though I am surprised nobody on the other drum forum said anything at all!
Most likely because drums forums is not where you should go to fins out how to build a studio!
:) What I mean is, a drum forum is where drummers go to talk about drums, and you can't expect those folks to also know about acoustics. This forum is all about acoustics, but you won't find too many folks here chatting about why one brand of drum head is better than another for jazz, but lousy for rock, provided the you use zzz brand of sticks, made of yyy type wood... or some such... : different purpose to the forums, different sets of expertise. Folks over there know their drums, inside and out. Folks over here know their acoustics, inside and out. Different worlds...
We'll obviously deal with the acoustics aspect on the inside once the "outside" is done...so I see the mission here now as being: accomplish as much of an acoustical improvement as possible through the construction, or rather (right now) -- reconfiguring the dimensions to set the construction template.
That's the basic idea. Another big thing that takes a while for most people to get their head around, is that room isolation and room treatment are two entirely different and in fact opposite things. The stuff you use to treat your room acoustically is really lousy for isolating it, and the stuff you use for isolating it is really lousy at treating it. In other words, stuff like fiberglass insulation and acoustic foam does nothing at all to stop sound. It sounds counter-intuitive that something that is
absorbing sound is actually not doing anything at all to
stop sound, but that's the way it is. There are a lot of things about acoustics that just aren't intuitive.
So, your first order of business is to isolate your room. THEN you treat it afterwards. Isolating it will make it sound bad. Treating it will make it sound good again. Isolation makes your room sound bad, because it stops the sound from getting out. If the sound cannot get out, then it stays inside, bouncing arouuuuuuuuuundddddd..... Think of it this way: with both heads on your kick drum and no holes, that thing resonates loud and long. But fill it with towels and leave the front head off.... It sounds a little different! When you isolate your room, in effect you are making it into a kick drum with both heads on, and nothing inside. The sound stays inside, bouncing around.
OK, that's not a brilliant analogy, but you get the idea.
So the idea is to design the isolation such that it does the least "bad stuff" possible to your room. That's where the ratios come in. Just like you can make a drum sound bad or good by tuning it, and control resonance in various ways, so to you can "tune" your room, but not in the same way as you tune drums, of course!
It works like this (simplified explanation): You probably already know that for each frequency there is an associated wave "length", meaning the distance between the peak in one cycle of the wave and the same peak in the next cycle. For the frequency where that distance happens to fit in between two walls of your room exactly, the room will resonate. So if you have two walls in your room that are 16 feet apart, then any time you play a note of 35 Hz, that wave will fit perfectly between the two walls, and you have a "mode". The same happens at 70 Hz, because two waves fit in. And 105 Hz, because 3 waves fit in. Etc, all the way on up the scale. For every harmonic of 35 Hz, the room itself will resonate in between those two walls. You will have "room modes" at every multiple of 35 Hz. Basic physics.
So let's say your room that is 16 feet long, is also 8 feet high (for example). You probably see the problem already. If two wavelengths fit into 16 feet, then clearly one wavelength will fit into 8 feet. So now every time you hit 70 Hz, you are going to activate TWO room modes: the one where two waves fit into 16 feet down the length of your room, plus also the one where a single wave fits in vertically: So now the room resonates twice as loud for 70 Hz.
OK, lets say your hypothetical room is also 8 feet wide... Now you have the room booming away fantastically THREE TIMES as loud, every time you hit 70 Hz. But if you hit a note at 80 Hz, the room does nothing: it does not respond, because an 80 Hz wave doesn't fit: it dies, fast. But if you could make the room 13 feet wide (instead of
8) then now you have a mode at 80 Hz too, and you lost one of your modes at 70 hz. Good!
Obviously, modes are not nice: You want to choose dimensions for your room where the modes for the length do not line up with the modes for the width, and neither of those lines up with the modes for the height. You want to choose dimensions that "smooth out" the modes, so that they are spread evenly around the spectrum, with out any of them lining up, and also with no big gaps between modes.
So far so good. But there are other ways that waves can bounce around a room. The above is just for waves that bounce back and forth between two parallel walls (axial modes), but they can also bounce around between any four walls (tangential modes) and even between all six walls (oblique modes). So it gets complicated...
That's the basic idea (yeah, I know: half waves, not full waves, etc. Just trying to keep the explanation simple).
Hence, "ratios". Scientists have already figured out what the good and bad ratios are, so you don't have to do it. Just look at the ratio that you already have (or rather, then one you would have for your inner leaf with your current design), find a "good" one that is fairly close to that, and "nudge" your dimensions a bit to get even closer. Simple. You don't need to go overboard, down to the last 64th of an inch: just get in the ball park.
You might think that you can "cheat", and put your walls at angles so that the modes go away: they don't, unfortunately. They just move to different frequencies and different places in the room, and they get harder to calculate, but they are still there. There are other reasons why you might want to splay some walls, but getting rid of modes is not one of them.
Some folks seem to think that they can simply put egg crates on the wall, or carpet on the ceiling, to somehow "confuse" the modes, or absorb them, or something, but that doesn't work either: modes are a fact of life. You cannot kill them. All you can do is stop them piling up and spread them around the spectrum evenly by choosing a good ratio, and you can take some of the "bight" out of them with abundant bass traps in your room.
OK, that's the end of Acoustics 101 for today!
:)
accomplish as much of an acoustical improvement as possible through the construction, or rather (right now) -- reconfiguring the dimensions to set the construction template.
Exactly. At least as far as modal issues are concerned.
The thing is we've gotta think about new dimensions within the original dimensions I put out there.
Your inner-leaf wall won't take up too much space: If you design it carefully, you can probably get the entire width of your wall, from the outside of the siding to the inner surface of the inner leaf, to around 8 inches or so. And there are some "tricks" you can use to improve the use of space...
so comfort is really more of a luxury when we're talking about acoustics in the same sentence.
It can still be comfortable, and it can also look great, even if it is small inside. Take a look at something that John did with a container:
http://johnlsayers.com/Pages/Spark_1.htm
But I was wondering why one can't have a square or rectangle box for a room and trap it up with acoustic stuff post-construction, to make things less...parallel? Just curious
.You can have it rectangular if you want: but never square. Rectangular is fine, but putting some angles on the walls does help with other issues, and looks cool too! You don't need to angle much, and you don't need to angle all of the walls. One or two is plenty.
Does the narrowness of what we are working with affect the drum sound in a bad way at all (as well as obviously the angles)?
Yes. No. Maybe...
:) That ain't very helpful, is it? It all depends on what you do with the room. 9 feet isn't much to work with, but if that's what you have, then that's what you have. We'll just have to make the most of it. If you can supply an accurate SketchUp model of your garage, we'll see what we can come up with.
Scroll down to the post dated "Wed, 13 Oct 2010, 12:36:31", listen to those drum tracks that Lou recorded in his studio, and then look at the photos in the very next post about how he set up the mics. You can see from those photos that his drum room is even smaller than what you are proposing, but I don't think you'll complain about how they sound in that room!
:)
viewtopic.php?f=10&t=9156&p=105294#p105294
If so, what if we were to keep the original dimensions, for starters, and next cut it into two sections (creating essentially a two-sectioned "soundproofed" room)? The part of the garage where the ceiling of the projected room has to drop due to the structure of the garage's ceiling & garage door track...that's where we could have one wall separating the whole new room into two.
Mark that on your SketchUp model, as one possibility...
If this were to happen, the drums would be more (if not entirely) secluded underneath the high part of the ceiling, with the back of drummer facing away from the arrowhead tip of the room.
Good! Height is good! Height is your friend! Any time you can add height (or add more space in general) is most likely going to improve your acoustics. Especially if you ever plan to record your drum kit: You don't want your overheads too close to the ceiling, or you'll get comb filtering artifacts. So height over your kit is good.
That's good to know. So we're NOT going to be having a new floor, built from scratch, connected to the new walls. The reason why I thought we'd be raising the floor earlier is simply 'cause I figured we'd also be building a new floor. That was the reason for that.
Most people do think that: I thought that way when I first arrived here. I thought I knew that studios just HAVE to have a raised, floated floor... until I started studying acoustics, and figured out that most people do not need to float their floor, and if you do need to float it then you better have lots of money, and you better do all the calculations to do it right. But a plain old concrete floor is just great.
We'll probably be avoiding that which you said to avoid. Luckily we do have some experience with electrical but I had to run it by in the questions given it'll be in this kind of room...which is a first for us.
One other point on electrical: use "star grounding". You aren't planning a control room right now, but you might get one eventually, so start out now with star grounding to avoid hum issues later.
Anyway, I will definitely be returning here to pick back up this terminology for further researching.
Do yourself a huge favor, and buy two books:
"Home Recording Studio: build it like the Pros" by Rod Gervais.
"Master Handbook of Acoustics" by F. Alton Everest.
With those two, you'll have the perfect background for understanding all this stuff, and for building your room intelligently. Rod's book goes into things like how to figure your HVAC needs. And Rod is a regular poster right here on the forum, too.
:)
You said I CAN get where I want to be (and by that I assume you meant within our budget),
well, you CAN get there, but the budget might be another story... However, you did say that your uncle will do much of the work for free, and that he can get trade pricing on construction materials, so that works in your favor. But you could blow your entire budget just on the HVAC system... You might want to consider increasing your budget a bit.
We do want to get this thing going as soon as possible, but obviously get it done right, as it's not a cheap project, or a quick project, especially for us, the inexperienced within this realm.
That's why you are here! If you design carefully, and post your designs, questions and photos here for the experts to look at and comment on, then you should achieve success!
What of doing any lite-soundproofing to the main room (the garage's interior walls, as well as garage door, if the latter is even possible)?
"lite" and "soundproofing" are two words that just do not go together! They are natural enemies: you can't even put them in the same room...
:)
Isolation needs mass, period. If it is "lite" then it has little mass, so it wont isolate. There are no magical materials that can defy the laws of physics (despite what you might read on some manufacturer's web sites!
:shock: ) The only way to stop sound, is to put something in its way that it cannot move. That implies something large, solid, rigid and massive. I sure do wish there were some way around the laws of physics, but so far nobody has discovered any (and folks have been trying for thousands of years already...).
So; sorry, but that wont work. If you want to isolate well, you can't do it "lite". And the reverse is also true: If you only do it "lite" then it won't isolate well.
Still reading the thread...
Cool! It's a fascinating read. Took me a couple of weeks to get through it, because I kept on following all the links to other threads and other places, and read that stuff too. But I learned a LOT from that thread.
- Stuart -
P.S. You're hired!
Cool! Send the cheque! All major credit cards accepted... Cash too!
:)
