Shape of Studio

[Mike Sommer]

Originally Posted by FLZapped

Once again diffusion in a small room is not that effective. It takes several wavelengths for them to create a diffuse field.

Here is another forum on just acoustics:

Acoustics Forum • Index page

BTW - Absorption is just as effective in reducing echos, it just does it in a different manner and it is the preferred method in a small room.

The guys at Skywalker are not using their diffusers in a small room and they are using them to color the sound for the reason I stated above.

-Bruce

I think you may be a little confused here.

What I'm prescribing is exactly what you are saying USE ABSORPTION TO KILL THE "ROOM ECHOS" those would be the various types that I described: Flutter, Comb and Early Refection.
Eliminating these will make the room sound Dead, Flat or Dry and very small. But in practical matters this is not a good idea unless it is for a small booth (5'X5' and smaller) where any other effective treatment would be impractical, otherwise just get a EV RE20 or 27 and call it a day. But in a room as I've illustrated above (10x15) the effect is very practical and effective. If you note in the illustration, all the walls except one are not entirely covered with absorption panels, between the panels is bare wall, thus allowing a some refection in the room. The back wall where there is 6'' thick base trap -that would covers the entire wall floor to ceiling, that would be tuned to the room to reduce excessive boom. It is on this wall diffusion panels would be placed, and will provide a neutral, uncolored diffusion of sound that is very effective, in any space that is tuned. And that's my entire point - tuning the room.

Acoustic sound diffusion keeps sound waves from grouping, so there are no hot spots or nulls in a room. In fact, sound diffusion greatly widens the "sweet spot" and lends a strong, 3D sense of openness to a room, making it easier to hear "into" a mix. Diffusion obliterates standing waves and flutter echoes without simply removing acoustic energy from the space or greatly changing the frequency content of the sound.

Acoustic sound diffusion can make a small space seem large and a large space seem even larger. This is a good thing, and is why a the the big boys record on large stages- need I mention Disney Stage B?

Sound diffusion in a control room imparts the all-important Initial Time Delay (ITD) that keeps early reflections off room boundaries from getting to your ears too soon and smearing the direct sound you hear from your monitors. In conjunction with sound absorption, sound diffusion can effectively turn virtually any space into one that is appropriate and useful for the purpose of recording or monitoring sound with a high degree of accuracy.

A flat concrete wall with a flat smooth surface produces a pretty distinct echo when sound reflects off from it. However, a brick wall while still reflective, tends to diffuse the sound reflections and produces a much less distinct echo. This is due to both the surfaces of the brick itself and the mortar between the bricks (more specifically the edge diffraction of the joint between the two). Sound diffusion is a very important consideration in acoustics because it minimizes the coherent reflections that cause problems. Diffusion is an excellent alternative and or complement to sound absorption in acoustic treatment because it doesn’t really remove much energy, which means it can be used to effectively reduce reflections while still leaving an ambient or live sounding space. When speaking of a live sounding space I'm not referring to it sounding like the Grand Canyon, just a little action that is neutral in its resonance that will allow the voice to bloom. In the end you will have better sounding and more accurate recordings.

Another way to do this is to instal floor to ceiling bookcases and fill the shelves with knickknacks, books, plants and the like -this in fact will become a bass trap/diffuser combo. If you've ever walked into a room that is stuffed to the gills with crud by an avid collector or hoarder and listened to the sound such a room makes, you'll then know exactly what I'm referring to.

[FLZapped]

Originally Posted by Mike Sommer

I think you may be a little confused here.

What I'm prescribing is exactly what you are saying USE ABSORPTION TO KILL THE "ROOM ECHOS" those would be the various types that I described: Flutter, Comb and Early Refection.

Yeah, you're right, I misread, sorry.

However, unless the room approaches 5000 cubic feet, diffusion just won't give you its full benefits. Setting up diffusion properly is tricky enough without having the room work against you. For the average room, absorption is far easier to make work well and is far less expensive. It can also be a great DIY project.

-Bruce

[edwinoldfield]

So here is the space. I am thinking that if I cover the walls and ceiling with fiberglass insulation and then cover it with a jute like material (as you have mentioned in another post Mike) (again what about contamination of fibre glass particles), and then use base traps along with other asorbtion techniques. On the skylight i am thinking about a double glazed window, and on then glass on the other window on the side. I really like the idea of the skylight allowing natural light in (plants, etc). The first two pictures are facing one way and the 3rd picture the other way. 4th picture shows skylight and in the middle center of ceiling.

The walls approx measure approx:
Longest wall is 13 feet,
Other long wall is 12ft 6 inches.
Width of room: thinnest point 6 ft 6 inches, middle width 7 feet 4 inches, widest 8ft 8 inches.
Height is 8 feet 9 inches to the slats.

The floor is wood with floor with tiles as seen. Underneath the wood is very solid. Do I need a false floor?

The walls are adobe type 100 year old things thick and solid, and the area is quiet.

The control room will be on the other side of a door.

Any suggestions or help on what I am thinking/should do greatly appreciated.

[Mike Sommer]

This room is perfect for a voice booth about 104 sq. feet and about 884 cubic feet. Of course you'll need to kill it dead -in terms of echo. But since it long an narrow it will be much easier to fix.

You might want to look into double doors (I like exterior jambs with curf in close-cell weatherstripping) or at least solid core doors with Pemko sweeps and ridged insulation on the jambs. You want to seal those doors like it's 40° below zero outside.

If you are going to this much expense you'll need to consider your equipment, and the kind of noise it makes. If there are any kind of fan noise or clicks you might want to consider building a small sound proof machine room/closet to keep all that stuff in, or be ready to shove it all in another room.

How wide are those exposed ceiling joist?


If you are going to make soft walls and ceiling I would look into ordering 2x8 sheets 703, you'll get a better yield from the material. Check out Rockwool too.

Check out the studio construction section over at Geatslutz you'll get a good understanding of will need to be done or can be done.
Studio construction & acoustics - Gearslutz.com

Studio porn -softwalls and all.

[edwinoldfield]

This room is perfect for a voice booth about 104 sq. feet and about 884 cubic feet.

The room will only be for voice booth, the control room will be on the other side of one of the doors.

How wide are those exposed ceiling joist?

20.25 inches

I am going to look into the corning 703 sheets and rockwool. The soft layer fiber glass insulation that they sell in rolls, is that an option?

I intend to insulate doors on both sides, double would be a little difficult.

[edwinoldfield]

What about the floor, should that be a carpet, false, or what is the best option?

Also on the skylight an double glazed pane, is that fine?

Many thanks!

[Greg Houser]

Here's a crazy question, and perhaps I missed it earlier in the thread.

For the folks asking about their rooms, has anyone taken any acoustical measurements with a microphone (as in a measurement microphone) as of yet?

It helps to know just what frequencies are more in need of taming compared to the rest of the room. Iit's more than just about the measurements of the space. The composition of the room (all six sides) and whatever else is in there will have an effect and personal experience has taught me that it pays to take a measurement microphone (you don't have to spend much for one... even the cheapies aren't bad), play some test tracks in the area and let the mic (and a good application like Room EQ Wizard) and you might be looking at things a bit differently.

I just find using a measurement microphone to determine room response a good first step when it comes to determining any changes that need to be made to the recording environment (even those which require a change in the shape of the room itself, though obviously you want to do that right the first time).

Especially for those folks who aren't using an acoustic consultant or are recording in less than ideal environments, I recommend this approach. Then again, I'm obsessive when it comes to the audio of my room.

[Mike Sommer]

Yeah Greg I was going to suggest that. It would be a good Idea to get in there and get some measurements. But I'll bet that room is full of modes and with a room that small, it's generally best to make it dead. The one thing it has going for it is that almost twice as long as it is wide and it way out of square. He may get away with just killing the ceiling one long wall and the two sides, with bass traps in each corner.

You could also build a smaller booth in that room with double walls and ceiling and a raised floor, but by the time your done with that it will have cost more than killing the room. And if you kill the room it would make a great Digital 5.1 Surround TV room.
~~~
No Pink Fluffy stuff. That is virtually useless in sound control.

The best sound you'll get is with a hard floor (wood) and a soft ceiling. You'll end up with maybe an area rug where you record but that's it.

For your sky light I would block in between the joist to bring those ends down, that way you can insulate right up to the skylight. I would get a pice of 1/4 or 1/2 safety glass and cover the opening with it that, this should keep any big noise out. I would also insulate the Skylights ceiling and walls as much as I can. Also caulk and seal every joint and gap.

If you really want to go the double windows, I would go with full pains with faux muttons -if you need that kind of thing. But I would still put the glass at the bottom opening.

[FLZapped]

Originally Posted by Mike Sommer

~~~
No Pink Fluffy stuff. That is virtually useless in sound control.

This is simply not true.

As the panels get thicker, less dense material is actually better which is counter-intuitive, but acoustics is often that way.

-Bruce

[Mike Sommer]

There are only two things that kill sound: mass and distance.

That's why 703 Rockwool and high density cellulose batts trap and control sound. Look at OC's data sheets.

The fluffy batts are full of air, which is good for insulating from heat and cold, and 703 is not.

Fluffy batts will knock out some frequencies, but not the wide range we are looking for here.