Cool. That wasn't hard was it?
Now we can get down to business. Ok, lets look at each statement and expand on its implications.
Q. 1. Who is above, (neighbors or family and what room of the house is it)
A. 1. Family and it is the tv room.
This implys that at certain times, people will be generating noise at the same time you are. This translates into a ROBUST MASS ceiling solution. What this means is ADDING MASS to the UNDERSIDE of the floor above. This is called the 2nd LEAF. Once this is installed CORRECTLY, and I do mean correctly, then other things can be done. However, there are many other things to do prior to this step. I'll give you a list of things to do once our schedule of solutions is in place. One thing I ask here.
DO NOT JUMP THE GUN AND START ANYTHING UNTILL EVERY DETAIL IS ADDRESSED. Otherwise, you could jeprodize the entire project by overlooking an important step before I can post it. OK? Ok. Now that we are clear, lets move on.
Q. 2. Are you trying to keep sound from entering the space above COMPLETELY?
A. 2. completely
Let me make something absolutely clear here. There is NO such thing as absolute "soundproof", especially with LOW FREQUENCY. But what we can do, is guarantee we meet a TRANSMISSION LOSS RATING. Let me explain.
The ONLY way designers of structures know that what they are designing will meet "sound transmission criteria", is to know what that criteria is, and trust the RATING given to a type of assembly by a TESTING LABRATORY.
These ratings are usualy given in whats known as STC ratings, which means SOUND TRANSMISSION CLASS. For instance, a standard residential wall assembly built with WOOD STUDS and ONE layer of 1/2" drywall on each face is given a rating by a labratory after testing for SOUND TRANSMISSION through it. Here are a set of examples showing the ratings of various types of WALL ASSEMBLIES. However, STC is a rating of how the assembly inhibits the transmission of SPEECH, not music. But it will serve to illustrate some concepts.
Notice that the one on the far left is a standard residential wall assembly. This is called a TWO LEAF assembly, as it has ONE LEAF of mass, an airgap, and another LEAF of mass on the opposite side of the framing. Note it has an STC rating of 33. Now look at the next one. It is also a TWO LEAF system. However, the stud cavity, or airgap, has been filled with batt type insulation, and the STC rating has improved to 36.
Now look at the next one. This is a DOUBLE WALL, with drywall on each face of BOTH walls, and it has an improved STC rating of 40. This assembly is called a FOUR LEAF system, as it has four leafs of mass, and THREE AIRGAPS, two of which are filled with insulation in the stud cavitys, just as in the prior example. The airgap between the walls is empty. But now look at the next example.
HOLY SHIT. In this example, one leaf of mass has been removed, and the STC rating JUMPS to 50!!!! This is called a THREE LEAF system, and it has a better rating than the four leaf system. WTF?????
Now look at the next example.
GOOOOOOOOOOOD GRIEF...In this example, ANOTHER interior leaf is removed, one layer of drywall is added to each leaf, and the STC skyrockets to 63...AND, we are back to a TWO LEAF system. However, because each leaf of mass is DECOUPLED from each other by virtue of their OWN FRAMING.
Now do you begin to see why we must use DECOUPLED MASS?????? My friend, this is called PHYSICS. These are proven concepts, and this is why, in order to achieve the rating we are after, you MUST ADHERE to the concepts. This means paying attention to EVERY SINGLE DETAIL, in order to keep the decoupling intact. However, there are a ton of details to address. Later on those issues though.
But now we have a problem
How do you know the rating you need to COMPLETELY stop the transmission of sound through the existing structure, if you don't know how much sound transmission you have currently? I'll tell you how. MEASURE IT
And how do we measure it? With a sound level meter, thats how!!! So, your first assignment is to purchase a sound meter. You can get one from Radio Shack.
They're not very expensive, and fairly easy to use. More on that later. But here is what you have to do. Move your setup to this space you are going to enclose, and set up the speakers in the general location that you will ultimately have them setup(More on that subject later). Proceed to playback some TYPICAL music like you will be recording, at the TYPICAL volume. Now you will measure the sound at 1', 3', & 10' from the speakers(you will have to set the meter to an "A" wieghting I believe. More on that later} Once you know the TYPICAL sound level you will be generating, THEN, its time to do the same thing in the ROOM ABOVE. Once you know what sound level you are generating(db profile), and how loud it is in the room above, we will have an idea of how good/bad the EXISTING transmission loss through the floor and structure is. However, even though this is something only experienced acousticians can ABSOLUTELY determine and interpret into a solution, it will give us an approximate idea of what you are up against. Once we have these values, there are some experts here that we can call on to interpret them, and suggest an appropriate set of solutions. More on that later, although I'm sure our experts have an opinion on this suggestion, good or bad. Lets hope good
In any event, this is what I would do in your shoes without the luxury of hiring an acoustician. Hey, whatta ya want for free?
Ok, listen, for the moment I'm outta time, but I'll be back later to carry on.
And PUUUUUUUUUUULESE, excuse my verbose replys, but how else can one TRULY help someone under these circumstances. Simply telling you a MASS AIR MASS system is what you need, actually tells you nothing in regard to actually BUILDING THE DAMN THING. So hang in there, I'll be back.
fitZ
