Dan, you still seem to be missing the
forum rules for posting (click here). Please take another look at those.
2) Current floor is concrete slab / 2x6s on edge nailed into slab / beefy AdvanTech flooring on that ...and was going to put bamboo on top of Advantech. The "raised floor" was in place before this project started.
If that were my place, I'd take that out, get down to the bare concrete again, and lay your bamboo flooring on that. You'd gain 6" in room height, and you'd lose the resonant drum head that your room is built on right now.
it is directly on ground and a similar slab on the property can get wet / slick from moisture
Then you have a vastly more serious problem!
If the slab gets wet, that means water is seeping up through the slab from below. That is a serious problem, and right now you don't even know how serious it is because you have ti hidden from view by the raised floor, which (even worse still) is trapping all that moisture in the floor cavity: Can you say "mold, mildew, fungus, rot"? That's a major problem and should be fixed before you go any further. You'll need to call in specialist who deals with this type of problem, to open up the floor, take a look at just how bad it is, and give you alternatives for fixing it.
If this place was built recently, you probably have legal recourse to getting the original contractor or realtor to pay for the repairs. It means the slab was not poured correctly over a suitable DPC or other type of waterproof membrane.
This is your biggest problem right now, and is way more important than finishing the studio. Don't underestimate this issue.
And since you will probably need to take out much of the raised floor to fix it, you might as well take it all out and do the studio floor right.
Don't fully understand exactly what I lose by not returning to slab.
You lose isolation, since that cavity acts as a resonant system, you lose room height, and you lose acoustic quality in the room, since that floor basically is a membrane trap, which is very likely not tuned to a useful frequency, so it will be sucking out frequencies that don't need sucking out, and not sucking out the ones that do...
Will it effect the quality of sound while tracking if there is sound that travels through the AdvanTech / floor or is it more an issue of bleed into control room for monitoring?
Probably both.
3) The holes in the walls were to be covered by wall mounted plates ..but yeah I see your point. Those holes are really big and it is logical that they may cause yet more bleed. What if I only leave a hole in wall for size of wires and either add more sheetrock behind the plates or fill the holes some other way.
Even tiny gaps can have a huge effect on isolation. For example, a 1/8” opening around all four sides of a door will reduce the effective rating of an STC 52 door down to an STC 21.... Your electrical boxes add up to substantially more than that, at a rough guess...
So how much isolation do you want between the CR and LR? If 20-something decibels is good enough, then you are OK. But if you need the type of isolation that most studios need, in the range of 50-something and up, then you can't have any holes like that in your walls.
would be looking first to correct the problems that require minor effort with little or no big re-construction as I think this project might lose momentum if we knock everything down and start again.
You don't have to knock everything down and start again: you just need to take some things down, and re-do those parts.
And you have the choice here of "losing momentum" and ending up with a great studio done more slowly, or a far-less-than-great studio done fast. If that were my studio, I know which course I would take...
(See my signature block at the bottom of all my posts...)
Even if I need to monitor with headphones in control room while tracking, that seems better than the re-construction alternative
They why go to all the trouble of building an isolated control room, if you can get the same effect for the cost of a good set of headphones? I'm not following your logic here...
Besides, headphones can never give you the same sound as a good set of speakers in a good room.
4) I bought the surround sound monitoring system with a bunch of other gear because I got a deal when buying it all. Initially I thought this was overkill because not sure if I am going to do surround mixes any time in the near future. Would you sell this and buy stereo monitors?
Absolutely! No doubt. If you are not going to be doing 5.1, and don't have the equipment or the need or the skills to do it, then sell the 5.1 stuff and use that to buy yourself a pair of good quality studio monitors, such as maybe the Adam A7X or A8X, or maybe some Genelecs or Events, or something like that. They will be way more valuable to you than a 5.1 system that you can't even install decently in that room, and even less use. Since you say that this studio is basically just experimental, to see if you want to turn the hobby into a career, then wait until you make that decision to see if you also want to follow that career down the 5.1 path, or the 2.0 path. No use in taking a decision on that now, when you aren't even certain that tracking and mixing are going to be your future.
In the case of the drums, they sit on a platform of 2x4s on edge ...and that sits on the "subfloor" mentioned before that is raised off of the concrete slab in the whole building ... which is 2x6s on edge.
Hoo boy... That's a triple-leaf resonant cavity, that is doing some very strange things to the room acoustics, as well as to your isolation. That's not the right way to build a drum riser, and the floor is wrong too, as mentioned above.
QUESTION: Is there something that I can put under the drum platform that will be use at all in absorbing some of this sound, especially lows from the kick and floor toms
No. The issue is rather more complex than that. The drum riser that you have built is a resonant box, that resonates at some frequencies but not at others. It both absorbs some of that resonance, transmits some of it to the next layer down (the resonant floor), and also re-transmits some of that resonance back to the room, smeared in time. So it is doing multiple tings at once to harm the room acoustics. There is no material in the universe that you could put under the drum riser to solve those problems, simply because thy are not due to the riser sitting on the floor. They are due to it being a resonant cavity. The only way to fix that is to get rid of the resonant cavity! Scrap that, and build a proper drum riser that actually does isolate the drum kit from the floor.
Correct! It most certainly is not your "best cost / benefit"!!! That's like trying to put a band-aid on a severed artery. And a very expensive band-aid, too!
Another option we have considered is just to use some sheetrock to make temporary walls right next to existing walls. Maybe decoupled with the actual building walls, the two together can limit enough noise to make it viable
Then you would have three-leaf walls, which are even worse at isolating low frequencies than two-leaf walls: That's not intuitive (like many things in acoustics) but is simple fact.
If I did this, I'd frame normal 2x4 with sheetrock covering one side. Then what. Do I fasten another MLV product to the back? Just put rigid insulation inside? Acoustical foam anywhere (maybe on the room side).
I chose answer "E": "None of the above". You'd get a much greater increase in isolation (at least ten times better, perhaps as much as one hundred times better) by taking off the drywall from the interior of the rooms, using it to "beef up" the mass on the other side (in between the studs, which you will expose when you take off the drywall), putting suitable fiberglass or mineral wool insulation in, THEN building your new framing an inch or so away from that, and putting two layers of 5/8" drywall on only ONE side of that framing (not both sides). That would get you upwards of 50 dB of isolation, if done correctly, as compared to the roughly 20-something you are getting right now.
Another option would be to do the same as above, but instead of making the second frame, put Resilient Channel on the existing studs and put the drywall on that, or even better, put RSIC clips on the studs and put Hat Channel in those, then put the drywall on. That won't be quite as good as doing the second frame, but will still give you a huge increase in isolation, compared to what you have now.
2) The sound of the room - Does the temp 2nd wall hurt the sound of the room in any way?
Isolation does not have much effect on the room acoustics, except in the sense that the sound that you are stopping from getting out, now has to stay in, so yo increase the overall reverberant field inside the room. But that's independent of the materials that you use to do it.
Isolation and treatment are two different things, not very much related. They are both aspects of acoustics, yes, but very different aspects. You will still need to treat your rooms with proper acoustic treatment, regardless of how you isolate them.
I have ordered a couple of books on acoustics and hope to know a bit more before I start treating the space for sound.
The best book on that is "Master Handbook of Acoustics" by F. Alton Everest (that's sort of the Bible for acoustics).
If I put some treatment under the platform and built another temp wall (in connectable partitions) how much can I expect to lower the DB bleed outside on a % basis?
You can't measure transmission loss in percentage. Or rather you can if you want, but is is pretty meaningless to most people. If I said that doing what you propose would reduce the intensity of sound transmission to the outside by 50%, you'd probably think that is wonderful, but in reality reducing sound by 50% is only reducing it by 3 decibels... And if I said it was 75% reduction, you'd be ecstatic... until you realize that 75% reduction is the same as 6 dB. The reason is that the decibel scale (and the way we perceive sound) is logarithmic, while percentage is linear. You have to get really large percentages of sound isolation to have a meaningful
perceived reduction. Even 99% reduction in sound intensity is only 20 decibels. What you need for your room is likely something like 50 dB reduction, which is a reduction of about 99.999% in sound intensity.
With that in mind, what you propose would probably reduce sound transmission from the drum kit to the outside world, by about 30%.
Am I missing a better potential solution ...one that won't require major de-construction?
Yes .... no. !
In other words, the answer to the first part of the question is "yes", and to the second part it is "no".
But you don't need to tear it all down and start again: if you really do want to have a good studio, with good isolation, there are simple things you can do that only involve partially dismantling some of what you have done, and re-using most of the materials that you take down, so there is not much waste involved either.
I guess the question is whether you are willing to bite the pullet, put the brakes on, take a few steps back, and then continue building to get a great studio, or whether you prefer to carry on and settle for a mediocre studio with poor isolation and so-so acoustics,... like the one in my signature line, below....
Dan, I'm not trying to be a wet blanket, or to deflate you, or denigrate the work you have done so far. Rather, I'm trying to be helpful, buy pointing out what is wrong and how you can fix it. So please don't take all of the above negatively: You certainly aren't the first person to come to the forum and get his parade rained on! Many people come here with similar issues, then do the right thing and end up with great studios. Some don't do the right thing, and carry on their own way, but their threads sort of tail off into emptiness, and we never seem to hear about how their studios turned out. And if they DID turn out great, I'm sure they would have told us. But they don't. It's a hard choice to make, but hopefully you'll make the right one!
- Stuart -
. Present exterior walls are just 5/8"" sheetrock (I think), fiberglass bat insulation in the wall, plywood, and clapboards on outside.