AudioNervosa
Systemic Development => Psycho-Acoustics => Topic started by: richidoo on January 24, 2008, 05:07:43 PM
-
I want to make a sound attenuating partition to block out some of the reflections from the kitchen behind my listening seat. It will not be totally sealed off because there is a 5' wide walkway connecting the rooms which can't be sealed. But there is a half wall about a foot behind me, and I want to place an accordion wall on top of it to attenuate some of the dirty cold sounding reverb from the kitchen.
It was suggested by my wife and a couple audio friends to just hang curtains. But to me curtains will look weird, especially the variety thick enough to attenuate sound. Thick shiny velvet curtains hanging in there would look too freaky. I figured out a way to mount an accordion wall so it hides up against a corner kind of unobtrusively, I think.
I'm concerned that cutting the 39 foot length in half with a wall might screw up the decent bass response I have. I guess if it is not reflective then it shouldn't be a problem. Is 1/8" mass loaded vinyl sheet reflective to bass? Does it matter??? :)
I was thinking of making the panels about 2" thick, with a sheet of vinyl in the middle, and 1" rigid fiberglass on either side of it. 6 hinged panels will cover the 126" span. Felt pad to slide on the top of the half wall. Maybe a brush at the top to seal the ceiling a little, but probably not necessary.
What can I use a mask to prevent it from sounding too dead, so close to my head?
I'm sure there is a better recipe for a thin attenuating wall than my first uneducated guess. Maybe it can be thinner, maybe I don't need or want vinyl in there. Any and all advice, opinions, and wise cracks are all mucho appreciatos.
Thanks!
Rich
(http://www.audionervosa.com/gallery/128_24_01_08_5_02_57.JPG)
-
Hey Rich.
Just be careful putting any kind of mass there. Your seating is very close to that short wall. As soon as you put something there with mass, you'll get bass buildup. If it was me, I'd likely do the curtain thing but get something you can sew a lining in and use limp mass vinyl in the pocket for the lining. That will damp things but not allow the bass buildup.
Bryan
-
My advice would be to cover the windows in the dining room with fairly heavy drapes that you can close for critical listening. You avoid standing waves and the problems they cause by as well as near field reflections from a partition behind your listening seat.
Scotty
-
Thanks guys.
Bryan, you mean this stuff (http://sensiblesoundsolutions.com/product_info.php?cPath=23&products_id=40) sewn into or hung with the curtain? Blackout curtains come with vinyl sewn in, also claim to be sound deadening for noisy streets, but that thin white vinyl is much thinner than the 1/8".
So 1/8" LMvinyl will not stop bass? Attenuation curves for it seem to say not much attenuation in bass freqs. That's good.
Scotty, she only wants a topper on that window. I would put FG across the whole ceiling if I had druthers.
Thanks
Rich
-
I like the accordian wall idea but nothing like the kind I've seen in community centers or commercial applications.
I have an oriental screen I modified that you can try to see if it is close to what you want to do. If so, maybe we could build something interesting and that looks good.
From a design perspective, I'd rather see a flat surface across that wall rather than wavy like a curtain. I like the idea that it can hide away also... but it needs to look good either way.
So, while the screen is not in use, it could be behind what looks like a little pantry on the wall. When in use, it can look like a straightened out oriental screen, with about 7 or 8 1" thick 'panels'...
My screen is your screen. :)
-
Rich, I've got a similar problem in that my living room has a large archway joining the dining room which has very large glass windows. While I decided to not block the archway, I did put up double-cell cellular shades (accordian-type) over the windows that made quite a big difference. They're top-down and bottom up, so it's real easy to open fully, open partially and fully close as needed. I wonder if that would work for you? Might be less obtrusive when you want it fully open, and very easy to fully or partially close while creating a non-reflecting surface. They come in single, double and triple cell with different weight materials. Just a thought.
If you're not sure what I'm talking about, check out justblinds.com or selectblinds.com and look for cellular shades.
-
A lot of the ringing you're getting is going to be from say 400Hz up. The vinyl will help with that. What it won't do is form a hard rigid flat boundary to allow modal activity and bass buildup. It will actually 'move' with the wave and dissipate some of the energy.
I was thinking of something that was sewn into the fabric so that it looked good on both sides since they're both highly used living spaces.
Bryan
-
Mike, that's exactly what stereofool suggested a few months back, cellular shades. Thanks for reminding me of that good idea. Not sure momma will go for the control rack mounted across the ceiling, and a little pricey for 126 x 76 coverage with a quality brand. But simpler than building something.
Vinyl sheet gives very high attenuation on midrange like Bryan suggests, so I am leaning strongly towards trying to incorporate that into panels that I can slide away. If I use pin hinges on the wall end I can remove the whole system for hiding easily. Otherwise I would leave it on the hinge folded away ready to use easily.
I already have a mechanical plan to make a folding panel wall with 6-7 panels ranging 14-20 inches wide. It is designed to fold away into the corner on hinges. I can use up to 2 inch thick solid panels and still not be too obstrusive. From what you guys are saying, I think maybe 2" thick might be overkill since complete soundproofing is impossible with the hallway gap leaking sound anyway. If I could get >30dB attenuation I think that would be enough to stop the kitchen reverb from distracting from direct sound.
Carl, now you can use that rice paper screen to enjoy silhouettes in your bedroom, as it was intended!
-
You're not going to get 30db- sorry. That takes a wall or a solid core door. Anything that will give you that kind of reduction is going to be massive enough to cause the bass anomolies we're trying to avoid.
Bryan
-
Well, I guess I mean just noticing the reduction in reverb. Whatever that is in dB.
Thanks Bryan
-
Pulling one out of mothballs... Only so Bryan doesn't say "Rich is just a big talker... " ;)
I built the doors with pine boards and hardboard, screwed one to the wall with some small hinges. This is about a year ago. Shane took a look and said, no way man, those little hinges will not hold up 6 doors. So eventually I redesigned the whole thing with a real budget so I could buy some good folding wall hardware and do it right. This is what I am using. http://www.johnsonhardware.com/100rd.htm Very nice quality, and a decent price. I got the track in two pieces to avoid shipping by freight. I just shimmed the ends to meet perfectly. The total span is 126 inches. The doors are 22 inches wide, so the hanger is at the center point to balance the doors so they will open very easily. You see the gap at the end of the track, the glider bearings only need to get to 11" from the pillar. The gap I will fill with a block of wood. The ceiling is not flat in those last 4 inches, so the track had to stop short. No biggie.
It took a while to design this one, because of the complexity, and the tolerances. Big doors 2' x 6' that have to glide 1/8" away from a wall for 10' distance, then seal shut with very little leakage. After a couple weeks the CAD was finally done, I started cutting parts yesterday. YAY! :D
Of course, the joist I need to hang the system from was 3.5" away from where I needed it. So I made a header board out of my secret stash of rock hard baltic birch plywood to transfer the load of the wall to the joist. I have 2.5" screws every 8" and 3" of cantilever on the other side of the screw line to prevent bending of the screws, so I hope it's strong enough. The doors aren't so heavy, it should be fine. (Famous last words....)
Here is a picture of the track bolted to the headerboard.
(http://www.audionervosa.com/MGalleryItem.php?id=559)
Tonight my wife and son helped me on the table saw to dice up a full sheet of plywood into 2" strips to make all the door frames. My wife was holding the outfeed, and clouds of sawdust were billowing all over her. What a trooper. My son ran around turning the saw on and off and helping to line up the cuts. My younger son wanted to help earlier in the afternoon but the plywood was too heavy for him to handle by himself.
It is midrange noise that I want to attenuate from the kitchen, hums and motor noise from appliances. But most important is to get rid of the midrange echo from the music system bouncing back from the hard surface kitchen. They will be stuffed with 2" OC703 FG. The side facing the music room will be hardboard with a section of goodpanel at the bottom. I don't want any absorbtion that I don't need. I like a live room as long as it's not out of control. I still need to hang curtains for lonewolf, so that will add some tame. The side facing the kitchen will be thin plywood all the way. Both sides will be painted, but not in time for the G2G.
-
I would just bare with it, you are not going to be able to anything without making it look real oddball....
-
I feel special Rich :rofl: Looks like an interesting project.
If the middle is hollow, watch the 'thin plywood' thing or you can end up creating resonances right in the range you're trying to avoid.
Bryan
-
I would just bare with it, you are not going to be able to anything without making it look real oddball....
Werd, are you talking about my nose, or the paint? :D
Bry, you are special!! The innards are stuffed with 2" 703. Should I glue it to the skins? The frames are 2" wide, so it matches the FG thickness.
-
Hmmm. Well, it's damped at least. Just concerned about how much vibration and transmission you're going to get through it without a lot of mass. Are both exposed sides going to be thin plywood or just the kitchen side? Define thin :-s
-
Living room side will be 1/8 hardboard to match the binary mask thickness, Kitchen side will be 1/4" luan. Both sides will touch the FG. One cross brace inside too.
I could make it again sometime. I already had the FG and the wood is cheap. SO if I want to lower the freq of absorbtion, then the materials need to be heavier right? What's a good recipe for best sound proofing inside a 2 - 2.5" thickness? I guess I oculd go 3", but then it is starting to protrude a lot when folded up. I'm also concerned about hanging too much weight from the header board. Vinyl would be OK if it really performed good, but layers of MDF would be too heavy for comfort.
Thanks
Rich
-
Unfortunately, soundproofing takes mass. To stop it acting like a huge membrane (and the living room side will be dominant), you might try putting some non-symmetric braces behind the 1/8" so you have odd shapes and different sizes of panels free to vibrate.
Can you go thicker on the other side to give more mass?
Bryan
-
Hi richiedoodledoodledoo
I would not screw with that house its too nice.. I think your speakers are too big for your room with that complaint. To much energy getting past you. You might want to try toeing in your speakers so all the directional energy crosses right in front of you and look for a lower volume to enjoy. I dont know, you can kick me in the crotch if you want, just a suggestion. :rofl:
-
I don't want to put more weight on the ceiling so I'll stick with the FG only for now. What about sticking on some vinyl to the outside in the future?
Werd, thanks for the compliment. I'm gonna try toeing in for more treble anyway. I'll let you know how it works. Thanks
Rich
-
Or if your want, take the wife to Mcdonalds and get the kingsize mac meals for the next couple of months. When she gets nice and fat have her wear some real thick clothing while she cooks and cleans in the kitchen. If she gets fat enough she'll obsorb all that extra energy. She should be in the kitchen anyways. But what ever you do don't mess up your house.... OH!!! :shock:
-
She should be in the kitchen anyways.
Wow, if my wife heard those kind of words out of me sound comming out of the kitchen would be the least of my worries. I would have to be looking out for airborne frying pans! :twisted:
-
She should be in the kitchen anyways.
Wow, if my wife heard those kind of words out of me, sound comming out of the kitchen would be the least of my worries. I would have to be looking out for airborne frying pans! : :rofl:
-
I have noticed that my listening room sounds best when it is full of well fed audiophiles. :D
-
Making some progress on the wall this week. Rob and I started to hang the panels but ran out of time and had to fudge it for the meet, using a wood board stapled to the halfwall to hold the bottom, and some strong tyvek tape to hold the top. It still worked acoustically, but I underestimated how long it would take to hang them so them would fold correctly.
A couple days of fiddling, some more cutting, and a couple minor problems and it is up and working, but not done yet. The last two panels didn't fit as intended, so there are gaps that I will fill up with wood. Then paint everything, install the diffusion masks where the FG is showing now. Fabric matching the paint will be behind the mask holes.
I tried to reduce the gaps called for in the hardware mfgs instructions, but they put them there for a reason, so I had to shorten the panels by 1/8". The gaps range from 1/8" - 1/4", my house is bent. :duh
Instead of painting the kitchen side to match the wall color on the halfwall, my wife wants a landscape scene mural. I did a space mural for my son, now everybody wants in on it. I'll pick one with angel nymphs trotting around half naked through tuscan sunset. haha
The thickness of the folded wall when it is folded is bulkier than I though, because the pin hinges force a 3/4" gap between the panels when they're folded. It will be less conspicuous when painted, but it's big. But it works, that's what counts.
The sound is awesome. The listening room is finally quiet. The echo from the kitchen is gone, and the room has it's own sense of acoustic space. The folding wall and door combine to cut the appliance noise way down. I will measure it sometime.
(http://www.audionervosa.com/MGalleryItem.php?id=582)
(http://www.audionervosa.com/MGalleryItem.php?id=584)
(http://www.audionervosa.com/MGalleryItem.php?id=583)
(http://www.audionervosa.com/MGalleryItem.php?id=585)
-
A little late, but what about "piano" hinges with the thickness of the closed hinge accounted for by using
a router to remove the thickness in equivalent material in the surface of panel that it is mounted to.
The hinges would show on one side or another of the door when closed but it looks like from the picture that you would save three inches of stored width when the panel is open.
Scotty
-
Thanks Scotty. You are right, a traditional hinge would allow a flatter closed bundle. I have some hinges left from the first iteration. I thought about different kinds of hinges for this wall, but the hardware kit came with these pin hinges so I decided to give it a try. During assembly it I was glad I did use them, because the drop in pin hinges allow easily connecting the doors to the rolling knuckle at the top. A traditional hinge would be more difficult to assemble the whole system. I may still explore using flatter hinge if painting doesn't help.
When I was doing model airplanes we used to hinge control surfaces with heat shrink mylar covering film. At one dark moment of frustration I was about to chuck these built doors and hang straight and true MDF slabs, with a sealed flex hinge, like tyvek glued on with contact adhesive or epoxy, or Monokote would actually work pretty good. Then sanity returned. I can't spend another week on this. But then it would be airtight, no gap, but it would require hanging all 6 doors at once, without damaging the thin glued on hinges which would be tough. It's almost done, I'm glad...
-
Hi everyone
I was looking through the acoustics section to get ideas to help make a temporary soundproof partition for the doorway to where my listening room is and I found this thread. Richidoo and company did a great job making that partition. Really cool. I can't make anything like that for my doorway but was hoping for ideas on a temporary soundproof partition for the space to reduce the music from disturbing others in the house.
Something foldable maybe like portable singing booths like this?
(http://www.soundcontrolroom.com/wp-content/media/Vocal-Booth2.jpg)
I've attached a picture of the doorway for reference.
Also I do have 8 panels of Owens Corning (48"x24"x2") semi-rigid FACED fiberglass (insulation) boards. If I get a couple of stands like this, put the panels in them and stagger them on the stairway would that reduce the amount of sound getting out of the room?
(http://mixmasteredacoustics.com/wp-content/uploads/2012/08/Mixmastered-Acoustic-Panel-Stand.jpg)
The base of the stairs is about 35" wide and the overall width of the doorway is about 48". Those stands I found wouldn't fit together side by side.
Sorry to bump and old thread. If it is better for me to start a new thread entirely I will just let me know.
Any thoughts on my situation are much appreciated and if I'm missing anything please let me know.
-
The best thing to do honestly in that case would be to use a solid wood door - likely what is there is a hollow core. Staircases are going to be tough to do.
Bryan
-
So that black cabinet on the lower left sits in the 48" opening? Can you install double doors there? Find a great carpenter who can install doors precisely with small uniform gaps so you can add weatherstrip all around for airtight seal. Or make FG panels that you can stack up on edge to close up the opening.
Placing a bunch of individual absorbers on the stairs will not do anything to stop sound going upstairs. You need a sealed barrier. You have to find one place where you can make a seal all the way around. The handrails on the stairs preclude the stairway. The mouldings at the top of the stairs might make the opening hard to seal.
-
Looking good there professor. Nuttin like a good room.
charles
-
Professor and Bryan. Many thanks for the input. I appreciate the honesty and guidance. I checked the 48" opening and I don't think I can get some double doors in there. I'll try to find a good quality carpenter to see if it can be done. Bryan's idea of putting a solid wood door right at the stairs got me thinking. I may try to see if I can get a solid wood folding door in there. It may be something that I would have to insert manually myself before any intense listening sessions.
I was looking at something like this maybe.
ReliaBilt 36-in x 79-in 6-Panel Solid Wood Interior Bifold Closet Door
There are more expensive solutions but I'll try something like this first.
Thanks again.