' curtain. It's simply not that heavy and sealing is a big issue. 30 minutes ago, wasabijim said: I've read of 'plugging' windows n doors with an acrylic sheet that is couple minute job to put up/take down. It needs to sit flush n tight with the door (rubber or felt sealing). Having an air gap to the glass further helps as energy diminishes at each medium boundary. Not so much diminishing at each boundary, its that it has created a resonant system which has both amplifying and attenuating properties. At a simple level, you have two masses (the panels) connected by a spring (the air gap). With no air gap, you've just added mass which needs to be a significant increase otherwise it's pointless. But you've also increased stiffness by creating a thicker total panel, which can make some frequencies worse as it changes modes and also the effective speed of sound in the combined panel. As above, I'm happy to calculate the benefit so they can judge if the cost and effort is worth it. I'd be using specialist commercial software that is specifically for designing windows and wall layups. Edited September 25, 2022 by DrSK
jezzaboogie Posted September 25, 2022 Author Posted September 25, 2022 (edited) 8 hours ago, DrSK said: If you tell me what glazing your door currently has, and the maximum gap that can be achieved, I can tell you the maximum noise reduction. There is a 15mm gap from the glass to the door frame (on both sides). Unless my memory is playing tricks, it's laminated glass. Thanks in advance for your help. Edited September 25, 2022 by jezzaboogie
jezzaboogie Posted September 25, 2022 Author Posted September 25, 2022 Sorry, lazy measurement. The gap is more like 15mm. I'd say the glass itself is ~7mm.
Luc Posted September 25, 2022 Posted September 25, 2022 On 22/09/2022 at 11:40 AM, jezzaboogie said: I'd like to sound proof this (laminated) glass door. I'm thinking a heavy duty curtain that I can roll up when not in use. What material is best for this? The glass needs to remain to bring light into the room when light is the priority. Further down the track, we might get a double glazed door (I wished we'd done this in the first place!) Can't really add much to what has been said but when I built by room, I researched glass and it's ability to block sound or lesson it's impact from a source. I was told by many wise heads on here at SNA(don't get me wrong, they were all trying to help) to fill my bespoke door with double glazing. I went to G.James Glass and they told me there is double glazing for heat retention and noise reduction and then there is 'Acoustic double glazing' which according to them is two panes of glass with the air gap between the two which is basic run of the mill double glazing. Acoustic double glazing though has two units of glass which have a different molecular structure. By the time the sound gets through the first pane and then through the airgap and then through the second pane... it's much dissipated. Prior to us putting the panes in. And hung.
Guest DrSK Posted September 25, 2022 Posted September 25, 2022 (edited) 9 hours ago, Luc said: I went to G.James Glass and they told 9 hours ago, Luc said: Acoustic double glazing though has two units of glass which have a different molecular structure. By the time the sound gets through the first pane and then through the airgap and then through the second pane... I'm sorry, that is bollocks. No difference in molecular structure, it's the same glass. For thermal, it may have a coating. And their description isn't how double glazing works to reduce noise. Complete nonsense. At a molecular level, the only difference in glass is toughened glass which is either heat treated or chemically treated to put the outer layers into compression so it can flex more before shattering. You may use laminated glass for its improved acoustic properties, but nearly all laminated glass is better at reducing noise as an accident as the 0.38mm lamination was simply to stop it shattering into pieces. VLam Hush is about the only laminated glass with a specifically designed damping layer. But none of these are changes on a molecular level, the glass component is still just glass. I'm continually surprised at how regularly glazing manufacturers don't even understand an acoustic glazing specification, same with many architects. I've had a project where the glazing company and architect through concept, detail design to tender drawings, through multiple spec drawings by myself, performance specifications from me etc failed to get glazing into the drawings that meets the acoustic requirements for the building to comply with planning approval. Could not conceive that they needed a particular air gap, glazing thickness and a minimum lab rating to reduce noise from live music. Similar problems on other specs with the building with the architect too, they've designed a $40m facility for live music that will fail environmental noise compliance because they ignored acoustic advice. My tender report is basically a massive disclaimer explaining to the end client why their building won't work referencing the time and date of all the advice that got ignored by the architect. Edited September 25, 2022 by DrSK
Luc Posted September 25, 2022 Posted September 25, 2022 Bollocks eh? Well let me put it this way. It works. The door when closed seals up the room nicely and the rest of the house is saved from overly loud Mrs Mills in her prime. @ the OP certainly worth checking out the big glass suppliers for their take on this bollocky glass
Guest DrSK Posted September 25, 2022 Posted September 25, 2022 1 hour ago, Luc said: Bollocks eh? Well let me put it this way. It works. The door when closed seals up the room nicely and the rest of the house is saved from overly loud Mrs Mills in her prime. @ the OP certainly worth checking out the big glass suppliers for their take on this bollocky glass Explanation is 100% bollocks. Either complete ignorance or sales spin. Doesn't mean they can't sell you some standard glass as an acoustic product and make something that works.
Guest DrSK Posted September 26, 2022 Posted September 26, 2022 (edited) 22 hours ago, jezzaboogie said: Sorry, lazy measurement. The gap is more like 15mm. I'd say the glass itself is ~7mm. I had to make some assumptions as to timber density. I've assumed 6.38mm laminated glass based on your measurement. Your door and window seem reasonably well matched, the door has a bit of a dip in performance around 800Hz. I then added a 10mm perspex sheet to the entire facing to also improve the wood. This was with the 15mm gap over window and against the timber. Much bigger gaps will destroy the base performance. I've used dBA for noise reduction as levels will be lower up the stairs than in room. Improvement is around 3‐5dBA across Metallica - Enter Sandman, Post Malone - I Fall Apart and Jacques Lousier - Toccata and Fugue in D Minor. About a 20% to 30% reduction in overall loudness noise level. I wouldn't bother unless hitting a target for legal reasons. If it was annoying before, probably still will be. And a very small difference in volume setting will do the same. Although vocals etc will be much less noticeable. No reduction in levels through 160Hz to 400Hz as in resonance region for masses and 15mm cavity. Some reduction in base, biggest reductions above 600Hz. Triple with 10mm perspex each side is no significant improvement. 20mm perspex over entire door is 7‐8dBA improvement. Around 40% reduction in loudness. All this assumes door seals are working 100% and perspex is air tight. And assuming your walls around the doors are up to it. With the 20mm perspex, it would bring the door up to the same rating as the walls assuming standard internal walls with no insulation. Depending on the relative surface area of your door and walls externally, your walls may be ok, near to a problem or already a problem too. Edited September 26, 2022 by DrSK
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