Fixing an overtreated room...

Size = 21'4"x19'x7'6" *excuse the mess. also I have Adam A7X monitors on order so ignore crappy rokit 5's as well. :lol: The room used to be a detached garage, but it was turned into a room. Plywood and insulation was placed on the garage floor with carpet over that. No neighbors to worry about, 10 acres of land! :twisted: The walls are mostly fabric with fiberglass insulation (paper side) behind it. The wall with the gold colored fabric in the picture with the door just has polystyrene insulation behind it. The ceilings just have thick blankets on them hanging down, and plywood ceilings are above that. Now what I've decided to do is put DIY rigid fiberglass 705 bass traps in the corners, put plywood over the carpet, and add various vertical strips of 1x2, 1x3, and 1x4 lumber on the walls covering about 30% of the walls. I've just come here for some more input on what I'm doing. Should I add diffusion? More bass absorption on rear wall? Should I put fiberglass between the blankets and the ceiling for more bass trapping? I might want to reconsider the placement of the monitors and drums as well. I'd like to keep this DIY to save money. I'm willing to spend up to $2000, but I'd really rather not if I don't have to. :lol: This for my small personal home studio if you can tell, recording all kinds of instruments (including drums) just one at a time. Indie pop/experimental rock music. Let me know if you need more information, thanks for the help! :yahoo:

Where to start??? :) OK, what problems are you hearing with that room? What is it going to be: a practice room? A live room? A control room? All of the above rolled into one? Something else?

Plywood and insulation was placed on the garage floor with carpet over that.

Ouch! So at least you plan to get rid of the carpet by covering it with more plywood, but what is UNDER the original plywood? If it is bare concrete, then maybe ripping out all the plywood, insulation and carpet might not be a bad idea. That would leave you with a good surface, and would gain you a little bit of height, too! And you sure do need height! At 7'6", that is a really low ceiling. Not good for tracking drums (mics too close to ceiling), not good for listening either. Ever millimeter of height you can win back is going to help a tiny fraction extra. So I'd say rip out what ever you can on the floor. Even if it only gains you an inch or so, that's still an inch or so that you didn't have before.

The wall with the gold colored fabric in the picture with the door just has polystyrene insulation behind it.

The polystyrene isn't doing anything much for you, acoustically. Pretty worthless. That should go too. Maybe replace it with plain old 703, or some such. Re-using the "gold colored fabric" is up to your ... err ... sense of decoration! :)

The ceilings just have thick blankets on them hanging down, and plywood ceilings are above that.

Ouch again! So you hard a semi-soft carpeted floor, and a hard ceiling? Pretty much the opposite of what it should be. Leave the floor hard and reflective and put something thick, soft and absorbent up where the plywood is: Fiberglass or mineral wool. Once again, putting the "decorative" blankets back in place afterwards is up to you!

Now what I've decided to do is put DIY rigid fiberglass 705 bass traps in the corners,

Any reason why you want to use the 705, instead of 703 or even plain old pink fluffy stuff?

and add various vertical strips of 1x2, 1x3, and 1x4 lumber on the walls covering about 30% of the walls.

Suggestion: Do the "strips" horizontally, space them carefully, and make it into a proper slot wall, using John's design and dimensions. Much better!

Should I add diffusion?

The room doesn't really look big enough for diffusion to be of much help. Having said that, some folks like diffusion even in small rooms.

More bass absorption on rear wall?

Yup. Bass trap as much as you can. It's a small room, so more bass trapping can only help. Make it deep. My 0.02 - Stuart -

Soundman2020 wrote:

Where to start??? :) OK, what problems are you hearing with that room? What is it going to be: a practice room? A live room? A control room? All of the above rolled into one? Something else?

All the above. I really just do recordings for myself and a few friends. I track the instruments one at a time.

Soundman2020 wrote:

Ouch! So at least you plan to get rid of the carpet by covering it with more plywood, but what is UNDER the original plywood? If it is bare concrete, then maybe ripping out all the plywood, insulation and carpet might not be a bad idea. That would leave you with a good surface, and would gain you a little bit of height, too! And you sure do need height! At 7'6", that is a really low ceiling. Not good for tracking drums (mics too close to ceiling), not good for listening either. Ever millimeter of height you can win back is going to help a tiny fraction extra. So I'd say rip out what ever you can on the floor. Even if it only gains you an inch or so, that's still an inch or so that you didn't have before.

:evil: All of that hard work putting that carpet and floor in gone to waste! :cry: That would gain me about 7 inches btw and a bare concrete floor.

Soundman2020 wrote:

The polystyrene isn't doing anything much for you, acoustically. Pretty worthless. That should go too. Maybe replace it with plain old 703, or some such. Re-using the "gold colored fabric" is up to your ... err ... sense of decoration! :)

Ok.

Soundman2020 wrote:

Ouch again! So you hard a semi-soft carpeted floor, and a hard ceiling? Pretty much the opposite of what it should be. Leave the floor hard and reflective and put something thick, soft and absorbent up where the plywood is: Fiberglass or mineral wool. Once again, putting the "decorative" blankets back in place afterwards is up to you!

Heh, as I said I could fill up the area between the blankets and ceiling with fiberglass.

Soundman2020 wrote:

Any reason why you want to use the 705, instead of 703 or even plain old pink fluffy stuff?

I read Ethan's Guide and he said the 705 is slightly better, especially if it is 4" thick vs 2". http://www.ethanwiner.com/acoustics.html

Soundman2020 wrote:

Suggestion: Do the "strips" horizontally, space them carefully, and make it into a proper slot wall, using John's design and dimensions. Much better!

Why horizontally? Ethan's Guide said to do it vertically, plus it's much easier for me as I don't have to measure as much. :P Also could you link me to the design you're referring to?

Soundman2020 wrote:

The room doesn't really look big enough for diffusion to be of much help. Having said that, some folks like diffusion even in small rooms.

How big does a room have to be? 20x20 doesn't seem that small to me. :?

Soundman2020 wrote:

Yup. Bass trap as much as you can. It's a small room, so more bass trapping can only help. Make it deep. My 0.02 - Stuart -

Would stacking up bales of rolled up fiberglass in the corners work well enough? Besides that if there is already soft walls with insulation behind them, and if I put 703 in the ceiling, is that not trapping bass? I don't understand how I'd go about adding more bass trapping. Thanks! :D

All the above. I really just do recordings for myself and a few friends. I track the instruments one at a time.

Are you also going to use it as a control room? Meaning will you actually mix in there?

That would gain me about 7 inches btw and a bare concrete floor.

7'6" plus 7 inches is 8'1". Much better! Some people stain the bare concrete, and they get really cool effects (search the forum), but if you want something a bit warmer looking, you could try laminate floor. It will only take a few millimeters of the height, and some of the latest stuff looks pretty darn good. Hard to distinguish from real wood, unless you take a real close look. And very reflective, acoustically.

Why horizontally? Ethan's Guide said to do it vertically, plus it's much easier for me as I don't have to measure as much. :P Also could you link me to the design you're referring to?

Well, sound waves don0t really care which way the wood runs! Personally, I think horizontal looks better than vertical, and its easier to build, IMHO. But spacing and depth are important. Slot wall: http://www.johnlsayers.com/HR/index1.htm search.php?keywords=%22I+like+Bruce%27s+slots+%22&terms=all&author=&sc=1&sf=all&sk=t&sd=d&sr=posts&st=0&ch=300&t=0&submit=Search Also try searching the forum for slot walls. Many examples here. And they work really, really well.

How big does a room have to be? 20x20 doesn't seem that small to me.

But you are not a sound wave! You can't even fit half of a 20Hz wave in your room, end to end... :shock: :lol: OK that's not really relevant to diffusers, but the point is that sound waves don't necessarily behave the way things look. Most diffusers produce some kind of lobing up close, where levels vary greatly over a small area. It takes several meters for the lobes to blend and smooth out. So they say. Some people like they way it sounds in a small room, others are more purist and trust the math. Personal choice, I guess.

Would stacking up bales of rolled up fiberglass in the corners work well enough?

Yup!

Besides that if there is already soft walls with insulation behind them, and if I put 703 in the ceiling, is that not trapping bass? I don't understand how I'd go about adding more bass trapping.

basically, the issue with bass trapping is depth. An inch or two thickness of absorption will do wonders for highs, less for mids, and practically nothing at all for lows. In order to absorb bass frequencies effectively, it has to be thick. Several inches thick. John can tell you stories of rooms with bass traps that are several FEET deep, hidden behind cloth. The trouble with very thick absorption is that it does good things to bass, but totally kills all the highs, which isn't so good. So one idea is to wrap the insulation in plastic, to reflect the highs more. Another is to put something reflective in front of it, such as maybe some strips of wood, with gaps between them, tuned to certain frequencies.... also known as a slot wall... :) There are other ways of trapping bass: hangers is John's favorite, I think. Panel traps. Etc. Bass traps are more effective in corners, since you get a free 12 dB boost from the walls (theoretically), so corners are the best places for them. But many people forget that there are twelve corners in a room, not just four of them... plenty of space to put effective bass traps in. - Stuart -

Soundman2020 wrote:

All the above. I really just do recordings for myself and a few friends. I track the instruments one at a time.

Are you also going to use it as a control room? Meaning will you actually mix in there?

Yeah. I just cover up the drums with blankets to stop them from resonating. :lol: I record myself though, and if I had the computer in another room it would be kind of awkward. :? Although technically the computer in is the other room to cut down on noise. :wink:

OK well I couldn't remove the floor since I actually need the insulation under it. I did however put some 1/8" sparta oak 4x8 boards I had down on half of the floor. I don't notice much of a difference yet except in one part of the room where there is a bit more echo. :? I guess it's because there is nothing else reflective in the room except for some of the 2x3's in the frames on the walls.

OK slat walls hurt my brain. :shock: Are you suggesting I build a box with a slat wall or just put the strips onto the wall in that configuration? How do I figure out what the specific measurements of the slats and gaps are for my room? Does it stay the same across the room? Do I build a corner one or just stick with the bale of fiberglass idea? :?