Construction Diary - Stockholm/Sweden

no real advantage for putting it into the resilient channel unless you're not using anchors. i like either of these two products: http://www.simpsonanchors.com/catalog/m ... sure-wall/ (drill point anchors) and for long deep areas - http://www.toggler.com/pdf/TOGGLER_catalog.pdf - the heavy duty toggler as it allows you to fish it through 3-4-5 layers of drywall.

Thank you Glenn! On the caulk question Glenn I presume that caulking thoroughly by covering any holes is all you need right? Sincerely, Useg Diaz-Granados

caulk is your friend :-) seal everything. if you have a large gap, use backer rod to plug it then caulk.

Thanks Glenn! :D Don't mean to be redundant Glenn but I still have some questions concerning the Flush mount speaker stands and insulation. The flush mount stands I constructed have a gap were the air can cool the studio monitors of 270 mm. The insulation i purchased for sound treatment purposes has a density of 50 kg per cubic meter and it is 80 mm thick. 270mm - 160mm (to cover the four sides of the flush mount stands) leave me with an air intake of 110mm. Q1) I know you recommended not using hangers because of the limited space I have but would using hangers not be a practical way of insuring proper air intake going to the monitors? Q2) I am going to have a considerable amount of space between the monitor stands behind the broadband absorber that is going to be in between them. The broadband absorber are going to be removable in order to make sure that I can get to the monitors if needed. Filling this space with with low density fluffy insulation would be messy and itchy. If I go with the sound treatment insulation it would be expensive. I want to use the 50 kg per cubic meter insulation on the saw, the broadband absorbers, the sound cloud and the bass traps (plan to use 2 x 80mm for them). I have currently 43 square meters to my disposal. Does it not makes sense making hangers that I could hang from the ceiling to cover the 320 mm gap that stretches between the monitors from the floor all the way up to the ceiling Glenn (might be less itchy if the insulation hangs in an organized way :wink: )? http://www.johnlsayers.com/phpBB2/viewtopic.php?f=1&t=5518&p=38268&hilit=build+hanger#p38268 To make sure that the ceiling does not carry to much weight ( the sound cloud can not be over 20 kilograms) I can make a simple wood frame that can sustain the weight of the hangers. Q3) I assume that the insulation needed for the flush mount construction does not have to be of the same density as the sound treatment. What density/brands do you recommend for sound insulation Glenn? I think I read in a thread that you need low density insulation for hangers, is that correct? Q4) As far as the MDF and the flush mount construction is concerned, is it enough to have only the face plate (the front side visible in the control room) made out of MDF (and the sealed box with an open back for air (rear ported monitors) containing the monitors but not the sides of the monitor stretching up to the ceiling)? Sincerely, Useg Diaz-Granados

MDF is good for the face plate and speaker box - open back is fine. if you can put in hangers, do so, if not consider wrapping your low desnity insultion in a loose cloth bags (or bags) which you can hang on hooks. use 15kg/m3 for light insulation needs. you could construct a frame to span the room to support the bulk of the cloud weight - maybe even steel tubes for example - ensure they can support the weight on the span and perhaps as backup some ceiling hooks and chain in the middle.

Thank you so much Glenn for the (always) insightful information! :D An update; while waiting on the electrician I decided to start varnishing the studio door we made. Here are some links for those of you out there who need to varnish wood. http://www.youtube.com/watch?v=1Zum813aR9Q http://www.essortment.com/yourself-tips-applying-wood-varnish-properly-12141.html After the door is complete (one side of the door is done) I will start assembling the wood frame for the broadband absorbers that are going to be placed after the saws and after that I'll (I do not want to start on the saws and the flush mounts until the drywall is up in order to insure that everything is as symmetrically accurate as possible) might start on the bass traps. My hesitation with regards to starting on the bass traps is that the room (after the drywall is up) might prove to be in need of either heavy bass trapping (lower frequencies) compared to a more broadband (mid-low) absorption. It might be more sensible to acoustically measure the room first. As far as the sound cloud is concerned there are some designs where the back of the cloud is wider then the front, others are angled. My presumption is that it would be pragmatic to wait until the room is measured before engaging in the construction of the sound cloud. I think I can make the cloud under 20 KG (including lights) which means I do not need to construct a frame to support the weight of the cloud (really would like to avoid that if possible :wink: ) I'll post some pics of the door when it is done. Glenn I have some questions regarding how to properly design a sound cloud. I have collected these links (see below) but feel I need more information in order to properly construct the sound cloud. http://www.johnlsayers.com/phpBB2/viewtopic.php?f=1&t=15773&p=112039&hilit=knauf+insulation#p112039 http://www.johnlsayers.com/phpBB2/viewtopic.php?f=3&t=11107&p=100555&hilit=make+cloud#p100555 http://www.johnlsayers.com/phpBB2/viewtopic.php?f=3&t=2916&hilit=make+cloud Q2) I understand that if you leave an air gap after placing a 8mm (or is it 4 mm Glenn?)MDF board caulk to the back of the sound cloud it is possible to absorb lower frequencies more efficiently, Is this correct? Q2) If you use a 160 mm thick insulation instead of 80 mm insulation then you also absorb lower frequencies better without killing the high end of the spectrum, Is this correct? Q3) Which of the the two above questions (Q1 versus Q2) is the best method to contain both low,medium and high frequencies? Q4) If my presumption of sealing the cloud with MDF is correct, is it possible to use a router to router the sides of the cloud in order to reduce the total weight of the cloud? Q5) What kind of cloth/plastic do you recommend Glenn in order to keep the insulation particles from penetrating the cloth and getting into the room (I know you mentioned something about the cloth; do you have any links/recommendations Glenn?) Sincerely, Useg Diaz-Granados

Here is the pics of the door after it has been varnished and the door handles been put into place; it still needs some tree molding to cover up the "ugly parts". Sincerely, Useg Diaz-Granados

That is a beautiful door, I would have installed three hinges, all things considered with the weight, and moved the top hinge more to the top about 7 inches rather than the current placement. Still, nice looking :)

Thank you Brien! Your comment is encouraging. :D I think you are right about the hinges, so far they are holding, the door has been up a few months before the varnish was applied to it. My goal is to make the door look better by using the molding when the mix room is closed to being completed. Sincerely, Useg Diaz-Granados

use the MDF on plywood to ensure a rigid structure. you can route out parts to lighten. see the cloud example i posted on JohnH's thread. i would go with the deeper insulation if your headroom can accommodate. 3.5mil plastic sheet will work. cloth - any fire retardant treated cloth of your choice will suffice.

I tried to locate the JohnH thread without success Glenn. Could you be kind and link the thread please? Never mind, I found it Glenn. Thank you! :D Have a question Glenn. Q1) 3/4 inch is about 20 mm thick plywood you have on your example. It seems to me that the sound cloud will be heavy using plywood if you add the MDF (even after it has been routed). Another potential weight problem is that I have to make boxes for the lights made out of MDF which will also add weight. Is there any other materials that could be used in order to make the cloud lighter? Q2) The routed parts on your cloud example, can you tune the cloud by routing in order to optimize the rooms sonic characteristics? Q3) How big should the cloud be to obtain the best possible result? Q4) In your example there is a part of the cloud that is only plywood and no absorber (3 inches), can you exclude that? Is it not reflective??? Q4) (This is more of a request) Can you provide some other Sketchup file of a cloud that I could learn from that might be closer in line with what we are facing with my project? :wink: Q5) My cloud would be 160 mm=6.2992126 inches thick. Would the low height of my room (2.2 Meters after drywall is in place) present any acoustical problems Glenn :?: Q6) I made a sketch of the absorbers on the corners of the saws. Is it OK Glenn? This post (see below) answers some of the questions I asked. Still need assistance with the rest Glenn. http://www.johnlsayers.com/phpBB2/viewtopic.php?f=3&t=15553&p=109691&hilit=cloud#p109691 viewtopic.php?f=3&t=9063&p=63188&hilit=cloud#p63188 An update; We have started work on the electrical aspects of this project, I will post pics in the near future. Sincerely, Useg Diaz-Granados

Here is a model of the saws, broadband absorbers and the bass traps. The broadband absorbers are 80mm thick while the bass traps are 160 (insulation+100mm empty space)mm thick. Q1) Anything you think could be improved Glenn? Q2) The wood for the frame of the broadband absorber (not the saws) I am thinking of making is 118 mm (thickness), the insulation is 80 mm. What are the sound treatment advantages/disadvantages of making a frame that is 118 mm to house the 80 mm insulation, placing a properly caulked 6mm MDF plate behind the insulation and then leaving the remaining space empty Glenn? I am thinking of leaving a 65mm space that goes between the saw and the broad band absorber and make similar absorbers to the one you posted that neutralizes the reflective corners of the saws. Sincerely, Useg Diaz-Granados

assuming cloth behind the slats, the air gap between the cloth and the insulation will be fine, the rigid insulation inside will dampen the cavity resonances.

Thank you Glenn. :D Q1) Could you be kind and answer the questions I asked that have to do with the sound cloud, the broadband absorber thickness/basstraps and the wood frame Glenn? Q2) Is the information on the links below accurate or is it outdated pertaining to the open compared to the closed back bass trap and broadband absorbersGlenn? http://www.johnlsayers.com/phpBB2/viewtopic.php?f=3&t=2423&p=17890&hilit=basstrap#p17890 http://www.johnlsayers.com/phpBB2/viewtopic.php?f=3&t=13226&p=91697&hilit=basstrap#p91697 My understanding is (from the information I've obtained in this forum) that you can tune the bass trap in order to enhance lower frequency absorption by using space and a sealed/caulked back. Do you seal the back twice (when the insulation ends and after the space)? Please correct me Glenn if I happened to miss-interpreted this important piece of information. Sincerely, Useg Diaz-Granados

Something went wrong when we installed the star led lights due to what I presume to be a defect in the product. The lights transformer blew right in front of my eyes; watching this made me made me wonder why human beings would be so sadistic; and decide to use electric current in order to execute someone in the name of a sovereign state in order to enforce the Law ...... (It is GREAT being in SWEDEN; no Death Row here, honorable members of this forum; it is also illegal for a parent to hit her or his child; I don't know why but I just felt compelled to share that with Y'all LOL) :twisted: ...... Anyway, I sent the lights back to the manufacturer so we can get new ones quickly. In order to be able to move forward with the project; I would need the questions that I asked answered. Since I am getting impatient ; I will make the frame for the broad band absorbers after celebrating midsummer, sort of like your thanksgiving Glenn although I don't think the Swedes would eat lunch with Indians after stealing their land; after all they stayed neutral during WW2; and made a hefty penny by selling steel to the Germans during that time-period :wink: . I can not put up the drywall until the star led lights are up (don't you hate it when things get in the way of progress?). I still need to know if the closed back+caulk or the open back option is the best way to pursue the assembling of the broad band absorbers and the bass traps. ...... Sincerely, Useg Diaz-Granados

the slat air cavities need to be sealed to work effectively. the panel traps you show in one of the links can be tuned by putting the panel on a soft rubber edge and adjusting the tension - but - it's not necessarily easy to do, so start with broadband. on the broadband absorbers - the cloth cover rigid insulation, no need to seal them but leaving an air gap behind them will help increase the absorption.

Thanks Glenn :D . I will follow your recommendations. Q) What about the Bass Traps? Don't they need to be sealed/caulked Glenn? Sincerely, Useg Diaz-Granados

if they are membrane (panel) absorbers - they need to be sealed - the air cavity is part of the equation, if they are just deep absorbers, no.

Thank you! I have to use the search function and learn more about the difference in between a panel absorber bass trap and a deep bass trap. :wink: :mrgreen: Here are some links that others here might find useful; due to my lack of understanding/knowledge concerning this subject matter I can not guarantee the accuracy of this content. http://www.johnlsayers.com/phpBB2/viewtopic.php?f=1&t=345&hilit=membrane+absorber http://www.johnlsayers.com/phpBB2/viewtopic.php?f=3&t=1105&hilit=membrane+absorber http://www.johnlsayers.com/phpBB2/viewtopic.php?f=1&t=1967&hilit=membrane+absorber http://www.johnlsayers.com/phpBB2/viewtopic.php?f=3&t=3762&hilit=membrane+absorber http://www.johnlsayers.com/phpBB2/viewtopic.php?f=3&t=6446&hilit=membrane+absorber I found the last thread amusing...... :lol: :lol: :lol: :lol: :lol: :lol: Once again, my assertion after reading the post is that Eric Desart is the man! Sincerely, Useg Diaz-Granados

Eric is truly the man.

After reading a little I believe that the most pragmatic approach to achieving my main objective with the mix room is to go with the deep absorption bass traps and broad band absorbers. If you believe this to be the least efficient way of sound treating the room please let me know Glenn. If everything goes according to plan I will start assembling the broad band absorbers (not the saws) tomorrow. Q) I wonder how problematic this design for my bass traps might be Glenn. My thought process is that I need some weight in order to keep the bass traps stable since they are 2330 mm high. I have decided to make the traps 240 mm thick. There is some left overs from the door project which I presume will keep the bass traps stable (66 mm thick composite wood). There will be some reflections since wood is a reflective surface; I wanna know what you think Glenn? By the way, the back of the bass traps is not suppose to be made out of a solid material (it will be stapled cloth and sound treatment insulation). Sincerely, Useg Diaz-Granados

you could make smaller bass traps (ala BBC 1992-11) and stack them. either way, you'll want the bass traps as close to your corners as possible.

As always, thank you Glenn! I am feeling adventurous enough to try the 2330 mm tall traps with the composite wood (around 5 kg weight for each trap and 310 mm wide) made out of MDF which is a heavy material. Not being a builder, I presume that the bass traps will stand sturdy like a abnormally large book shelf. The bass traps I plan to make would not be the BBC version since those traps have a sealed back and, as I understand it, should be placed in direct proximity of a wall. Q) Am I wrong in my presumption about the BBC traps Glenn, are there any disadvantages to making the traps with and "open" back and front that you are aware of? A quick update; I started on the broad band frame and :cen: up when routing the wood :evil: :evil: :evil: :evil: :evil: :evil: I got better (although NOT perfect) on my second set. I checked the second piece out and it looks good for the tall people who will actually be able to see it (will be on the top part of the frame). I will nevertheless use the bad piece since it will not be seen (place them on the bottom of the frame closest to the wall) once it goes on the wall. I got two (2) pieces done and IT WAS A PAIN IN THE :cen: :cen: :cen: :cen: :cen: :cen: !!!!!! Ahhh I feel much better :lol: :lol: :lol: :lol: :lol: :lol:. If it was not for the economics of it; I would have Noooo problem letting somebody else do the work. Next week I plan to do the other two (2) "long" pieces of the frame (1800 mm long); after that I hope my wood skills have substantially improved since I will attempt to make the "short" sides (1200 mm long) which, by the way, will be visible to the eye. Have a great weekend everyone :wink: Sincerely, Useg Diaz-Granados

depends... leaving open the back a reasonable distance from the wall would likely improve things. too far out (say > 1m) may end up less effective.

Q) Glenn, just want to check and make sure that I get you right. Less then a meter from the wall with an open back is OK? Or is it the other way around? Sincerely, Useg Diaz-Granados