What's your opinion, spend $550 (leftover + budgeted) for treatment or $825 and forget the Green Glue?
Hi Robn, I'm glad you asked. Yes, I have an opinion. And that is.. you need to do some SPL tests to make this decision. First off, the WHOLE isolation issue hasn't been addressed from a point of ACTUAL Transmission loss standpoint. In my opinion, why spend the money on TL strategys IF you don't really need it. And btw, remember my disclaimer. I am NOT an expert by any means. This is only my non expert opinion.
Here is what I'm talking about. You have THREE isolations issues. (that I see)
1. Sound propagation to the outside world via transmission through the building envelope. In your case, transmission through the floor/garage door/roof, towards your neighbors. Westward, I assume you have a neighbor closest to your garage door. Southwise, there is nothing, other than a bedroom. East, you have another neighbor. However, they are not adjacent to the garage door. North, is a street, which means there is distance to a neighbor across the street(if there is one
). However, you have a brick wall with a weak link..ie..window, which I don't know what you did to improve TL through it).
2. Sound propagation to other living areas via airborn paths( common HVAC ducts, which hopefully your baffle boxes will help), leakage through door/jamb gaps and latchsets and or minute drywall gaps), low TL values through the rear wall assemblys(door/drywall/floor mass) and STRUCTURAL transmission via non-decoupling of the interior shell/ and or direct monitor coupling.
3. Reverse TL....ie...exterior/houshold noise propagation through the building envelope and HVAC.
Basically it boils down to this. WHY do you need additional isolation values above those that standard residential construction provides? Seems like a fair question, no? Well, this is exactly the point. Usually it is the FEAR of annoying some "persons" to the point that you must either:
1. Lower your monitor/performance volume levels to that which may "affect" subjective performance criteria, or subjective listening criteria, or even keep you from making CRITICAL listening decisions.
or..2 Improve the Transmission loss of your studio envelope to reduce this potential FEAR.
There are no other choices. Simple as that. Unless you DON"T fear.
In that case...whats the point.
So,first off, lets define these PEOPLE who you potentially "fear"
Who is it that you are trying to keep from annoying, where are they, what SPL is arriving within their sphere of reference, and what do you do to reduce it. Simple as that.
In order to DEFINE exactly what it is you need to do to successfully meet your TL goals, you need to find out EXACTLY what will possibly occur when your studio is performing what is designed to do....that is...PRODUCE sound.
But what exactly is the SPL of the sound you are producing? Without knowing this, you have no reference to the SPL reaching potential "fear inducers"
Not only that, but what sort of EXTERNAL sound do you either anticipate or actually experience that:
1. Masks or "colors" that sound which you are producing via instruments(your vocal chords are an instrument
) or your monitors.
2
This means you need to perform some tests to identify the EXISTING TRANSMISSION LOSS. Here is what I would do. I believe you have an SPL meter, no? If so, you need to find out the SPL of your LOUDEST monitoring/performance, at different SPECIFIC bands of frequencies, as well as broadband sound such as different types of music, and then,
SPL of sound that is arriving at these potential fear inducers "sphere of influence", which may mean a neighbors yard boundary, an adjacent room, or rooms downstairs. So....
1. Purchase or download a CD of TEST TONES. Heres a few.
2. Gather some CD's of a broad range of music that is similar to what you might actually record or even listen to in your studio. Then
3. Set up an amp, playback device(CD, computer..whatever), and your monitors, guitar amp, and what ever else you may use to produce LIVE sound.(yes, you will also have to SING
at the level you would during a recording performance.
4. Meet your neighbors and explain what you are trying to do. See,at their convenience, if they are willing to (help) to your effort to keep sound from potenially annoying them. Arrange for a time when they can listen over a period of say a half hour(maybe while doing houshold chores), when you can conduct these tests. IF, they are not willing, or you just don't want to bother them, then you must decide WHERE the boundary of influence is. Unfortunately, without acknowling their PERSONAL threshold of "annoyance",
you have to decide(guess) the maximum SPL that reachs this arbitrary boundary, such as the property line or fence. From that point, to the inside of their home, you have no idea of what TL occurs...ie...sound decay due to distance from fence to their building envelope...and the actual TL that their building provides.
5. Arrange for some help. You either have to:
a. record a continuous stream of tones and music so you personally can measure SPL and note, ... inside your room, the hall, the bedroom, downstairs rooms, especially the HVAC register locations( not to mention possibly at the HVAC units themselves in the attic) in the garage and outside the garage(with door open and closed) and at the various boundarys...like each neighbors fence...WHILE the stream is playing. OR,
b. Have someone do the measuring and notation of the SPL reaching the various locations while YOU playback the various tones and music as well as PERFORM....ie...play and or sing LIVE.
6. Actually perform the tests. I suggest you make up a sheet for each location, and make a column of frequency bands, like 40hz-100hz,100hz-250hz etc or whatever your Test Frequencies are. You might have to calibrate your monitors to something on the specific Test tone product. Then make rows of locations. Now playback each frequency at a specific maximum playback level that your ears tell you is the maximum level at 1000hz.
Note each of the SPL levels at each of the frequencys, at the ENGINEERING POSITION IN THE STUDIO.
Now do the same thing while playing your guitar, and then SINGING.
Now playback each of these frequencies again while listening at each of the locations and note the SPL levels at each of the frequencies. This is where you probably will need help. Either someone operating the playback or doing the listening/SPL meter notation.
Once you have all this info, then you will be able to somewhat get an idea of the TL at each area/location. From this, we can formulate an idea of what it will take to bring your TL up to snuff. Unfortunately, it really takes an expert to analyze this type of data, but I'm certain it will tell us something about your existing TL vs what you need to do to improve it. OTHERWISE...
go for the BRUTE FORCE methodology and simply bang up two layers of 5/8" with NO green glue. I believe the only way you will know if you need the GG or not is to do these tests as from my understanding, as GG removes double coincidence dips in two panels(makes them act as one). Whether or not you actually need GG withOUT testing, is sheer guesswork. Even with the tests, it would probably take an expert to decipher EXACTLY what is taking place, but at least we would have some data to work with vs none.
To go ahead and use it arbitrarily is probably the same thing as BRUTE FORCE. Same with the RC. At least in my estimation. However, thats a LOT of extra money and effort to gamble on, given your studio purpose, unknown maximum monitoring level, unknown existing TL, unknown FEAR INDUCER tolerance levels etc.
What I'm trying to say is this. If it were me, knowing what I DO know about your situation , I'd forget the GG, Slap up 2 layers of 5/8" and spend a BUNDLE on treatment. I paid $600 for 4 sheets of 4" thick 4'x10' and 2 sheets of 3"x4'x10'. If you spent $825...I'd submit your studio would sound grand. Remember, the smaller the room, the more LF trapping you need. To the point where yea, it may get deader than a doornail in there, but you aren't trying to make a "live room" anyway. And theres always the FRk approach as well. (use a film over the traps to reflect the mids/highs).
Anyway...you asked, thats my opinion. Do what is best for you though Robn.
These are only my non expert suggestions to make decisions. An expert may disaggree. But so what. They disagree amongst themselves.
Sooooo, heres what we'll do. I'm going to run this across the bow of some very acoustically "in tune"people cause like I said, I'm no expert on the science side of this stuff. BTW, before I do, tell me something. What "weight" setting did you have on the SPL meter? I completely forgot to tell you to use the "C"...uh, that is, I THINK I forgot to tell you...my memory sucks.
D) is the most difficult. Naturally, you don't want ANYBODY to hear a thing! However, lets put it this way..if you needed 60db of isolation between you and each FI's, and the maximum TL you can realistically achieve was only 45db...well, I think you get my drift.
I had to remove the wood threshold and replace it once the boards were in place. Oh well, it worked and all was good.
