Howdy folks,
Building a studio in Brooklyn, NY. We are building on top of a concrete slab at least 1 foot thick. (Probably a foot and a half.) Is it necessary to decouple the walls from the floor and heavily-built ceiling?
We are building each room completely isolated from the next with two exceptions: (unless I hear otherwise from you pros) the walls will be built on the same concrete slab, and will all have contact with the same ceiling. The building was an industrial construct, so the ceiling is made of 3x10 joists.
We have learned of a product called u-boats (from Auralex) but it doesn't seem to fit our purposes.
Any thoughts?
Once, again, much thanks!!!
floated walls
Originally posted at johnlsayers.com, topic 9265.
Yes, I've heard of U-boats... And I've gone on record here talking about how, in my opinion, in the absence of credible evidence to the contrary, they are not appropriate.
As I mentioned in the "Is a Floating Floor Right For You? Answer: Probably NOT" sticky thread:
Chances are you do not need to float your rooms, provided the slab on which you are building is on the ground. Study that thread I linked. It's required reading for anyone who even thinks for a moment that they should float a floor. --Keith :mrgreen:I have posted about U-boats specifically in the past. Their manufacturer's cavalier attitude about specifications only adds fuel to the "I think I need to float my floor" fire. :evil: In my opinion, the U-boat is the poster child of inadequately engineered floating floors. They most likely do more harm than good. Do a search for "auralex" by author "sharward" for all my rants about it. I will gladly eat my words if the manufacturer ever backs their product up with legitimate third-party test results and posts detailed optimum loading specifications. Until they do that, my recommendation is and will continue to be to consider it to be in the "soundproofing snake oil" category.
I hear ya. I think, though, I may have asked my question inaccurately. It is not our intention of floating the floors, but rather floating the walls. I mean: do we use some sort of method to decouple the walls from the floor? We know that vibration is sure to travel through our floor, so does it make sense to do that? Again, our entire studio sits on the same 1 foot (or more) thick concrete slab. Again, we don't plan on floating the floors, though we are using double-wall construction, which we hope to give us good isolation. Thanks!Yes, I've heard of U-boats... And I've gone on record here talking about how, in my opinion, in the absence of credible evidence to the contrary, they are not appropriate. As I mentioned in the "Is a Floating Floor Right For You? Answer: Probably NOT" sticky thread:I have posted about U-boats specifically in the past. Their manufacturer's cavalier attitude about specifications only adds fuel to the "I think I need to float my floor" fire. :evil:
There may be some specially engineered products available at Mason Industries or Kinetics Noise Control to accomplish that, but you'd really need to ask yourself what kind of "flanking" you'd be trying to avoid.
It probably takes more energy to vibrate your one foot concrete slab than the theoretical flanking path of your wall could ever dream to generate from airborn noise.
Your priority should be to isolate the walls between rooms from each other.
--Keith :mrgreen:
I know I'll hear about this from Keith and Rod, but I'm weighing in anyway. :D
I did both floating floors and walls before I found this forum after checking a number of sources (several books, magazine articles written by studio designers, web articles, etc.), unfortunately not Rod's book (I never saw it until I found this forum).
First, I have a road about 100 ft from my studio which has occasional farm equipment traffic and a train about 2 miles away. I was concerned about outside noise primarily.
I didn't have the funds for a full floating concrete floor. So, I chose to use U-Boats for the floors after speaking to Auralex about their proper use (I'll spare the details of the conversation about loading). I have no proof that it improved anything other than my rather non-scientific test of having a friend drop a sledge hammer on the slab within inches of the floated floor and not having any percievable transfer. (If you do the same test with concrete alone, you can easily feel the transfer). I figure at worst it didn't hurt anything.
The floor covering will be genuine hardwood. (Over 3/4 OSB and plywood) Only the control room is finished and yes, the floor has a slight LF resonance, but so far it hasn't been a problem.
For the walls, I built the walls on top of the floated floor with Sonex's equivalent to Sheetblock between the floor and the floor plates. Again, I can't prove that it worked, I just used it according to my sources' instructions.
Scott
PS: Keith - man, I'm glad I don't have your inspectors and codes - and earthquakes. :D
Hi Scott,
Actually, would mind please sharing the details of their conversation with you about loading? That's the "elephant in the room" (no pun intended) that the U-boats product seems (to me at least, in terms of their online resources) to be so blatantly cavalier. Perhaps, just perhaps, they have more data than they have gone to the trouble of posting...? :roll:II chose to use U-Boats for the floors after speaking to Auralex about their proper use (I'll spare the details of the conversation about loading).
Sorry, Scott, but I have to adamantly disagree with you on that. You're experiment of dropping a sledgehammer is a test of impact transfer -- and while you may be right that you may have helped along those lines, you still have...I have no proof that it improved anything other than my rather non-scientific test of having a friend drop a sledge hammer on the slab within inches of the floated floor and not having any percievable transfer. (If you do the same test with concrete alone, you can easily feel the transfer). I figure at worst it didn't hurt anything.
...(ahem)... the issue of the floor resonating and thus possibly (probably?) amplifying airborn noise. That's one of the (several) points made in the "the "Is a Floating Floor Right For You? Answer: Probably NOT" sticky thread:" sticky thread. So, by solving the "dropping sledgehammers" problem, you have, in essence, created a "low frequency resonance" problem... In my opinion, that's not a good plan. I realize it's probably too late for you to change course, Scott -- but I do want to go on the record on this in an effort to help others who come along after you. I really am crossing my fingers for you that you will be satisfied with the results of your labor and investment when you are done. :) Maybe you'll come to enjoy and/or get used to the rumble in time...? --Keith :mrgreen:the floor has a slight LF resonance, but so far it hasn't been a problem.
Hi Keith-
Like I didn't see this coming. :)
That was about 2 years ago, but as I remember it, the U-boats are designed with a "typical" load in mind. That is to say that unless one is going to know, within tolerance, exactly how much load is going to be on the room and that the load will be equally distributed, doing a lot of math to find out just exactly what the required spacing of U-boats is necessary for a particular application is a bit futile. To rephrase: Unless one has a room with static (never changing) load, then doing all of the calculations required to fine tune the spacing is pretty useless. Example: I build a room to be empty so that I can take advantage of the acoustics of the room (a live room in a studio - imagine that) then record (as in my case) a string quartet. The next day I bring in two full sized grand pianos. The next day I want to record a solo vocalist that weighs 100+ lbs. The loads are less than static. In order to compensate for every conceivable circumstance, you would have to be able to adjust the floor. With any elastic type device, be it springs, pucks, U-boats, etc., there is a reasonable tolerance. I described to them what my normal use for the room would be and they suggested the space needed between the U-boats. In my case it was very typical 16" spacing. Since their "model" was based on floors using 16" centers, with a load similar to mine, that is how I built my floors. Where the floor joists meet the walls, there are additional U-boats along the walls (I forget the exact spacing).Hi Scott,Actually, would mind please sharing the details of their conversation with you about loading? That's the "elephant in the room" (no pun intended) that the U-boats product seems (to me at least, in terms of their online resources) to be so blatantly cavalier. Perhaps, just perhaps, they have more data than they have gone to the trouble of posting...? :roll:II chose to use U-Boats for the floors after speaking to Auralex about their proper use (I'll spare the details of the conversation about loading).
I have no proof that it improved anything other than my rather non-scientific test of having a friend drop a sledge hammer on the slab within inches of the floated floor and not having any percievable transfer. (If you do the same test with concrete alone, you can easily feel the transfer). I figure at worst it didn't hurt anything.
Your objection is noted. But I would like for you to explain to me how a kick or snare drum is not a impact transfer. My understanding of vibration are that most (if not all) start with some type of impact, regardless of how small. The vibration of an internal combustion engine is caused by the impact or explosion within the combustion chamber. The sound of a piano is caused by the initial impact of a hammer against a string. I'm not trying to be combative, I simply disagree with your reasoning. Please explain.Sorry, Scott, but I have to adamantly disagree with you on that. You're experiment of dropping a sledgehammer is a test of impact transfer -- and while you may be right that you may have helped along those lines, you still have...
...(ahem)... the issue of the floor resonating and thus possibly (probably?) amplifying airborn noise. That's one of the (several) points made in the "the "Is a Floating Floor Right For You? Answer: Probably NOT" sticky thread:" sticky thread. I have read that thread and although I agree with a great bit of it, I disagree that it's direct trade of one problem for another. Given the choice, I would much rather have a small amount of predictable resonating in sympathy with the instrument that I am recording than some uncontrollable noise outside seeping into the room.the floor has a slight LF resonance, but so far it hasn't been a problem.
Again, I would disagree that I have a problem. I said that there is a slight LF resonance. I did not say that is was a problem. Actually, what I said was that so far it has not been a problem in the control room. I do not anticipate it being a problem in the studio either. Before one assumes that I am simply in denial, let me assure you that I have been in more than one big budget commercial studio that has a small LF floor resonance. In fact many of them do, due to having removable floor panels to gain access to wiring, etc. Also, there are any number of cases where a small resonance is preferable to a dead floor. Ever see a solo cellist on a stage sitting on a small riser? That riser is for resonance. The previous paragraph might also be placed in the "acoustics" section of this forum. But since this is where we are. :)So, by solving the "dropping sledgehammers" problem, you have, in essence, created a "low frequency resonance" problem... In my opinion, that's not a good plan.
I appreciate your efforts to steer people clear of what you consider to be my (and others') mistakes. Please bare in mind that although there are obvious accepted ways of doing things and I agree with all of them, there are also alternative ways and that some of us here do not have the funds to construct full floating thick concrete slabs. Also, that even though some methods are not proven to one person's or group of persons' satisfaction, it doesn't mean that they do not work. I have seen reversal or perceived reversal in one's opinions right here in this forum. Please also understand that everyone here has a purpose for their project and that some variances in design are good things. We can all remember (or have read about) the changes in acoustical designs and preferences through the past decades.I realize it's probably too late for you to change course, Scott -- but I do want to go on the record on this in an effort to help others who come along after you. I really am crossing my fingers for you that you will be satisfied with the results of your labor and investment when you are done. :) Maybe you'll come to enjoy and/or get used to the rumble in time...?
As previously stated, so far I am very pleased with the results and as for having a rumble, you have made an assumption. You have not heard the room, nor have you any information other than what I have given you. That information being that the floor has a slight LF resonance. The floor has no more resonance than walls or ceilings that are not constructed of concrete but of wood and gypsum. If I were to take readings of the room it is more likely that LF issues are due more to the size of the room (approx 13'x16') than by the floor construction. Most of those issues have been addressed and as with any studio, will be an ongoing process for some time. Honestly, I am not trying to be offense, or defensive :). I am simply stating things as I see them. I greatly value the information presented by you and others here. Please accept the post in the manner in which it is intended. ScottI really am crossing my fingers for you that you will be satisfied with the results of your labor and investment when you are done. :) Maybe you'll come to enjoy and/or get used to the rumble in time...?
Whoa.... Looks like I got somethin started.. Hooray for me.
Thank you all VERY MUCH!!!! I really appreciate the wisdom. Hopefully I won't bug you all with too many more newb questions, but I will let you all know how the studio looks/behaves when it's done!!!!
-hildy
Scott, my hat's off to you. :-) You present really good perspective and are very respectful in the delivery.
You are correct that I'm making assumptions, and ironically, that's the main point of the sticky thread -- not to make them.
I still maintain my point of view that you haven't necessarily helped with airborn noise isolation by having a floating room moreso than you would have had with a firmly attached room on the existing slab with just as much attention to detail not to bridge in the "sideways" or "upwards" direction...
Nevertheless, they are your ears, not mine, so I ought to respect that! :-)
That's fair, right? :-)
Oh, and I must just say for the record that Auralex's stance that measuring loads in dynamic weight environments is futile and pointless is just utter bull... :evil: ...At least they're consistent! :lol:
--Keith :mrgreen: